93Rubie

If you want your car to ride like crap but handle really good put a complete Z07 package on your 92-95 C4.

The car feels REALLY planted with the Koni's but I can feel the road surface texture thru my butt and my hands. Good AND Bad Thing.

Did my alignment today at work, FINALLY...
I figured with my the NOS LCA's (Correct HD Z51 marked ones) I would loose some front end camber over the worn stock non-HD ones. Not so.
LF=-1.0 RF=-1.5. Basically same as before. NO SHIMS on the upper control arm at all.

I lost a bit of caster in the LF it went from 5.5 to 5.3. The RF gained from 5.8 to 6.0. I have a slight drift to the left because of this but nothing I can do without sacrificing camber. NEED camber.

I went with -1.5 in the back. Last year was -1.4 and tire wear as awesome. Which indirectly tells me I'm using all of it and not just part of it. Very flat wear on those Dunlap ZII's. FYI, 200+ runs, 3K street miles and maybe about 25 more runs before they cord. 255/40/17's for now.

Brakes feel better (hard to tell on the street) J55's with Ferodo DS2500 front and Hawk HPS rear.

I'm basically done with mods for "stock" class. Need a set of 18X9.5's and some ZII's in 285/30/18. Next year.....

I need to auto-x this thing now....when the snow stops....maybe....

WVZR-1

You determined this how? Snapshots of them?

3JsVette

You always provide great feedback and helpful information. Thank you!
I do think that it's safe to say that the C4 handles better than it rides and for the most part the more you improve the handling the more the ride suffers. The price of admission I guess. IMCO it seems to be a lot more fun going fast around corners than cruising down Main St. I'll take that trade off but that my preference.

93Rubie

I've made my choice on the ride versus handling thing. LOL. More modern Corvettes do a better job of both handling better and riding acceptable. Dealing with 80's and 90's tech, you cannot have both. I will say the Z07 when coupled with the FX3 shocks did a good job of providing both, but for what I'm doing the Koni's are the way to go.

The 88-96 Z51/Z07 cars had HD LCA bushings the arms are stamped 3Z51 and 4Z51 on the bottom. Here is a link to a ebay ad for a set. http://www.ebay.com/itm/1988-96-Corvette-Corvette-C4-Z07-Z51-Lower-control-arm-pair-/301055469033?pt=Motors_Car_Truck_Parts_Accessories&hash=item46184de5e9&vxp=mtr

milsurpman

should of refreshed my screen. Rubie93 answered as my car is also marked.

milsurpman

[QUOTE=93Rubie;1586538224]I've made my choice on the ride versus handling thing. LOL. More modern Corvettes do a better job of both handling better and riding acceptable. Dealing with 80's and 90's tech, you cannot have both. I will say the Z07 when coupled with the FX3 shocks did a good job of providing both, but for what I'm doing the Koni's are the way to go.

yes as I would say my stock bilsteins would probally be a stiffness of between low and high stiffness. Where you can get low stiffness with the fx3 shocks.

blackozvet

are you running toe in or toe out ?

Race Prepared

Why are you running .5 degree more camber in the right front? Also, why did you not balance the caster on the front of the car? Have you reversed the convex washers on your a-arms?

93Rubie

Milsurpman, set them to touring the ride is quite comfortable at least in my mind.

Blackozvet, zero toe up front, -.09 of toe-in for the rear. I may play with this depending on how the car feels. Ditto rear camber, I might have a bit too much, well see. I need to shake the car down at an actual event. I want the front zero as I drive on the street so I don't chew my tires. I know I COULD mark the rod ends to get toe-out at events and set it back but I just don't have the time and I need to concentrate on the driving more so than the "perfect" car setup. IMHO.

Raceprepared, the front camber and caster is set by the fact I have ZERO shims in the front. I wanted max. camber and that is all I can get. If I add shims to even out the caster I'll lose Camber in the RF and that is BAD. As the C4 is heavy on the RF, I need as much as I can get.

I cannot reverse the washers on the a-arms. That is NOT a factory approved procedure. In SCCA Auto-x Street Class (was called Stock last year) the rule set is VERY limited. If it does not specifically say I can do it, then I cannot.

My caster and camber is what it is up front anyhow. Hope this makes sense.

93Rubie

Just to give you guys an update after we have had our 1st two events of the season on the car.

I did a EVO school Phase 2 (did Phase 1 last year) with the car on the old (last seasons) tires and didn't have time to pay much attention to the car but it seemed to be working good.

Now our events I did have time to pay attention to the car.

The $$$ and wrench time I put in last winter TOTALLY paid off. This thing handles amazing does EXACTLY what you want it to do. So well balanced (just a touch of understeer in the dry, and in the wet it walks the over/under line very well, I can actually change the attitude of the car mid corner with the throttle/brake in the wet). Transitions are phenomenal with the Koni's so precise. I had to learn how to turn in again. LOL. Rear end grip is stupid good. Me and my co-driver for the day last Sunday where getting on the throttle HARD BEFORE the apex and it stuck. Amazing. Fresh Dunlap ZII's have a part in this but the car did not do this last year.

I had 2 other guys drive the car this past weekend and they where surprised. Guy who typically drives an S2000 was amazed by only using 2nd gear (LOL) and the lack of understeer. He seemed impressed by how quick on its feet it was for a big car. (His S2K is much more nimble, take my word for it, I've beat him in his own car :P).

Brakes are excellent the change in pad to DS2500's we a good one. LOTS of bite and good modulation. I can haul this 3300lbs beast down very quickly.

Saying I'm very happy with the car is an understatement. 1 FTD, and 2 PAX wins over our 2 events last weekend. I'll take that!!

volkswagens-for-life

Interesting to know that a stock s2000 can outrun a modded c4 vette...

93Rubie

I think you mis-read that. I drove HIS S2K and beat him in his own car. His car is not "stock". Both cars are setup for SCCA Solo B-Street (was B Stock in 2013) class rules. They are on the same level playing field. They are in the same class. Very close in performance and time. I've been beating him in the C4 versus his S2K but I attribute that to a bit better driving on my part. He is good and getting better, put it this way, I'm stepping up my game because of the heat.

Also define modded, because the rules are VERY strict. Not much of anything is really done to the car. Its a 93 Z07 LT1 ZF6 coupe, with tires, alignment, shocks, brake pads, fluids, and a cat-back. That is really it.

volkswagens-for-life

Ohhh thanks for the clarification. I definitely had the wrong idea going on here.