I know this is a LS430 forum but just for comparison I got my 99 LS400 dyno'd on a Mustang dyno which reads about 15-20% lower approx than a dynojet from what I read unless someone wants to correct me.

www.tamaquatech.com/t1m3r/dyno.jpg

I am pretty sure the 98-00 tranny wasn't as efficient.

 

Dynojets tend to put out a higher number. That is why many of the import tuners like Dynojets as the numbers look real good. My old 92 NSX that is rated for 270 HP put down 240HP on a Dynojet. Normal numbers are generally around 230HP for my car. That said, automatic trannies have become a lot more efficient than what it used to be, so I can believe 15% loss with today's current cars.

 

Yes, Mustang dynos do generally read a decent bit lower than the typical Dynojet, assuming the Mustang isn't programmed to give an 'abnormal' reading. From my experience with about 3 of them, they typically indicate ~10% lower. DynoDynamics dynos read even lower than that. There's alot of discussion over which is more 'accurate', how much real loss there is through a drivetrain, etc., and arguments can be made in support of various views. One of the best tests of real-world power is the quarter mile trap speed, IMO.

 

99hp with nitrous....lol

 

ohhhh....look who is clublexus....mah supra pepz!!!