No more need for dynos: MAF value vs HP

harkes · 11-05-2020, 07:56 PM

OK, so probably not the first time you hear this but recently I got into this again and checked my MAF values (g/s) vs measured HP.

g/s / 0.8 = crank HP

PerfExpert = 503 crank HP
VD says 440whp = 517 crank HP
MAF says 403 g/s = 504 crank HP

IMPORTANT NOTE: I only think this will be accurate running stock intake, but that is still somewhat easier/cheaper to replace than going to a dyno

ZM2 · 11-05-2020, 09:46 PM

Depends on the car. M2 MAF maxes out at 43.4lb/min.

harkes · 11-05-2020, 10:57 PM

Quote:

Originally Posted by ZM2

Depends on the car. M2 MAF maxes out at 43.4lb/min.

That sounds odd when the peasant model N55 does not - weird. Could also be that the MAF value is calculated and not measured

ZM2 · 11-05-2020, 10:59 PM

Quote:

Originally Posted by harkes

That sounds odd when the peasant model N55 does not - weird. Could also be that the MAF value is calculated and not measured

I don’t know about calculated vs actual, but I’ve always been jealous that you guys can read more than 43.4lb/min.

Now that’s a statement most people wouldn’t understand!

akgambino · 11-06-2020, 10:25 PM

What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low.

n55david · 11-07-2020, 02:40 AM

Quote:

Originally Posted by akgambino

What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low.

what intake do you have?

harkes · 11-07-2020, 07:40 AM

Quote:

Originally Posted by akgambino

What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low.

Share the log?

akgambino · 11-07-2020, 08:10 AM

Quote:

Originally Posted by Phantom10R

Quote:

Originally Posted by akgambino

What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low.

what intake do you have?

Stock with afe drop in

akgambino · 11-07-2020, 08:12 AM

Quote:

Originally Posted by harkes

Quote:

Originally Posted by akgambino

What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low.

Share the log?

https://www.bootmod3.net/log?id=5efe...729b7db9fa964d

Pray for Mojo · 11-07-2020, 10:27 AM

Quote:

Originally Posted by akgambino

https://www.bootmod3.net/log?id=5efe...729b7db9fa964d

You have a custom tune for low quality gas?

akgambino · 11-07-2020, 10:40 AM

Quote:

Originally Posted by Pray for Mojo

Quote:

Originally Posted by akgambino

https://www.bootmod3.net/log?id=5efe...729b7db9fa964d

You have a custom tune for low quality gas?

No, this is the ots stg2 91 map (v8.1) with a couple tweaks from halim specific to 6mt.

AmuroRay · 11-07-2020, 10:45 AM

MHD also has engine torque/clutch torque which can be used to calculate HP.

11-05-2020, 07:56 PM	#1
harkes Colonel 1089 Rep 2,376 Posts Drives: M135i, E39 M5, NSX and AE86 Join Date: Apr 2014 Location: Xiamen, China iTrader: (0)	No more need for dynos: MAF value vs HP OK, so probably not the first time you hear this but recently I got into this again and checked my MAF values (g/s) vs measured HP. g/s / 0.8 = crank HP PerfExpert = 503 crank HP VD says 440whp = 517 crank HP MAF says 403 g/s = 504 crank HP IMPORTANT NOTE: I only think this will be accurate running stock intake, but that is still somewhat easier/cheaper to replace than going to a dyno Attached Images __________________ M135i 8AT PWG, MHD, Pure Stage2, WMI via Torqbyte CM5-LT, Custom tuned by PureBoost (A Dane in China) Last edited by harkes; 11-05-2020 at 08:02 PM..
	Appreciate 1 FastF30521.00 Tweet Quote

11-05-2020, 09:46 PM	#2
ZM2 Brigadier General 2828 Rep 3,703 Posts Drives: 2017 LBB M2 Join Date: Mar 2017 Location: Baltimore iTrader: (1)	Depends on the car. M2 MAF maxes out at 43.4lb/min.
	Appreciate 1 harkes1088.50 Quote

11-06-2020, 10:25 PM	#5
akgambino Lieutenant 272 Rep 529 Posts Drives: 2013 F30 335xi M-Sport (PWG) Join Date: Mar 2017 Location: Saskatchewan iTrader: (0)	What is the equivalent logging channel in bootmod3? Default channel is MAF HFM (lb/min) and my car hits consistently around 34lb/min and doesn't climb like that log shows in the OP, so this would calculate out to like 320 crank hp according to OP logic, seems very low. __________________ 2013 F30 335i xDrive M-Sport 6MT (FBO/BM3 custom tune by HCP, 91 oct, 550i clutch, xDelete)
	Appreciate 0 Quote

11-07-2020, 10:45 AM	#12
AmuroRay Brigadier General 2315 Rep 4,174 Posts Drives: M235i Join Date: Aug 2019 Location: Florida iTrader: (0)	MHD also has engine torque/clutch torque which can be used to calculate HP.
	Appreciate 0 Quote