Tamago's guide to ultimate yaris handling

[Tamago]

the information given in this post is here merely to provide a starting point for your future autocross or road racing endeavors. this is not the end-all-be-all of information on the yaris. as i come across exact situations related directly to the yaris i will add them to this post

[cleong]

Just to highlight - the Yaris has a front stabilizer bar/anti-roll bar/swaybar.

[eTiMaGo]

great writeup, thanks!

[Tamago]

edited: i completely spaced out the front alignment ;)

[Loren]

It is SO rare to see someone get all the details right for a change. Kudos!

I would add that alignment is a very personal thing, and that if you're searching for performance outside of the "stock alignment" envelope, you're going to have to experiment. What works for someone else might not work for you because even if the car is identical, the driving style might not be.

I've been running 2.5-2.8 degrees of negative camber in the front with no tire wear issues, FWIW. And my experience was that zero front toe made the car wander far too much for my tastes, so I ended up going with about 1/16" of toe-in.

I haven't messed with the rear alignment on my Yaris, but I did on my old Saturn. (which was factory-adjustable for camber and toe, unlike the Yaris) Be VERY careful with rear toe-out. A little bit goes a LONG way. About the smallest amount of toe-out that you can measure (1/32-1/16" maybe?) will be enough to make the car feel like the rear is steering around a sweeping turn. The yaw angle will feel just like you're about to lose the back end, it's freaky!

Lastly, I'm not sure I like the idea of using washers to adjust the rear alignment. I've seen a lengthy engineer's discussion on why wheels that use conical lugs are not hubcentric (and thus don't need those silly plastic spacers that don't do anything, anyway... but, I'll try not to digress). What it comes down to is that the lugs hold the wheel against the hub. The lugs themselves can't and won't support the weight of the car! It's the friction between the wheel and the hub (held in place by the meager torque of the lugs) that supports the weight of the car. I can't help but think that the hub-to-axle interface works the same way. By sticking a washer in there, you're eliminating the large friction area that's supporting the hub and putting most of the stress on the bolts, which weren't designed to handle it. I think the proper solution here would be a machined alignment shim that will cover the whole friction area of the hub/axle joint and maintain the friction that is meant to support the hub.

Probably the biggest thing that anyone who's serious about suspension tuning should take away from this is far simpler, however: "too low" and "too stiff" are very real possibilities and can hurt your handling far more than they help it!

[Tamago]

It is SO rare to see someone get all the details right for a change. Kudos!

I would add that alignment is a very personal thing, and that if you're searching for performance outside of the "stock alignment" envelope, you're going to have to experiment. What works for someone else might not work for you because even if the car is identical, the driving style might not be.

I've been running 2.5-2.8 degrees of negative camber in the front with no tire wear issues, FWIW. And my experience was that zero front toe made the car wander far too much for my tastes, so I ended up going with about 1/16" of toe-in.

I haven't messed with the rear alignment on my Yaris, but I did on my old Saturn. (which was factory-adjustable for camber and toe, unlike the Yaris) Be VERY careful with rear toe-out. A little bit goes a LONG way. About the smallest amount of toe-out that you can measure (1/32-1/16" maybe?) will be enough to make the car feel like the rear is steering around a sweeping turn. The yaw angle will feel just like you're about to lose the back end, it's freaky!

Lastly, I'm not sure I like the idea of using washers to adjust the rear alignment. I've seen a lengthy engineer's discussion on why wheels that use conical lugs are not hubcentric (and thus don't need those silly plastic spacers that don't do anything, anyway... but, I'll try not to digress). What it comes down to is that the lugs hold the wheel against the hub. The lugs themselves can't and won't support the weight of the car! It's the friction between the wheel and the hub (held in place by the meager torque of the lugs) that supports the weight of the car. I can't help but think that the hub-to-axle interface works the same way. By sticking a washer in there, you're eliminating the large friction area that's supporting the hub and putting most of the stress on the bolts, which weren't designed to handle it. I think the proper solution here would be a machined alignment shim that will cover the whole friction area of the hub/axle joint and maintain the friction that is meant to support the hub.

Probably the biggest thing that anyone who's serious about suspension tuning should take away from this is far simpler, however: "too low" and "too stiff" are very real possibilities and can hurt your handling far more than they help it!

all good information, and i'm addressing the part that's bold.

bold portion 1: i agree, toe out will definitely change the way the car turns. you will definitely want to experiment with toe-out (mine is toe-out but still within factory allowable specs) at slower speeds before hopping on the highway.


bold portion 2: when adding a thin washer between the axle and hub, your hub is still inset into the axle. the pilot of the hub/axle is still in full contact with each other, therefore the weight is still being carried by the hub itself, and not the bolts.

[TheRealEnth]

bumpin;

[largeorangefont]

Good post.

[botchilah]

Nice to see very good technical info sans BS / useless comments from the pros :)

[turboyaris]

i gotta interject, as far as tire pressures and camber is concerned.... I would say you would be wise, in investing in a tire pyrometer. Longacre makes some basic models for 100-150$. This will allow you to take tire temps at the outer side/middle/ inner side and determine that if the middle is higher then the outer and inner side your tire pressure is too high and you need to reduce... Likewise, if the outer edge temp is higher then the inner edge temp, you want to add more negative camber. basically with this method, you get much easier quantitative data to help determine what to do.

As for using this with autocross, a quick little self made track, should get you enough data to setup your camber and tire pressures properly.


This process will get you theoretically ideal setup, however, if you need to compensate for another handling issue, then adding or subtracting camber or tire pressures may be needed.

[whooppee777]

BEST THREAD EVER!

[CtrlAltDefeat]

thank you so much for the info... :thumbup:

[Loren]

Tamago, I thought about the hub/axle interface some more, and concluded that the forces at play there are NOT like the forces put on the mating surface of the wheels. The wheels are pushed almost straight UP when they receive their greatest forces (hitting a hard bump). The hub junction is effectively being bent upwards at an angle rather than forced straight up. The major forces should be on the lower hub bolts, which are probably pretty beefy high-grade bolts. So, with that, I'll rescind my previously stated concern... thin high-grade washers used there should be okay for adjusting the rear alignment. Thanks for setting me straight and making me think about it some more!

Hmmm... now do I want to mess with it?

[eTiMaGo]

Hmmm... now do I want to mess with it?

I'll take it that is a rhetorical question :biggrin:

[largeorangefont]

Tamago, I thought about the hub/axle interface some more, and concluded that the forces at play there are NOT like the forces put on the mating surface of the wheels. The wheels are pushed almost straight UP when they receive their greatest forces (hitting a hard bump). The hub junction is effectively being bent upwards at an angle rather than forced straight up. The major forces should be on the lower hub bolts, which are probably pretty beefy high-grade bolts. So, with that, I'll rescind my previously stated concern... thin high-grade washers used there should be okay for adjusting the rear alignment. Thanks for setting me straight and making me think about it some more!

Hmmm... now do I want to mess with it?

Yes you do. I did on the old solid axle CRXs. It worked great.

[at3GG]

.....yes....yes you do. But only if you report back to us!

[ddongbap]

Damn Loren.

You talking about how changing the toe just a little bit would get it to rotate better got me wet.

[TheRealEnth]

LMAO thats sick

[mikenacarato]

good thread! :)

[Loren]

don't forget however that changing your camber, toe in/out will affect the lifetime of your tires. Tamago you wrote so much im not sure you mentioned this (my fault probably i fat read your post)
Done properly, it won't necessarily affect the wear of your tires. In fact, depending on your driving style, it could IMPROVE your tire wear.

I'm running factory alignment in the rear (-0.9 camber, slight toe-in), and -2.5 camber in the front with very slight toe-in. My tire wear is very event all around. If I DIDN'T have all that front camber, my front tires would be wearing on the outside edges.

Excessive toe, especially when coupled with agressive camber will cause tire wear issues. But, with neutral toe settings, up to 3 degrees of camber is not a problem even on a daily-driven vehicle.

(trivia: The factory alignment on the rear of my Triumph is 3 degrees negative camber)

[Loren]

Damn Loren.

You talking about how changing the toe just a little bit would get it to rotate better got me wet.
Yeah, I'm sexy like that. You should hear me talk about rev-matching and heel-toe downshifting.

[SEVEN]

basic "autocross setup" springs... if you're gonna autocross, and you've installed lowering springs, please get a set of shocks that were built to be coupled with a lowering spring. stock struts and "lower" springs just don't fit into autocross land.[/size]

will tein s.techs and trd shocks work???

[Loren]

will tein s.techs and trd shocks work???
What you'll eventually conclude with that setup and really think about it is that a) you don't have enough suspension travel so you bottom out both in hard turns and over bumps and b) the shocks don't sufficiently control the motion of the springs on rebound.

Will it "work"? Yes, but not if you want the car to handle as good as it could.

[SEVEN]

Are there TEIN shocks for yaris??? I can't find any ...

[cleong]

Cusco does make a front anti sway bar (part no. 900 311 A26). So its available for a price should you feel the need for it. As I cannot read Japanese I cannot say if it is stiffer than stock or not.

I found that running too much negative camber on skinny street tires reduces its off-the-line traction. It might not really hurt acceleration that much but it seems easier to get the tires to break loose.

[ChinoCharles]

Bravo Tamago.

[Loren]

thanks for clarifying Loren. I just though since you're changing the vertical angle (camber) the contact patch will be offset to either side.
Well, it does, but it's just not enough to be a problem unless you combine it with too much toe.

Running 2 degrees of camber with mild toe settings and doing strictly highway miles might result in 2mm more wear on the inside of the tire vs the outside. Of course, if you do strictly highway driving, you don't NEED that much camber! If you have that much camber, it's probably because you do some mountain driving, or autocross, or track driving... and that performance driving is going to largely equalize the wear. You might still see maybe 1mm more wear on the inside vs. the outside... but who cares? That's close enough.

[Loren]

Cusco does make a front anti sway bar (part no. 900 311 A26). So its available for a price should you feel the need for it. As I cannot read Japanese I cannot say if it is stiffer than stock or not.
The last thing you want on a FWD car is a larger front swaybar. It would just require you to stiffen the rear that much more to reach something close to "neutral" rather than "obscene understeer".

The only reason Cusco makes it is because people who don't know any better WILL buy it... not because anyone really needs it.

[Tamago]

I'll take it that is a rhetorical question :biggrin:

talk to Russell teh Pirate, i helped set up their yaris :)

[cleong]

We can't be certain of that fact which is why I stated the bar was available but can't speak for its effects. If it would make the car understeer worse like you say it would, then if you took the front anti roll bar off, would it cure the understeer without having to fit a rear anti roll bar?

I think it is possible that a correct front anti roll bar would reduce front roll, and optimize the tire contact patch in the corners, because too much roll unloads the inside tires. I'm not saying the Cusco would do it, because I've never tried it, but it is a tuning option that should be tried before being written off.

[Tamago]

don't forget however that changing your camber, toe in/out will affect the lifetime of your tires. Tamago you wrote so much im not sure you mentioned this (my fault probably i fat read your post)

yes, it will.. absolutely.

this guide is to help those who are interested in handling, before tire longevity, etc etc.

[Tamago]

i gotta interject, .


stolen word for word and added to the guide.

keep the good info coming guys!

[Loren]

We can't be certain of that fact which is why I stated the bar was available but can't speak for its effects. If it would make the car understeer worse like you say it would, then if you took the front anti roll bar off, would it cure the understeer without having to fit a rear anti roll bar?
Yes, we can be certain that fitting a stiffer front swaybar (with no other changes) will make the car understeer more. That's just simple suspension physics at work. That's just the way it is.

And, yes, removing the front swaybar would probably make the car understeer less (it's been done on some FWD cars with success), but while it might have higher cornering limits, the steering would feel very "sloppy" and it wouldn't be enjoyable to drive. One absolute truth about suspension tuning: It's always a compromise.

I think it is possible that a correct front anti roll bar would reduce front roll, and optimize the tire contact patch in the corners, because too much roll unloads the inside tires.
Body roll is not the "evil" that so many people think it is. Look at some of the best handling cars in the world... a Lotus Elise, for example... lots of body roll. Even purpose built race cars have some body roll in as much as their suspension moves. (look at an F1 car full-on in a corner, the outside is compressed visibly more than the outside) Body roll isn't bad. It's a by-product of weight transfer. What you want is control of that roll (good damping), and balance of the weight transfer (spring rates and sway bar rates).

If eliminating all body roll was the answer, every race car and high-end performance car would have NO body roll. Eliminating more body roll (with a larger front swaybar) at the expense of moving the handling balance of the car further in the wrong direction is no solution.

This whole discussion is much like arguing about lowering springs with ricers. They think that "lower is better" no matter what... and "stiffer and flatter" is better no matter what. It's simply not true.

I'm not saying the Cusco would do it, because I've never tried it, but it is a tuning option that should be tried before being written off.

I've not tried it on a Yaris, but most of my suspension tuning knowledge does come from experience. One of the first suspension mods I did to my Saturn when I started autocrossing was to put a bigger front swaybar on it. Same reason everyone else wants to: to get rid of the body roll. I then spent the next 3 years finding ways to eliminate the understeer that it caused. I was stubborn and refused to remove the front bar that I'd spent good money on, which would have solved the problem instantly. (as a side note, the Saturn S-Series cars had two swaybar options, the twin cam front bar was larger than the single cam bar... and the twin cam had a rear bar whereas the single cam had none... the hot ticket is simply putting the smaller front bar onto a twin cam car!) To balance the larger front bar, I ended up having to put a rear bar on that was so stiff that it actually BENT the stock rear end link mounts.

Wanna play with what removing the front swaybar would do? It's easy, just remove an end link on one side. The other side will hold the bar in place and keep it from flopping around, but with one side disconnected, the bar will have no effect. Very simple experiment. Somebody do it and report back. (maybe I'll do it when I have time)

If you have a stiff coilover suspension, you might get away without the front swaybar. I tuned the suspension on my old Miata with really stiff springs and NO swaybars. People thought I was nuts, but I wanted to prove that it could be done. It took really stiff front springs to get it to feel right, of course.

[cleong]

But similarly with tire pressures, generally softer yields better traction. Yet you could go too soft and cause tire contact deformity, or too hard, which causes lack of tread compliance. Hence optimizing is the key, what you have called compromises. But I respect your experience, which I do not have. If I manage to get my hands on this Cusco bar, I'll report back with what I found, at least it'll help others make a more informed decision.

[Loren]

Adjusting tire pressures does two things: adjusts the shape of the tire's contact patch, and adjusts the effective "spring rate" of the tire.

Today's high-end performance tires have SO much reinforcement of the tread area that tire pressure has little effect on the shape of the contact patch. It stays flat no matter what. If you're on craptastic all-season tires, you might see some change in the contact patch with pressure. (but this thread isn't for those people!)

The change in effective spring rate of the tire, as long as you don't distort the contact patch too much, is primarily what we feel with our tire pressure changes when we're tuning a car. We work within the "window" of pressures that the contact patch stays flat in. (with a good performance tire, that can be a big window... like the Azenis... easily 30-50 psi!) Within that window, you're simply fine-tuning a spring rate that has the same effects as changing any other "spring rate" in the suspension.

So, whether you're adjusting tire pressure, spring rate, sway bar rate or shock damping, the general effects are the same:
Stiffen the front = create more understeer or less oversteer
Soften the front = create less understeer or more oversteer
Stiffen the rear = create more oversteer or less understeer
Soften the rear = create less oversteer or more understeer

Those are the facts. You can look them up in any suspension tuning book or even on one of a thousand different suspension tuning guides that you might find on the internet.

Knowing that, if you NEED to fit that larger front swaybar to prove it to yourself, go for it. There really is no substitute for experience. I'm all for experimentation that will help people learn and quantify what suspension changes really do. I just hate to see people waste money on parts that aren't going to help them. Do the cheap or free experiments first... like playing with tire pressures... disconnecting the front swaybar... stuff like that.

Those cheap rubber donut spring spacers that you can get from JC Whitney for like $20 a set are a GREAT experimentation tool. Toss a set of those on your springs... take some measurements and figure out what you've changed the spring rate to, and document the results. (I tried a pair on the rear of my Yaris, my calcs said it raised the spring rate from about 2.0 kg to 2.5 kg... it was a happy understeer-reducing change, just like it was supposed to be, and it's why I never wanted to fit the 2.2 kg rear springs that came with my K-Sport kit)

[id3379]

great writeup, thanks!

:thumbsup:

[markitect]

First off awesome writeup!!!!!!!!!!!

I have one question though, for those looking to stay in HS what shocks/struts work well with stock springs? Any side affects with that combination?

Most are designed to be paired with lowering springs so it seems like this would affect their range of motion (I need something that can go over potholes). Of course if anyone knows of reasonably priced adjustable ones let me know.

[Tamago]

First off awesome writeup!!!!!!!!!!!

I have one question though, for those looking to stay in HS what shocks/struts work well with stock springs? Any side affects with that combination?

Most are designed to be paired with lowering springs so it seems like this would affect their range of motion (I need something that can go over potholes). Of course if anyone knows of reasonably priced adjustable ones let me know.

i would imagine that the TRD shocks would fair well with stock suspension, since TRD is for their mild 1"ish drop.

R comps will take you a lot further than shocks in HS though IMO

also, keep in mind, if you run a "shorter" shock with stock spring, you'll be compressing the stock spring beyond its original setting, thereby raising your static spring rate :D which isn't bad, but may get you kicked out of HS in a nationals environment. (not that an HS mini is gonna be scared of a yaris.......... )

[Loren]

Hmmm... in SCCA stock class, you can't change the springs or alter the ride height. Dampers are otherwise unlimited... Hmmm...

Seems to me that you could get a generic race shock to replace the rear shocks on the Yaris pretty easily. It's just an eye at the bottom and pin at the top, very common configuration. Get something that you can dial in really some really stiff compression damping for autocrossing and it should do a world of good for reducing understeer.

That, plus maxing out the front camber, and the tires mentioned above... that should do a pretty good job of challenging the competition.

footnote: One of the caveats of the "shocks are free" rule is that you can't alter the spring perch height. Since the spring perches aren't part of the Yaris rear shocks... you should be free to replace those rear shocks with ANYTHING.

[Tamago]

..... and getting the yaris to rotate is by far the most important thing in stock class :D

it's a shame you won't get any real camber out of the front though :(

[markitect]

Seems to me that you could get a generic race shock to replace the rear shocks on the Yaris pretty easily.

I hadn't thought about that, sounds like I have some measuring to do before May.

[2006fronty]

Seems to me that you could get a generic race shock to replace the rear shocks on the Yaris pretty easily.



I hadn't thought about that, sounds like I have some measuring to do before May.

I've looked at the rear shocks and it does seem pretty easy get a shock that fits, Radflo makes a GREAT race shock and they'll make shocks to your dimensions (collapsed and extended lengths) I've ran several sets of their shocks on my previous trucks. The front would be more of a task considering the mount from the strut to the knuckle would have to be figured out. 2.5 inch diameter race shocks on all 4 corners of a Yaris would be fun (well maybe 2.0's would be more reasonable haha)An External reservoir or internal floating piston shock would be nice.

[rob323]

An External reservoir or internal floating piston shock would be nice.
Very nice infact :biggrin:.
http://i39.photobucket.com/albums/e154/rob323vr4/ghecho/New_Picture039-1.jpg
http://i39.photobucket.com/albums/e154/rob323vr4/ghecho/New_Picture040-1.jpg

Now I just have to save up to get the same on the fronts :frown:

[2006fronty]

Ohlins right^^^^^^^??? I'm pretty sure that's how they set up their external reservoirs.

[rob323]

mcasuspension.com

[tk-421]

Question: How would 10mm rear hub spacers affect handling?

[kngrsll]

Question: How would 10mm rear hub spacers affect handling?

i have been meaning to look this up as well.

[Loren]

Wider track usually means more grip (for various reasons). So, widening the track in the rear would make the rear stick better. Not really what most of us are fighting for, with a FWD car, you want more grip in the front.

The rear hub spacers are purely a cosmetic mod. (not to be confused with alignment shims)

[kngrsll]

Wider track usually means more grip (for various reasons). So, widening the track in the rear would make the rear stick better. Not really what most of us are fighting for, with a FWD car, you want more grip in the front.

The rear hub spacers are purely a cosmetic mod. (not to be confused with alignment shims)

ah, thats right... i remember a friend of mine use to use them on the front when he would autox (SE-R, fwd).

im still working on this shocks thing, i have to turn in a research proposal this week and its consuming all my time! :(

[d1nzfe]

Very nice infact :biggrin:.
http://i39.photobucket.com/albums/e154/rob323vr4/ghecho/New_Picture039-1.jpg
http://i39.photobucket.com/albums/e154/rob323vr4/ghecho/New_Picture040-1.jpg

Now I just have to save up to get the same on the fronts :frown:

whats so different when its invented?
:confused:

ooops.... just saw the canister! its remoted and camouflaged!

[tropicalsuckerpunch]

Post #1 of this thread doesn't show me yaris handling information?

[d1nzfe]

canister like this?
http://img14.imageshack.us/img14/1091/p9280327.jpg
AND this?
http://img15.imageshack.us/img15/3191/p9270319.jpg
:biggrin:

[HTM Yaris]

How the fudge did I miss this kick ass thread ?

:bow::bow::bow::bow::bow::bow:

[CtrlAltDefeat]

the information given in this post is here merely to provide a starting point for your future autocross or road racing endeavors. this is not the end-all-be-all of information on the yaris. as i come across exact situations related directly to the yaris i will add them to this post

uhh... where did the info go? :iono::iono::iono:

[Tamago]

fortunately i kept a backup. PM me and i'll email it to you. until i know it won't get deleted again without explanation i'm not going to post it in the original post.

edit: lol look! it magically re-appeared.

[Tamago]

Wider track usually means more grip (for various reasons). So, widening the track in the rear would make the rear stick better. Not really what most of us are fighting for, with a FWD car, you want more grip in the front.

The rear hub spacers are purely a cosmetic mod. (not to be confused with alignment shims)

so we ran a track day with the spacers installed. although there was rubbing on the streets, with the spare and other junk removed, there was no longer any rubbing. If you remove a little weight, you can get away with the 15x7 +10.

The really important thing is how the car drove. My co-driver and i did 2 sessions a piece. He has driven the car at ever event that i have, so his feed back is just as valuable. The spacers had a noticeable increase in rear stability. It made it a little easier to carry speed into the corner without the rear wanting to chase you, so turn-in speeds may have been a little faster. What was more important was stability increased the "trust" in the car in the corner. As you may know, if you feel confident about the car, you will be able to drive it well.

Since I needed to remove the spacers for street use, i pulled them off before the last session. The rear end felt a little more unstable (duh) and if you gave the same inputs as before, the back end would tend to slide a little more. That may be good for autox, but not for the track. As easy as the are to take on and off, i may swap them on depending on the type of course. Tight courses may favor the spacers out, while the more open courses (like the one we were one) would be better with the rear spacers in.

All in all, i think they helped with the stability of the car. If i were not running such low offsets, i would continue to use them. If you have anthing more than a 35 mm offset, they are a no brainer, they easily fit and increase rear stability. The 10 mm should put the track in the front and rear dead even, while the 13 mm spacers may make the rear track greater than the front.

Great mod, track approved :)

taken from : http://www.yarisworld.com/forums/showpost.php?p=373971&postcount=6

[fmicle]

I am looking for a little advice. So the wheels I have now on the Yaris were the very first mod I did and I must say, I didn't do my homework before buying. So I ended up getting 16x7" with 195/50-16 tires. After finding this kick-ass thread and doing more reading on the subject, I'm thinking about going back to 15x6.5" with 195/55-15, as recommended here :smile:

Now, I also have lowering springs (NF210) and shocks on my list, which is the next thing I had in mind, but I was wondering, would it make more sense to replace the wheels first and then get the springs and shocks or get the springs/shocks first?

[Tamago]

I am looking for a little advice. So the wheels I have now on the Yaris were the very first mod I did and I must say, I didn't do my homework before buying. So I ended up getting 16x7" with 195/50-16 tires. After finding this kick-ass thread and doing more reading on the subject, I'm thinking about going back to 15x6.5" with 195/55-15, as recommended here :smile:

Now, I also have lowering springs (NF210) and shocks on my list, which is the next thing I had in mind, but I was wondering, would it make more sense to replace the wheels first and then get the springs and shocks or get the springs/shocks first?

do the suspension first, and then worry about wheels/tires after.

remember, the tire itself is the most important mod. size is less of an issue, whereas the tire compound itself is VERY important. don't go cheap on tires, and it'll reward you.

[kngrsll]

do the suspension first, and then worry about wheels/tires after.

remember, the tire itself is the most important mod. size is less of an issue, whereas the tire compound itself is VERY important. don't go cheap on tires, and it'll reward you.

there is much truth in this statement... if i could only do one mod to the car, id buy star spec direzza's for it.

[CtrlAltDefeat]

there is much truth in this statement... if i could only do one mod to the car, id buy star spec direzza's for it.
it's funny you mention those.. I'm thinking about upgrading my stock wheels to 17x7 Enkei RPF1 wheels with 215/40 star spec direzza's... I plan on keeping my stock steelies for winter use. The RPF1wheels are about the same weight as the the stock 15s, so I don't think weight will be an issue. This is my daily driver, so I am wondering if I'm going dangerously low profile and whether or not the ride will be too rough... Any one got any advice? Tamago? :respekt:

[Tamago]

sidewall is less important than the tire you choose. a 55 sidewall StarSpec is gonna be better than a 40sidewall (17inch) somethingelse..

sidewall is only detrimental when you're working with crappy tires like the Falken 512. the sidewalls are soft, and flex way too much in cornering loads.

[JumpmanYaris]

Tamago u need to work on my vehicle make it like urs

[kngrsll]

it's funny you mention those.. I'm thinking about upgrading my stock wheels to 17x7 Enkei RPF1 wheels with 215/40 star spec direzza's... I plan on keeping my stock steelies for winter use. The RPF1wheels are about the same weight as the the stock 15s, so I don't think weight will be an issue. This is my daily driver, so I am wondering if I'm going dangerously low profile and whether or not the ride will be too rough... Any one got any advice? Tamago? :respekt:

that set up sounds fine to me. i prefer smaller tires mostly bc they are cheaper and i see alot of fast people use that set up. im not an engineer, so i just copy what works. im using 15x7's with a 195/55/15 dunlop. its a great set up. you can get the wheels for $120 a piece or less, and the tires are like $80 a piece. awesome deal, awesome set up... ive passed corvettes on hoosiers with this set up lol, seriously. cant wait to get the LSD installed and get some real race tires to try out nasa TT!

[CtrlAltDefeat]

that set up sounds fine to me. i prefer smaller tires mostly bc they are cheaper and i see alot of fast people use that set up. im not an engineer, so i just copy what works. im using 15x7's with a 195/55/15 dunlop. its a great set up. you can get the wheels for $120 a piece or less, and the tires are like $80 a piece. awesome deal, awesome set up... ive passed corvettes on hoosiers with this set up lol, seriously. cant wait to get the LSD installed and get some real race tires to try out nasa TT!

the derezza star specs were on sale iguess becausethey were $111 a piece for the 17" wheels

[Tamago]

Tamago u need to work on my vehicle make it like urs

like the xA, not like the MR2 haha the MR2 is awful right now! Drift City!

[fmicle]

that set up sounds fine to me. i prefer smaller tires mostly bc they are cheaper and i see alot of fast people use that set up. im not an engineer, so i just copy what works. im using 15x7's with a 195/55/15 dunlop. its a great set up. you can get the wheels for $120 a piece or less, and the tires are like $80 a piece. awesome deal, awesome set up... ive passed corvettes on hoosiers with this set up lol, seriously. cant wait to get the LSD installed and get some real race tires to try out nasa TT!

I was actually looking at some rims today and saw that if I went with 15x7" I'd have more to choose from as opposed to 15x6.5", as recommended by this thread. I want to go as light as I can for a reasonable price on the wheels. Maybe Enkei or something.

So how much can I deviate from "the letter of the law"? :wink: Are there any trade-offs? Most tires seem to fit a range (such as 5"-7" for instance), so that wouldn't affect the tire selection much. What would I sacrifice/risk with a 15x7 setup?

[Tamago]

What would I sacrifice/risk with a 15x7 setup?

nothing if the weight was on point :)

[advocate]

Tamago could you offer your opinion on these wheels:

http://www.good-win-racing.com/Mazda-Performance-Part/21-1045.html

Things I need help choosing:
Tire sizes: for street use. going for good mix between weight / traction. have 205s now would like to go smaller.
Wheel size: 14s vs 15s. i want a good mix between weight / looks. i'm thinking 14s just might be too small since the car is not a miata after all.
Wheel width: 15x7? 15x7.5?

Relevant info:
Running the DF210s and Tokico blues.

If I had to take a stab in the dark i'd probably go with 15x7.5 with 195/50/15.
Any thoughts? More importantly is that Miata wheel even going to fit? I picked them because they're cheaper than hell, amazingly light, and from konig. Figured it was a great combo.
Thanks!
:bow:

[Tamago]

Tamago could you offer your opinion on these wheels:

http://www.good-win-racing.com/Mazda-Performance-Part/21-1045.html

Things I need help choosing:
Tire sizes: for street use. going for good mix between weight / traction. have 205s now would like to go smaller.
Wheel size: 14s vs 15s. i want a good mix between weight / looks. i'm thinking 14s just might be too small since the car is not a miata after all.
Wheel width: 15x7? 15x7.5?

Relevant info:
Running the DF210s and Tokico blues.

If I had to take a stab in the dark i'd probably go with 15x7.5 with 195/50/15.
Any thoughts? More importantly is that Miata wheel even going to fit? I picked them because they're cheaper than hell, amazingly light, and from konig. Figured it was a great combo.
Thanks!
:bow:

if you're going for looks, avoid 6.5" wide wheels. they simply don't fill the fenders very well. if you're looking to save weight, the wheel above is the one for you, very lightweight for the money, but you're sacrificing (IMO of course) looks FOR weight, i think that wheel looks awful :eek: hehe.

[kngrsll]

I was actually looking at some rims today and saw that if I went with 15x7" I'd have more to choose from as opposed to 15x6.5", as recommended by this thread. I want to go as light as I can for a reasonable price on the wheels. Maybe Enkei or something.

So how much can I deviate from "the letter of the law"? :wink: Are there any trade-offs? Most tires seem to fit a range (such as 5"-7" for instance), so that wouldn't affect the tire selection much. What would I sacrifice/risk with a 15x7 setup?

i use a 15x7 and it works great, i would use anywhere from a 195-225 on it and it will be fine. you wouldnt be sacrificing anything but a tiny bit of weight.

[kngrsll]

the derezza star specs were on sale iguess becausethey were $111 a piece for the 17" wheels

another reason i like 15" tires, they are MUCH cheaper.

[kngrsll]

Tamago could you offer your opinion on these wheels:

http://www.good-win-racing.com/Mazda-Performance-Part/21-1045.html

Things I need help choosing:
Tire sizes: for street use. going for good mix between weight / traction. have 205s now would like to go smaller.
Wheel size: 14s vs 15s. i want a good mix between weight / looks. i'm thinking 14s just might be too small since the car is not a miata after all.
Wheel width: 15x7? 15x7.5?

Relevant info:
Running the DF210s and Tokico blues.

If I had to take a stab in the dark i'd probably go with 15x7.5 with 195/50/15.
Any thoughts? More importantly is that Miata wheel even going to fit? I picked them because they're cheaper than hell, amazingly light, and from konig. Figured it was a great combo.
Thanks!
:bow:

i use a spec miata wheel right now (Team Dynamics) and it is a perfect fit as if it were made for the car.

[advocate]

Need some pics kngrsll! Also, thx for the confirmation

[kngrsll]

Need some pics kngrsll! Also, thx for the confirmation

ive posted some before...

http://www.yarisworld.com/forums/showthread.php?t=19355

[ROCKLAND TOYOTA]

TAMAGO,
on a 205-55-15 setup what tire pressure should be ran for commuting at speeds between 70-90 on a daily basis? current pressure is 36 lbs......

[Tamago]

TAMAGO,
on a 205-55-15 setup what tire pressure should be ran for commuting at speeds between 70-90 on a daily basis? current pressure is 36 lbs......

sounds good.

if you want better fuel economy at the risk of wearing the center of your tires out prematurely, go up a few psi.

if you want better grip, drop a few psi off.

i run 36 front, 28 rear on my xA, but i also don't have a standard alignment or weight bias.

[ddongbap]

I remember running my Re92s at 52~ psi. They started splitting down the middle. Cool stuff.

[allyart]

i have a yaris 5doors hatchback, may i ask some question:

1. when tamago says yaris is he refer to the yaris sedan or the yaris hatchback?

2. when tamago explain the rear swaybar, does he means something like ultra racing Rear Anti-roll Bar / Rear Sway Bar / Rear Stabilizer Bar (Code : UR-AR23-197) OR the ultra racing Rear Anti-roll Bar / Rear Sway Bar / Rear Stabilizer Bar (Code : UR-AR16-126)?

3. lastly, how do you feel about ultra racing Front Strut Bar / Front Tower Bar (Code : UR-TW2-402). is it a good investment to buy?

many thanks for the reply, sorry for my bad english

[eTiMaGo]

wow hadn't read this thread in a while :)

1) I think this would apply to both, but I'm quite sure he meant the hatchback

2) At the time of writing there was really only the TRD rear swaybar. UR offers swaybars now in two thicknesses, The thicker one will have a stronger effect and induce more oversteer.

3) front strut bars are a bit of a controversial topic. Some say that because the shock tower are more or less directly connected to the firewall, there's no point in adding a bar. But some say that at higher cornering speeds (i.e. on track or autocross), you can feel a difference.

So in the end, I think it depends if you plan to seriously race the car or not? If it's to enjoy a spirited drive, you should be fine with the smaller swaybar and no strut bar, as you'd probably never push the car to the limits of handling on a public road (at least I hope not)

[allyart]

wow hadn't read this thread in a while :)

1) I think this would apply to both, but I'm quite sure he meant the hatchback

2) At the time of writing there was really only the TRD rear swaybar. UR offers swaybars now in two thicknesses, The thicker one will have a stronger effect and induce more oversteer.

3) front strut bars are a bit of a controversial topic. Some say that because the shock tower are more or less directly connected to the firewall, there's no point in adding a bar. But some say that at higher cornering speeds (i.e. on track or autocross), you can feel a difference.

So in the end, I think it depends if you plan to seriously race the car or not? If it's to enjoy a spirited drive, you should be fine with the smaller swaybar and no strut bar, as you'd probably never push the car to the limits of handling on a public road (at least I hope not)

ahh i got it, thanks for the explanation

for now i just want to enjoy a spirited drive, so i will just buy the smaller swaybar. but i have to say, having a strutbar is kinda cool though :w00t:

[eTiMaGo]

Yeah it does look nice under the hood :p But due to the rather small engine bay, it makes access to the battery and other stuff at the back a bit difficult, just so you know.

[tooter]

i use a spec miata wheel right now (Team Dynamics) and it is a perfect fit as if it were made for the car.

Even this two year old thread still has useful information. I also ordered wheels (Rota RB's) to Mazda Miata specifications, and they'll be arriving any day now. :smile:

My thanks to the good folk who left these messages of good advice.:thumbsup:

[Viperoni]

3) front strut bars are a bit of a controversial topic. Some say that because the shock tower are more or less directly connected to the firewall, there's no point in adding a bar. But some say that at higher cornering speeds (i.e. on track or autocross), you can feel a difference.


In my echo, and on my old slicks, in bumpy corners, I absolutely felt a difference with the strut bar. The front end gripped while the rear didn't, I had oversteer in a couple corners while I was getting used to it, almost got in trouble.

[Tamago]

In my echo, and on my old slicks, in bumpy corners, I absolutely felt a difference with the strut bar. The front end gripped while the rear didn't, I had oversteer in a couple corners while I was getting used to it, almost got in trouble.

what were your tire pressures? (this has a lot more to do with your issue than any suspension component, especially on R comps)

[Autocross72]

Not only does a front strut bar make a difference, there is a difference between strut bars. My first strut bar was a Tanabe. I installed it and adjusted the preload. As I did so, I discovered that I could easily deform the bar by pushing on it. If my scrawny self can bend it, just think what a 2,200 pound car can do. When I drove the car with the Tanabe, I wanted to believe that there was a difference in turn in because of the money I spent on it, but ultimately I could not really tell a difference between the Tanabe installed and no bar installed. Eventually, I bit the bullet and ordered an Ultra Racing front bar. That, I can tell you, made a very noticeable difference! Turn in was much more crisp. Of course, this is all relative to my set up, so here are my details; Megan racing coil-overs and adjustable shocks, 23mm Ultra Racing rear sway bar, front and rear under braces, and 16.3 lb, 17x7.5" Motegi MR125 wheels with Toyo Proxes 4 205/40 tires. The main reason I chose that tire and wheel combo is that it keeps my speedo correct. This is my daily driver. I have a 1972 240Z for autocrossing and track days, but if I ever decide to Autocross my Yaris (I did once), I will definitely buy some 15x7" wheels with 205/50 or 225/50 Kumho V710s. The underpowered Yaris needs all the help it can get from the lower gearing of the smaller wheels.

By the way, has anyone ever tried an off set tire set up? I'm thinking of 225/50/15 in front and 205/50/15 in the rear. With that set up you might not need as much front camber which would give you better acceleration and braking (camber reduces the contact patch when the car is going straight).

[arnoldod]

Thanks for this great guide! :)

I had problem with handling in my first 4000 miles but now the handling has changed drastically. I do not do autocross. My driving characteristic is spirited driving, but only in the weekend. I am stuck in the traffic for the rest of the week with 19 Mph average speed.

I am using Toyo Proxes R1R 195/55/R15 with Advanti Storm-1 wheels (10.9 lbs). I understand that the tires won't last to 20,000 miles but my mileage is short (40 miles weekdays, 28 miles weekend).

The air pressure for both front and rear is 35. What is the recommended air pressure for my tires?

[Tamago]

Thanks for this great guide! :)

I had problem with handling in my first 4000 miles but now the handling has changed drastically. I do not do autocross. My driving characteristic is spirited driving, but only in the weekend. I am stuck in the traffic for the rest of the week with 19 Mph average speed.

I am using Toyo Proxes R1R 195/55/R15 with Advanti Storm-1 wheels (10.9 lbs). I understand that the tires won't last to 20,000 miles but my mileage is short (40 miles weekdays, 28 miles weekend).

The air pressure for both front and rear is 35. What is the recommended air pressure for my tires?

if you are commuting, and experience little rain, you could up that pressure for better fuel economy (provided the roads are dry). if it rains, keep the pressures at or slightly below the recommended pressure. remember too, your vehicle weight distribution. there's no reason to run the same pressures front and rear (if you don't carry many passengers, or heavy loads in the rear of your car) as your weight distribution f/r is at least 15/20 percent in the rear "less". less tire pressure in the rear will prevent oversteer, but also may induce understeer on sweeping turns.

as you aren't actually racing the car, all of the above is just theory. enjoy the yaris, and i'm sure tire pressures won't really be a factor. there's really no reason to ever push your car past 70% capability on the street, legally.

[cali yaris]

^ Whoa. Welcome back. :smile:

[tk-421]

Yeah, no kidding. :thumbsup:

[arminius]

Hello,

A noob question for Tamago or suspension experts, I purchased a 2004 Echo that was kept by the original owner in his garage and only had 49,000 miles. The car was certified by Toyota and the engine bay is mint and looked new.

I already purchased a Tanabe NF210, and is looking to upgrade the shocks and struts to Koni Yellow or KYB GR2s.

The question is: Will a 15x7 offset of +25 XXR 527 or 522 work for the car without any issues, using 175/50/15 Yokohama S Drives?

Tamago has mentioned using 15x6.5 offset of +38 for street use is fine.

Thanks in advance.

[arminius]

Sorry, wrong tire specs.

Should be:

195/50/15 Yokohama S Drive

[hondajt]

Since it's a sticky, I don't feel bad reviving this old thread.

My '13 Yaris is really twitchy on the highway. My wife's '09 is very smooth by comparison. We both have stock suspension and tires. I'm hoping someone will have some advice. From what I've read in this thread, I'm hoping it's a simple toe or camber adjustment.

[LTHatch]

Hondajt: I had the exact same issue, the Yaris felt unstable at highway speeds, felt nervous. 205mm wide tires and lowering springs knocked that down a good bit, but driving time is what fixed it for me. The more time i spent driving it the less noticeable it became, now i don't notice any twitchy behavior at all.
Rear sway bar also seems to be a well praised mod that knocks down the nervous feeling the Yaris has at highway speeds, it might be worth a look into if you want to leave the Yaris mostly stock.

[CoryM]

Since it's a sticky, I don't feel bad reviving this old thread.

My '13 Yaris is really twitchy on the highway. My wife's '09 is very smooth by comparison. We both have stock suspension and tires. I'm hoping someone will have some advice. From what I've read in this thread, I'm hoping it's a simple toe or camber adjustment.

Incorrect toe, camber and caster can all make the car wander, or feel twitchy. Keep in mind, they are two different cars. Different track width, tire size etc can create different feels.

Cheers.

[Tapokata]

So, after nearly 160K miles, I'm getting ready to replace the rear shocks on my 09 liftback- changing out the OEM units for a a pair of Bilstein B6's. I plan to replace the bushings, bumpers, and supports with new OEM bits, and retain the other hardware. At the same time, I'm intend to add a TRD torsion spring / sway bar. I'm also going to add a Universal Racing two-point rear strut bar. The suspension is otherwise stock (I'll have the front struts changed out- they're still factory OEM- at a future date). I upsized the wheels and tires from the 14" base to a 15", running P185/60R15's on them, last year. Except for the back end being a bit light, especially on the freeway in high winds (or being buffeted by semi's), it handles pretty well- I like throwing this little washing machine on wheels around our fair city streets.

Lots of experts on this forum- so I'll ask: anything that I need to watch out for or otherwise be aware of in this re-fit? The shock replacement looks to be pretty straightforward, as is the installation of the sway bar and strut. Just checking one more time to see if there are any known (or unknown) gremlins to watch out for in this process. Thanks in advance...

[CrankyOldMan]

Lots of experts on this forum- so I'll ask: anything that I need to watch out for or otherwise be aware of in this re-fit? The shock replacement looks to be pretty straightforward, as is the installation of the sway bar and strut. Just checking one more time to see if there are any known (or unknown) gremlins to watch out for in this process. Thanks in advance...

Dropping the large washer between the wheel well and the plastic interior trim. You will lose your mind trying to get it back out. Same goes for the jam nuts.

I recommend getting it up on a lift if you can, makes the whole process so much simpler than putting it on jacks. I would also suggest buying extra bolts--I've had a few of the lower bolts shear off when changing them.

[DarkShadowFox]

Dropping the large washer between the wheel well and the plastic interior trim. You will lose your mind trying to get it back out. Same goes for the jam nuts.

I recommend getting it up on a lift if you can, makes the whole process so much simpler than putting it on jacks. I would also suggest buying extra bolts--I've had a few of the lower bolts shear off when changing them.
if you just put all your nuts and bolts into a bag and label/tape them together you will be a okay.

Sent from my LG-H918 using Tapatalk

[Calrenman]

Great thread! Worth reading.

[Hausapes]

Is there any specific advice or tips you would share regarding the re-fit process and potential challenges mentioned by CrankyOldMan and DarkShadowFox, especially concerning the large washer and jam nuts?