redtopz

I have been tracking my C5Z for a couple years and I've done the following to the car:

LG longtube headers, vararam, Pfadt coilovers, T1 bars, Dewitts radiator with EOC, DRM/LG cooling ducts, LG G-stop wilwood front calipers, seats/harnesses. Everything else is stock. I'm very happy with the performance of my car setup.

I've been debating buying a T1 or ST2 prepped car and selling my vette. But at this point I think I will just build my car to ST2 specs. My last track day at Laguna Seca seems to have done some damage to my rear diff as I have black oil all over my rear end and part of my tranny. I was getting "transmission overheating" warnings at the track and I was running pretty hard for 30 minute sessions. I'm looking for opinions on what I should do to my car for TTS/ST2 racing class. This is what I have thought of so far:

Roll cage/fire suppression system (6 point? 8 point?)
Dry sump
Front splitter and rear wing (brand and size?)
New rear diff with cooling
Tranny cooler

I appreciate any advice/ideas. Will the stock pfadt coilovers be suitable for aero downforce? Thank you,

Bill.

AU N EGL

Bill

Have you looked at NASA tech regulations for race cars, and then the ST2 rules?

J.R.

Bill,

SCCA or NASA approved cage is critical.

Fire ext. system. I would recommend 10 lb so you can run 4-6 nozzles.

A dry sump system is expensive (5-6K) and with LS6 engines I have had good results with an Accusump system.

DRM oil/trans cooler setup is very important. Call Randy for the trick schematic and setup. Wrap exhaust system in the area of trans and diff.

The Pfadt coilovers will work well. Settings depend on which spring package you have. PM me for setup info or call Josh or Aaron at Pfadt.

You should be able to be competitive with that setup and a good set of tires.


J.R.

wtknght1

If you're running an LS6, a dry sump is probably overkill - you don't need that for the LS6.

You can't get too much cooling...the more the merrier.

Have you had the car professionally set up? Ride height? Cornerweight? Sway bars zeroed? Engine properly tuned?

Another thing you could think about is some good shocks - Penskes...but only if you have lots of seat time and know how to adjust them. Otherwise, I'd just stick with a good set of SACHS or other good non adjustable.

And if you're going to race, you need to think about racing radios, a good Cool Shirt (driver cooling system), and possibly a good data acq device (DL1, Traqmate, etc).

gkmccready

I'll plug tony@tcdesignfab.com as a good local NorCal place to get your cage built. He's also worked with Randy@DRM in a couple of instances and has been through my C6 for a radiator, ride height, alignment, corner weight now, too. And he's got some C5 customers as well.

davidfarmer

I'd fix what you have first. The transmission and diff are two different things, and you need to isolate the problem and fix what is broken.

NASA races here are pretty short, so diff/trans coolers wouldn't be at the top of my list. I'd get a legal cage built, add the required fire system and master power switch, and just go racing. An ACP nose with splitter and a wing (several decent ones to choose from) will certainly make you faster, just you should optimize what you have first. Even with the added cage weight, you probably have enough power as it is. Just get a decent setup and go racing, then see what you need to be competitive.

0C5stein

Hi Bill,
I would start by fixing your problem, then a cage, you already have a seat and belts, I would switch to AMSOIL on everything and skip the trans and diff coolers.
The diff is most likely leaking because the heat from the exhaust tends to make the seals brittle and start leaking. If the diff isn't making noise, I'd recommend fixing the leaks and wrapping the exhaust to control the heat.
We can do a nice NASA and SCCA legal and safe cage for you.

The ACP splitter and a complementary rear wing would do you well, but will affect your spring rates and shock valving.
We can optimize your spring shock setup, do a cornerweight and alignment

PushinTheLimit

Just FYI... ST2 states that you have to have a power to weight ratio of 8.7 to 1. Which is great for the C5Z as it fits very close to that stock with minor adjustments. I would imagine having headers and the vararam will put you under that limit. Anything under that puts you into ST1 and you don't wanna go there unless you wanna spend some $$$$ to be competitive.

Good cage, coolers, fire system, shocks,2-3 sets of extra wheels and lots of seat time will take you far into that class. Aero would be the last thing I would do and it would be because I maximized everything else on the car first.

ryan0

I would leave my options open... get a T1 spec car and run in ST2.

Once you slap aero or coilovers on it, you cant go run SCCA.

We are going to have 7-8 cars in T1 down here this year... that's more than show up for ST2

redtopz

Thanks a lot for the responses and great info. I have read the TTS rules, but not the ST2 rules. I would make sure everything I did met the specs obviously .. I've had my car dynoed recently and it put down 365 hp before the tune and 380 rwhp after the tune. I guess my engine is not that strong. I figure I will easily remain above 8.7 lbs/hp with a cage and fire system, etc ( I weigh around 180 lbs). It's good to hear that a dry sump is not necessary with the LS6. Are most people using an accusump or just running with the stock oil system?

Building my car to T1 specs is also something to consider. I suppose the cage would be legal in either class so it would just be a matter of removing my coilovers and installing some T1 springs. I have not read the T1 rules either so I'm not sure if I would need to remove/modify anything else.

I looked a little closer at my rear diff and it might not be so bad. I'm missing a bolt on the top left side where it is leaking. I have wrapped my exhaust near the tranny, but anytime I have to use 2nd gear at the track my tranny tends to overheat.

It sounds like the best way to start might just be to get the cage and fire system installed and start doing time trials and work on getting a racing license. Mark, I sent you an e-mail. Thanks,

Bill

0Randy@DRM

Bill our coolers are legal in both classes as well:o 380RWHP that is very ST2 friendly. I think my horsepower is going to be somewhere in the 360-390 ish to the wheels. Getting rid of all the interior+heat box is about the same weight a cage is going to add. So you can get a ruff idea on weights.

Randy

ryan0

ST2 is pretty much the same, but with safety rules... cage, seat, belts, window net, center net, fire extinguisher, hans, etc

8.7 puts you at 3306lbs exactly... and you want to figure in a margin of error.. That's pretty fat. You may need to de-tune.

Most or our T1 cars are down to 3200 with us sitting in them.

Some LS6 guys run accusump.. a lot don't. I never have.



T1 rules are pretty much 'if the book doesnt say you can... you cant'

T1 springs, sways, any shock, big radiator, better brakes this year, headers, any cooler, remove interior, remove seat, 315 DOT tire max, and thats about it... and the usual safety stuff

come on down to willow this weekend... we've got 5 entered so far with 2 maybes... and cal club super school is next month at button willow.

gkmccready

ITE. I think MSI built a sweet ITE C5 that runs in SFR. Throw on slicks instead of DOT-Rs and run SP, too.

ryan0

ITE is the money podium.. he with the biggest gun wins. What fun is that? I already spend enough on my 'stock' car.

redtopz

So far, everything I have done to keep my car running cooler has been a good investment. I'll check out your website .

I appreciate all the info. I didn't know you T1 guys got your cars down that light. I doubt I can do Willow, but Buttonwillow would be great! Is that the Speed Ventures event on March 18th or April 11th?

96CollectorSport

A T1 car is plenty fast, if you look at the TTS/ST2 lap records at any track and compare them to the T1 lap records they are very close.

The problem is a C5 in T1 runs a hp/weight between 8.0/1 and 8.2/1, that means you have to add between 300 and 200 lbs of ballast. Depending on your hp, I think you are going to see the strong C5 T1 cars make right around 400 rwhp (if not more). And I don't mean to start a C5/T1 with headers debate that is just what I think. With a T1 cars min weight of 3180 that makes for a damn quick car. But if you want to run the car the same in NASA (no ballast) you're running in TTU or ST1 - not a fair fight.
So really you can do two things - kill some of the power with a different tune or add ballast (or both).
I really don't think you need aero yet in TTS/ST2, now that the T1 cars can have real brakes, I think any of the top sorted T1 cars would be a fast car for ST2/TTS. But I also think that there is a lot of potential for the ST2/TTS cars in the future. This is still a fairly new class and people are still working on ways to get the most out of there cars and the rules.
But as the classes are now building a car that can do both isn't a bad idea. Run with both groups and see where you're having more fun.
Since you're in Cali it looks like the fast C5's are running with SCCA.
In the southeast it seems like NASA TTA is a fun place to play, Arizona has a good group of NASA guys too. Midwest/Great Lakes seems to be favoring NASA as well. I'm not trying to single out any one organization, that's just my opinion off of what I've been reading off the SCCA and NASA forums.
This is all about fun, and from my experiance once you find a group that you really have fun running with it doesn't matter what the orgaizing body is.

0Randy@DRM

Here is the latest picture of our kit

ryan0

BW is the SCCA Super School... you can get your race license in 2 full days.

redtopz

Thanks, I might want to do that .

Does anybody race T1 in Northern California? I was looking at the SF Region of SCCA results from 2009 to get an idea of how many cars were in that group and I didn't see one car listed. There were a bunch in ITE and other groups.

gkmccready

Not that I've noticed. There're a couple of T2 cars, but in all my years of following The Wheel (SCCA-SFR's publication) I don't think I've really noticed any T1 cars consistently showing up in the results.