Need advice from racers / time trialers

[Orange Crush 1LE]

Originally Posted by tw78911sc

Most IMSA/Tudor/LeMans classes make performance adjustments between mfg's by restricting air. Cheap, easy to restore, and saves your internals since it never gets near the peak HP/torque ... They should be able to swap out restrictors on the dyno until you hit your hp/wgt sweet spot.

Yes I looked into that. I called LG Motorsports as I know they've done restrictor plates on LS3s before. They said that if I just choke a 500 RWHP motor down to say 430 RWHP, the torque curve will be less than ideal. I won't be maximizing the area under the torque curve, so it won't perform as well as it should. They suggested designing the engine around the restrictor plate rather than trying to force my current engine to work. I would probably do better with just a bone stock LS3 with long tube headers, a CAI and a tune. So far, the restrictor plate idea has fizzled but I'll keep an open mind to it if I find something encouraging. I may call Lingenfelter, I heard that they've also done a restrictor plate on an LS3.

[trackguy]

Originally Posted by Orange Crush 1LE

My engine builder uses a Dynapack dyno, and NASA uses a Dynojet to test cars. I had heard dynos vary by +/-2%, so if I wanted to be conservative I'd have my engine built at 529 RWHP - 4% = 508 RWHP. Any advice on this?

My tuner uses a Dynapak to tune my TT3 car (it's a BMW), and the car put out 285.0 HP when it was last tuned. On a Dynojet 224 (NASA's required dyno), it put out 318.8 HP. Same tune, but on the Dynojet it had improved headers and a CAI, which on my motor don't make nearly the difference that they can/do on a small block.

I had expected a 10% increase on the Dynojet instead of the 11.9% that I got, but like you say, these things aren't exact. In my case it didn't matter, because with 1 gallon of fuel I was still over the 9.0 class minimum at 9.15 lbs/HP.

If resources are an issue, one thing I'd suggest before going ST2 is that you consider buying a car instead of building one. You can do quite well if you're careful and make sure you're getting a car that's been taken care of and that its condition at the time of purchase can be established to your satisfaction. Just a thought.

[Orange Crush 1LE]

Originally Posted by trackguy

My tuner uses a Dynapak to tune my TT3 car (it's a BMW), and the car put out 285.0 HP when it was last tuned. On a Dynojet 224 (NASA's required dyno), it put out 318.8 HP. Same tune, but on the Dynojet it had improved headers and a CAI, which on my motor don't make nearly the difference that they can/do on a small block.

I had expected a 10% increase on the Dynojet instead of the 11.9% that I got, but like you say, these things aren't exact. In my case it didn't matter, because with 1 gallon of fuel I was still over the 9.0 class minimum at 9.15 lbs/HP.

If resources are an issue, one thing I'd suggest before going ST2 is that you consider buying a car instead of building one. You can do quite well if you're careful and make sure you're getting a car that's been taken care of and that its condition at the time of purchase can be established to your satisfaction. Just a thought.

Holy cow, I didn't know the difference could be as much as 10% - 12%, that's good to know. To be safe, I'm going to have my car dynoed on a Dynojet immediately after my engine builder finishes his tune on the Dynapack.

It may be a little late on buying an ST2 car, as my car is mostly there already. All it needs is a cage and a fire system and it's ST2 ready. So I'm committed to this path with the Camaro. However first I need to get through a full season of TT2 time trials and see how I enjoy it, then decide whether to progress to wheel-to-wheel. It's going to be a year of learning, looking forward to it. I may also have my car tuned with a TT3/ST3 tune so I could run that class if it is better populated.

[SPCBA]

Not sure if i commented on this before or not... ST2 is competitive, populated, and fun. Tho i think the geometries and physics of the camaro give us an disadvantage. Really would suggest a vette.

ST2 requires you to be already licensed i thought.

[Orange Crush 1LE]

Originally Posted by SPCBA

Not sure if i commented on this before or not... ST2 is competitive, populated, and fun. Tho i think the geometries and physics of the camaro give us an disadvantage. Really would suggest a vette.

ST2 requires you to be already licensed i thought.

LOL, I think you're right. I do well against Vettes on HPDE days but it will be a challenge to win in the Camaro against more serious drivers/cars in ST2. The hope is that the 0.6 points that they give us for having a car over 3800 Lbs will help even the playing field and give me a chance against the lightweight Vettes.

I was just thinking about this, how I started out just having fun on track days. Then one thing led to another, and ended up with a built Camaro. If I were to do it over, I'd probably start with a Vette. I may end up switching to some other form of racing such as American Iron if I can figure out a class that makes sense for my Camaro.

I have a NASA time trial license now, and yes I would need a competition license for ST2. Other than that, I need to upgrade my roll bar to a roll cage and put in a fire suppression system, then the car is ready for ST2. My plan is to do a full season of TT2 time trials next season, have fun with it, and then decide if I want to do ST2 in 2016.

Yesterday I just put a deposit down on my new motor. Pretty excited about this. It will be an all-forged 416 with a Brian Tooley cam that has gentle lobes for the road course and will make ridiculous amounts of low end torque. I may be in the neighborhood of 520 to 540 Ft-Lbs of torque at the rear wheels!

It will be fun to see how competitive a big heavy Camaro will be. This is a fun journey.

[SPCBA]

To be honest i think about acquiring a miata to gut and throw a LS almost daily. Super miatas arent as slow as you think. The days i dont i think z06.

[Orange Crush 1LE]

Originally Posted by SPCBA

To be honest i think about acquiring a miata to gut and throw a LS almost daily. Super miatas arent as slow as you think. The days i dont i think z06.

That would be a beast! I think it's cool to do your own thing, whatever that is. Have you done NASA wheel to wheel?

[SPCBA]

The v8 miata competitions are pretty legit if you can get over the little car phobia. Easily the most affordable car i can think to road race.

w2w yes. NASA no. My background competitively is on a different surface.