Imaginary STF build

[Ben_]

Hey guys,

I don't have money to spend on lots of expensive parts plus next season for Utah region SCCA doesn't begin till next March, but I still love writing up potential builds. Here is one for the STF class, which has a pax of 0.801 compared to the HS pax of 0.797. Not a huge difference for the MUCH greater possibility to maximize the performance of our little cars! This build has parts with bang for buck and performance in mind.

So beginning from the ground up, since that is the best way to build a car for auto-x IMO.

http://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=g-Force+Rival&partnum=245WR5GFR&i1_Qty=4

225-45-15 BFG Rivals maximizing the tire width limit of STF, maximizing the UTQG limit of 200 for 2015, and keeping a small diameter for gearing benefits

http://www.tirerack.com/wheels/WheelCloseUpServlet?&target=runWheelSearch&autoMake=Toyota&autoModel=Yaris+Liftback&autoYear=2010&autoModClar=5-Door&initialPartNumber=SM57100355B&i1_Qty=4&wheelMake=Advanti+Racing&wheelModel=Storm+S1&wheelFinish=Black+Painted&wheelFinish=Black+Painted&showRear=no&package=W&association=2

Advanti Storm S1 15x7 e35 which is the exact width to match the tires also is within width limits of STF and is more budget oriented than Enkei RPF1 but is only 1 pound heavier per rim

All of the following are available on Micro Image

R1 concepts drilled and slotted rotors with carbotech track pads, SS brake lines and custom venting from the fog light holes or lower bumper grill rear brakes must remain drums to keep the factory parking brake

Whiteline 23mm rear antiroll bar, Megan Coilovers

micro image intake manifold, 1.8L TB, AFE 1.8L intake, remove plastic engine cover

Megan Header, custom 2.25" straight pipe with high flow cat

APEXI AFC-neo piggyback tuner

DENSO spark plugs, MI lightweight crank pulley, K&N oil filter

Micro Image shifter cage bushings, MI shifter cable bushings, MI short shift kit


Total Cost = 4586.94 + shipping + tuning + exhaust fab

[ilikerice]

you can't change your manifold out on in STF class. that will put you in FSP

You can't do piggy back unless it is a plug'n play. No splicing wires allowed

You also can't run piping for brake cooling either. Has to remain oem.

I would go with Hankook RS-3 in 225/45/15 personally. Rivals are good also, but the RS-3's like cold weather a bit more and are more forgiving than the Rivals. Rivals don't talk back, when you break that grip, its over. RS-3 are more forgiving and like more tire pressure.

[ilikerice]

Everything else you got is pretty standard in stf. Only thing i would suggest is alignment. Get some crash bolts for the front to get more camber. I would not mess with rear alignment shims. Play with tire pressure first.

[Ben_]

Intake manifold can be swapped in stf. Anything leading up to the block is fair game. Obviously I don't understand how the apex fc works. Is there a fc that is stf legal?

There was some talk going around about the hankooks this season. One of our regions best drivers got a set for his focus st in stock class and did not like them. I don't remember his comments in specific but he liked his previous set of tires better. I'm not sure what they were. Anyways the rivals are the most popular tire in our club and there are a lot of great drivers who swear by them. Maybe its because all of the venues we use have 'coated' or 'sealed' asphalt and gives minimal grip compared to concrete or plain asphalt.

My personal experience is with OEM bridgestone potenzas, khumo all seasons, and 1 weekend on concrete (my only cross on concrete) with a set of proxies r1r I got used from another Utah region guy with not much life left. The proxies had greatly improved steering feel and I'm not too sure about grip, but I'm sure it was a great improvement.

[CoryM]

Not sure what the seat rules are in STF, but in HS I run a 3" lap-belt for safety reasons. By strange coincidence, it works well to hold your butt in the seat so you can concentrate on driving. If you have an expired harness around, might be worth doing..... for safety ;)

I'd say camber, and whatever you can do to make use of as much of the front tires as possible (instead of the usual outside 1/3) will be the first priorities. Saves you money on tires in the long run too.

[ilikerice]

Rule book states in 14.10.C
Air intake systems up to, but not including, the engine inlet may be modified or replaced. The inlet is the carburetor, compressor inlet, throttle body, or intake manifold, whichever comes first

There fore the throttle body cannot be changed, but cai is allowed.

[ilikerice]

Anything allowed in HS is allowed in ST. So harness belts are allowed. Racing seats are also allowed, but have to weigh at least 25 lbs. including brackets and rails.

[ilikerice]

http://www.scca.com/solo/content.cfm?cid=51804

If you check out the scca site and look at the archives, hankook is the dominating tire that 1st place drivers are running.

This year i ran toyo up front and hankook in back. Decent setup, but i miss my hankooks.

I placed 2nd this year in my region running stf.

[ilikerice]

As far as piggybacks. You can make your harness or see if someone can do it for you. Its alot of work. Boomslangs run about $500.
I dont think its really worth it because you cant change timing with it and the toyota ecu does a great job on its own calculating a/f to compensate for the increase of air flow cai adds

[Ben_]

I was looking at the rules for street prepared, haha. Good eye.

Without the cost of the manifold and the fc the total cost would be much lower at around 3450. A very reasonable chunk of change but I'm sure this is worth at least a few seconds on lap times. Are the mods you have similar to this list? How much of a time improvement do you think this is worth? How much HP increase do you think the mods are worth?

As far as the seatbelt goes I usually lean my seat back and pull the seatbelt hard to lock it and use that to keep my butt in the seat. Works much better than nothing but I'm sure a good seat and 5 point harness would go a long way towards decreasing lap times. I often catch myself using my left leg to brace myself in the seat. No good :(

[xnamerxx]

no need for a 5 point or harness bar, risk of submarining is very low with autocross.

[Ben_]

It is cool seeing some yaris taking trophies in stf. :D

[ilikerice]

I have a sparco fixed racing seat. I agree with xnamerx with the harness and bar. It looks cool to have, but not necessary if you got a good seat. I was using a lap belt for my first year in the yaris. Basically a seat belt that wraps around your waist and around the back of the seat. I was getting annoyed by the same problem you are having. I still braced myself with my leg against the door and the center console, even my left arm against the door on some occasions. Now I have a good seat that fixed my butt in place, but I still use my oem seat belt.

Yes, your setup is very similar to mine.
My engine
AEM CAI
Megan Headers
High Flow Cat/custom midpipe
Tunabe axleback
NST light weight crank pulley
Ballistic Ultra lightweight battery (2.8 lbs)

Suspension
Megan coilovers
23mm UR rear swaybar
Front TRD Camber bolts (2.8 neg camber in the front)

Interior
Sparco Racing seat

Grip
Rota GT3 rims 15x7 ET40
Hankook RS3 225/45 (psi: front 40ish rear 55ish)

Brakes
Currently OEM
I do plan on getting stainless steel lines and Hawk pads eventually for more bit, but I am doing good with what is on the car currently.

[CoryM]

re: harnesses, it's my understanding that only lap belts are allowed.
"non-factory upper body restraints may only be used in open cars,
cars with targa-tops in the open position, or cars with T-tops in the open
position"

I just use the same lap belt holes as the OE and it works fine ( I use both belts on course). Just yank it tight before each run. You also don't really want tight upper harnesses without a HANS or similar. Basal neck fractures and all that.

[ilikerice]

I don't know where you found that. What chapter, section did you get that from? That may be true for Street class, but I do believe Street Touring is allowed to have a harness bar and a harness

[ilikerice]

Harness bars are allowed for a harness also in street class, therefore, its allowed in all classes
13.2
H. Driver restraints as outlined in Section 3.3.1 are allowed. Seats may
not be cut to allow for the installation of alternate seat belts or harnesses.
Passive restraint systems may disabled but may not be removed.
Removeable seat headrests may be repositioned using the
original mounting hardware only if the OE components permit it with
no modifications. This includes removing a headrest and reinstalling
it backwards. A horizontal “harness bar” may be used as part of the
installation hardware for allowed driver restraints provided it has no
more than 2 attachment points to the chassis and is bolted at those
locations. A C-type harness bar may also be used. It may have 4
bolted attachment points to the chassis (2 primary and 2 supporting
connections to resist rotation). Truss-type harness bars are not allowed.

And in street touring section 14.1
AUTHORIZED MODIFICATIONS
All Solo® Rules Street Category allowances, plus all allowances contained
here in Section 14

[CoryM]

The part I posted is 3.3.1, which your part references. I asked on my local club and the reply I got was to run the lap belt AND the OE 3-pt. Which makes sense with airbags.

Cheers.

[ilikerice]

Yea, you gotta kinda read that as a whole instead of picking parts out of it.

Seat lap belts are required in all cars, and must be installed in cars with
passive restraint systems that do not include a lap belt. Installation and
the use of shoulder belts or harnesses is strongly recommended, however
non-factory upper body restraints may only be used in open cars,
cars with targa-tops in the open position, or cars with T-tops in the open
position when two conditions are met:
A. The roll structure must meet either the requirements of Appendix C
or the Club Racing General Competition Rules (GCR) 9.4.
B. The top of the roll structure may not be below the top of the driver’s
helmet when the driver is in the normal driving position.

The whole lap belt required is that back in the day, they didn't have seat belts. So a stock car wouldn't have them. Then they came out with cars that had the mechanical shoulder belt that would choke you when you closed the door (80s accords). The lap belt was a separate buckle from the should buckle and could easily not be buckled in.

The part that is says:
however
non-factory upper body restraints may only be used in open cars,
cars with targa-tops in the open position, or cars with T-tops in the open
position when two conditions are met

This saying that, aftermarket harness can only be used in open cars when 2 conditions are met which is A and B.

In other words, you can not use aftermarket harness in an open car if you do not meet these 2 requirements:
A. The roll structure must meet either the requirements of Appendix C
or the Club Racing General Competition Rules (GCR) 9.4.
B. The top of the roll structure may not be below the top of the driver’s
helmet when the driver is in the normal driving position.

[Ben_]

I really hate scca rules sometimes. I have to keep telling myself there has to be rules to make the competition fair :x

[ilikerice]

It's not that bad. It's just people don't like to read these days. I see this all the time. People will always ask someone else before they read the book themselves. Grammar also plays a part, like what I just broke down. You gotta pay attention to commas, periods and paragraphs. How is the sentence being used in this paragraph. So when someone asked someone about a rule, they are going by memory and their interpretation.
So that alone will play into the effect of asking the solo chair, be cause he has the final call on that current solo event. If he says, shoulder harness' are not allowed unless you have a Targa top or convertible, then that's the rules of that event. Unless you want to pull the book out and challenge it.

I need to know the rules because I am the Solo Chair in my region. I get these kinda things all the time. I have to dissect the rules in every class and car

[Ben_]

So I have been doing more thinking. Tire rack says the largest tire that is guaranteed fit is a 215. Are there rubbing issues with coilovers and a functional amount of negative camber? Also thinking about a good exhaust setup for n/a. 2" or 2.25" high flow cat glass packs something that will be relatively quiet while having some kind of cat and being least restrictive. Maybe a side dump exhaust for less piping

[ilikerice]

Either 2" or 2 1/4" is fine.. wouldn't go any higher than that. As far as tires. The new rules state that treadwear has to be at least 200. Hankook, Toyo, or BFGoodrich hasn't released their new 200 treadwear tires yet (RS3, R1R, or Rivals). Which are suppose to be the competitive tires. They still have 140 treadwear on the shelves still. You probably wont see them for a couple of weeks yet, but when you do, I would hurry up and order them asap before they run out of stock.

For rubbing. Rules say you can not modify the fenders or liner to accommodate for wider tires and offset. I run 225/45 on my 15x7 rim. about 2.5 neg camber on the front, stock on the rear on Megan coilovers. BUT, if the tire rubs the fender liner til there is a hole there, its technically still OEM. just some wear. as long as the fender liner is there. Mine has worn off completely, and where it has worn, I have just used a drimmel to trim it up a bit but not actually take it out.

[ilikerice]

I was wrong, the 200 tread wear is now available from TireRack.com in Rivals and RS3 v2. The Toyo R1R are still at 140 treadwear. Give it time.

Only downfall they are only available in 195 in 15's... that sux

[Ben_]

The biggest reason I want to run camber right now is that I get obscenely uneven treadwear. Only the outer half (pretty much literally) shows wear after track/auto_x use. What camber setting would be good just to see even tread wear?

Right now I am using 2 sets of tires one for daily driving and one I change out in the parking lot for track events. If there was a good balance between too much wear on the inside for my daily tires and too much wear on the outside for my track tires that would be easiest with what I have now.

Otherwise I'm planning on a set of 225s to run as a set of summer tires and then switch my current dailys for some winter tires. I'm thinking this because maybe there isn't a good compromise between even wear for 2 sets of tires.

Maybe this is a bit confusing because I'm talking about doing a few different things here

[Ben_]

Also if there were camber plates to make camber setting changes on the fly that would be sweet too. Maybe the best option

[ilikerice]

The rear have camber shims that are pretty much what your asking for as far as swapping on the fly, but that is just the rear.

You are asking to have your cake and eat it too. I run -2.5 in the front like I said. This is a very good setup for DD and track driving for me. If you are going to be wearing your street tires out using this camber, then the only other option is to have your tires flipped every 5k miles to get the most out of them. When I say flipped, I mean taking your tire to the shop and having the same tire on the same rim flipped so the outer is now the inner and inner is now the outer. A lot of autocrossers so this also. I have been fortunate to not have this problem.

Again, my track tires are 225/45 on a 15x7 with offset of -40 and my DD are 205/50 on a 15x7.5 with offset of -30

Track tires with RS3 I run 40psi up front and 55psi in the rear
If I run R1R, I run 30psi up front and 45psi in the rear.

my DD I run 40psi all around

[Ben_]

If only the world was that simple and I could have my cake and eat it. Thanks very much for your advice. We shall see what happens next season

[xnamerxx]

I run -3.5 when my car was my DD didn't really make all that much of a difference as far as tire wear goes toe was the only thing that really caused bad tire wear. At one point I even had -4.5 camber if the car was better dynamically I probably would have stayed with that much camber, but power and braking suffered too much to keep it. I run rear camber as well I use .5mm shims on the hub works pretty well.

[CoryM]

Track tires with RS3 I run 40psi up front and 55psi in the rear
If I run R1R, I run 30psi up front and 45psi in the rear.

Just curious, how did you end up at those pressures? Maximize front grip, then tune rear to suit driving style?
My car runs about 10psi more up front than rear in HS and HS-R. Obviously I need more front pressure to keep the edges alive with stock springs, but the car savagely understeers if the rear pressures are any less than 10psi lower than front.

Also, how bad is the extra weight of the 225s and do you get enough heat in them every run?

Thanks.
Cory

[CoryM]

Regarding camber: I am also running about -2.8° and I wouldn't suggest any more (or any less really). I've tried a few different amounts of front camber (free alignments) and the loss of traction in braking and acceleration is just starting to show up with -2.8°. If your tires are wearing well you could drop down to -2.5° to gain that traction back, but I don't know that any Yaris would avoid edge wear due to the high CG.

[xnamerxx]

Regarding camber: I am also running about -2.8° and I wouldn't suggest any more (or any less really). I've tried a few different amounts of front camber (free alignments) and the loss of traction in braking and acceleration is just starting to show up with -2.8°. If your tires are wearing well you could drop down to -2.5° to gain that traction back, but I don't know that any Yaris would avoid edge wear due to the high CG.

At -4.5 with 500f springs I was able to get even tire wear. It was a good setup for the most part but the car just really wanted to lock em up.

[ilikerice]

Just curious, how did you end up at those pressures? Maximize front grip, then tune rear to suit driving style?
My car runs about 10psi more up front than rear in HS and HS-R. Obviously I need more front pressure to keep the edges alive with stock springs, but the car savagely understeers if the rear pressures are any less than 10psi lower than front.

Also, how bad is the extra weight of the 225s and do you get enough heat in them every run?

Thanks.
Cory

Well, the 225 are only 1 extra pound per tire compared to the 195.
http://www.tirerack.com/tires/tires.jsp?tireMake=Toyo&tireModel=Proxes+R1R

I will sacrifice some acceleration for the extra grip. As far as keeping heat. I don't have that much of a problem. They are not R-comps, so they don't need to be above 200 degrees in order to be sticky. RS3 are fine after the 1st run. They hold 150 up until my next run. Granted, there is no way of me knowing how hot they get while I am running. After I park in grid, I will check the temps and my fronts are usually 200ish across the tire and my rear are 180ish outer and usually 10 degrees less on the inner. Probably due to the high tire pressure. I am sure if I got .5 shims in the back that I could get the heat the same across the rear tires, but I dont want any more grip in the rear that I have already.

I get my tire pressures from experience and my driving style. I like my rear to swing out when I come up to a turn or during a turn when I lift off the throttle. I would rather lift off the throttle than left foot brake to maintain my momentum during any kind of turn.

With that said, The R1R like little bit of pressure unlike the RS3. R1R if more than 35psi, I get more under-steer than I like. Even with 30 psi up front, I am still wearing out the tires evenly. The shoulders on the R1R are very tough and dont flex as much as the RS3 either.

The RS3 like more pressure up front because they have a softer side wall and will roll on it if the pressure is not enough. A lot of heavier cars wont run RS3 in Street Touring class because of this. They will run Direzza Star Specs because of the side wall issue.

Hope this clears up my reasoning behind my choice in tire pressures. Again, its all about driver style, trial and error.

[CoryM]

Thanks for the info.
I think I'll probably stick with 205/50 NT01 this year as they are my street tires as well: That extra mass (in the worst spot possible) just gets too painful going up the hills around here. Heat wise, I'm going to guess lack of temp is more of an issue here than Ga. I also do a winter autoX series and run the NT01 until about 10°C wet or dry (which can be exciting).
I think the soft front springs are crippling the car too much to "properly" set it up. If I make it any more tail-happy, it is going to be too hard to control on turn-in. The car will rotate a little off-throttle in corners but not great. But then again, I am used to rwd so not sure how to judge.

I've decided since the rule changes make it impossible for me to compete on NT01s that I don't care about PAX anymore. Next step is LSD :)

[ilikerice]

I have been driving FWD since I got my license in 1999. I had a miata for a couple months that my dad wanted me to sell it for him. I almost kept it. People say I can power slide like I drive a RWD, haha

LSD, I second that. The yaris is painful to drive with out it. It is definitely on my next Item to purchase before I go turbo.

[ilikerice]

Yaris is now FSP legal.

#16432 Yaris, Fit, Versa Classing Proposal
Per the SPAC, add the following new listings in Appendix A, effective immediately upon publication:
FSP
Honda
Fit
Nissan
Versa (2007-15)
Toyota
Yaris

[ArmstrongRacing]

Might as well post up my setup...
Engine- AEM cold air intake, DC header, Magnaflow custom 2" cat--back, NST crank pulley, Simota oil catch can.

Suspension- Tein Basis coilovers(testing purposes only, Normally TRD springs and Tokico HP), Whiteline control arm bushings, TRD strut top mounts, TRD rear sway bar, Eibac crash bolts.

Brakes- Stoptech slotted rotors, MI brake lines, Hawk HP pads

Enkei RPF1 15x7 + Dunlop Z2 205/50R15

[7:34pm]

Did you do a 2zr swap at one point?

How was it? And what did you do for mounts?

Might as well post up my setup...
Engine- AEM cold air intake, DC header, Magnaflow custom 2" cat--back, NST crank pulley, Simota oil catch can.

Suspension- Tein Basis coilovers(testing purposes only, Normally TRD springs and Tokico HP), Whiteline control arm bushings, TRD strut top mounts, TRD rear sway bar, Eibac crash bolts.

Brakes- Stoptech slotted rotors, MI brake lines, Hawk HP pads

Enkei RPF1 15x7 + Dunlop Z2 205/50R15

[ArmstrongRacing]

Correct, we did perform a 2ZR swap in a fellow NCVC members car. We used a Scion Xd as a donor car, and everything fit perfectly. We then put the 1NZ in the Xd, and that's his daily driver. Scott was a major help with the wiring!

The power increase is noticeable in the lighter Yaris chassis, and even with no mods on the 2ZR it's a blast.

[CrankyOldMan]

Correct, we did perform a 2ZR swap in a fellow NCVC members car. We used a Scion Xd as a donor car, and everything fit perfectly. We then put the 1NZ in the Xd, and that's his daily driver. Scott was a major help with the wiring!

The power increase is noticeable in the lighter Yaris chassis, and even with no mods on the 2ZR it's a blast.

I'm curious about the cooling system of the Yaris being able to cope with the 2ZR. Any issues to report on that end?

[ArmstrongRacing]

We used the radiator from the Xd, it's the same size core with a slightly different upper hose outlet. Fits perfectly in the Yaris core support. No cooling issues.

[7:34pm]

Correct, we did perform a 2ZR swap in a fellow NCVC members car. We used a Scion Xd as a donor car, and everything fit perfectly. We then put the 1NZ in the Xd, and that's his daily driver. Scott was a major help with the wiring!

The power increase is noticeable in the lighter Yaris chassis, and even with no mods on the 2ZR it's a blast.
Thanks!

Always was curious about similar platform swaps but unfortunately there doesn't seem to be enough write-ups.

So would you say it was mostly plug and play? Was it a fairly expensive swap? And what mounts were used?

[ArmstrongRacing]

Mostly plug and play, everything from the XD was moved over to the Yaris. Just a few wiring differences.

[ilikerice]

I remember that thread. I had that thread subscribed and was one day put together a write up for that swap. Now that website is gone, so is that information. Any chance one day you guys could get a small write up on the swap. I do remember having to swap some wires inside a fuse box or connectors for something, ABS maybe? You didn't use all the same mounts either right?

[ArmstrongRacing]

We are currently doing a write-up for SubCompact Culture, then we can re-build a thread here!

[kwkshft]

Might as well post up my setup...
Engine- AEM cold air intake, DC header, Magnaflow custom 2" cat--back, NST crank pulley, Simota oil catch can.

Suspension- Tein Basis coilovers(testing purposes only, Normally TRD springs and Tokico HP), Whiteline control arm bushings, TRD strut top mounts, TRD rear sway bar, Eibac crash bolts.

Brakes- Stoptech slotted rotors, MI brake lines, Hawk HP pads

Enkei RPF1 15x7 + Dunlop Z2 205/50R15

Do you have the P/Ns for the TRD strut top mounts? Are these for all 4 corners? I may look into getting these, thanks

[ArmstrongRacing]

I don't know what the part number is, I got these from MicroImage(CaliYaris) years ago. You only need 2 for the front strut tops. Cusco offers a mount also....I think.

[ilikerice]

Cusco IICR is a solid mount... wouldn't recommend that for daily driving.

[ArmstrongRacing]

Here is a shot of the 2" vertical trunk spoiler I made from Aluminum from HomeDepot. $25 an 1.5 hours labor.

This is completely removable, I only want to use it on Track days and not bump myself into another class.

[ilikerice]

Thats cool. How about getting a long Piano Hinge and rivet it that 2 piece and then tie in a few adjustable anchors to the bottom and you got yourself an adjustable spoiler.....

[ArmstrongRacing]

That was my original plan... But due to the dual inward and downward curvature of the trunk, it was a stretch to get the angled base flush.

[ilikerice]

OH yea, I see what you are talking about

[MugenRep]

Might as well post up my setup...
Engine- AEM cold air intake, DC header, Magnaflow custom 2" cat--back, NST crank pulley, Simota oil catch can.

Suspension- Tein Basis coilovers(testing purposes only, Normally TRD springs and Tokico HP), Whiteline control arm bushings, TRD strut top mounts, TRD rear sway bar, Eibac crash bolts.

Brakes- Stoptech slotted rotors, MI brake lines, Hawk HP pads

Enkei RPF1 15x7 + Dunlop Z2 205/50R15

Hey Sir!

Which Whiteline Control Arm bushings are you using in the Yaris control arms? Are you using the CASTER + or just the normal?