My HS build

[CoryM]

Hey guys. This is probably a useless post as few will run HS, but in case it helps anyone (I'm also sitting around, bored after surgery) here is my setup:

-09 5dr
-205/50R15 NT01
-15" Mini Imola rims
-Rear TRD bar
-Front Tanabe bar
-Tokico blue struts shocks.
-Tire pressures 46/36psi (could lower a hair if you didn't care about edge-wear)
-harness lap-belt
-everything else is OEM

Balance is good but you must get the weight onto the front to prevent understeer. It is the most critical part of driving this car, maybe tied with being early enough to let the soft springs settle. So long as as you get the weight to the front, the car will turn in, just hint at understeer, then immediately (and controllable) rotate.

At this point, I think the car is as done as it's going to get for HS in autoX. The next steps would be spending more $$$ than is practical for the car. Hoosiers, lighter rims, and Tokico Reds (or customs). I can't justify that for this car. I might see some improvement from pads/braided lines, but they are enough for autoX (barely... another 10kph faster and I'd need to upgrade).

And yes, I know I'd be more competitive in STF. However I get NT01s cheap, and HS keeps me from spending $$$ on the Yaris (and lets me spend it on my faster car :biggrin:). In terms of making the car faster while ignoring classes, springs would be step 1. Most of what I do (the parts and driving style) is to try to compensate for the soft springs.

As is, this setup has let me PAX 3rd or 4th a couple times in a VERY competitive area (admittedly on courses that were perfect for a Yaris, or when few fast drivers showed up). I probably PAX an average of ~20th of 80+ drivers which isn't bad for this little car with a meathead behind the wheel.

Cheers.
Cory

[invader166]

I wonder...

I don't know if anyone's ever tried this, because i have no clue if they're back-wards compatible, but is there any regulation that prevents you from using OEM springs from a newer Yaris model? Say...a 2015/2016? I've heard the SE trim apperently has stiffer springs. :iono:

[CoryM]

Stock class requires stock springs. The only thing you can do is upgrade options if they were available for the car (eg. if the RS had stiffer springs I could convert my base model to an RS).

This is one of the reasons why STF is a better class for the Yaris. You can do basic bolt-on mods which will get you stiffer springs and better dampers.

[ilikerice]

Suggestions...
Get rid of the front sway bar. It's dead weight. There is no need to stiffen up the front because the engine cradle is already stiff enough, and if you are trying to get rid of a bit more understeer, you need to relax your front end a bit.

Also may help, and this is what I do in STF because I like my rear end to rotate, try reversing the tire pressure, 35/45. If you are experiencing excessive tire wear on the outer edges, I would go with a 195 on the 6" wheel. Reason being is that street tires have a thinner side wall and benefit the most if there is a slight stretch or at least lateral with the rim. I run 205 on a 7" rim, and I feel that 195 may be a better route.

Also, either the BFG Rival S or the Bridgestone RE71 (which are on backorder right now) would be a better tire to run.

Sounds like your running SCCA, so H Stock is actually H Street now. R-comps are no longer allowed in this class, the min tread wear is 200.

just some suggestions from a fellow yaris autocrosser

[CrankyOldMan]

If you don't mind a bit of "rules lawyering" in the mix, the rules really only become an issue at the national level, and even then there has to be a formal complaint filed to dispute your setup. Yes, it's best to follow them at the regional level (or with non-SCCA clubs that use Solo rules) but there's a fair amount of grey area.

I have a set of Imolas as well, but they're on snow tire/rallycross duty. Too narrow for the tires I wanted to run, but I'm in SMF anyway, so sky's the limit for me. You're stuck with a 5.5" wheel, and a 205 is severely pinched on that width (I had 205/50R15 DZ101's on them when I first got them). There's not a lot of options in the 185 or 195 width sport tire market, but they can be found. Looks like the Dunlop ZII star spec (what I run in 205 on a 7" rim) is available in 195/50R15. Treadwear is 200, so you're good in HS or STF. Toyo Proxes R1R is also available in a few 15" variants at 200 TW.

To be fair, I'm not a very good driver, so I don't have much to offer other than technical advice. I normally land in the top 50% in raw, but my PAX is terrible and I'm not properly setup for SMF.

[Jason@SportsCar]

Hey guys. This is probably a useless post as few will run HS, but in case it helps anyone (I'm also sitting around, bored after surgery) here is my setup:

-09 5dr
-205/50R15 NT01
-15" Mini Imola rims
-Rear TRD bar
-Front Tanabe bar
-Tokico blue struts shocks.
-Tire pressures 46/36psi (could lower a hair if you didn't care about edge-wear)
-harness lap-belt
-everything else is OEM

Balance is good but you must get the weight onto the front to prevent understeer. It is the most critical part of driving this car, maybe tied with being early enough to let the soft springs settle. So long as as you get the weight to the front, the car will turn in, just hint at understeer, then immediately (and controllable) rotate.

At this point, I think the car is as done as it's going to get for HS in autoX. The next steps would be spending more $$$ than is practical for the car. Hoosiers, lighter rims, and Tokico Reds (or customs). I can't justify that for this car. I might see some improvement from pads/braided lines, but they are enough for autoX (barely... another 10kph faster and I'd need to upgrade).

And yes, I know I'd be more competitive in STF. However I get NT01s cheap, and HS keeps me from spending $$$ on the Yaris (and lets me spend it on my faster car :biggrin:). In terms of making the car faster while ignoring classes, springs would be step 1. Most of what I do (the parts and driving style) is to try to compensate for the soft springs.

As is, this setup has let me PAX 3rd or 4th a couple times in a VERY competitive area (admittedly on courses that were perfect for a Yaris, or when few fast drivers showed up). I probably PAX an average of ~20th of 80+ drivers which isn't bad for this little car with a meathead behind the wheel.

Cheers.
Cory

The NT01 is a brick, try a 195 Bridgestone RE71R - much better fit on those skinny wheels.

Also ditch the bigger front bar, all you are doing is increasing understeer. A 2014-15 hollow front bar would be a much better choice.

[ilikerice]

^what he said.. after what I said.. :lol:

I feel STF is the best class and probably the cheapest after you spend the most money in coilovers, rims and tires.. after that, its just squeezing every ounce of torque you can out of the motor but it comes down to driver mod.

I won Dixie national tour in STF with stock mid pipe, header, axleback, CAI, rear sway bar, -2.8 front camber and some 15x7.5 heavy ass rims with 205 Rivals..

I would like to say I have been doing very well. Hell, I drove a Factory Five Cobra last event. First time ever, and was able to get Fastest Raw Time http://buccaneerregion.com/ce-4-16.html

The order I think is most important, Driver mod, tires, suspension, power. I started 8 years ago, and I was horrible in my SSM crx. After 4 years, one day it just clicked and my car control started getting better and better.

I would like to hit up a Lincoln National event this year.. but STF is running Mon & Tues.. If I wasn't already going to be at DragonCon that weekend before, I would do it, or if it was Wed & Thur I could do it....

[invader166]

Also ditch the bigger front bar, all you are doing is increasing understeer. A 2014-15 hollow front bar would be a much better choice.

I guess that makes sense. After all, reducing front stiffness increases front tire contact. You just have to get used to the increased body roll though...:thumbdown:

[ilikerice]

I guess that makes sense. After all, reducing front stiffness increases front tire contact. You just have to get used to the increased body roll though...:thumbdown:

That upper sway bar isn't really doing anything that you actually feel on FWD cars because the subframe cradle Is soo stiff already. Most of your understeer come from being front heavy and designed from the factory to be more understeer happy

[Jason@SportsCar]

I guess that makes sense. After all, reducing front stiffness increases front tire contact. You just have to get used to the increased body roll though...:thumbdown:

Its not like I am telling him to remove his front bar (while using OE springs), its a small change in roll stiffness that helps keep the inside front tire in contact with the road - lts less of a change than he already made putting that big front bar on there.

[CoryM]

Late reply as I was moving house and having surgery.

Thanks for the input guys.

Looking at the 2016 rules, it looks like this truly was a useless post :rolleyes: . I use the Yaris in a winter series, so up until now I was still on 2015 rules. Looks like this winter I'll just be racing for fun as I'm not doing a STF build. I run on NT01s because I get them cheap to the point I'd be stupid to run anything else. The raw grip, and resistance to heat cycling makes them a pretty good street/autoX tire IMO. Enough to forgive the low responsiveness.

Regarding the front bar at autoX, have you guys tried this exact setup? The front bar was the last change I did (after 5yrs), and definitely seems faster. I am familiar with suspension design (I have designed/built a car from scratch), and I understand that the front bar is "wrong" for a FWD. However I saw pictures of my car with only 1-2" of rubber on the drive wheel contacting when on power in corners: I figured I would try a front bar to reduce the savage body-roll. From photos it appears to have nearly doubled the amount of rubber on the road, without causing the understeer to be unmanageable. It is absolutely faster in many elements with the front bar. Slaloms, offset gates, keyhole turns. Also allows me to brake later/harder without losing the rear. Basically anything except corners on launch, and bumpy sweepers. The only place (which never happens at autoX) that the front bar shows massive understeer is trying to turn hard without transferring the weight to the front (turning without braking or lift-off). That being said, it's certainly possible that I have gone too far, and that the 2015 bar may be a better option. For my driving, I'd say the current setup is pretty solid.

On the track, or with stiffer springs, I doubt you'd want the front bar. You really need that aggressive weight transfer like you get at autoX. I'm not a track guy, so I can't say for sure, but I bet it would be worse.

Cheers.
Cory

[Jason@SportsCar]

Late reply as I was moving house and having surgery.

Thanks for the input guys.

Looking at the 2016 rules, it looks like this truly was a useless post :rolleyes: . I use the Yaris in a winter series, so up until now I was still on 2015 rules. Looks like this winter I'll just be racing for fun as I'm not doing a STF build. I run on NT01s because I get them cheap to the point I'd be stupid to run anything else. The raw grip, and resistance to heat cycling makes them a pretty good street/autoX tire IMO. Enough to forgive the low responsiveness.

Regarding the front bar at autoX, have you guys tried this exact setup? The front bar was the last change I did (after 5yrs), and definitely seems faster. I am familiar with suspension design (I have designed/built a car from scratch), and I understand that the front bar is "wrong" for a FWD. However I saw pictures of my car with only 1-2" of rubber on the drive wheel contacting when on power in corners: I figured I would try a front bar to reduce the savage body-roll. From photos it appears to have nearly doubled the amount of rubber on the road, without causing the understeer to be unmanageable. It is absolutely faster in many elements with the front bar. Slaloms, offset gates, keyhole turns. Also allows me to brake later/harder without losing the rear. Basically anything except corners on launch, and bumpy sweepers. The only place (which never happens at autoX) that the front bar shows massive understeer is trying to turn hard without transferring the weight to the front (turning without braking or lift-off). That being said, it's certainly possible that I have gone too far, and that the 2015 bar may be a better option. For my driving, I'd say the current setup is pretty solid.

On the track, or with stiffer springs, I doubt you'd want the front bar. You really need that aggressive weight transfer like you get at autoX. I'm not a track guy, so I can't say for sure, but I bet it would be worse.

Cheers.
Cory

If you are happy with it dont change it. :iono:

Body roll is not a bad thing if you have enough camber, and with the crash bolts you should be way better off camber wise than most HS cars. The softer front bar really helps mid corner rotation, and will certainly help power down with that open diff. I will take corner exit over transitional speed every time - you can pick the transitional speed back up with better shocks.

[ilikerice]

I would say it is in your head. Its like when someone tells me they changed from 87 octane to 91 octane and the car feels more stronger....

After 5 years, maybe the driver mod has improved? Like Jason said, if you feel like its faster, then stick with it.

If you are going to be running NT01, that will throw you in F Street Prepared.

I have ran that setup, and its just dead weight. You can control much more with just tire pressure in autocross

[rabbito]

sway bar do make difference, so does front tower strut...higher octane do make a difference...after i upgraded to E85 with larger injectors and ecu, i gained good 10whp+

Sent from my ASUS_Z00AD using Tapatalk

[CoryM]

If you are happy with it dont change it. :iono:

Body roll is not a bad thing if you have enough camber, and with the crash bolts you should be way better off camber wise than most HS cars. The softer front bar really helps mid corner rotation, and will certainly help power down with that open diff. I will take corner exit over transitional speed every time - you can pick the transitional speed back up with better shocks.

Yeah, it always comes down to keeping the driver happy. You're right, mid corner shows a hint of understeer, but immediately transitions into rear rotation so I am OK with it. It's very brief, to the point you don't have time to correct it before it sorts out. As far as camber, I was after more contact patch on the inside tire, which the front bar gains and more neg camber reduces.

I would say it is in your head. Its like when someone tells me they changed from 87 octane to 91 octane and the car feels more stronger....

After 5 years, maybe the driver mod has improved? Like Jason said, if you feel like its faster, then stick with it.

If you are going to be running NT01, that will throw you in F Street Prepared.

I have ran that setup, and its just dead weight. You can control much more with just tire pressure in autocross

I can't see it being in my head. After 4.5 years of racing the car, put the F bar on and after 3 events to get used to it and tune pressures: I'm certain on this car at these autoX events it is faster. I realized last night I'll just run my wet tires for the winter series and hope for enough wet days to compete. You've run this setup? This exact setup? On a 5dr with 205/50/r15 on 15x5.5" rims? .... why? :laugh:

As far as the front bar goes I want to be clear: I did not install the front bar to control balance. When chassis tuning, I always try to maximize grip first, then adjust until balance is right. This is the same as tire pressure tuning; maximize grip with temp probe or chalk, then adjust pressures to reduce grip where needed for balance. The sway bar does the same, except I am using it to help compensate for the high CG. I wanted more grip from my inside front tire, and the front swaybar accomplished this. I was able to reduce neg camber up front to -2.5° (which I forgot to include in my first post), this not only improves the inside tire contact patch further, it also makes a large difference to the braking grip(VS -2.8° which was my previous). After adjusting the balance with rear tire pressures, I am comfortable that it is well set-up, and the co-drivers (once they get used to timing the soft springs) agree so far. I also have pictures to show I have much more contact patch than before.

Who knows, maybe I'm crazy but I've always figured the whole point of suspension was to keep as much rubber in contact with the road as often as possible (or at least when it's required). The front bar seems to accomplish this without causing too many compromises so I am happy.

All that being said, the Yaris is now getting totally forgotten about while I sort out the E-mod car for it's first season.

Cheers.

[brushforhire]

sway bar do make difference, so does front tower strut...higher octane do make a difference...after i upgraded to E85 with larger injectors and ecu, i gained good 10whp+

Sent from my ASUS_Z00AD using Tapatalk

Going to just a higher octane and nothing else, will not give more power, on a stock yaris. Now if other things are changed and modified, that's a different story.

The only reason why a higher octane would give more power, is if the car was compensating for detonation, running rich. Since our cars are designed to run on lower octane, nothing happens by using a higher octane.

[rabbito]

Going to just a higher octane and nothing else, will not give more power, on a stock yaris. Now if other things are changed and modified, that's a different story.

The only reason why a higher octane would give more power, is if the car was compensating for detonation, running rich. Since our cars are designed to run on lower octane, nothing happens by using a higher octane.
yes, running higher octane does not do anything but running higher octane, larger injector and advance timing or controling fuel does make a difference [emoji16]

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[brushforhire]

yes, running higher octane does not do anything but running higher octane, larger injector and advance timing or controling fuel does make a difference [emoji16]

Sent from my ASUS_Z00AD using Tapatalk

Fair enough. LoL

[ilikerice]

This exact setup? On a 5dr with 205/50/r15 on 15x5.5" rims?

Nope, but played around with front strut bars. No bueno. Actually took my front sway bar off completely at one point to help with some front tire contact in the slaloms. Just wasn't flowing for me and my driving style.
Again, to each their own. My setup has got me to a 1st place National Tour twice, but then again, my driving style is a bit different. I don't even left foot brake.


higher octane do make a difference...after i upgraded to E85 with larger injectors and ecu, i gained good 10whp+

My point was that people who drive a yaris with no mods feel that the car is faster if they use 91 octane over 87... Also, that feeling that your car is faster after you fill it up.. SMH

[Jason@SportsCar]

Yeah, it always comes down to keeping the driver happy. You're right, mid corner shows a hint of understeer, but immediately transitions into rear rotation so I am OK with it. It's very brief, to the point you don't have time to correct it before it sorts out. As far as camber, I was after more contact patch on the inside tire, which the front bar gains and more neg camber reduces.



I can't see it being in my head. After 4.5 years of racing the car, put the F bar on and after 3 events to get used to it and tune pressures: I'm certain on this car at these autoX events it is faster. I realized last night I'll just run my wet tires for the winter series and hope for enough wet days to compete. You've run this setup? This exact setup? On a 5dr with 205/50/r15 on 15x5.5" rims? .... why? :laugh:

As far as the front bar goes I want to be clear: I did not install the front bar to control balance. When chassis tuning, I always try to maximize grip first, then adjust until balance is right. This is the same as tire pressure tuning; maximize grip with temp probe or chalk, then adjust pressures to reduce grip where needed for balance. The sway bar does the same, except I am using it to help compensate for the high CG. I wanted more grip from my inside front tire, and the front swaybar accomplished this. I was able to reduce neg camber up front to -2.5° (which I forgot to include in my first post), this not only improves the inside tire contact patch further, it also makes a large difference to the braking grip(VS -2.8° which was my previous). After adjusting the balance with rear tire pressures, I am comfortable that it is well set-up, and the co-drivers (once they get used to timing the soft springs) agree so far. I also have pictures to show I have much more contact patch than before.

Who knows, maybe I'm crazy but I've always figured the whole point of suspension was to keep as much rubber in contact with the road as often as possible (or at least when it's required). The front bar seems to accomplish this without causing too many compromises so I am happy.

All that being said, the Yaris is now getting totally forgotten about while I sort out the E-mod car for it's first season.

Cheers.

Swaybars build grip on the opposite end of the car they are attached to. They do this by providing a lifting force to the inside tire - as the outside tire compresses the swaybar transfers the load and pushes the connected tire in the same direction. You are in fact reducing grip on the axle the bar is attached to.

Swaybars in general are a crutch for a poorly tuned suspension. That said, you are limited in HS with the mods you can do, and one of them wont be fixing the lack of spring rate, so you do what you can. In a fwd car the last thing I want to do is remove front grip, and that is what a bigger front bar is doing.

I would go the other way and find a way to transfer as much grip from the rear of the car to the front. Go with a bigger rear bar, or get a set of proper rear shocks that will help suck up that back tire quicker, forcing grip to the front.

In our car we dont even run a rear bar, just droop limiters in the rear shocks that pick the back tire up almost instantly.

[Jason@SportsCar]

sway bar do make difference, so does front tower strut...higher octane do make a difference...after i upgraded to E85 with larger injectors and ecu, i gained good 10whp+

Sent from my ASUS_Z00AD using Tapatalk

A front strut tower brace will offer no improvement on a Yaris if you are still using the stock upper strut mounts. You have a strut that is mounted in an inch thick rubber doughnut, that is not even positively affixed to chassis, the damn thing just floats in there.

Replace the top mount with a proper bearing plate first, otherwise you are just burning money.

http://www.carid.com/ic/wp/genuine/w01331784575oes_6.jpg
http://wp-content.rpmware.com/wp-content/uploads/2011/06/centerlock_pillowball_upper_mounts.jpg

[ilikerice]

^^^This^^^

What I was trying to say, but much better worded and technical.

[CoryM]

Swaybars build grip on the opposite end of the car they are attached to. They do this by providing a lifting force to the inside tire - as the outside tire compresses the swaybar transfers the load and pushes the connected tire in the same direction. You are in fact reducing grip on the axle the bar is attached to.

Swaybars in general are a crutch for a poorly tuned suspension. That said, you are limited in HS with the mods you can do, and one of them wont be fixing the lack of spring rate, so you do what you can. In a fwd car the last thing I want to do is remove front grip, and that is what a bigger front bar is doing.

I would go the other way and find a way to transfer as much grip from the rear of the car to the front. Go with a bigger rear bar, or get a set of proper rear shocks that will help suck up that back tire quicker, forcing grip to the front.

In our car we dont even run a rear bar, just droop limiters in the rear shocks that pick the back tire up almost instantly.

That way of thinking is definitely the right path for the vast majority of FWD cars. This is why I waited so long to try a front bar on my car. Where the traditional way of thinking goes wrong is Stock class when the CG is high and/or springs are too soft. High body roll, high neg camber and struts cause the inside front tire to lose a large amount of contact patch. In my car I was losing ~1/2 of my inside F tire contact patch. That's a lot of rubber, and it shows everytime I try to accell out of an element.

Yes the F bar loses grip by transferring weight to the rear, but it also gains grip by almost doubling the contact patch of the inside F tire (and gains a little outside F contact patch due to reduced pressures). Is this enough to net more F grip over all? No idea, but it sure feels like it. If I had the tire-curve, I could do a bunch of measurements and math to figure out which gains more grip (on paper). In practice, it would take a serious test and tune session to confirm one way or the other.

Again, this pretty much only applies to HS cars and maybe only over-tired HS cars. It's possible it needs R-comps to see gains, and maybe this winter running my street/wet tires will show the front bar to be detrimental.

[Jason@SportsCar]

That way of thinking is definitely the right path for the vast majority of FWD cars. This is why I waited so long to try a front bar on my car. Where the traditional way of thinking goes wrong is Stock class when the CG is high and/or springs are too soft. High body roll, high neg camber and struts cause the inside front tire to lose a large amount of contact patch. In my car I was losing ~1/2 of my inside F tire contact patch. That's a lot of rubber, and it shows everytime I try to accell out of an element.

Yes the F bar loses grip by transferring weight to the rear, but it also gains grip by almost doubling the contact patch of the inside F tire (and gains a little outside F contact patch due to reduced pressures). Is this enough to net more F grip over all? No idea, but it sure feels like it. If I had the tire-curve, I could do a bunch of measurements and math to figure out which gains more grip (on paper). In practice, it would take a serious test and tune session to confirm one way or the other.

Again, this pretty much only applies to HS cars and maybe only over-tired HS cars. It's possible it needs R-comps to see gains, and maybe this winter running my street/wet tires will show the front bar to be detrimental.

Not sure who sold you on that, but if you like it go with it.

[CoryM]

I was sold by seeing the car on course from outside, photographs, experienced co-drivers' opinions (after they have driven the car), my understanding of suspension design, and that the car feels faster through many sections on course. More rubber with less dynamic load, or less rubber with more dynamic load: Unless someone does a test and tune (or some serious engineering) of both setups there is no way to confirm which nets more grip, in more situations, on this setup.

[invader166]

That way of thinking is definitely the right path for the vast majority of FWD cars. This is why I waited so long to try a front bar on my car. Where the traditional way of thinking goes wrong is Stock class when the CG is high and/or springs are too soft. High body roll, high neg camber and struts cause the inside front tire to lose a large amount of contact patch. In my car I was losing ~1/2 of my inside F tire contact patch. That's a lot of rubber, and it shows everytime I try to accell out of an element.

Hmmm...your OP states that you have Tokico blues installed? I've heard they are a pretty stiff shock. Why not try some softer shocks with the front bar? That way, maybe you can load and unload your tires at a faster rate and be able to further increase your tire contact with the road.

Just another idea, but like you stated above. No way to really find out without some serious tests, and proper math.

[CoryM]

Hmmm...your OP states that you have Tokico blues installed? I've heard they are a pretty stiff shock. Why not try some softer shocks with the front bar? That way, maybe you can load and unload your tires at a faster rate and be able to further increase your tire contact with the road.

Just another idea, but like you stated above. No way to really find out without some serious tests, and proper math.

I could definitely do better in the shock department. I'm not sure what the blues are intended for, but stock springs is not it. I only got them because I needed something to replace a damaged OE strut. The Yaris only gets new parts when it *needs* them. The whole point of me driving the economical car is to spend less on it so I can spend more on faster cars :smile: . This is also why I've stayed in HS as it reduces the temptation to buy stuff for the little car.

Cheers.