I have a 1990 C2 which has the Cross Suspension on it, RS steering rack and RS wheels. I have an engine with sport grind cams, head work, ARP rod bolts and all the other 'while you are in there' mods. The transmission is a factory optioned LSD box. I presently have the engine and trans out.

Here are my questions:

1. If I were to do any gearing changes to my trans what should they be?

2. What would be the right sway bars to run?

Thanks guys

 

Impossible to answer the sways question without knowing the spring rates and tracks you plan to run. For gearing, figure out your max speed at fastest track you plan to run. Then figure out he slowest speed in the tightest turn you will run. Pick 1st & 5th based on these and then spead evenly in between.

How exactly is this a cup clone as you have no cup parts?

 

For the transmission, you'd really need to know the engine's torque curve, the top speed you desire at the longest track, and then you can regear the transmission accordingly. You don't want the same RPM drop between each gear, so the gear spacing should not be even.

 

thanks for the reply's. I have the JIC CROSS 964 coil over kit with monoballs, etc. My hope was that there might a change I could make rather than going into the whole gear box e.g. by a r&p, etc. As for tracks, Mid Ohio is the closest and will probably be where the car sees most of its action.

you are right, its not got all cup parts. my understanding was that cup cars had coil overs and RS cars had springs and struts.

 

Your JIC Cross are probably better than the factory Cup damper and spring, with much newer technology and adjustability. Your spring rates are probably much softer though. The Cup cars had springs about twice as stiff as the Euro RS road car.

You could probably install an 8:32 R&P, however, that does not alter the RPM between gears which is the real problem with these cars.

 

Your stock G50/03 is already geared the same as the G50/10 RS trans in 3 -> 4.
1 is integral w/ the main shaft, as a result it is prohibitively expensive to change.

that leaves 2 as slightly lower in yours vs the RS

w/ relatively stock engines, which are quite flexible w/ broad torque curves 3 -> 4 are used the most.

if you want you could chnge 2 to the taller RS ratiop and then just live w/ the slightly taller step form 1 to 2

I think that ~160 is a reasonable top for these cars(JMO)

 

cool! thanks Bill. so if I see an RS ring and pin for 1200 bucks is it worth it? and would you by chance know the part number for second gear? and finally what about 5th?

THANKS!!

 

Don't forget that the 8:32 R&P has a higher wear rate than the standard R&P

 

No, you already have an 8:32

RS 36:19 second gear is 950.302.902.12

 

1400 bucks just for second!!!

wow. Hayden is going to rebuild my LSD for me so I think I will still with that and maybe a Gamroth short shifter

 

BTW, thanks so much all of you, I appreciate the knowledge very much.

 

so would RS sways be ok to run? or should I just run after market sways (26 front, 24 rear).

?