Hello, I have a C7 GS 7-speed I use almost exclusively for track/HPDE. I've already upgraded brakes to AP racing, Apex wheels, 200tw tires and have an aggressive track alignment. I'm looking to add more power reliably to the car while keeping it N/A, and drivable on the street. Also looking to solve an issue with the transmission tunnel getting very hot during track sessions. I don't need ultimate power, but rather more top end since I am finding myself using top of 3rd often on the track.

I spoke to a local engine tuner and this is what they recommended. We have a high local labor cost ($200/hr) and a high sales tax in WA state. My question is: does this look reasonable for what I'm trying to do?



I'm leaning towards pulling the trigger on this. Here's the dyno graph of the car currently:

 

I think you will be disappointed in the results for that much spend. The stock intake is plenty efficient already so you are spending $13k for headers and a canned tune. You will feel a little more top end but probably not more than 30hp. In the process you car will become very difficult to ever resell. If you want more power I suggest you put that money toward buying a C7 Z06.

 

To get the hp increase you're looking for you'll need a cam flat out- considering labor costs I would opt for cam kit over an intake + headers + tune. Plenty of dyno #s to back those mods w/ that caliber of power gains!

 

Who is the shop, Speedware? Seems like a waste of $13k. You get get a lot of AI tokens for that as well as many 3 dayer track weekends at T-Hill. Install a 4.11:1 rear end ratio and you'll be in 4th instead of top of 3rd.

 

Give Tony Mamo a call. How much rwhp did the shop quote this package would make? I also wouldn't get an intake manifold unless it's ported. Maybe consider the BTR Trinity manifold as well.

For reference, I have Frankenstein heads, BTR Stage 2 V2 cam, headers, Nick Williams TB and Mamo ported MSD intake ran me around $25k installed and I'm at 606rwhp.

 

Why ceramic coat AND heat shield everything? And do you not have carpet/insulation? Even without carpet and insulation in the tunnel, it gets hot but you know. Race car.

also don’t get a mishmoto Tstat. Stick to oem, all others fail. Always.

if you haven’t yet. Pull all the front and rear carpet, and trunk plastic and subwoofer and leave 1 race seat in, that’s 170 lbs removed. That’ll do more than a little hp.

 

I could skip the thermostat and the heat shielding, going with ceramic coating only.

 

Last line item in "#5 DYNO" is HPTuners Dyno tune.

Says 1@$200 but extends to $900.

What's that add'l $700 for?

While all this is well & good, you DO realize that cars that are subjected to regular HPDE use can be readily discovered by getting under the car? These cars can take a certain amount of beating...to a point.
Your focus seems to be on "more power." Let's not forget about "LESS MASS." A lighter car will change speed AND direction easier than a heavier car. And, it'll be easier on consumables, too.

 

That is a lot of money for 60 HP?? I know what you mean about being at the top of third gear near the end of a straight. Going to 4th gear is such a big change in gear ratio that you don't want to make the shift. My C5Z used to have that same problem going into the toe of the boot at the Glen. Shift to 4th without gaining much in acceleration, and then a few seconds later, shift back to 3rd in the braking zone for the turn, where each shift is a chance for an error. Or, just hold in third on the rev limiter until you get to the braking zone. You really don't need HP you need a few extra hundred rpm. I know people who have bumped their rev limiter on their LS5s but a few hundred rpm could also shorten engine life, although most LS6s seemed to be happy running to 7000 on the stock components. I solved my problem by going to a C6Z with better transmission gearing and 100 more horsepower, and with an engine capable of easily pulling to 7,000 rpm.

How much distance are you running at the top of third gear? Have you tried the shift to 4th to see how long you can stay in the higher gear? The tracks I have been on in the US are mostly 3rd and 4th-gear tracks. Depending on track distance and layout, adding 60 HP may not do much to lower lap times. As mentioned above, reducing weight may be a better and lower-cost improvement.

Bill

 

Might be cheaper to send to GPI or Pray Performance including shipping.