Toyota Celica GT-S

M

MarkM

New member
The car is a 1990 former pro-celebrity car. I could use some help in setting this car up suspension wise. It handles well, but constantly lifts the inside rear wheel on hard turn in ("does the dog").

Some say it's chassis flex (but they don't race FWD). The main hoop in the 6 pt. roll cage has the two down tubes that are attached to the rear shock towers. I would think that this would stiffen things quite a bit.

I'm thinking that the shock/spring set up might be the root cause. Any help would be appreciated.

Shocks: Tokicos
Springs Front: Eibach 10" 300#
Rear Springs: Eibach 12" 175#
 
Springs sound too soft. I have a early FWD 1200 Civic that did the same thing. A Civic driver told me that if the rear tire comes up that the front spings are too soft. I bumped up my spring rate and it cut the lifting by about 80%. Now if it does lift it only is a few inches and its not lifting all the way around the corner.
 
Thanks Don. I appreciate your input.

How much did you need to increase your spring rate to get the desired effect?
 
My car is at the minimum weight per GCR at 1710 Lbs. I think the minimum weight for your car would be much higher? I don't think we can compare apples to oranges here. This is a non-educated guess but I would hazard a guess of at least 75- 100 lbs in the front and 50 in the rear for starters but get a few sets (test, test, test). Allot of people on the board post crazy rates, but remember different suspension designs and weights will require very different rates. Slightly softer spring rates like the conservative starter ones I guessed at, that still don't allow "the dog" usually are more forgiving to track and driver error. Also your shock may have to be replaced or re-valved if you go too stiff on spring rate. I found a few guys in Scca’s higher classes that run the same car as mine to be valuable for input. Try locating a Toyota guy?
 
Thanks again Don. I appreciate your insight.

I was hoping to locate a fellow Toyota person by posting my problem via this forum. So far as the NW region SCCA, I'm pretty much "it" when it comes to the Toyota Celica (or any other for that matter).

As limited as the resources are for this car (or any Toyota), I'm beginning to think that jumping ship might not be such a bad idea. TRD isn't any help, so I was hoping to find another Toyota die-hard via this web site.

The car weighs in at 2575#, with me in it and the tank empty. 1625# on the front and 950# on the rear. I've talked with some other FWD racers in my region (all Honda) and they are running heavier spring rates in the rear (by ~100#) vs. the front. I find this rather odd as you would think that for FWD it would be just the opposite.

I do agree with you that the chassis are different and will require different spring rates accordingly. My common sense tells me that FWD is FWD and the weight differences can be extrapolated proportionatly to arrive at a decent set up for any given FWD car.

If you know of any good reference material on chassis tuning FWD cars, I'd really appreciate it! - Mark
 
Mark, your car weight and distribution are very similar to mine (Olds Calais). Without knowing the suspension (front-struts?, rears-irs w/coil-overs?) You would probably be okay to double the spring rates you are using. I wouldn't hesitate to try it (I run higher rates). Of course the shock/strut tuning, suspension settings may need to be changed.
 
Ditto what John said. I'm about the same with weight (2560, with about the same split), RWD though.

I run 600 front/400 rear as a rookie and so far have found it controllable. I'll probably experiment more next year after I edumacate the driver some more.

Note that some people have told me this is still too soft, but I'm too new (and with nothing to really compare it too) to say.

Jeff
 
John & Jeff -

Thanks for the reply. Sorry I didn't get this posted sooner, but have been away from the computer.

In answer to your question John, I am running with coil overs both front and rear.

I plan to switch over to Koni$ this off season. The Tokicos that are on the car are out of production. My original choice in replacement shocks was KYB, but alas all they have for this car are street shocks.

Any other advice would be appreciated! - Mark
 
Matt, talk to Lee or Jay at Koni and let them know what you are doing. They will let you know if something off the shelf will work or if you should get custom valving. Definately go with the higher spring rates and let them know. If you can afford it, go with a double adjustable. Feel free to drop my name with them. Also,the strut tuning will not prevent you from lifting the wheel, springs and sway bars will. Struts control only how fast the motion will happen. However, most FWD will lift a wheel in some corners. Do not get too concerned about it unless it is excessive, which given your rates it probably is. If you are driving the car hard, this will be obvious when looking at your FRONT tires because the outer edge will be very worn compared to the rest of the tire. Increasing the front stiffness will actually improve your handling because the front tires will not roll over as much. It seem counter-intuitive, but it works.
 
Hi Mark,

> The car is a 1990 former pro-celebrity car.

My brother and I also have a '90 Celebrity Challenge Celica. It came to us by way of a few years at FastLane driving school at Willow Springs and some SCCAN NASA competition in the NC/VA/WVA area. We haven't gotten it on track yet, though, so we can't be much help other than commisseration. :-)

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CaptainWho
http://www.NutDriver.org
 
CaptainWho:

Same place my car came from! I bet I can tell you who the last owner was. I've talked with his father at length and knew he was racing the sister car to mine back on the east coast.

What kind of sway bars/shocks and springs does it have? Same as mine or did he change them?
 
<font face=\"Verdana, Arial\" size=\"2\">What kind of sway bars/shocks and springs does it have? Same as mine or did he change them?</font>
Click to expand...

I'm not intimately familiar with the car yet, so I don't know. The car is stored at my brother's and he made the deal. I know we had to replace the front struts because one was completely snaked. Contact either of us by email for more information. I'm at DougF at NutDriver.org and he's at ScottF at NutDriver.org.

------------------
CaptainWho
http://www.NutDriver.org
 
Hey MarkM, The Nuts are taking the Celica to Carolina Motorsports Park (Kershaw, SC) next Friday (21 Nov) for seat time and test-n-tune. Will let you know how things go. I forgot to ask my brother about the shocks. Let me know if you're still curious.
 
Cool!

I have one too, from way back in 1985 - still racing it (Corolla GT-S)!

How did you get it? (cost?)I wouldn't mind one as well...

If chassis was weak, it wouldn't lift, it would stay on the ground... Stiffer fronts will help, but it will also understeer more requiring a stiffer rear...
 
Originally posted by John Herman:
Mark, your car weight and distribution are very similar to mine (Olds Calais). Without knowing the suspension (front-struts?, rears-irs w/coil-overs?) You would probably be okay to double the spring rates you are using. I wouldn't hesitate to try it (I run higher rates). Of course the shock/strut tuning, suspension settings may need to be changed.
Click to expand...

John, you still around
wink.gif
Haven't seen you in a few years (I'm from Lansing and run the White IT/A Corolla)

I'm amazed by the horrendous spring rates.

On my 2030lb car, I ran 200lb front springs for a long time when others were running 400lb...

I suscribe to the carrol smith (and others) idea that your tires are only as good as the contact patch, so you should run a soft a spring as possible to maintain contact with the ground.

In this case, when the rear picks completely off the ground it adds zero to the cornering force, but it does sent its load to the opposing front corner.

What are the spring rates now? I would start with stiffer front springs and see what happens - maybe 100lbs greater? - should help, but understeer more. if it helps the lift, then change rear springs or bar to get the handling neutral again..

Only make one change at a time!
 
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