S50: lot's of powa when cold, less powa when warm

[static]

Hey

Got an S50 swapped with a bigarse K&N. Could it be that engine compartment warmes up and warm air makes it feel sluggish?
What else could it be?

I've seen most people's implementations and all of them have a cone/cylinder filter attached almost right to the AFM. There is close to no space there for any CAIs and alike.
Here is a pic of my bay (no filter yet, so just imagine it at the end of the AFM)



any ideas?

btw, i also got an 3.5 HFM and 24# + Turner chip now

Thanks
Alex

[DanGillan]

s50's generally run like that from what i've heard.

heatshield never hurts, but i dont know how much it will fix this problem.

[static]

^^ maybe you've heard that cause majority don't do CAI or heatshield due to very limited space?
Do M50s and S52s behave differently?

Alex

[Rev Engineer]

Are you running that thing without an air filter!? I'd at least put something over the intake.

Not sure why it would lose power at operating temp - it shouldn't. Maybe it's the hot air, but I don't think that would cause so much of a loss of power that you would notice it.

Maybe it's the wrong chip or configuration? The chip needs to match the 24# injectors and 3.5HFM. Maybe it's a bad coolant temp sensor?

[1990m3]

mine feels like a dog until its warmed out, then the beast comes out to play :) I also have a 3.5" HFm and 24lb injectors, I'm running the conforti chip, but until the o2 sensor goes to closed loop I can definitely feel a power loss

[f u z z]

Build a heatshield, even if thats not the problem.. you will have a heatshield.

[PeaveyBassist]

Something that keeps it in closed loop. i.e. ECT or o2 sensor. Probably o2 since it knows when the engine is cold (ECT).

Will

[Brew]

I was thinking 02 sensor too, but @ WOT the DME goes back into open loop.

[Ryan Stewart]

Mine does this odd bucking thing at 3k until its at least on the temp dial. It doesnt feel sluggish at temp though, its a problem.

[qimis]

That's weird, mine works the opposite and so does Adriano's S52. They work better on warm temp. and sluggish when the engine is cold.

[Rev Engineer]

Maybe they all run a little different. The s52 in my 98 m3 runs pulls strong warm and cold. In the winter it does feel a little faster, so maybe intake air temp matters. The only bad thing my s52 does is stumble upon the first clutch release in the morning - sometimes I stall it. After it's been running for about a minute this problem goes away.

[static]

I do run a big-arse K&N as i mentioned in the first post
i run 24# , hfm and conforti chip tuned for all that jazz
o2 sensor is recently changed

could it be air temp sensor? maybe something is whrong with it? i heard that DME pulls timing when the intake air is hotter (so it wouldn't detonate)
It just feels like there is more bang in the motor when car is cold, esspecially at 4+krpms.

Alex

[PeaveyBassist]

Could still be the ECT. If it thinks that the coolant is always cold, it will try to richen it up. Might wanna start testing things before replacing them though. If you had a scan tool, you could easily see what the computer sees and probably diagnose it better. i.e. a bad ECT

Will

[Brew]

It just feels like there is more bang in the motor when car is cold, esspecially at 4+krpms.

Alex

Eeek! Thats not very nice for your motor.

[aeryk7]

Yeah that just your intake ,hot air in your engine equals less horsepower . Cold air into your engine equals more horsepowe its just that easy .

Many times when people replace a stock airbox with a cone filter right on to a Air flow meter without a heatshield or air duct it will feel like they lost horsepower when the engine warms up because they are sucking much hotter air than they were before . When the car is first started the engine bay is still cool ,once at operating temp you are screwed and are forced to listen to your cone sucking air but with a nice horsepower loss.