M42 Dyno, HA

[Rob]

Spent the afternoon yesterday at P1 Auto (www.p1auto.com) which is owned by an old ITR buddy of mine. Got a set of Falken Azenis mounted up, no review yet as they're still brand new, seem stiff though which is good.

After the tires were finish, the owner said "wanna play on the dyno?" So we strapped the beast down and made a few pulls. I'm not really suprised at the numbers the car is bone stock motorwise, and its not exactly a super performance engine, but I have fun with it, so whatever.

Here's the plot:


the air fuel was pretty good


And here's the interesting one. My plot and a lordofmpower's plot. I'm 100% stock, he has a intake/heatshield, JC chip, exhaust, dyno tuned SAFC, no PS, and no AC (I think)



Needless to say I won't be spending any money on this motor, its just not worth it. Maybe a flywheel and muffler, and that will be all on the old m42.

I also did an on-dyno 1/4 run, pulled a 16 something, but I think drag racing is gay so I'm not really concerned

[KenC]

I thought stock HP was 136. At least that's what the tech sheet in the 'tech section' says. Or is that crank HP?

[e9nine]

..interesting graph. Nice to see the comparisons for the mods done. The m42 is probably the most untouched motor out there for mods. Fancy mods for the Honda crowd don't do shiet to it. I'd still like to get one eventually. Put a good suspension on it and drive it lookin like this :twisted: as people look at me like this :shock:

[Rob]

dynos measure wheel horsepower. ~104whp is roughly 134ish crank, so the motor is healthy.

There is no real tech in this thread, therefore its in general.

[matt325is]

Nice numbers Rob, yeah, i wouldnt expect too much out of teh engine without F/I or something. Unless you bore it stroke it, and rev to 9k.

matt

[rwh11385]

nice to see what you are making at least. like a good physical, turn your head and cough. and can also see if anything actually helps the engine, or just a pointless mod.

I think Stu laid out M42 mods pretty well in his tech article. I think a muffler and flywheel would be good, as might as well get a JC chip, and heatshield perhaps for that added sound.

[Rob]

I did the intake and it did absolutely diddly squat, ass dyno or sound wise. The JC chip makes the motor run lean, necessitating more fuel, either through a controller (megasquirt, safc, smt6, whatever) or bigger injectors. The chip supposedly helps throttle response, but I cant confirm nor deny. There is basically no cheap power to be had out of this motor, which is unfortunate. But like I said, I was happy that my motor is healthy, piece of mind owns.

[OreoGaborio]

i can dig... gotta dig a healthy 12 year old engine :up:

[318daily]

Sweet ! I was actually wondering what a stock M42 does on the dyno.

I dynoed my 318 a while back and did 116 to the wheels and 115 ft. lbs of torque. That was with a chip, intake/heatshield, and tri flo exhaust. Maybe one of these days i'll work on scanning my dyno sheet and post it.

[Bill 84 318i]

Cool info, thanks Rob.

[Rob]

Sweet ! I was actually wondering what a stock M42 does on the dyno.

I dynoed my 318 a while back and did 116 to the wheels and 115 ft. lbs of torque. That was with a chip, intake/heatshield, and tri flo exhaust. Maybe one of these days i'll work on scanning my dyno sheet and post it.

What kind of dyno was that? I guarantee it was either a dynapack or dynojet. Mustang dyno's like the one I ran on (and what AA uses) typically read lower.

A few things I'd like to add is that dyno's are not a measure of performance, per se, they are a tuning tool. There are so many minute variables that alter the #s that comparing dyno figures is pretty much asinine. Another thing, for the most part, peak numbers are worthless, its the area under the curve that matters. For example, looking at Jay (lordofmpower) and I's peak numbers, he's at 110/102 while i'm at 104/98. This may sound like a decent difference, but when you look at the graphs, you'll see that we are pretty close even until the top 500rpm. therefore, making arguements based on the peak figures alone is not a very good way to do business

Phew---and i'm spent

[E30godz]

i thought mustang dyno's dynoed high?

[Bitburger]

Cool! I always wanted to know what the little m42 is putting out. Now there's documented proof as to why my cars so slow.

[Fred]

Interesting graph, I've never seen an M42 dynoed before. But my old eta engine still put out more power than that :D.

[bimmerphile]

dynos measure wheel horsepower. ~104whp is roughly 134ish crank, so the motor is healthy.

There is no real tech in this thread, therefore its in general.

Yeah you can figure about 17% drivetrain loss on a manual E30.

RWHP = Crank - (.17 x Crank)

Through algebra:

RWHP = Crank (1 - .17)

RWHP = .83 x Crank

Crank HP = RWHP / .83

Not insulting you rob, just a reference to others. :)