ITS Integra - setup help?

high_rpm · #1 12-24-2002, 04:16 PM

Hi Guys. I just bought a GS-R Integra for the ITS class, and will be selling my ITC Civic soon.

My question is regarding suspension setups. From what I've seen, the Integras tend to run very stiff springs (approx. 700F/1100R), stiffer swaybars, and much wider tires than the Civics?

Do you guys have any basic setup information that I can use regarding springs, tire sizes, etc?

Mike
Shelby Twp, MI

Jay · #2 12-26-2002, 12:23 PM

Im also looking into building a DC2 GS-R
I know from the rule book that the Integra gets 14" rims. Other than that i dont know.
If anyone has any set up info on this car, Iwould love to hear about it..that and the pros/cons of the car.

------------------
Jay Taylor
Soon to be racer!
AIM:driftfreak

krshultz · #3 12-27-2002, 01:55 PM

I'm not aware of any requirements for 14" wheels. I'm pretty sure 15x7 is the wheel of choice for the DC2. I'm at work though and don't have the GCR with me to back this up.

You're spot on with the observation that people are typically running very high spring rates, especially in the rear. I can't afford fancy shocks right now so I'm at 425F/600R. Seems adequate to me, I'm not sure I understand the super high rates either. Esp. on a bumpy track.

I'd suggest maybe switching the front upper control arms side to side. You pick up about 3 deg. of caster and its well worth it. Since caster = added negative camber while turning, think of this is a poor man's alternative to offset bushings.

I've just done Honda Challenge racing with NASA to this point, and doubt I can add ITS to my schedule due to financial reasons. But the cars are more or less the same.

Interesting to see increased interest in building these cars for S. If we can get SCCA to help us with the weight, I'm convinced they can run up front. But right now we're simply outgunned in the power to weight ratio.

Good luck with the build...

Catch22 · #4 12-27-2002, 03:42 PM

Depending on the shocks, anywhere from 600 to 900 front and 1000 to 1400 rear springs appears to be the popular ticket. a 300 to 400lb front to rear difference is common.

I run the stock front bar with an adjustable rear bar from Saner Performance. 15x7 wheels with 225/45/15 Hoosiers.

But why build???
Mine is for sale.
scott@honda-challenge.com

JimH · #5 12-27-2002, 09:53 PM

Is it possible to do the control arm switch on the 2nd gen CRX also?

spsspeed · #6 12-28-2002, 09:00 PM

I agree with Scott (Catch22) on the springs rates for the front and rear. It is really going to depend on which shocks you are going to run on the car. If you run really high spring rates on shocks that are not valved for them the shocks will wear out faster and may not be able to dampen correctly.

Stick with the stock front bar and get an aftermarket rear bar close to 1" in size.

The 14" wheels are required for the Integra RS, the 15" wheels are required for the GSR.

Since CRX lower control arms never came on the Integra they will never be legal.

You can also call Tom at OPM and he can answer any shock/spring questions you have.

Scott Seck
#38 ITS GSR

JimH · #7 12-29-2002, 12:13 AM

Actually, I was interested in finding out if switching right and left control arms with each other on a CRX has the same results as on the Integra.

krshultz · #8 12-29-2002, 02:27 AM

Quote:

Originally posted by JimH:
Actually, I was interested in finding out if switching right and left control arms with each other on a CRX has the same results as on the Integra.

No idea. I know that the effects on 92-95 Preludes is WAY too much caster. Outer CV joint busting kinds of caster. Its best to try it and check the alignment.

OK, back (somewhat) on topic. Catch22 and I have talked about this occasionally and I'd like to hear spsspeed's viewpoint. On spring rates for these cars...why so high?

Seems to me like this would be a problem at bumpier tracks, or tracks where you use a lot of the gators. I know that my car versus Catch22's car is a lot more "settled" through turn 10 at CMP...and I think it's the softish springs.

Tracks like Summit Point, or Watkins Glen (been a while, but I remember some harsh transitions at the concrete patches), or the infield at Lowe's...seem like they would reward softer springs. If the spring doesn't give AT ALL...that seems bad. Just speculation.

I'm not doubting that there's a Good Reason. I'd just like to know what it is before I pony up the cash for pimpy revalved shocks.

spsspeed · #9 12-30-2002, 12:38 AM

Why the high spring rates?

I am not sure that I can give a great answer for that. I do know that the pro teams that run these cars and similiar cars (Integra GSR, 99 Civic Si) all run close to the same spring rate.

So instead of testing all the different spring rates possible I started with something close to what the pro cars were running then depending on the track, tires, etc I will make adjustments up or down in spring rates.

If you want to know why the Integra uses 700-1300 lbs springs and why the RX7 uses 250-350 lbs springs it has to do with the motion ratio, effective sring rate, suspension design, etc and things that you need to calculate.

Also when I was co-driving a ITA CRX we did some real good testing on spring rates and generally the higher the spring rate the faster the lap times, until a certain point when the car starts to bounce, skip through the turns, which will result in a car that is hard to drive and harsh over the bumps.

Scott Seck
#38 ITS GSR

Catch22 · #10 12-30-2002, 12:31 PM

I've found that the calculations needed to figure this stuff out are well beyond my engineering skills, so I just call it "magic."

Seriously. I stopped trying to understand it and just do what works. As Scott S. mentioned, it's all a function of the layout and geometry of the car. For instance, my FWD car runs a BIG rear bar and springs that are 400lbs heavier in the rear and I still fight a slight push in certain situations. Try that on a Neon sometimes... It won't work. That car oversteers in a straight line with heavier rear springs. The same is true for the VW Golfs and Rabbits from what I've heard.

It makes my head hurt just thinking about it. Thats why I'm thankful for people like Fowler and Seck (and many others) who are willing to share what they've learned.

Knestis · #11 01-01-2003, 10:00 PM

Rules NERD Attack!

Sorry, guys. There is no provision in the ITCS to swap A-arms side-to-side.

"...will be prepared to manufacturer's specifications except for modifications permitted by these rules."

Kirk

Catch22 · #12 01-02-2003, 02:18 AM

I swapped mine back to stock location earlier in the year when screwing around with the whole "Why is it still pushing!!!" thing. I saw no real difference either way.

Since Karl runs less static camber and softer springs it might be having a more pronounced effect for him.

four27 · #13 01-10-2003, 04:36 PM

Great advice from Scott and others. On my 94 gsr it seems to like 800 f and 1000 rear. With those spring rates you are, I believe, outside the range of Koni sport shocks so that is why I had Tom Fowler send me some Koni race shocks. very expensive. I run a Ground control 25mm rear swaybar and stock in front. My car hands very well. You need to rotate tires after ever track session as front tires take a pounding in these cars. I am running same tires and wheels as Scott but I have a set of OZ light weights that I like also. I run 2 neg in r and 3 neg in front on the camber. My engine dynos at 170 at wheels with a race prepped bottom end and OPM prepared head. I use a comptech cold air box, and Mugen JDM 4-1 header (900 bucks!) MSD. I also have a JDM final drive and LSD. I typically come off the track at about 2700 pounds with about 60 pounds of ballast.
As mentioned earlier SCCA needs to let us shed about 100lbs.

Ron Cramer, Ore division
#55 gsr ITS

LTBMotorsports · #14 01-10-2003, 07:33 PM

Ron, sound like you have a nice car.
But why are you running front sway bar?? from my experience if you remove it you get better traction exiting the turns.

Louis B.

il8apex · #15 01-11-2003, 08:29 PM

Quote:

Originally posted by LTBMotorsports:
Ron, sound like you have a nice car.
But why are you running front sway bar?? from my experience if you remove it you get better traction exiting the turns.

Louis B.

Removing it would probably help you turn and solve the "eating front tires" problem, too... Give it a shot, and let us know how it works!

-Tom

Will · #16 01-15-2003, 06:14 PM

FYI - Anyone who is interested in racing an Acura GSR and having all the developments necessary to win in ITS, we have our Acura Integra GSR for sale,

There is no need to guess the spring rate, if and what sway bars to use, tire pressures, etc.....

Update on price of Acura, reduced to $22,500 - Must make room in shop for new car to be built for different class.
Also have some negotiable opportunities, such as lower price without engine, plus extra spares such as tires, wheels, rotors, brakes and a Tow Dolly Bonus,,,,

FULL DETAILS:
Fastest GSR in the Country. Has only had 10 Pro Races: 1 Victory and 4 Podiums. Watkins Glen- 2:17, Mugen Shocks, 4-1 Header, Full Cage, $22,500 Contact: Will Nonnamaker (330) 497-4484 ext 23 or Will@TheRaceSite.com

Includes: Mugen Differential * 4-1 King Motorsports Header & Straight pipe exhaust * AEM cam gears * Fluidyne Radiator * Oil Cooler * Brake Ducts * Screened radiator shield * Seatbelts * Race Seat * Auto Meter Water Temp, Oil Temp and Oil Pressure Gauges. * Set of 6 Volk lightweight wheels (9 pounds) with 225-45-15 Hoosiers, * Hawk Brakes front and rear * Comptech Brake Lines * Comptech Spark Plug cover * Comptech Battery tie down bracket * Removable Wheel Spacers * Extra long Wheel Studs * AEM Fuel Pressure Regulator * Mugen Rear Swaybar * Comptech Rear Swaybar Mount Brace. * Comptech Front Strut Tower Brace * AEM Long Air Tube, with reflective wrap * Full Welded Rollcage, with NASCAR style Driver's side door bars, and rollbar padding * Energy Suspension Bushings * Mugen Suspension Camber Links front and rear * Fire Suppression System. * Accusump System with Aeroquip hose and fittings. * Drybrake Refuling System with discriminator valve. * Mugen single Adjustable Shocks, front and rear. * Eibach springs * Lightweight Battery. * Camera Mount on roll cage * Momo Steering Wheel with Mugen adapter/extender * Front and rear tow hooks * Radio wiring harness, with push button on steering wheel * Wide angle rear view mirror * Hood pins * Metal plate in place of glass sunroof

lb2 · #17 01-15-2003, 10:46 PM

Nice Integra but you need to remove some of the illegal item listed on your post since they are not legal in IT.
Louis B.

Will · #18 01-24-2003, 03:12 PM

Both of the 2 previous Acuras Integra GSRs that we have sold have competed and cleared tech inspection as LEGAL for in Improved Touring racing. This GSR is the same as those Integras and will be eligible and LEGAL to race in SCCA IT races.

All inquirements can call Will Nonnamaker at (330) 497-4484 ext 23 - or - Will@TheRaceSite.com

Greg Gauper · #19 01-24-2003, 05:41 PM

All of the items on the above list look legal for IT except for two.

1) The AEM cam gear might be illegal depending on what it does. The ITCS specs are very specific on what is permitted in order to correct cam timing back to factory specs. Cam gears that permit the cam timing to be adjusted are specifically prohibited unless they came that way from the factory.

2) 'Lightweight' battery. This was discussed on a different thread awhile back regarding the wording "same size and type". Minor detail and easy to correct.

All other items appear to be perfectly legal in IT....Looks like alot of good high quality stuff!!!!

BTW..just because a car passes tech does not make it legal!

Chuck Davis · #20 01-28-2003, 11:56 AM

The theory of using 40-60% higher spring rates on the rear is to reduce weigth transfer in front wheel drive cars and thereby reducing understeer. The higher rates make rear sway bars very ineffective because of the limited suspension travel. Actually, the rear sway bar should bew used as a "trimming tool". The object of a properly set up front wheel drive car is to get as close to "neutral" as possible and then go to the next step to develop a slight "oversteer" condition using the throtle to control the oversteer. Keep in mind that you need properly valved shocks the handle the increased spring rates.