shadowskill

I come from a LS1/Z28, but the Z will not be rolling for some time... (too much torque and slippery road on the rain ). Now, as I'm using the vette more often, I'm falling in love with it and now I want to take it to the track and the twisties too; love it.

I'm looking for the best goal for a track/street (track days, twisty roads & some autox just for fun) for my 94 A4 LT1 C4 (maybe a ZF swap will follow on the long term).

I just really liked what 4/4 koni yellows with strano springs did to the Z28, but after diving on several shocks/springs issues on the autocross and road racing subforums, I'm confused:

I wouldn't like to go coilovers (overkill for the streets)
I will look into rear suspension upgrades from banski, camber brace, beam plates, and front poly bushings after I replace my really worn stock shocks.

Which would be a good set of shocks (cornering wise)? I am willing to sacrifice any ride comfort for good cornering grip. Willing to change springs if necessary.

Options: Bilsteins (sports, HD) or KYB shocks? Hyperco HPT composite leaf springs?

RickF

Why not go with Koni Yellows again? That's what I put on my 94 street/HPDE car. I can't tell that they are better than your other options as I replaced the well worn stock Bilsteins.

The adjustability is nice, although the rears cannot be adjusted on the car, and they were about the same price as Bilsteins. The Bilsteins have alot of fans.

From what I've read the KYBs are a good less expensive option.

blue94

get the Koni's

Kubs

As for the rear end kit, I have the kit from Banski and love it!! It really works well and is easy to install and adjust.

As for shocks talk to Randy at DRM (dougrippie.com) He can set you up with some Bilsteins custom valved to your suspension and needs. The price is pretty good too.

shadowskill

I hope konis are not as expensive as they are on the Z28 (around 1K for the set). But, I will look who has them. From what I've read here, Bilstein and KYB are really not bad (and would let me do bushings and alignment, while I save for the rest of the stuff while going to the track and cruising around). So far the prefered choice would be koni yellows or DRM custom valved. Second, Z51 or sport bilsteins, or KYB and poly bushings.

Any Idea if stock leafsprings are any good?

jaa1992

FIrst of all determine what class you want to autocross or road race in.
That will determine what you can and can't do.

For instance I'm building mine for NASA TTB and NCCC IIG.
NASA lets me replace the flywheel with a lighter one, NCCC does not.
NCCC I can put on the best shocks, springs (no coil over) and swaybar.
As my car came from the factory I have to take points in NASA for shocks, springs and swaybar.

96z51

ls1's and lt1's have the same torque curve.

shadowskill

Nice to have many pointers and opinions

Sometimes I've been along higher class cars with full caged european cars and I don't mind; I'm not after the best times, I just want to have fun and be able to cruise on the twisties and highway on the car (will just get as far as a 4pt. rollbar, keep interiors, asr and a/c), but want to get nice upgrades (sway bars, shocks, camber brace, x-brace, 4pt. roll bar, decent shocks, leafsprings, etc.)

Now that you mention it, which sways have a great balance for DE/autox? (something like 35/22 chromoly hollows for the f-bodys)

Thinking about it, I may just start with DRM blisteins or KYB and poly bushings and upgrade from there while getting more seat time on the vette (if KYB are decent enough, which would also let me add the poly bushings and HPS brake pads).

Also, the DRM P.steering braided line seems nice before a PumbOne or PS cooling upgrade.

RickF

I share my 94 so the car is on the track alot. This was the single best mod we made. Before, the PS fluid would always over heat. Since the Turn One rebuild, no issues.

jaa1992

OK, when did you last rebuild the suspension?
Never - research the Banski rear suspension upgrades and maybe delrin bushings for the front.

Coil overs is the best shock/spring combo. If you want to stay leaf spring/shocks look at VBP's kits. Same for sway bar.

If you are putting in a roll bar the x brace is redundant and just adds weight.
Camber brace

Get a transmission cooler! I had an 88 that I started my road course carrer on. Manually shifting the trans between 2nd and 3rd would make everything hot after 20 min to the point where I had to pull off and lose 10 min of the 30 min session.

Brakes - If you don't have them, upgrade to J55. I like Carbotech pads, I'm running XP12 front and XP8 rear. I'll probably try Hawk DTC 70/60 pads when these wear out.

You will need to cool the brakes, Quantum makes some good parts. They direct air across the hub and to the center of the brake rotor instead of just on the rotor.

Good luck - there are a bunch of us still running C4's on the road courses!

subtlez28

I'm pretty much in your same shoes. I have raced my 02 Z28 for the last 3 years (high speed autocross), and have Stranos springs, sway bars and Konis.

Now I'm working on an LS1/T56 swapped 84 C4 to take it's place. It did seam easier to pic a combo for the Z28, C4s have a lot of choices.

Here is a spring and alignment chart that makes a good reference:
http://www.vettenet.org/susp_chart.html
http://www.vbandp.com/instructions/h...ruct/align.htm


Really? Have some dyno results to back your statement?

OP: As you know, owning and LS1, time has marched on (LS1>Lt1 or SBC). But save yourself some time and typing by not getting into arguments on here. Alot of C4 guys on here cannot except the LS1 makes more power than SBCs or LT1/4s (stock for stock or mod for mod).

shadowskill

Its a 95 so I got J55, maybe the tranny cooler will be urgent too. With a roll bar I wouldn't be needing header? that would be great as I've not seen anybody clear their long headers with the Xbrace.



Definitively, great info here, thanks to sutblez28, jaa1992, Aardwolf, Kubs, and all the guys in this thread; So let me see If I got it right,

** Optimal Road Racing / Street build:

Shocks/springs:

• Best: Coilovers (which ones?)
• Good: Konis, Bilstein DRM revalved if not looking for adjustablility yet.
• Decent: Bilstein Sports

Swaybars:

• VBP solid sways (solid tend to be stiffer than tubular --Kupps --Aardwollf). (which swaybars' thickness?)
• Poly bushings (DRM)

Chassis rigidity:

• Camber brace (R&D)
• Beam plates
• 4pt. Rollbar (Wolf)

Brakes:

• Best: Wilwood 6-piston (and 4piston rear, maybe a swap for the front ones)
• Good: C5 upgrade (if you don't have J55, J55 if it came with it (There is not a whole lot of performance benefits other than C5 rotors are thicker and cost less than the J55 brakes. --Kubs)
• Brake Coolers: Quantum (Quantum makes some good parts. They direct air across the hub and to the center of the brake rotor instead of just on the rotor. --jaa1992 )

Pads, Break bias:

• Carbotech pads, Hawk (HPS with either the HP+ or HT-10 on the front -for street/track purpose)
• DRM brake bias spring

Steering:

• PS Cooler w/high pressure braided line
• Steering rack bushings rebuild
• TurnOne rebuild (recommended up to the point on very sticky tires)

Front suspension:

• Del-Alum bushings

Rear suspension

• Best: Banski upgrades

Alignment specs:

• http://www.vbandp.com/instructions/h...ruct/align.htm

Cooling:

• DeWitts aluminum radiator

If A4 tranny:

• Tranny cooler (on venting line)
• Catch can
• Rebuild or upgrade kit

LS1? Yeah, but right now I'm focusing on killer handling, and would be a PITA if I want to keep ASR and digital dash (wich I like them very much).

Aardwolf

Re catch can, I had a lot of trouble with it venting on the track with mine. Do add the can to the vent line.

If your not on race slicks you would likely be fine without changing the PS pump. Add Redline or whatever synthetic PS fluid. Add a cooler when you can.

I would not even consider KYB for a track shock.

I used the tubular VBP sways, there was a nice sale going on. I also have a thread on them. Search up my threads.

Adding brake cooling ducts is a good idea, plus high temp fluid. You can race on the J55 setup though. Braided brake likes are good if your stock lines are old.

Clean out between the condenser and radiator if you still have A/C on it. Consider tossing it and a lot of other things to lose weight.

There are lots of guys racing and winning without the camber brace, don't consider so much to be mandatory. Prioritize here! The single biggest thing that is fun and will make you faster is seat time.

One of the best mods I did was race seats and a harness!

shadowskill

Niice :-) An autox and a TrackDay are next month, and plan to have fun 1 event each month. I want to to upgrade one step at the time (while having seat time, and saving $$$ for the next mod). I was just getting used to the nice automatic A/C feature, but I did dump that on the Z28 too... (have to have courage to do it one of these days -will look on to how to remove it without breaking anything- )

I think the first step (to pick things from the list) will be a nice priced bilsteins, brake pads, P.S. fluid, and front poly suspension rebuild; on a couple of months PS and tranny coolers will follow along w/ the catch can, next 2 months sways and the next 2, banski rear. That should play nice along with the driver mod on the events the following 6 months.

Updated my wishlist based on your feedback, thnks guys; I'll even organize the list on priorities. Yay, this is gonna be fun

95wht6spd

What do you have on it now? What codes, FX3, etc?

shadowskill

FE1 - Base suspension
G44 - Rear axle 3.07 ratio
G92 - Rear axle performance ratio
J55 - High performance brake package

MX0 - Automatic transmission
M30 - Automatic 4-speed electronic transmission

pologreen1

[QUOTE=Aardwolf;1572800019]
I would not even consider KYB for a track shock.

x10

I have had several different shocks on vettes or driven different c4's too, and I say NO to KYB's for performance.

The have no pressure, so they don't grip well, and they are more suited for driving.

I have them on mine, because they came with the car new in boxes, and only take a couple hours to do.

I am changing over at the least if not doing coil overs right away.

Kubs

Hope this helps. This is just my opinion, I am not saying this is what you have to do.

Toy90

PS minimum needs the pressure line from the pump to the rack replaced with braided from DRM. I broke 2 on my 94 6 speed before figuring that out. On my 96 I didn't bother trying to track it without it. I had no PS problems after that on the 94 but my 96 destroyed the pump the first track day I used it so I got it rebuilt by Turn One and now it takes my abuse.

2nd biggest problem I had was overheating. I would defintely make sure you have a clean radiator. I ended up replacing mine with a Dewitts as the plastic end cracked on the track and I wasn't putting in another baby sized stocker that wouldn't cool sufficiently anyway.

STEVEN13

Hi

on my 1992, I use an underdrive pulley which turns the pump slower. I use the stock PS lines with RedLine fluid. I have also used Nitto R2s-great tire to drive to and from the track. PFC 01 and 97 with the GS brakes. Z51 bars with FX3 shocks and VBP springs.

Have fun!
Steve