The road to a 295/30/18 Hoosier A7 / RPF1 square setup.

Currently I am running 275/35/18 Front and 295/35/18 Rear BFG KDWs on 9.5+15F and 10.5+15R Enkei RPF1s.

Alignment is as follows:

Front Left Side/Right Side
Camber -1.7/-1.9
Caster 8.8/8.4
Toe .06/.07

Rear Left Side/Right Side
Camber -1.4/-1.6
Toe .13/.08

Ride Height from Hub is 14"ish front and 15"ish rear to the top of the fender.

Corner Balance Results ¼ Tank
Front 54.8% Rear 45.2% Cross 50.1%
Total Weight 3463 w/165 lb driver

Current weight now ¼ Tank is 3381 w/185lb driver <<This was from the track scale at Heartland Park; I’m not sure how accurate it is.

I will be having the car realigned and corning balanced at the same time I have the tires mounted and balanced. I’m taking recommendations on what settings to go with. I’m thinking 3 degrees up front and somewhere between 1.6-1.8 out back. Running 4.08 gears traction is an issue.

Below is a picture of the 295 BFG up front to get an idea of what I might be dealing with. The front and rear fenders are already rolled. But looks like I will need to pull and or cut the fender to keep the front from rubbing, especially after reading how people went 285 up front had to take some serious measure for proper fitment. To do this I’m considering picking up a junkyard set of fenders so I don’t have to hack up mine considering I just had the whole car painted less than two years ago.

I will keep this updated with my progress and hopefully have this completed by the end of the month.

Question Recap:

Considering the setup whats recommend for alignment?

What do you think I will have to do to get these to fit and function for AutoX and the occasional track day?

Link to current setup.

On a side note the 10.5RFP1s clear the akebono's much better than the 9.5s did.

 

I'm running 275F/295R tires on mine. I did not need to roll or pull my fenders at all, your offset on your rears is off.

Up front I was at -3 and the rear at -2.2 for camber. Toe was 1/16 inch out up front and 1/16 inch in on the rear. Everything is tucked in with no rolling or pulling of the front or rear fenders. I'm not sure how i'm going to get more meat up front, but I do want it.

 

What do you mean the offset on my rears is off?

 

My 18X10.5 +15 RPF1's w/285's required the rear fenders to be rolled and I run -2.5 camber in the rear. The front has the same wheels and tires with -2.75 camber. It's a tight fit.

 

You're going to want to try and target 3.1-3.2 up front and 2.2-2.5. I ran 315's on 10.'5s for a bit without any cutting pulling. Once you go up to 11's and 315's up front you'll become good friends with the cutting wheel.

 

i run 295 30 r18 a6 on 18x10.5 with 20mm offset front an a 18x11 20mm offset rear. -3 camber front an -2 rear.

 

pic of setup

 

I meant that if your not into cutting or pulling the fenders, your offset is too low. My 295 rears are on a +25( or 22 I cant remember) offest and tuck in nicely to the wheel well.

 

Ahh, currently the rears fit a 295 on with a 15 offset fine. They didn't before I had the fenders rolled but with the current ride height and camber they don't rub at all.

 

Put your car on a level surface, adjust camber so it is tilted 35mm at the top of the tire. That will be roughly -3.2 , see how you think it will work.

You may want -3.5 for those tires.

 

I got pretty even wear/temps once I got to -3.

 

I was reading the A7 Care and Safety Guidelines last night and came across the follow..


Chassis Setup Recommendations
For optimum performance the Hoosier P-Metric radial tires require about 3 degrees of negative camber. There will be a trade off in maximum performance to maximize
wear. Generally, 1/2 degrees less than optimum will result in the best compromise for wear and speed. Less than 2.5 degrees negative can result in excessive wear
on the outer shoulder junction. Higher pressures are needed when the vehicle has limited negative camber.

Now I'm curious about the camber in the rear and will 2 degrees be enough for max performance.

It also talks about tire pressure between 30-34 cold and 40-42 hot for a car over 3000lbs. I'm likely going to give them a call as is recommending for cars of 3000lbs but I'm curious if anyone has recommended pressures for these tires.

 

double post

 

I never ran over 35 hot on my BSP car....ever. I usually ended up around 34/33 on concrete and 33/31 on apshalt.

 

Step 1: Buy Hoosier A7 295/30R18
Step 2: Get tires mounted.
Step 3: Profit!

(I ran A6 295/30R18 on the stock V1 track wheels in SCCA Stock class -- a great combination!)

 

Wheels showed up today 18x10.5+15 in Bronze. My official race rubber wheel set.

I'm anxious to get the tires in and mounted.

 

a little off topic, but what UCA are you guys using to get -3 camber? I have kinetix UCA and the most i can get is about -2.5. Probably SPL can get there, but any other UCA that will get me -3?

Or is off bushing the way to go?

thanks.

 

You should talk to Z1NONLY in his post "My STU Build" he mentions the following:
2) Removed SPL UCA's and installed Kinetix UCA's and modified them. (shortened the threaded part of the arm to get more negative camber than in OTS form)

Personally, I've been building the car for me and not really a class so I run the SPL arms.

 

Subbed

Great info being thrown around here

 

Here is how to modify your kinetix arms, It got me to -3.2 deg camber.



The top UCA is how it comes, the bottom has been cut.

Also for your PSI's, I ran 30 cold up front and 29 cold in the rear. It ended up putting me at around 34 warm and 35 warm F/R.