HP loss through drive train?

[my2SSRS]

Wondering what the loss from crankshaft to rear wheels is, or close to it?, I've got ROTO-FAB CAI, BFE 1 7/8 long tube headers, 3" into SpinTech 6000 mufflers, 4.10s, and a JRE custom tune, dynod 404 hp, so just wondering what engine hp would be??

[litle88]

15-20% is what it is for M6's and a lil more for the A6's.

[SSDan]

Most use a rule of thumb of 15% drivetrain loss for the m6. So your estimated crank HP would be 404/.85 = 475

[daveagogo1]

About 14-15% M6 & 17-18% A6. 20% would not be the norm even on an A6.

[LeanPocket]

Higher altitude lowers your hp #'s aswell.

Had a arh long tubes.. Only.. M6 dyno 400 locally. Stock catback too.

[Paparazzi 1]

I concur with Dave.

I was one of the guys who put his car on the chasss dyno at the Sunshine State Rally 2 in Kissimmee, FL earlier this month. The dyno operator estimated a typical 14-15% loss through the manual and 18-20% loss thru the auto trannys on Gen5 Camaros. He tests all mfgrs. vehicles.

My bone stock 2SS/RS A6 w/factory (SAE) crank rating of 400hp/410lb.ft.(@5900/4700) pulled 3 times in 3rd-4th gear to 6200 RPM.

Maximum: 320 RWHP @ 5700 RPM 337 lb/ft @ 4500 RPM. All the numbers were SAE corrected for temp/RH/air pres.
Actual highest pull on this cool 62 * day was 329hp, uncorrected.

An 18- 20% loss as expected.

It appears to be a good, factory stock, baseline.

A TBC club member with a similar SS, but modified only with a cold air box and cat back Borlas pulled 370 RWHP.

Keep in mind that any other drivetrain mods, i.e. torque converters and heavier rear end components will affect the % loss. So adding some slicker grease really won't compensate for all that rotating mass !

My compliments to Dave and his crew for coordinating a wonderful 'All Camaro' weekend !

'The guy from New York' !

[VADER SS L99]

I wouldnt be surprised if our cars have more drivetrain loss than most. Like with the A6 it has to go through the big 6L8OE, 2 piece heavy driveshaft, IRS, and 20inch heavy wheels.

[LeanPocket]

for informational purposes? 15% is what i would expect.
Otherwise dont get hyped up on numbers.. a dyno is a tuning device, nothing more.

[biggerisbetter]

Originally Posted by LeanPocket

for informational purposes? 15% is what i would expect.
Otherwise dont get hyped up on numbers.. a dyno is a tuning device, nothing more.

[SSDan]

The fact of the matter is that all we can do is speculate and use the general wisdom and common believes out there about powertrain losses (15% for manual and 20% for auto) since the only way to know with hard facts is to pull the engine and put it on an engine dyno. Who is going to spend the money to do that? Not me!

So I go with the flow and say 15% for an m6. Which I think is actually generous.

Why do I say generous - Here are some hard numbers to digest from my personal experience. My car dynoed at 378 rwhp bone stock for the baseline prior to my cam/LT install. My final dyno number with a nice safe tune for the cam/LTs as 461 rwhp. So I gained 83 rwhp (same dyno, same operator, same weather conditions).

Thus my percent of gain was 461/378 = 1.22 which means a 22% increase. GM SAE certifies the LS3 in the Camaro at 426 hp at the flywheel. If I gained 22% at the wheels then did I gain 22% at the flywheel all other things being the same? Well I guess I did or at least common sense would say so. Thus my 22% more powerful engine now makes 520 Hp (426 X 1.22 = 520). Following this logic then my powertrain loss at 461 rwhp is 12.8% (520 - 461 = 59 and 59/461= .128 or stated as a percentage 12.8%).

If I use a 15% driveline loss then I would say my flywheel HP is 542 HP (461/ .85 = 542).

Bottom line does my engine make 520 HP or 540 HP? - I don't really know. So when I am asked I say 461 rwhp to those that know what rwhp is and to the rest of the general population I say I am not sure but somewhere around 540 hp. All I do know is that I have 22% more HP going into the ground and when I jam a few gears with it - I am all .