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View Full Version : Dyno today - 91 Z


VetteMed
09-28-2009, 04:29 PM
Lucky me, there's a speed shop 4 miles from home, with a dyno!=D> And for the summer, they're offering 2 pulls for $40. So, now that my fuel pumps are behaving, I drove on over.

The guys running the dyno were fairly knowledgeable about the ZR-1 and LT5, which I was surprised about.

I stood behind the car during the runs, in order to experience the sound of the LT5 through the Corsas at 7000 rpm. I'm glad I did - it was music like I've never heard before, at least not on a car I've actually owned. I've got a video clip I'm uploading, I'll post when it's done.

Anyhow, I'll cut to the chase. 368 rwhp, 350 ft-lbs torque. The HP curve is nearly flat from 5700 rpm all the way to 7000. Conditions: Temp 93F, Humidity 33%.

As I suspected, my tach is WAYYY off, the dyno operator said that when the dyno computer indicated 4500 rpm, the tach on the dash was over 6K. At 7K actual, the tach was maxed out. Guess it's time to do something about that...

THere was quite a bit of black smoke blown out on the first run (also blew out the sniffer probe!). The second run looked "cleaner" but with nearly identical results (within 0.05 HP). A/F ratio was around 12.2 to 12.4 for most of the run, so there's probably some HP to be gained there.

Oh, my mods -- longtube headers (not sure which brand, PO installed em), no cats, and Corsa resonator/mufflers. Open airbox. Z-Industries PROM.

So, I'm happy with the HP, and happy that I got to hear my LT5 singing. Of course, now I want my top end ported... :razz:

Here's the video of the first run:
http://i680.photobucket.com/albums/vv163/agchoset/th_smallrun1.jpg (http://s680.photobucket.com/albums/vv163/agchoset/?action=view&current=smallrun1.flv)

-Andrew

Kb7tif
09-28-2009, 06:08 PM
Cool :cheers:
Good think that car is anchored down good.

secondchance
09-28-2009, 07:48 PM
Cool!
Marc Haibeck said there were about 20 horses with headers and cat back. So it all adds up.:cheers:

VetteMed
09-28-2009, 09:30 PM
Yeah, I guess it adds up based on the mods in place...
Dyno chart:
http://i680.photobucket.com/albums/vv163/agchoset/IMG_1644.jpg

Jim Nolan
09-29-2009, 01:59 PM
I also have a Corsa, SW headers, no cats and a ported top end and mine peaked 397 hp at 5500 rpm and fell off to 394 hp at 7000 rpm. Heads up porting will add another 30 hp and you will be able to tell the difference. I also added 3.91:1 gears.