I am currently building a 2000 Acura Integra GSR for time attack racing. I need some advice as far as choosing spring rates for my coil over setup.

General info:
The car will probably be near full weight after adding the cage, turbo components and other safety tid bits. I will be running a 16 x 9 inch wheel with 245/50/16 in the front and 16 x 8 inch 225/45/16 in the rear (DOT R compounds). I run the stock GSR front sway bar and a type R rear.

My question is:
With more weight added to the front of the car (turbo setup) and a much larger stickier contact patch what would be an adequate spring rate?


Modified by track1646 at 7:55 PM 8/30/2007

 

PM SENT

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mlrmotorsports &raquo;</TD></TR><TR><TD CLASS="quote">PM SENT</TD></TR></TABLE>

why?

why not answer the question with a reply so everyone can see it. now if someone has the same question they are going to have a harder time finding an answer.

 

why the crazy tire sizes? which tires are you running? Hoosier R6? Nitto NT01? Toyo RA1?

the 245/50/16 is really going to kill your gearing. that is a giant tire. you're going to be over 25.5" OD in the front. most people rarely run anything bigger then 225/50/15 which is around 23.7" OD.
it's also going to limit how much you can lower your car. not to mention the extra weight inherent with large diamter wheels and tires.

if you are doing time attack, and want alot of tire up front, why not look at the Hoosier A6 in 275/35/15.
then run a 225/45/15 out back. will save quite a bit of weight and diameter, also won't have to get so crazy with your tranny gear ratios..
you'd only have to get custom rims in the front of the car. 15x10". (i.e. Kodiak Racing). should be able to clear fairly large diameter brakes too.
not to mention it's going to get up to the proper operating temperature in the limited laps you will be doing in Time Attack since they are their autocross compound.

even the 225/50/15 Hoosier R6 is VERY close to the width of the Nitto Nt01 245/50/16 and the Toyo RA1 245/45/16 (hoosiers typically run wide)

just the weight difference using 15" rims and 15" tires vs. 16" stuff is going to be pretty big difference.
275/35/15 is only 20 lbs. a custom 15x10" wheel would be around 15 lbs.
even some of the lightest 16x7" rims are in the 15lb minimum range. a 16x9 i would imagine would be 18lb+. and that 16" size tire is going to be at least 22lbs or more.

 

thanks for the info. i was initialy looking at toyos mounted on custom kodiak's. weight is a large issue and i didnt really compare the 15inch to 16inch as they cant really give me any hard numbers (due to variables in construction)

the more i read, the 225/45/15 may be enough to suport my needs. and ill save $ and weight going with the 15 inch wheel.

any more info or oppinions are much apreciated

thanks,
arron

 

225/45/15's will save you alot of money.
quite a few light 15x8" wheels out there.

15x8 949 Racing 6UL (12.9 lbs) $149 each
http://949racing.com/index.asp...&HS=1

15x8 Rota Slipstream (14 lbs+) $550 shipped for 4 wheels
http://www.18racing.com/wheel_slipstream.html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mlrmotorsports &raquo;</TD></TR><TR><TD CLASS="quote">PM SENT</TD></TR></TABLE>

Please share with the rest of the community whatever your advice or experience may be.

Enquiring minds would like to know.

 

those 6ul wheels really caught my attention. that is a pretty light weight 15x8. does anyone have any experience with them? quality and whatnot

with my mind made up on a 225/45/15 does anyone have any recomendations on spring rates....the only opinion i have gotten so far is an off the shelf 14k front and 18k rear setup. with a uniform tire size front to rear ill need the extra stiffness in the rear to force rotation

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by track1646 &raquo;</TD></TR><TR><TD CLASS="quote">those 6ul wheels really caught my attention. that is a pretty light weight 15x8. does anyone have any experience with them? quality and whatnot
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Yes, I've been running them all season. Nice wheels.

 

well the wheel and tire combo is mostly set ill be going with the 225/45/15 on the 15x8 6ul's. Power is done (other than my backordered intercooler); stopping done (fast brakes), turning (almost done) now to figure out the final piece (suspension). if i can get this finished hopefully ill be doing the first time attack/shake down at summit point at the end of the month.

thanks for the help keep the input comming

arron

 

anyone with more info feel free to post it up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by track1646 &raquo;</TD></TR><TR><TD CLASS="quote">anyone with more info feel free to post it up</TD></TR></TABLE>

What rules are you building it to? Any limits on tires or wheels?

 

cap the sunroof. 30 lbs of weight in the worst place possible.

 

The car is curently being built for the modified class. the only real restriction i see on tires is they must be above a 50 treadware.

 

+1 for 6ULs, also been using them this year with no problems. For spring rates, 14K or 16K in the front with 18K in the rear should be fine. The Spoon N1 Showa dampers with rates right around that are friggin' fantastic, if your budget allows for them.

 

the 6uls are the wheel that i am going to go with. and i was thinking 14k f 18k r that seems to be the setup that i have heard most about. thanks alot for all the good info.