M6 on a dyno.

[rost12]

Took my M6 to a local dyno day with a variety of other bimmers. We did several pulls in 4th, 5th and 6th gears, M6's best result was 409 whp, which seems short of 500 hp at the crank even with 20% drivetrain loss (I thought SMG would be as efficient as a manual, guess it's closer to a slushbox)

Dyno was DynoJet, which seemed to give somewhat optimistic numbers for all other cars.

I don't have any aftermarket software on the car, so maybe (hopefully) it just didn't like being dyno'd It had all sorts of ABS, DSC faults while on the dyno, all cleared after 5 minutes of driving.

Here's the video: http://www.youtube.com/watch?v=PuZFHmyqcow, M6 is at 5:26 there, but the quality of the video makes it worth watching whole

[Red_M6]

that seems low for a dyo jet. When my car was stock it pulled a best of 440 cold and average of 435. With intake, filter removal and evo pulley i got an average of 450whp. My pulls were SAE corrected and on a DynoJet.

[Tiptronicsoldier]

Originally Posted by rost12

Took my M6 to a local dyno day with a variety of other bimmers. We did several pulls in 4th, 5th and 6th gears, M6's best result was 409 whp, which seems short of 500 hp at the crank even with 20% drivetrain loss (I thought SMG would be as efficient as a manual, guess it's closer to a slushbox)

I think in the video it said you had a cat-delete. The loss of back pressure w/o programming could have been the culprit. I'm going to leave my primary cats on if I can finally get a hold of one.

[cjm6]

I made 429rwhp SAE corrected stock minus charoal filters on a dynojet. Also I added my exhaust(cat delete, xpipe and mufflers) without any software and gained 10rwhp and 10rwtq so I dont think that would be the prob. I think its only when you add headers that you run into the backpressure prob.

[bonehead]

Originally Posted by Tiptronicsoldier

I'm going to leave my primary cats on if I can finally get a hold of one.

Think you mean 2ndary cats. Unless you get aftermarket headers or cut them off yourself, the primary cats are integrated into the OEM manifold.

Don't think backpressure should be an issue with just a cat delete. I gained about 40 rwhp on a dynojet with addition of headers and Evosport Stage II software. 409 on a dynodynamics, maybe, but a dynojet? Something's amiss....
And that HPF M3 is just nuts

[rost12]

No cat-delete here, just cat-back Dinan mufflers. Something is amiss

[Tiptronicsoldier]

Originally Posted by bonehead

Think you mean 2ndary cats. Unless you get aftermarket headers or cut them off yourself, the primary cats are integrated into the OEM manifold.

Don't think backpressure should be an issue with just a cat delete. I gained about 40 rwhp on a dynojet with addition of headers and Evosport Stage II software. 409 on a dynodynamics, maybe, but a dynojet? Something's amiss....
And that HPF M3 is just nuts

What's the purpose of the secondary cats? Do they O2 sensors behind them? I've never looked under an M6 so I'm not too familiar, but I have read on here that the primary cats are bolted on to the exhaust manifolds. Yeah usually back pressure corresponds with torque. That S2000 had no torque at all but alot of hp probably due to the high redline then the RX8's were a real disappointment. For the stg II software did you just mail in your ECU or did you have to take it in for tuning?

[bonehead]

Originally Posted by Tiptronicsoldier

What's the purpose of the secondary cats? Do they O2 sensors behind them?

Yes. Other than that, they probably serve no other purpose than to appease the tree huggers.

I've never looked under an M6 so I'm not too familiar, but I have read on here that the primary cats are bolted on to the exhaust manifolds.

I believe they're actually welded, not bolted

For the stg II software did you just mail in your ECU or did you have to take it in for tuning?

Since I'm 3000 miles away from Evosport, I had to remove it myself and send it in.

[///Marshall]

Originally Posted by rost12

No cat-delete here, just cat-back Dinan mufflers. Something is amiss

Any other M6s run on that same dyno? What were their numbers?
Comparing your numbers to other posted dynos never works. The
operators are different, perhaps the calibration is off. You need
to get someone else to dyno with you so at least you know where
you stand relative to another M6 or M5 on that same dyno.

[keang24]

Originally Posted by ///Marshall

... You need
to get someone else to dyno with you so at least you know where
you stand relative to another M6 or M5 on that same dyno.

+1.

[FikseGTS]

can you post the graph?