Toyo R1R Setup Suggestions

[kpower]

I'm using a set of new R1Rs as my track tire this season (chosen after winning some Toyo gift certs and the need for a 140 treadwear for Time Attack classing) and was looking for some suggested setups with respect to camber, hot pressures, etc. I'm using these on a 2006 WRX. I have been out once on them already and was quite pleased, but I noticed a fair amount of roll over on the front left tire.

Current Spec:

Track: TMP
Hot Pressures: 34F / 32R
Camber: -2.2 F / -2.0 R
Temps: need to review data from tire pyro still

Cheers,
Kyle

ps. loving the new forum layout

[JoeT]

Can you give us some detail:

Spring Rates: Front / Rear
Rim Width and size (this makes a huge difference)
Is the car lowered, if so, how low?
Oh yeah.. tire size too please


Thanks

[kpower]

Hi Joe. As requested...

Coilover: HSD HR series - ride height was between 13.5" - 14" from centre of wheel to u/s of fender (fairly conservative)
Spring Rates: 8kg/mm Front / 6kg/mm Rear (I believe this is the standard rate)
Wheels: 18x9"
Tire Size: 255/35/18

[JoeT]

With regards to your ride height, how much lower than stock is it? Sorry with all the questions, just seeing how much camber you'll need. Subaru Mac Struts and low caster on Subies kind of suck.

[kpower]

It's at least a couple of inches lower than stock. I haven't taken ride height measurements at stock height, so I can't be exact.

I currently have my camber plates rotated to induce positive caster as well. Running 5 deg positive, if I recall my alignment spec sheet correctly.

Here's a picture to give you an indication of the ride height.

http://i703.photobucket.com/albums/ww34/hawkeyewrx/2012%20Track%20Journal/IMG_0314.jpg

[JoeT]

Unless you're using a roll center relocation kit, like the whiteline one, the spring rates are a bit too low and your ride height is too low too by about 1". For track use, I'd go with pretty close to 13Kg front and 10 kg rear, using stock rear sway bars. Camber should be -3.5 degrees in the front and you'll be ok with -2.5 rear. With the proper valving, you'll be ok with for street use. With the Mac Struts up front and the poor camber curve on our cars, your tire temps will vary from outside to inside edge, the inside being hotter.

On my car I run -3.5 degrees camber, 13kg front and 15kg rear with effective spring rate of around 9ish kg in the rear. It'll drive like a go kart if you do that, very predictable at the limit, and very responsive to throttle steer. Steve D can chime in on the setup of his STI.

[kpower]

I am using the Whiteline roll centre relocation kit as well. I'm trying to strike a balance here as I have a lengthy daily commute (60km driving if I take public transit, 160km without). I fear running -3.5 degrees would make short work of my daily tires.

Are your spring rate suggestions based on using OEM front and rear sway bars? I should have noted that I am using a Whiteline 24mm adjustable rear bar and an OEM front bar at the moment, but plan on adding a Whiteline front sway bar this weekend. I'm pretty well stuck with the valving of these HSDs for now. My goal for this summer was to not spend money on new parts (realizing there are better suited suspension options out there), but to spend it on seat time and bettering my skills. If I'm satisfied with my improvement at the end of this season, I'll consider some upgrades for next.

I appreciate the input, Joe.

[JoeT]

IMHO, sway bars are the 2nd last thing to do when setting up suspension, spring rates first, then sway bars. The issue with our suspension is the lousy camber curves for the mac strut setup. Couple that with body roll and that -2.5 degree camber turns to .5 degree positive upon cornering. If you enlarge your avatar photo it maybe possible to see it. I'm with you though, the less money spent, the better LOL, this is a hobby after all.

Try to get -3 degrees camber and fine tune with air pressures, you won't get too adverse wear specially if you're tracking the car. On my -3.5 degree camber setup, I used to drive that daily to the tune of 25K Km / season and ran with those tires to events and to work, and it survived for 1.5 seasons.

[kpower]

Thanks Joe! The feedback is good. I'll post my findings as I made adjustments to my setup and see what it does to my lap times.

[Fubawu]

What class are you in this year? I was on the R1R's as well but I am switching to RS-3 in the next week or so. Good tire with decent
life in them. TMP will really roll over the front driver side. I found on a stock MS3 35psi hot in the front worked well. 3200lbs
fwd so it is not that helpful for you. Lastly what tires where you on before and how have your times changed at TMP?

[kpower]

I'll be running in the street class for the CSCS series, which dictates classes by tire (for the most part). Trying to make it out to some Sigma and OTA events as well this summer, but I made my tire choice based on the CSCS classing. OTA classing would put me in GT2 as the car sits, if I remember correctly.

So far I've found that my best times on the R1R's was when running 34psi hot in the front. The GD WRX is similar in weight to the MS3 by the sounds of it. I haven't had my car on the scales yet, but I think it's in that range.

Last season I was running a couple different loaner sets of wheels and tires. My fastest time out was on a set of Starspecs, running a 1:25.300 with no interior. My fastest time with the R1R's this year was a couple weekends ago running a 1:25.500 (full interior), on a green track an 10 deg C ambient temps. I was having some overboosting issues that day as well, so I never saw full throttle in 4th gear.

I modified my alignment spec yesterday to suit the tire wear I was seeing and the tire temps we took that day. I'm now running -3.0 deg F / -2.0 deg R.

[Fubawu]

star specs to R1Rs are pretty close. Sounds like the R1R's are working well as the track temps were cold plus full interior. Not sure how stripped you go
but the biggest factor would be temps. Warm track should make things very interesting. What mods/power is your car making? Lastly and brake changes in the offseason?
Cheers
John

[STeveD]

The R1R sidewall behaves like an RA1. I prefer a higher camber differential front to rear, but your -3/-2 is a good start. If you are not going to change spring rates, I would guess that you might need about 25 to 27psi in the rear to help with rotation/reducing understeer. Lower the rears slowly from 29psi until you like the feel.

I've tried a stiffer front swaybar at the track and find that it adds to understeer, so I've gone back to a stock one. If you're looking to not invest more in parts, then the front sway bar may be one thing you want to defer. Best to try it back to back so that you can compare it for your driving style.

[kpower]

star specs to R1Rs are pretty close. Sounds like the R1R's are working well as the track temps were cold plus full interior. Not sure how stripped you go
but the biggest factor would be temps. Warm track should make things very interesting. What mods/power is your car making? Lastly and brake changes in the offseason?
Cheers
John

Time will tell! Not much for power mods. Stock WRX with an exhaust and a tune. Made about 250 wheel. No brake changes from last season. Running STi Brembo calipers, Stoptech & DBA rotors (front / rear) and Performance Friction PF-01 pads.

[kpower]

The R1R sidewall behaves like an RA1. I prefer a higher camber differential front to rear, but your -3/-2 is a good start. If you are not going to change spring rates, I would guess that you might need about 25 to 27psi in the rear to help with rotation/reducing understeer. Lower the rears slowly from 29psi until you like the feel.

I've tried a stiffer front swaybar at the track and find that it adds to understeer, so I've gone back to a stock one. If you're looking to not invest more in parts, then the front sway bar may be one thing you want to defer. Best to try it back to back so that you can compare it for your driving style.

Thanks Steve. The front sway bar is already on the car. Once I get back on the track, I'll feel it out and see how it goes. The car felt quite balanced with the OEM front bar, so I'm interested to see the difference. The main intent was to reduce some of the body roll. I can bring down the rear tire pressures a few notches if I'm finding there is too much understeer.

[BryceD]

This thread has lots of great info! Kyle, can't wait to see how your changes work out, are you going to get back out there before the first event?

[kpower]

Thanks, Bryce. I'm hoping to get out in the very last weekend of May when I'm back from vacation. The first CSCS event is that first weekend in June, so here's hoping!