geerookie

I was figuring two small turbo's at the back instead of the mufflers. Saves all the heat under the hood. Yes it's a bunch of plumbing but I figure you only need about 6lbs of boost up to 4500 - 4800 RPM.
Why would you need an intercooler for this?
I'm a NA guy but have started to see the benefits of a little boost....been hanging with the EVO and STi guys too much

Do you know somebody that would be good at tuning this type of setup? Most of the guys I know are drag racing shops so I'm not to keen on having them setup a road race car.

wallyman424

I know those rear mount setups don't need intercoolers for street use, but I feel like after a few hot laps there'd be a ton of heat soak in the plumbing and the turbos themselves. Maybe a rear mount + a front intercooler would do the trick. I also think 1 turbo would be more than fine. Cuts your plumbing in half, and 5.7L is more than enough to spin it up quickly.

I'd do the tuning myself, but I'm sure a drag race shop (or someplace like ECS) could do it. LS motors don't have variable valve timing and all the crazy stuff those evo/sti guys have. You can get a nice aftermarket boost controller to control the wastegate and psi through the rpm range, and just tune the ECU around that.

It's a lot more testing and work than I have patience for though.

DOUG @ ECS

We can help you out with the tuning if or when your ready. We have tuned many high hp road race cars.

(although my road race car is N/A if that means anything to you)

hamdog

I didn't think the C5s could get into the 2,500s. Good to know!

geerookie

I was hoping to be under 2550# but at this point I don't think I can make it without spending big bucks on CF or removing parts that actually are needed

drivinhard

what's the driver weigh

gkmccready

Can you replace the hatch "floor" with thin aluminum since it doesn't need to bear any weight and the cage should be adding all the structure you need now? Same for passenger side floor, etc.

geerookie

My weight has no affect on the 2550 for the car

But I may have to look at a diet for me if I want to get down to the 2855.
In ST2 the magic numbers are 2951 +/-5lbs or 2851 +/- 5lbs.

Right now the car is at 2585
+ 135 for the cage
+ 40 for coolers/pumps and extra fluids
+ 15 for a fire system
+195 for me and gear
Equals 2970, so if I lose 19lbs I will be at the magic 2951

I could stand to lose about 30lbs but then I still need to find 89 more lbs to take out of the car to make it worth while...I don't see it happening

geerookie

I'm posting pictures. Already done. Also makes work on the rearend and tranny easier.

geerookie

Finished posting more pictures
I hate posting pictures

throwit

I thought my car was light...that's impressive!! Congrats!

geerookie

What does your car weigh? What class are you running in?

Jason

Aren't you going to need the yaw sensor and accelerometer thingy to keep the abs happy?

geerookie

They have nothing to do with the ABS from the braking stand point. ABS is Steering Position sensor, and all 4 wheel speed sensors.

Lateral Accelerometer and YAW sensor only affect Active Handling. They interact with the EBTCM and the BPMV which is also part of the ABS system.

One of the advantages of removing the Lateral Accelerometer and YAW sensor is you never have to remember to turn off AH/TC!

brkntrxn

First, very cool project. Keep us posted on your results at the track.

Second, do you not plan on needing 5th gear at some tracks? At VIR-Full, I run out of rpms in 4th gear on the back straight. Especially when running on the smaller 275 Hoosier As.

As for the foam in the front bumper covers, I am not sure how the aerodynamics of our Vettes work, but I can remember from my drag racing Mustang Cobra days seeing several of the faster cars collapsing front bumpers on the big end. I cannot find any pics of the cars I remember, but I did find a pic of this Firebird doing worse than what I am describing:






-Kevin

SIK02SS

Nice job! Jason is right, leave the foam. It weighs very very little. When I had my bumpers off for bodywork etc I was going to pull them too, then realized how little they weighed and figured it could actually help staying where it was in case I ever have Ryan/Oli/Roy fighting me for a corner...which will probably happen

flink

Only in a vacuum! Once you're doing 90mph, you're using 200hp (a guess) just to hold that speed. So the 300hp car has 100hp left to accelerate while the 400hp car has 200hp left with which to accelerate.

And no, I don't know where the sweet spot is either. And it'd be hard to calculate mathematically, given the effect of non-linear grip-vs-weight and corner exit speeds, etc. Careful testing would be needed.

Check out Oli's recent Thunderhill race in ST2: http://vimeo.com/14402695

He was blowing the doors off those sevens-only rx7's on the straight. I believe those things are built to the max for ST2 but they're light as a feather and have less than 300hp. Despite having smaller bodies (and, I assume, less drag), they just run out of puff at high speeds. At a twistier track it might be a different story.

You need power to go fast!

Timz06

Because the limit is on HP. If you have tons of torque down low and midrange and can still make the hp, you will have a much faster car. Especially if you gear it for the torque.

HP is calculated from torque x 5250/rpm. So rpm and horsepower curves cross at 5250. Say your max hp was 380, you could set your torque to 380 at 5250 and then calculate the max torque all the way through the range.

What about a torque curve as follows, which is theoretically legal? Even if you could reproduce the numbers from 3500 up, you would have a HUGE advantage over a stock motor like an LS6.

RPM 1000 1500 2000 2500 3000 3500 4000 4500 5000 5250
TQ allowed 1995 1330 997.5 798 665 570 498 443.3 399 380
Max HP 380 380 380 380 380 380 380 380 380 380

The latest road and track has the corvette GT2 car, max HP 470 at only 4800 rpm!!! I wonder what the torque curve looks like on that motor, I'll bet pretty fat!

Tim

0RAAMaudio

Ask Randy at DRM about building an ST2 torque monster

A low weight car with a fat and healthy torque curve is going to be fast as long as you can keep from spinning the wheels that is.

Rick

OKsweetrides

I'll have to implement some of this diet this winter!
Nice results!