Had the car dynoed on a chassis dyno this weekend, needless to say I was quite disappointed. Only pulled 277hp and 307tq. The torque seems about right but the hp is ridiculous. My buddies 2000 Z-28 with more miles pulled a 304hp. I did notice an insane amount of richness right around 4800 rpms on both pulls. Any ideas whats goin on with this?

 

what brand of dyno?

Dynojet?
Mustang?

 

im gonna guess dynojet because otherwise his numbers are too high...if your car is running rich you are KILLING its power potential. i picked up 12 hp from my dyno tune just from adjusting the A/F ratio from 11.9:1 up to around 12.9-13:1.

EDIT: also, how high did you wind the car up on the dyno???

 

What size TC, what rear end and gears are you running in your 1983 Z-28 ?

 

it was a dynojet, my buddies 2000 Z-28 pulled 285HP on a mustang so obvious i'm a little confused by my numbers on the dynojet. I had him take it up to 6k RPM. I expected my numbers to be lower since he has the m6 and I have the a4 but not that much lower. I'm running stock TC (whatever the 4L60E comes with) and my stock 3.23s until I get my 4.10s.

 

What year motor and PCM did you get?

 

Assuming you have a 99 LS1 (from your cardomain page) I'd say your dyno numbers are right on. With a lid and choke-soundmaster exhaust my 2000 Z28 dynoed 291rwhp on a Dynojet. 304rwhp sounds a bit high for a 2000 Z28, not just because it was more than me at the time but seeing numbers other people are posting.

Someone else said it to, dyno-tuning is your friend. Not only can the right person, or yourself, adjust the air to fuel ratio and gain a lot (I gained 17rwhp horsies from a dyno tune) you can also make that 4L60 power shift. My auto now slams your head back when it goes from 1st-2nd


Edit: Sweet looking car!

 

Yup, everything is out of a 99. My friend did have a lid (that I gave him since the wrecked car i bought had it on there) and he did a resistor mod to the intake air temp which advances timing 2 degrees, but still my numbers sucked. I'll be going in for a big dyno session this spring, hopefully I can some of this cleared up.

 

Don't get hung up on the numbers. How does the vehicle run?

I have an 01 Z28 with 3.73's and Y3000 2.0STR, with a lid & catback.

293.5RWHP/348RWTQ

Vehicle runs like a scalded ape.

SteveC

 

The car runs good and I guess I shouldn't be hung up on the numbers. I did line up with my friend a few nights ago and despite my gears (my 3.23s to his 3.42s) and my huge traction issue I managed to keep with him almost all the way through second. Plus, I get 20MPG in town so I'm happy as hell.

 

Well then, that's all that matters. I see you have an A4, change the TC to a 3500 2.5 STR and keep the 3.23's. It will make your vehicle into a different animal.

SteveC

 

Found some old posts I had when mine was dynoed.

Mebbe some of this will help.

See : http://web.camaross.com/forums/showthread.php?t=156951


I still stand by the "how does it run" as opposed to "how much does it dyno" creedo, although 300+ RWHP sure makes for good bragging rights ...


Britt