dyno run conversion factor
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,313
Likes: 1
From: providence ut
dyno run conversion factor
dyno operater said the conversion factor from rear wheels to flywheel hp is 25% to 30%................this is TNT DYNO out of everton washington with a moble dyno, he was at a local car show ..............sounds good to me I had 299.6 rwhp on the blower and 384.2rwhp with a 100hp shot and he said my conversion would be closer to 30% that would be 389.48hp and 499.46hp at the flywheel were at 45,000 ft. up here in logan Utah but he said he corrected for that. sounds high to me, but he is the expert........also the 02 probe wouldn't fit all the way in my flowmasters and he said the a/f would not be accurate? comments?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: dyno run conversion factor (lead foot 85 vet)
I've had my Vette on a Dyno-Jet twice and the drive train loss calculates to 17% with my A4 tranny; a stick shift would be closer to 15%.
Just after several passes down the 1/4 mi I had the pulls made. I calculated CHP from trap speed and launch weight and compared with RWHP from the Dyno-Jet.
Dividing the Dyno-Jet RWHP by .83 gave the CHP calculated from trap speed and corrected for weather conditions.
Using the 83% figure your CHP numbers come out as:
-blower - 361chp
-blower * NOS - 463chp
How do these numbers compare with what you would expect?
Just after several passes down the 1/4 mi I had the pulls made. I calculated CHP from trap speed and launch weight and compared with RWHP from the Dyno-Jet.
Dividing the Dyno-Jet RWHP by .83 gave the CHP calculated from trap speed and corrected for weather conditions.
Using the 83% figure your CHP numbers come out as:
-blower - 361chp
-blower * NOS - 463chp
How do these numbers compare with what you would expect?
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
Re: dyno run conversion factor (lead foot 85 vet)
Those HP figures are too high. Listen to 65Z01. Dyno readings are supposed to be corrected to "standard", temp, humidity, and barometer. That would make these, "sea level" numbers. I don't mean to be critical of typos, because I make a lot of them too, but you are at more like 4500', 5500' maybe. Bring it down to RMR and let's see what it will really do. Let me know if you need any details on the track, or if I can help. Good luck, and...
RACE ON!!!
1984 Crossfire
Member NHRA
RACE ON!!!
1984 Crossfire
Member NHRA
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,313
Likes: 1
From: providence ut
Re: dyno run conversion factor (CFI-EFI)
dam that's high 45,000 ft...opps.......I meant 4,500 ft...what I exspected was 365 hp blown and 465 hp with a 100 hp shot and get this my peak torque was 481 at 4.000 rpm and peak hp was 384 hp at 4,600 rpm .........I've got the air coming in good now I have to work on getting it out.........its sad that a dynojet operator would be giving out bad information like that and that I can't trust his a/f ratio because of my flowmasters.
