Headers and tune complete. Interested in your thoughts.
 

I have an '02 Z with right at 2000 miles on it.

Just had LG Street headers, their cats, and x-pipe installed.

The base line pull was 345+-. After the headers and tune, it made 373. The actual gain with the headers/tune is consistent with what I see - roughly 30+ RWHP.

As a general obervation, I was a little disapointed and was hoping to see 380+. But, when I consider the baseline was lower than many stock Zs, I wonder. Do I have an underperforming Z? Is the dyno not reading as high of numbers as some others (its a Dyno-Jet). A combination of both?

The shop is very reputable and very nice guys. I know they've tuned other cars and gotten good numbers. And as I said, I am pleased with the net gain, just not the final number.

I am just curious of your overall observations.

It might be that at 2k miles your engine it's not quite seasoned yet. A baseline of 345rwhp is still under the average for a 02.

These LS6 engines seem like they go faster the more miles you put on them, I don't know who tuned your Vette up but I would put some miles on it and then have it retuned by a different tuner.

It sounds like the car's baseline is a little low. I haven't seen anything lower than 350 rwhp posted on a stock 02-04. Your gains seem pretty good so I wouldn't question the tune and you mentioned the dyno has put out some high numbers in the past, so that rules that out. It's really not horrible, your about 5 rwhp lower than a lot of 02-04 Z's that made ~350 rwhp.

I am not sure the actual tuner is in question as they got a very nice gain with the headers.

It just seems like the overall set of numbers is lower than I expected, even the baseline and that has nothign to do with the tuner.

I agree with the gains comment. THey seemed to get out of the headers what one would expect. As I've said, the numbers just seem 5-10 less than I thought they might be, baseline to finished number.

I am probably making something out of nothing. I just got back from a drive and it feels very strong. I've had faster cars than this and this thing feels very good.

Strong numbers I wouldn't be dissapointed.

Take it to the track to see how well it actually does perform to get your real comparison.

The numbers are good. The improvement is excellent.

Enjoy the car

Don't get too hung up on numbers. You should be able to FEEL the 30 extra horses and that is all that really matters.

Do you have big aftermarket wheels? Did they check the plugs? That could be 5hp maybe. It also could be your car that day. I have had +/- 10rwhp on the same dyno only a week apart, on the same tune. Like others have said, dont get caught up to much on the numbers, but on how well it performs.

My 03 Z06 only dyno'd 345RWHP (it has a very rich a/f ratio). However even dynoing this low it went 12.05 @ 114.5 in the 1/4.

With Intake, Kooks Headers, and Dyno Tune my Z only put down 377.7rwhp, 368.1rwtq. I would be happy with those numbers!

The numbers look good to me. As stated above LS series engines get stronger as they break in. Congrats.

do you have a soundclip? I'd love to hear how it sounds:)

Mine dyno'd about 345 when it had 3K miles on it for the baseline. Andy from A&A explained to me that their dyno is set up very conservative and that was about right for a bone stock Z.

They get more power with more miles. How does it feel to you?

Thanks for all the replies! It seems like I had seen too many "355-360 stock" estimations.

The car feels very good and strong, no soft spots in the curve. It idles very good and I am pleased with the gains the tuner got.

It is good to hear mine isn't the only one in the 370s with headers.

I also appreciate the comment on +-10 HP on same dyno. I never had a real grasp on what the actual margin of error was on a chassis dyno. I also was relieved to hear a number of supporters of the notion they make more HP as they break in a bit.

Hi LT4-CE

Nice numbers! The LGs are a real kick in the pants, aren't they?

best regards -

mqqn

The only numbers that matter are at the track.....People get hung up on dyno #'s but every dyno is different..... Just my .02

LT 4 CE- If you go to a dyno day where other Z's are putting out 350, 360 or whatever and yours in at 340, then, yes, you should check it out, but if the folks from you shop told you that 340(ish) was the norm, then your good.:thumbs:

I dynoed on the dynojet at 348 hp w/21k miles on the clock. The dyno here in Smyrna measures most all Z's within the same range. Don't believe all you read on this forum..

While the car was strapped to the dyno, I installed the Honker intake. HP jumped 11 and torque went up 13. If I remember correctly, I am now at 359hp and 347 torque.