Road Racing / Street C4 build
01-19-2010, 07:35 PM
#21
It really helps a lot 
specially choosing with what am I going to start with, and what will be next. Updated the wishlist.
1st stage
* Shocks: DRM revalved bilsteins at this moment will be very good, as I want to get considerable seat time before tweaking adjustables.
* Brakes: DRM brake bias, Hawk pads, braided lines, bleeding
* Steering: Braided high pressure line, bleeding w/synthetic, (will try to get the underdrive pulley)
specially choosing with what am I going to start with, and what will be next. Updated the wishlist.1st stage
* Shocks: DRM revalved bilsteins at this moment will be very good, as I want to get considerable seat time before tweaking adjustables.
* Brakes: DRM brake bias, Hawk pads, braided lines, bleeding
* Steering: Braided high pressure line, bleeding w/synthetic, (will try to get the underdrive pulley)
01-19-2010, 07:55 PM
#22
Race Director
Just be careful with that trans venting. I kept getting black flagged at one track and had to run slow. I'm curious what yours will do, please make a new thread with updates!
01-20-2010, 01:20 AM
#23
Race Director
OK, here are my .02
OTHER:
Seats: Kirkey Intermediate (up to 17" will fit)
Harnesses: 5-6 point. (If you like your nuts I suggest 6)
Oil cooler: Not sure about a smaller h.p., but I was WAY hot without one
Accusump: I dropped oil pressure to about 6 psi in sweeping turns without one. Now it is 50+ all the time
New wheel bearings.. you are gonna need em.
I'm sure there is more... but I'm tired
Some pics of above:
Camber brace
PS cooler/VBP spring
Other VBP suspension
Quantum spindle ducts w/homemade intakes
Wilwood SL6R
Kirkey seats on custom brackets
MOST IMPORTANTLY!!!!!
LET 'ER RIP!!!
** Optimal Road Racing / Street build:
Shocks/springs:
Swaybars:
Chassis rigidity:
Brakes:
Pads, Break bias:
Steering:
Front suspension:
Rear suspension
Alignment specs:
Cooling:
If A4 tranny: I have nothing to add to the A4 side
Shocks/springs:
- Best: Coilovers (which ones?) I don't agree. Unless you have a lot of time to test tune, you are just as likely to make yourself worse than better.
- Good: Konis, Bilstein DRM revalved if not looking for adjustablility yet. Get the revalved Bilsteins. They are a 95% solution for a lot less. Until you are consistent enough to be looking for a tenth of a second, you need to set the shocks and forget it.
- Decent: Bilstein Sports
Swaybars:
- VBP solid sways Agree
- Poly bushings (DRM) Agree
Chassis rigidity:
- Camber brace (R&D) 100% Without a doubt... yes
- Beam plates Take it or leave it
- 4pt. Rollbar (Wolf) For safety and harness more than chassis rigidity
Brakes:
- Best: Wilwood 6-piston (and 4piston rear, maybe a swap for the front ones) All you need is Wilwood SL6R fronts. Save yourself the money. The stock rears will do just fine with decent rotors and a medium/high friction pad. Mine work like a champ without adding a bias spring. I did a LOT of research on this one.
- Good: C5 upgrade Don't waste your money. J55 will perform pretty well. If you don't want to go for the 6 pots, go with J55. The only problem I have ever seen with them is that they go through pads and rotors like candy when they get hot. In a year, I saved enough money on pads and rotors that my Wilwoods paid for themselves.
- Brake Coolers: Quantum Great company, great part
Pads, Break bias:
- Carbotech pads, Hawk (HPS with either the HP+ or HT-10 on the front -for street/track purpose) Wilwood Poly B compound is perfect for these cars if you go the 6 piston route. When I was on J55, Hawk worked great but I blasted through pads and rotors WAY too fast
- DRM brake bias spring Don't assume that you need it. It is all about driving style and preference. I had one in and I didn't like the way it felt. Others swear it is the best thing ever.
Steering:
- PS Cooler w/high pressure braided line Agree
- Steering rack bushings rebuild Is it loose? I am still on the stock steering rack with a LOT of track miles
- TurnOne rebuild (recommended up to the point on very sticky tires)
Front suspension:
- Del-Alum bushings I have all VBP parts and have yet to meet a better handling C4. I'm sure they are out there... but I wouldn't ever change mine.
Rear suspension
- Best: Banski upgrades Again... I'm partial to VBP
Alignment specs:
Cooling:
- DeWitts aluminum radiator I'm doing just fine with a 560h.p. 383 and the stock radiator.
If A4 tranny: I have nothing to add to the A4 side
- Tranny cooler (on venting line)
- Catch can
- Rebuild or upgrade kit
Seats: Kirkey Intermediate (up to 17" will fit)
Harnesses: 5-6 point. (If you like your nuts I suggest 6)
Oil cooler: Not sure about a smaller h.p., but I was WAY hot without one
Accusump: I dropped oil pressure to about 6 psi in sweeping turns without one. Now it is 50+ all the time
New wheel bearings.. you are gonna need em.
I'm sure there is more... but I'm tired
Some pics of above:
Camber brace
PS cooler/VBP spring
Other VBP suspension
Quantum spindle ducts w/homemade intakes
Wilwood SL6R
Kirkey seats on custom brackets
MOST IMPORTANTLY!!!!!
LET 'ER RIP!!!
01-20-2010, 10:32 AM
#24
Le Mans Master
It really helps a lot specially choosing with what am I going to start with, and what will be next. Updated the wishlist.
1st stage
* Shocks: DRM revalved bilsteins at this moment will be very good, as I want to get considerable seat time before tweaking adjustables.
* Brakes: DRM brake bias, Hawk pads, braided lines, bleeding
* Steering: Braided high pressure line, bleeding w/synthetic, (will try to get the underdrive pulley)
specially choosing with what am I going to start with, and what will be next. Updated the wishlist.1st stage
* Shocks: DRM revalved bilsteins at this moment will be very good, as I want to get considerable seat time before tweaking adjustables.
* Brakes: DRM brake bias, Hawk pads, braided lines, bleeding
* Steering: Braided high pressure line, bleeding w/synthetic, (will try to get the underdrive pulley)
01-20-2010, 11:11 AM
#25
Melting Slicks
REDLS1GTO: very nice
Get the revalved Bilsteins. They are a 95% solution for a lot less. Until you are consistent enough to be looking for a tenth of a second, you need to set the shocks and forget it.
What comp/rebound do you use? Who did the revalving?
Get the revalved Bilsteins. They are a 95% solution for a lot less. Until you are consistent enough to be looking for a tenth of a second, you need to set the shocks and forget it.
What comp/rebound do you use? Who did the revalving?
01-20-2010, 12:42 PM
#26
Le Mans Master
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01-20-2010, 01:42 PM
#27
Race Director
I'm kidding.No, I agree with Kubs 100%. There are a few folks out there that do re-valving of Bilsteins. Personally I would go with DRM. They were racing C4s when C4s were new and know what they are talking about. Your shocks will depend on what you want and the rest of the suspension. Mine for example are great on a med/high speed road course, but not so much for low speed/AutoX (that's the 5% I was talking about above). Let them know what you want and they'll make it happen.
01-21-2010, 12:28 PM
#29
Race Director
I used 5' of hose on each side but I am going to cut it down to about 3.5-4 since it is bunched up. I wanted to make sure that the idea worked before I cut the hose.
01-21-2010, 03:06 PM
#30
Great info, guys! Will go with revalved, as I don't want to mess with adjustments yet. Nice place to attach the ducts. redls1gto, killer car, man. I guess springs and sways have to be the same time to play along; Any popular rates?
02-05-2015, 08:31 AM
#34
Intermediate
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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!
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!
