bowmanm98

Before you guys tell me the best mod is a DE and time behind the wheel; I know I could always use help there


I've learned from track days that having the rear planted on exit really helps when exiting the turn. In a Vette you already have a considerable amount of torque so I would think the SC car would be easier to drive coming out of the corners. Surely you dont want to get a sudden increase in boost at that critical moment (like one might expect in a turbo car). I would expect that the power curve on a supercharged car would be more linear with fewer surprises and thus might be better for track use. (I am guessing here; I'll admit I am far from being an expert) While the Turbo is more efficient and better torque curve resulting in better 50-140 acceleration.

FYI, C6 Z51 A4, completely stock. I am not satisfied with the power, nor am I completely happy with the suspension. I am leaning toward the coilover kit available and some adjustable sway bars.

I am contemplating a Vortech/Procharger SC, APS or HC TT kit. All on low boost (5-6 PSI on stock internals). I don't need to be the fastest car out there. Nor am I looking only for straight-line performance. It seems that the ATI kit is lacking some refinement with regard to the AC line and it's noisy from what I've heard. The APS kit seems like the best performance, but the turbos so close to the tranny/block etc have me a little worried. The HC tt kit in the fender seems like a good choice but I haven't really seen any cars with that set up.

Heat seems to be a major factor of the A4/A6s on the track. So which one would produce less heat contributing to engine/tranny temps? Which one would give better lap times given the same peak 6psi?

Coming from a 996 with sport coilovers and sways, I managed a 1.59xx at infineon raceway and I'm not even sure if I could manage that with my Vette stock. (Though with R comps I probably could)

I'm looking to have a car that is extremely fast for couple laps maybe 15mins max, not an endurance car.

I appreciate your comments and feedback...

dagon138

b4 the extra power, I'd suggest looking into protecting your A4 as that's going to be a likely source of failure.

CHJ In Virginia

If it was my car, I would not go with aftermarket forced induction for track days. There are serious cooling and heat soak issues when running forced induction for long periods of time. A forged normally aspirated stroker motor if the bucks are available or a good heads/ cam /headers /tune will yield a lot of performance increase. Your A4 transmission will need a complete "bullet proof" rebuild and a cooler if you expect it to live for any time at all.

AU N EGL

Neither what so ever. supercharges and TT are for little cars, not corvettes, BOTH WILL OVER HEAT way too fast.

Reason you have not seen cars with these set ups on a road course is for just that reason, they are not reliable and produce way too much heat.

We have seen a few on the track for DEs and non have made full sessions do to heat issurs. or the brakes gave out as the cars wore though stock brakes.

A6s are not made for more then 500 WRHP according to Tom Wallace. The automatic trans can not take that type of abuse and HP.

Keep the car stock, put on a larger oil and transmission coolers. Up grade the brake pads to some race pads, DOT 4 brake fluid. Lean how to drive and you will go faster with more reliablity then any SC or TT car could ever be.

Heck even TT996s have their reliabilty challanges too. Many of the T996s are weekend doctors or lawers cars. Several of them who decided to many more DEs sold the TTs and bought the GT3. Best track Porsche by far.

Good Luck.

63Corvette

How much money do you have to spend on racing? In one Sebring 12 hour race, the Ted Field/Danny Ongais Porsche 935 used 25 turbochargers up in 12 hours! Can you afford more than 2 per hour? the timing might just fit a DE event.

AU N EGL

Now I would say the is a reliabilty issure for sure.

63Corvette

Ted Field ran completely out of spares, so he went over to Roger Penske and asked to buy Roger's spares. He gave Penske a check for $25,000 for the spares. Roger took the check over to Teddy Mayer of McLaren and asked him "Who is this guy, and is his check any good?" Teddy answered "Marshal Field!"

danswofford

If you were to add forced induction and NOT suspension upgrades I would be willing to wager that you will NOT be substantially faster. Suspension and tire upgrades will make your car substantially faster. Your car has enough power to be one of the fastest cars out there at a typical track day, the car just needs suspension and tire help and the getting the power to stick.

bowmanm98

I have no interest in endurance racing. I am looking to do a couple warm up laps and then maybe two hot laps and then to the pits. About 10mins total each session. It's time trialing so only the single fastest lap of the day counts.

Thanks,

Happy Turkey DAY!!!

AU N EGL

bowmanm98

Ok besides R compounds what suspension upgrades would you recommend? Also what about a hot cam and 205afrs?

What recommendations for wheel and R-comps?

John Shiels

CCW's and Hoosiers, springs, roll bars, shocks, engines parts and on and on. How much money do you want to put in the car is the first question to ask yourself. It is a continuous patching of weak spots.

PA Z06

Have you thought about heads/cam and oil cooler, it would get you pretty close to where you want to be hp wise

bowmanm98

Yes I am starting to think maybe AFR 205s and a custom grind cam might be the ticket for me.

ace996

As we all know, even stock cars have heat/cooling issues...that's an oilcooler or radiator/EOC away...heck, I need to be able to cool down my car a little more.

I run an '02 Z06 with a magnacharger (475hp/475tq with a very conservative "roadcourse" tune) and I am AMAZED at how well it handles a roadcourse. I can usually go 15-20mins before oil temps go over 260degrees...at that point, I pull it in.

My Z's powerband is just about perfect for HPDAs and autoxes. The delivery is very "big-block" like, with a linear build in horsepower and a real strong torque curve...like 400lb/ft just over 2K rpm. I don't see a need to wring the weasel-**** out of it to make power, so I usually shift between 5500-6K rpms..this helps keep the temps lower. Average rpm range used is 3-6K rpms, and the power the engine makes is well above a stock or H/C car. It is lag-free, easy to modulate, and more than I could ever use...

Regarding the S/Cs for roadcourses and cooling- The centri systems require the radiator to be laid-down, flatter than stock, and have shown to be difficult to cool. They also have cooling issues as a result of intercooler location/designs. I'm not saying that it hasn't been done, there are many who've done it...but at significant cost and time.
The Magnacharger keeps the stock location of the radiator, so it's more efficient at cooling the fluid. As previously stated, an upgraded radiator or radiator/oil-cooler is a must even for stock cars, and for what you are looking to do...you shouldn't have an issue with the stock system...I really don't.

Really, the power delivery and driveability of the maggie is fantastic. It helps blasting out of low-rpm turns and is very reliable. Sure it adds about 80-100lbs (my guess) but the addition of hp/tq is amazing.

Again, for what you're looking to do...you shouldn't have reliability issues with any system. The turbos are quite expensive, and from what I've heard are difficult to modulate. The centri systems offer great upper rpm power but have cooling issues (inherent in the design of the intercooler/radiator). The maggie makes great torque but gives up some upper rpm power and adds some weight up front.

And if you drive the car on the street...the maggie is a wonderful partner. Also, with all the power-hungry street/strip guys upgrading all the time, you can probably find a good used maggie system for cheap and put in a 6-speed for the cost of a properly done turbo system.

Bottom line, they can all be done...just depends on what you want to do. Good luck and have fun.

Be good,
Tom

69427

Forced induction systems can be a lot of fun if done right. They don't suffer from the crappy idle syndrome (like my BB), but they pull like a BB when the boost comes on. Lotsa fun!

bowmanm98

Interesting. So you think the APS manifold design would be better or the HP design where they have coated headers to the turbos in the fender well? Sorry for my ignorance but what is a BB?

Solo2GS

Having quite a background racing a turbo charged car for years I can say that the biggest problem is going to be cooling. Not just the cooling of the water (radiator) and oil (EOC), but that of the air and exhaust temperatures when running at high speeds.

Keep in mind anything you run on a Vette is going to be lower than the 15-20 PSI (boost) I used to run on the Mitsubishi, but the same problems are going to persist since the compression ratio on a non-factory turbo performance car are much higher than factory turbo charged engines.

Too keep everything cool you are looking at a better radiator, a better EOC, water injection, and a big intercooler that is likely going to be in front of your radiator soaking up all the cooler air.

Even though I am still a big fan of turbo charged cars and never had reliability problems with the turbo itself I would vote for the procharger / SC over the turbos for the vette. A lot less heat involved in making that boost from the get go.

I know this doesn't really address how to be faster on the track since HP isn't everything, but I wanted to address the question you asked...

bowmanm98

Thanks Qwic, so doesn't the procharger have a big intercooler in front of the radiator too? Does the location of the turbos right by the tranny/engine play a major role too? What exactly is the reason the Centrifugal produces less heat?

ace996

Yes...big intercooler in front of the rad, or two intercoolers in the brake-duct cavity.

Turbo location....turbos absorb very hot exhaust gas temps, when they are close to the engine...it's an issue.
Prochargers/Vortecs don't do that with the exhaust gases...less heat in the engine bay.

So no Maggie consideration???
give this a look...
http://www.lingenfelter.com/img/press/ShannonZO6RR1.mpg
http://www.lingenfelter.com/img/press/ShannonZO6RR2.mpg

FWIW, any F/I system you run should have water/meth injection also. I use the ECS/Alkycontrol kit on my maggied-Z and it works wonderfully. I go through about a gallon of meth in 20mins...helps with detonation, IATs, octane, and keeping the maggie cool.

Be good,
Tom
ps- Pic from my last Limerock HPDE... that's a 600hp 996TT...exactly how it went all day!!!!!