CRUISIN

I had my engine dynoed, and it peaked at 500 hp on an engine dyno.
After installing the engine and running the car on a roller dyno I only got 330 hp at the wheels.

I was hoping for close to 380 - 400 hp ATW's.

What kind of power loss should I expect from flywheel to rear wheels?
The car runs a toploader and 9 inch 3.5:1.

RaceCraft

35% seems extreme... 25%-30% is usually accepted .. so 350-375 hp would of been more my expectations

Nod

With a manual I wouldnt expect much more than 20% loss. It could be tyre spin or a slipping clutch as thats a lot of power. See if you can find a Dynapak chassis dyno as these dynos run off the hubs eliminating the losses from tyre spin.

CRUISIN

Its a dissapointing result, i might try another roller dyno for a comparison.

Hub dyno would be good but they give higher figures then most roller dynos.

Ive lost 100 hp somewhere.

XD408

that doesnt seem right manuals dont absorb that much power normally in the range of 70-80 HP so either the engine dyno was wrong or the chasis dyno was?? what setup have u got ie.. heads manifold carby etc..?

CRUISIN

351 4 bolt main block
4MAB Crank crossdrilled
Zail Sump
Ross fully floating forged Pistons
302 Rods
Crane Roller Cam
Intake duration 266, Exhaust duration 268.5
Intake Lift .66807, Exhaust lift .66473
Milodon Gear Drive
Steel F/Wheel - Romac Balancer
Speed Pro 3 piece stainless valves
4 V closed chamber heads
Torker 4 V inlet manifold
Comp cams stainless roller rockers
Melings high volume oil pump
Twin points dizzy
830 annular Holley
10:58.1 Comp ratio

Would have thought 500 hp is not unrealistic with this lot.
I am running points now and no spacer plate under the carb. No other changes have been made since engine dyno run.

RaceCraft

For piece of mind, i would get it redone and STRAPPED down mega tight... You might of caught the dyno operater off guard and he didnt expect such a high output....Wheel spin on the dyno could be the root of all your dramas.. Dont be so hasty to chase your tail with the car

frdpwr

im not baggin anyone or where it was dynoed or who built it
but maybe it didnt really make 500 at the engine dyno, maybe the figures were tweaked a litile

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XE ESP 416w Injected 342rwk

xd351ute

What type of exhaust system do you run? You may have lost some power there. Engine Dyno would have been done with Extractors only.

brenx

I agree with this. The exhaust may be killing it alongside drivetrain loss. I've gone more hp to get the expected hp that you want with an auto.

Brenden

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XB Fairmont (street car) 11.07@123.02mph.