[3.0L]

I've read here and there that the N55 is somewhat under rated. I ran across a link today that stated their dyno runs were showing 270 kw, or about 362 HP at the flywheel. That seems pretty high to me. Some other dyno tests I ran across claim up to 307 HP at the rear wheels, stock. Thoughts?

[allthatisntnow]

I think its more the torque output thats underrated rather than the hp. Ball park 300hp at the wheels seems to be the general finding with the 235i which would make 350ish at the flywheel seem correct. Dinan found it to produce around 379 lb-ft at the wheels as opposed to the claimed 333 lb-ft which is more impressive and usable.

Im currently on stock tune and some days (probably more weather dependant than anything) the car car really hook up and push you back in the seat, whereas other times it can feel rather underwhelming. Mine is bloated with a load of options so won't be the lightest possible config either. I think if the conditions are right the n55 output can be pretty mega even in stock guise. With regards to dyno numbers, maybe its like a VW, only it can sense its being power tested.

[2msport]

Originally Posted by allthatisntnow

I think its more the torque output thats underrated rather than the hp. Ball park 300hp at the wheels seems to be the general finding with the 235i which would make 350ish at the flywheel seem correct. Dinan found it to produce around 379 lb-ft at the wheels as opposed to the claimed 333 lb-ft which is more impressive and usable.

Im currently on stock tune and some days (probably more weather dependant than anything) the car car really hook up and push you back in the seat, whereas other times it can feel rather underwhelming. Mine is bloated with a load of options so won't be the lightest possible config either. I think if the conditions are right the n55 output can be pretty mega even in stock guise. With regards to dyno numbers, maybe its like a VW, only it can sense its being power tested.

The N55 does not ever put out 379ft-lbs at the wheels, in Stock form. Dinan usually measures crank outputs and displays them in a way people misinterpret them as wheel power. I see it on the forums every day. With 17% drive train loss that puts the wheel torque at 315ftlbs. Which is much more realistic.

Never heard about VW cheating on the dyno. If it's true that's really unfortunate but wouldn't surprise me one bit with their huge debacle. For them to think they can get away with emissions cheating in 2015....

[allthatisntnow]

Originally Posted by 2msport

The N55 does not ever put out 379ft-lbs at the wheels, in Stock form. Dinan usually measures crank outputs and displays them in a way people misinterpret them as wheel power. I see it on the forums every day. With 17% drive train loss that puts the wheel torque at 315ftlbs. Which is much more realistic.

Never heard about VW cheating on the dyno. If it's true that's really unfortunate but wouldn't surprise me one bit with their huge debacle. For them to think they can get away with emissions cheating in 2015....

Ah yes, thats the thing with Dinan. They are crank number folk; not wheel. 379 crank still isn't shabby stock.

The VW comment was intended to be tongue in cheek.

[Jeff@TopGearSolutions]

Yea dinan uses crank and depending on the octane and elevation this car may be under-rated from the factory by a few HP .

[Boosted_six]

bottom line

BMW quote the power on their turbo engines as a global worst case scenario.

Auto manufacturers have been successfully sued for delivering less power or fuel economy than advertised, but never the other way round.

For example, an M235i sold in South Africa being driven in 40 degree c heat, 3000ft above sea level with questionable quality fuel, still needs to make the book figure.

Take the same car to northern Europe, where its 10c, 300ft and you have premium / 99RON fuel, the car is going to make much more power than the minimum.

[XutvJet]

Stock M235s typically see 305-310whp and 320-330wtq on the Dynojet depending on tranny and minor variables. Those numbers correspond to around ~350hp and ~370tq at the flywheel. Yes, these cars are quite underrated.

[gunnersfan10]

Yea the factory numbers felt underrated the first time I put my foot to the floor. The torque this motor makes is incredible.