Stock RWHP questions.

[jb92z]

Just had my 92 Z dynoed today. They used Dynojet dyno and measured RWHP of 313 at about 5600 RPM. They did the test in 4th gear. Do these figures seem correct. I know there is about 15% loss from the rated engine HP, but I have heard that the test should go to 7000 RPMs. The person showed me on the printout that the HP maxed out at about 5600 and he shut down at about 6500. Just curious because for now I am happy with the results (winter hasn't set in giving me time to tear it apart).

Thanks,

 

[jhong321]

i dynoed at 335 stock peak hp was at 6300 rpm i had 3 pulls the first 2 where around 325 rwhp. they reved it up to 7000rpm in 4th gear
you might also want to check www.corvetteforum.com there are alot of people that own zr1's

 

[Wegone]

My 91 did 324rwhp stock with around 20K miles..

 

[jb92z]

i dynoed at 335 stock peak hp was at 6300 rpm i had 3 pulls the first 2 where around 325 rwhp. they reved it up to 7000rpm in 4th gear
you might also want to check www.corvetteforum.com there are alot of people that own zr1's

What changed between the first 2 pulls and the last to account for the 10 HP increase.

 

[jb92z]

My 91 did 324rwhp stock with around 20K miles..

Do you know the RPM that you reached peak HP.

 

[jhong321]

What changed between the first 2 pulls and the last to account for the 10 HP increase.

The first pull there was some carbon build up (a pretty big puff of black smoke)

second pull still a little smoke.

third pull all gone

 

[Edmond]

I don't think that's too bad; you're putting down 313 and 85% of 375 would be 318-319.

 

[Wegone]

Do you know the RPM that you reached peak HP.

Around 5800rpms and it stayed until shutdown at about 6800rpms..The power curve on an LT5 is very flat..

 

[jb92z]

Thanks

 

[White 68]

Here my dyno sheet 91 331rwhp http://temp.corvetteforum.net/c3/sog871//trevors_birthday_pics_050.jpg

If your car sits alot you should run it pretty hard before the dyno and also put some fresh gas into it as it degrades fast when stored for awhile as most of these cars are...
A stock 93 dynoed after me and put 337 to wheels

Now I know 8388 has a freak stock motor so he don,t count ;;;ha ah

 

[8388]

Having a freak is good

 

[bans25]

My stock 90' w/35K miles put down 332HP last year.

 

[Hib Halverson]

Just had my 92 Z dynoed today. They used Dynojet dyno and measured RWHP of 313 at about 5600 RPM. They did the test in 4th gear. Do these figures seem correct. I know there is about 15% loss from the rated engine HP, but I have heard that the test should go to 7000 RPMs. The person showed me on the printout that the HP maxed out at about 5600 and he shut down at about 6500. Just curious because for now I am happy with the results (winter hasn't set in giving me time to tear it apart).

Thanks,

With C4 manuals, the parasitic loss through the powertrain averages 18%, so at 313 at the wheels, your right there where you should be.

As for the 5600 rpm power peak, that's actually a bit low. 90-92 was rated at 375hp@6000 rpm.