While its true that many variables are introduced on seperate dynos, i'm pretty convinced that the numbers are not too far fetched. On the same dyno day:

Stock Z got 237.
HFM got 255 with intake, exhaust, test pipes.
I got 257 with intake, exhaust, crank pulley

I'll go back to my original theory that the Z is limited at 260 w/ simple bolt-on breathing mods. Without cams & ecu you can swap out every component (intake, plenum, headers. cats, exhaust) and still be at ~260 and will just run lean. That's the cap. The stock ecu just won't compensate for anything over that and you'll need a custom job.

So my advice? Go the least expensive route to 260 ($1000-1200), and then consider cams and a custom ecu program together as a stage II to put you at about 280.

I highly recommend the borla + test pipes + pulley combo. Thats more than enough to put any Z at 260.

 

First off it was an exaggereation, and I was saying that the before and after should be on the same dyno not each car... that way you get at least a somwhat clear picture of how much is gained over stock...

-non

 

X * .85 = 255
X = 255/.85 = 300 hp at the crank!

No more having to say I have 287 horsepower! She's got 300 hp baby!

X = 257/.85 = 302 hp at the crank!

Ditto for you!

And, I agree with you man, this is definitely the way to go.