Hey Guys,

Just got some dynatech headers, x-pipe, and highflow cats installed on my '03 Z06. I also installed a Halltech Stinger. I had the car dynoed for a baseline before I installed/purchased anything to see where I was starting from. I was putting down 363rwhp/353rwtq. I then installed the Stinger and then had the headers, etc. professionally installed and then a tune at a shop that was different from the orginal dyno. The baseline run before the header install with the intake was 359rwhp. After the headers and tune, this dyno showed 379rwhp.

I know the manufacturers fudge their numbers to help sell their products, but I was thinking/hoping to be in the high 380s or low 390s. I friend had an '01 Z with the same mods in addition to an under drive pulley and his dyno showed 374rwhp (again, a different shop from either of mine). I know the pulley cannot account for much.

I was already 20hp ahead of him stock, does it make sense that I am only 5hp ahead after the mods? Is it that I do not get as much out of the air intake, etc. b/c mine is an '03 and the intake is already a bit larger stock, etc.

I am thinking about going back to the original dyno shop to see how it runs there so I can compare apples to apples. Even with some room for error, I was not expecting the baseline with the intake to be less than what I got before. And, yes, the original shop is very reputable, they just don't tune GM.

Any insight from the techies is appreciated.

Thanks!

 

All dynos are different, so you are saying, stock you were getting 363hp? Thats High Thats like 430 at the crank

 

 

That is what the dyno read and when compared to the list of stock HP #s on Z06vette, I was a little on the highside but not outside the box.

 

I was there when the car was dyno'd and tuned. Let's forget the original 363rwhp dyno and instead focus on the before/after of the headers/tune. Anyone see a problem with "only" picking up 20 rwhp with the install of the Dynatech headers AND a dyno tune? I picked up 15rwhp on my '01 Z06 with TPIS headers on the same dyno...and his setup is better with the hi-flow cats plus a tune.

 

Here's where I preach (and usually get flamed for saying) that the stock headers aren't THAT bad, esp if you aren't doing a cam or heads...

Add a small cam and have a little porting done and you'll see a huge increase and actually utilize the extra flow those headers are capable of.

edit: also, how does the curve look overall in comparison?? i've seen some ppl complain that the peak isn't up that much but they see huge gains everywhere else...which is where the real usable power is

 

 

379 RWHP is very healthy. I would be happy and forget about it