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Discussion Starter · #1 ·
I autocrossed for the first time with the GC yesterday, and I still can't get anything but understeer. My suspension is this:

AGX
GC (325/200)
Koni bumpstops
stock front sway bar with rear ST bar
N-Tech brace
front and rear Courtesy sway bars
ES control arm bushings
1.5 deg negative camber with slight toe out
1 deg negative camber and like 1 inch toe in with my lincoln log rear


Maybe I was expecting too much out of the GCs. Ride quality is much better than the ProKits. I have the car 1 inch higher now than with the Eibachs. Any thoughts?
 

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Discussion Starter · #3 ·
I forgot to add this: I have 205-50-15 Potenza RE730s and I was running 47psi front and started at 45psi rear. I used this tire setup at the NT in Meridian, and the rear felt great, easy to throw around. This course was not like the Meridian one, it was small and tight. What pressures should I use?
 

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Discussion Starter · #4 ·
My suspension is identical to George's except for the spring rates. How is his car compared to your old '93?
 

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eric96ser said:
My suspension is identical to George's except for the spring rates. How is his car compared to your old '93?
George's car was pretty close (he just sold his car, too, BTW) to mine. On race tires, we cranked the rear pressures to something like 50, and it helped. Still not quite like an IRS Classic but I think it was as close as you could get before bending the axle.
 

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I forgot to add this: I have 205-50-15 Potenza RE730s and I was running 47psi front and started at 45psi rear. I used this tire setup at the NT in Meridian, and the rear felt great, easy to throw around. This course was not like the Meridian one, it was small and tight. What pressures should I use?
I have stock springs, stock sway bar, AGX and the same tires. I had decent results with 47 front 36 rear. This was on an autocross course that was tight enough that I almost shifted to 1st for 1 turn.
 

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employment whiplash, NC
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Your front rates are too high, or you back rates are not enough. Get some more - camber up front (~2 negative). If you have a front strut tower brace, remove it and throw it away. Lower your front tire pressure.
 

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pwnd
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Swap the springs around? Hell i dont know. but id say with that nord-tech brace you are really tight up front and still way loose in the rear. Id definatly get some stronger springs in the rear. After driving Calum's car(pat's car) back from DC the GC's feel great. want to say 350 all the way around, pat will correct me on this. But with the agx's on 2/4 (IIRC) it rode great. Well better than what i thought it would ride. So I dont think you will be sacrificing ride quality with a higher rate in the rear.
 

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Discussion Starter · #9 ·
When I raced, I had the shocks at 2/7, then went to 1/7. I was trying to get the front softer, but no can do. I would try 2 deg camber, but all I can get is 1.5 left and 1.4 right. The springs seems like the cheapest and easiest solution. Maybe a bigger rear bar will help. Matt: I would try the STB idea, but it and a zip tie are all that is holding my POP charger up right now.
 

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SHIFTy
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I think your rear pressures are too high, for one. I keep mine *just* high enough not to roll over - like 30psi. Also consider your driving technique. Are you getting weight transfer to the front end during turn-in? The two most important factors in handling are the driver and the tires.

Chris
 

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96stse-r said:
I think your rear pressures are too high, for one. I keep mine *just* high enough not to roll over - like 30psi. Also consider your driving technique. Are you getting weight transfer to the front end during turn-in? The two most important factors in handling are the driver and the tires.
My friend George Perinis tried everything with his 200SX SE-R, and he had better results with the rear tire pressures cranked way high. Street tires, R-compound tires, it didn't matter. I drove his car with the pressures I usually ran on my Classic (exact same wheels and tires to boot), and it was a big difference once we upped the rear tire pressures to 50 psi or so.
 

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Discussion Starter · #13 ·
96stse-r said:
I think your rear pressures are too high, for one. I keep mine *just* high enough not to roll over - like 30psi. Also consider your driving technique. Are you getting weight transfer to the front end during turn-in? The two most important factors in handling are the driver and the tires.

Chris
Remind me to not run at an event with you there. It would not be any fun, because we would be fighting for the same numbers :)
 

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sleeper
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I'm running 300f/250r. My car still understeers. I'd say you'd need to go at least 300 in the rear to get it to step out some. I don't know how the street ride would be though. As for the tire pressures, you either have to jack the rear tire pressures really high or really low to get the rears to slide.
 

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Whisky Tango Foxtrot
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You need more spring in the rear. I run the 350/300 rates and feel I am only a rear swaybar away from completely nutural. I also agree with Matt. The front strut tower bar is not helping your understeer problem. I run 1.7* with 0 toe.
 

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On my Classic with stock springs, KYB's, ST rear Sway and a RTR rear strut tower brace, I can actually get a ton of oversteer. I run the Azenis in STS and I set my shocks to 3F 4R and pressures of 40F and 38R. I used to set the rear shocks to full stiff but the oversteer was fun but unpredictable. Mike Kojima attended one of our practice events and recommended that I reduce the rear settings to 4 and like magic I took a full second off my time. Now the car is very stable and will only understeer if I overdrive it. IMHO most people blame the understeer on the car when it's really the red mist which causes it. The best solution for curing understeer in that case is the middle pedal!
 

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Discussion Starter · #18 ·
Art, I was talking about my '96. In the '91, it will oversteer if I just think about it. I guess dead struts and a ST rear sway bar are the cause of that.
 

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Eric,
I drove a 98 SE-R at an autocross and I was able to get it to rotate by increasing the rear air pressure. They were Kuhmo 712's and we ran them at 45 lbs. If you think about it what happens when you increase air pressure?
1. The tire becomes more rigid.
2. There is less of a contact patch on the ground.
Both of these situations cause reduced traction.
Reduced traction in the rear results in oversteer.

I agree with Pat that higher pressures in the rear should help your understeer.

Art
 

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www.motorists.org
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I experienced the same thing with increasing the tire pressure in the rear of my 98 SE with AGXs and front STB. Kept increasing the rear pressre until I got just over 50psi and I spun the car. I then knew to drop the rear pressure a few pounds. :D
 
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