My car hit 600 rear wheel HP and 553 rear wheel torque on the dyno. What does that translate to HP/TQ at the engine roughly? 680? 700HP? Car is an 05 auto., ECS 1500, Alky Meth, 3.15 gears, stock 4L65-E and LS2.

 

15% loss on autos, so that figures out to be 706 HP and 651 TQ at the flywheel.

 

Thank you!

 

600 rwhp = 85% of flywheel power

so 600= .85 x FWP

600/.85 = 705.882 hp at the crank

without knowing what modes A vs. M lose in torque% I have no math for you

 

...and that is a lot of power for an LS2 by the way...any cam swap or heads "cleaned up?" obviously noting your centrifugally enhanced meth setup

 

M6 has about a 61Hp/torque loss, and the A4 has about a 75HP/Torque Drive line loss stock isntead (these are constant, unless you change something on the drive line to decrease of increase these numbers).

So engine HP is around 675, and the engine torque number around 628 instead.

Hence the 15% only works with stock HP since we know what the stock HP is to being with/what the RW readings are, and can come up with the percentages bases on the real numbers. Since nothing has changed in your drive line, and your just are increasing HP and torque, the stock percentage value of 15% no longer works, since this would increase the HP loss of the drive line, while is has not since nothing has changed from it being stock.

Hence stock LS-2 M6 will make 350/350 on dyno, A-6 will make 340/340 on dyno, and the motor actual HP/torque numbers are 411/411. With a tune alone on stock motor, you can bump the stock motor numbers up to around 426/426, but the 61/75 HP drive line loss numbers stay constant instead.

 

it's about right. Same basic stuff just with an LS3 instead I hit even higher numbers.

Power mods are only LT Headers and methanol with the same ECS blower. Stock CAM, no internal work done to add power (safety added dual titanium valve springs and rocker arms). Mustang dyno (which typically reads even lower than a dynojet) I hit even higher numbers


640 RWHP
588 RWTQ

640 / .85 = 753 HP
588 / .85 = 692 TQ

Now say I give myself 6% back on a Mustang dyno I probably on a Dynojet would hit 640 X 1.06 and 588 X 1.06 I'll be at...

678 RWHP / 623 RWTQ...play the .85 drivetrain loss gig and we're at...

800 HP and 732 TQ at the motor

...to go even further and take Dano's point of view....

640 + 61 ~ 700 HP
588 + 61 ~ 650 TQ

give me some HP/TQ back being a mustang dyno and go with 678/623 and I'm at ~ 740 HP / 685 TQ

Now I do have a Mantic Twin Disc which is altered from stock drivetrain so that even throws MORE VARIABLES into it.

BOTTOM LINE depending on day and conditions your dyno numbers can change...also from dyno to dyno they can. What I look at are what are the actual numbers the car pulls on a track. I also look at the power curve to get an idea where's the optimal shift points. I look for any abnormal dips indicating timing being pulled due to some other issue. It's more or less a tuning tool than a number spitter. Car keeps building with max power at just about redline...it's ridiculous pulling harder and harder with no letting up.

For my benchmark I use the track. Car hits almost 136 MPH in the 1/4mi. Top end is stupid...including having to shift from 3-4 the car goes from 105 to 135 MPH in 3.7 seconds. That's just about 10 MPH / second on the topend. Bring on the roller coaster of fun!

 

Stock engine, transmission, and rear end. Only additions are Kooks LT's, Kooks offorad x-pipe, Corsa Sport, ECS 1500, and Alky Meth.

 

Driveline losses are relatively fixed. That is they do not increase linearly with added HP over stock. While 15% is a good rule of thumb for a stock AT car, most horsepower you add makes it all the way to the rear wheels, as driveline losses have already been accounted for.