[Tethys]

Originally Posted by Dr Thrillride

Correct

Thanks, just wanted to make sure I understood. I'm still up in the air about tuning this car.

[Dr Thrillride]

Originally Posted by Tethys

Thanks, just wanted to make sure I understood. I'm still up in the air about tuning this car.

Well, we’ll see what stage 3 dyno says.

[AlexFL]

Originally Posted by mhbrownie

Those aren't at the wheel tho right? Those look like crank numbers.

I believe so too. Most likely some bs extrapolated bhp numbers, calculated with a fake 20% drivetrain loss.

[AlexFL]

Originally Posted by mhbrownie

Got my 2020 M8 Comp Coupe dyno tested (dyno jet) earlier this week. The car is stock with the exception of the carbahn Stage 2 hardware and Stage 3 DME flash (not piggyback):

https://carbahn.com/product/cbf9x-91...mpetition-pkg/

I had 92 octane pump gas in it.

HP: 647.63 at 6170 rpm
Lb: 667.85 at 3570 rpm

The guy running the tests has issues with updates to the dyno jet software so still waiting on better pics of other runs. I believe these were the two best though.

These are solid whp numbers for a dynojet dyno. It's basically ~720-730 hp at the crank.

[Justao]

Originally Posted by AlexFL

These are solid whp numbers for a dynojet dyno. It's basically ~720-730 hp at the crank.

Well, based on the online converter from whp to hp for all wheels it's 800+ hp at the crank

[AlexFL]

Originally Posted by Justao

Well, based on the online converter from whp to hp for all wheels it's 800+ hp at the crank

which online converter? calculating with more than 15% drivetrain loss is not serious.

[mhbrownie]

Originally Posted by AlexFL

which online converter? calculating with more than 15% drivetrain loss is not serious.

For what it's worth the dyno guy said closer to 20% is more accurate for 4wd.

[Vic55]

Originally Posted by AlexFL

which online converter? calculating with more than 15% drivetrain loss is not serious.

I think you are right although I dont know if there is a perfect science. The days of 20 percent tq converter DT loss appear to be gone. We have seen so many dynos of M cars where the WHP was translated to much more then OEM crank. Does that mean that BMW underrates? Maybe.

The ZF8 in my experience (had 5 M cars with it) has been very efficient. I think the draggys will be the best indicator of what was gained over stock.

[TheGreatM8]

So what exactly is the DYNO test measuring?
Wheels?
or
Crank?
Why does the human have to factor in any number which is debatable to the equation.

I don't understand. You go get the test and then add some mythical number to make the test sound better?

Not trying to be an ass here, just seriously asking.

[Vic55]

Originally Posted by TheGreatM8

So what exactly is the DYNO test measuring?
Wheels?
or
Crank?
Why does the human have to factor in any number which is debatable to the equation.

I don't understand. You go get the test and then add some mythical number to make the test sound better?

Not trying to be an ass here, just seriously asking.

Dyno is wheel testing but often in discussions since the before the birth of Christ, people like to see what the conversion is via supposition.

The OP is legit and just posted his dyno but the main reason people like to convert to crank is to compare to the OEM hp which is crank in nature when you buy the car.

I think its interesting banter for sure but like I said above, the rubber meeting the road is key on the gains.

[Dr Thrillride]

Originally Posted by Vic55

I think the draggys will be the best indicator of what was gained over stock.

I’ll try this draggy-thing (lol) with the winters and the heavy-as-fk M810s.

[AlexFL]

Originally Posted by Vic55

I think you are right although I dont know if there is a perfect science. The days of 20 percent tq converter DT loss appear to be gone. We have seen so many dynos of M cars where the WHP was translated to much more then OEM crank. Does that mean that BMW underrates? Maybe.

The ZF8 in my experience (had 5 M cars with it) has been very efficient. I think the draggys will be the best indicator of what was gained over stock.

very true, Vic. Dragy doesn't lie...

[VT3M33]

did you end up doing additional dynos now that you have accumilated miles ? any vbox runs ?