Dyno Results Opinion
Thread Starter
Instructor
Joined: Jun 2004
Posts: 247
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From: Derry nh
Dyno Results Opinion
Had my '91 auto dyno'd last week...
242 HP @ 4400 RPM
323 ft/lb @ 3582 RPM
Numbers are weather-corrected (WCF). Actuals are 237 and 316.
The fellow that ran the dyno said the torqe number is quite good for a '91 L98. The car has a mild cam, chip, lo-flo exhaust.
When I got home I checked the factory specs for the car.
'91 specs are...
250 HP @ 4400 RPM
350 ft/lb @ 3200 RPM
If these specs are at the flywheel then I'm happy with the car's dyno performance, otherwise not so. Factory torque and RPM seem much better.
242 HP @ 4400 RPM
323 ft/lb @ 3582 RPM
Numbers are weather-corrected (WCF). Actuals are 237 and 316.
The fellow that ran the dyno said the torqe number is quite good for a '91 L98. The car has a mild cam, chip, lo-flo exhaust.
When I got home I checked the factory specs for the car.
'91 specs are...
250 HP @ 4400 RPM
350 ft/lb @ 3200 RPM
If these specs are at the flywheel then I'm happy with the car's dyno performance, otherwise not so. Factory torque and RPM seem much better.
6th Gear
Joined: Apr 2008
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Usually the factory specs are taken at the flywheel wereas when you dyno it is at the wheel. This means usually there is a percentage lost from the drive train back usually around 10-15% manual and 15-20 % auto is an accepted number.
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Dynos will measure wheel HP, not flywheel like the factory rating, unless they are using some correction term already to get back to flywheel, which I doubt.
So you are probably in the ~290 chp range, 40 over the factory, which sounds reasonable given what you've done.
So you are probably in the ~290 chp range, 40 over the factory, which sounds reasonable given what you've done.
Thread Starter
Instructor
Joined: Jun 2004
Posts: 247
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From: Derry nh
Thanks for the inputs. I did take the car to my first SCCA autocross a few weeks back and although it was one of the bulkier cars in the field, performed very well and I finished in the middle of my class. Not bad for my first time.
