Anybody have a stock dyno?
#1
Anybody have a stock dyno?
The only stock dyno Ive seen put out 169.7whp on a SC300 5spd which equals almost a 25% drivetrain loss. Therefore I wanted to check and see if it was just a worn out motor or something. Plus dont "guess" as to what the drivetrain loss is....I want facts, not "It should be around 18%".
#4
I saw a 95 5-spd do a 186-hp pull on a DynaPack.
It had BFI and exhaust (no resonators but with cats).
The hood was closed, and 2 fans were blowing into the air dam.
Cheers,
~Alan
EDIT: Should have read more carefully...you were looking for stock. Sorry.
It had BFI and exhaust (no resonators but with cats).
The hood was closed, and 2 fans were blowing into the air dam.
Cheers,
~Alan
EDIT: Should have read more carefully...you were looking for stock. Sorry.
#6
Thanks for the info guys....I guess RWD + heavy flywheel and wheels do add up to 20-25% drivetrain loss. Yes, I know that dynos range a good bit depending on conditions, type of dyno used, condition of motor etc. I just wanted a rough estimate....its also unlikely that a stock motor is putting out a perfect 225hp so its taken with a grain of salt.
#7
Originally Posted by 95 Integra
Thanks for the info guys....I guess RWD + heavy flywheel and wheels do add up to 20-25% drivetrain loss. Yes, I know that dynos range a good bit depending on conditions, type of dyno used, condition of motor etc. I just wanted a rough estimate....its also unlikely that a stock motor is putting out a perfect 225hp so its taken with a grain of salt.
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#8
Originally Posted by Idrewfelix
225 is BHP, so you will never have a car with the advertised hp figures on a wheel horsepower spec.
Shocking news flash. The commonly accepted drivetrain loss for a RWD car is somewhere around 18-20% and my entire point was that the SCs seems to be a bit higher then I would've expected.
#9
Originally Posted by MongooseGA
Aren't the 400s only putting down about 190? Sad.
In 1995 Lexus changed the specs on the 400 engines but gave the LS400 better exhaust manifolds than the SC400. Officially the power on the 400s only went up 10hp/10tq but performance indicates a much higher power gain. Dynos for the 95-97 LS400s are around 195-200rwhp. Since the SC400 was left with the single tube exhaust manifold I believe Lexus originally did not change the power rating on the 95s as the 250hp/260tq was now more or less accurate. They did change it in 96 to the LS rating of 260hp/270tq but based on the performance between these 2 models I would say the LS enjoyed a power advantage due to the dual tube exhaust manifolds.
Personally I believe the power loss on the Lexus automatic 4 liter V8s is about 22%. When Lexus increased the power again in 1998 the GS400 gained an accurate rating of 300hp/310tq and a typical GS400 dynos right around 235rwhp or 22% drivetrain loss. The LS and SC are rated 290hp/300tq but the SCs still have the bad manifolds. I believe the LS is accurately rated but the SC is down another 10hp/10tq or 280hp/290tq. This is born out in performance of these models whereas the SC enjoys a lighter weight but not better performance than the LS. Power to weight is the key. Of course with more power and lighter weight the GS400 USUALLY outperforms the LS400s of the same years.
#10
Originally Posted by Idrewfelix
you will never have a car with the advertised hp figures on a wheel horsepower spec.
http://www.ls1tech.com/forums/showth...ght=stock+dyno
Cheers,
~Alan
#11
SPORTcoupe: i think what he means is that no manufacturer will give wheel horsepower readings like you get on a chassis dyno when tuning but instead a BHP rating from the flywheel on an engine dyno. it makes sense why they wouldnt.... it gives more variablity to the equation since trans/diff/clutch all are locations for power loss and would make for a "range" hp rating. kinda like what they just did for gas mileage now accounting for freeway acceleration, fast start acceleration and normal driving instead of trying to suck every last mile out of a drop of gas.
#12
I've driven every generation of the sc300, and sc400, and there isn't that much difference in power until 1998. 1998+ sc400's are in a completely different league than the 300's are. so, unless you plan on getting a 98+, there isn't that much difference. The 400 has alot better sound though
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