[satz]

Hi all

my unmodded 335i auto E90 seems to lose more power than I remember last summer when I switch on AC.

The car just loses its 'edge' as soon as I switch on AC. Doesn't spin the tyres, more laggy from standing start.

AC itself seems to run normally. No strange noises from engine bay. Wasn't using the AC all winter, so perhaps I've forgotten the power loss?

Same petrol. The only change was that recently had the plugs changed as part of service.

Any ideas?

cheers

[MJ80.]

Honestly i have days in mine where i think "fucking hell its slow today" and other times ill gass it and it will scare the shit out of me.

[tawfeeqh]

n54lyf lol

[titium]

Originally Posted by MJ80.

Honestly i have days in mine where i think "fucking hell its slow today" and other times ill gass it and it will scare the shit out of me.

I've never had that mine feels the exact same every time i drive it.

i barely even notice the difference with the ac on.

[DR-JEKL]

Originally Posted by satz

Hi all

my unmodded 335i auto E90 seems to lose more power than I remember last summer when I switch on AC.

The car just loses its 'edge' as soon as I switch on AC. Doesn't spin the tyres, more laggy from standing start.

AC itself seems to run normally. No strange noises from engine bay. Wasn't using the AC all winter, so perhaps I've forgotten the power loss?

Same petrol. The only change was that recently had the plugs changed as part of service.

Any ideas?

cheers

do some logs

[Boganian Rubes]

Get a shorter serpentine belt and do an AC delete

[satz]

MJ80- glad I'm not the only one that feels the car is different every drive.

I do the 'adaptive reset' pretty often. Not sure if it works, but makes me feel better

Could something have been done wrong in the recent service?

[Socket]

I run AC all the time... should I turn it off to get another 50kw??

[Boganian Rubes]

Originally Posted by Socket

I run AC all the time... should I turn it off to get another 50kw??

Lol unrealistic numbers much

It's around 47

[Socket]

Originally Posted by satz

Hi all

my unmodded 335i auto E90 seems to lose more power than I remember last summer when I switch on AC.

The car just loses its 'edge' as soon as I switch on AC. Doesn't spin the tyres, more laggy from standing start.

AC itself seems to run normally. No strange noises from engine bay. Wasn't using the AC all winter, so perhaps I've forgotten the power loss?

Same petrol. The only change was that recently had the plugs changed as part of service.

Any ideas?

cheers

it is impossible to accurately gauge output or performance by perception especially over a time period as long as a year

DrJ is right you need to do logs and get the data to see if your car is operating at peak condition or is losing pep over time

Doesn't really help you at the moment, but if you really feel the car is sluggish, do the usual maintenance like a walnut blast, coils and oil change (plugs are new so no need for those)

If it is really slug like then maybe there is a boost leak, check the rubber vac lines to see if any are split or have disconnected, check the diverter valves for leaks (or get the mechanic to check for leaks) the charge pipe hose might have come off the intercooler (passenger side front corner) etc etc

maybe what you need is a tune, JB4 and MDH flash is totally safe and will give you a good lift in performance... lots of peeps are concerned about putting on a flash tune (i was one of them once) The only danger is getting the mod bug and ending up like me

[Testercles]

Also a possibility for what you're noticing: Our cars are slower on hot days as the air isn't as dense so there may be a correlation between days you choose to crank the AC and external temperature.

[Socket]

Originally Posted by Boganian Rubes

Lol unrealistic numbers much

It's around 47

hahaha is disagree Rubes 48

[Avex]

Originally Posted by MJ80.

Honestly i have days in mine where i think "fucking hell its slow today" and other times ill gass it and it will scare the shit out of me.

This. Even on a n52, after a good warmup, boy does the car fly. I climb to 90kmh so quickly sometimes i tend to end up speeding on 70kmh streets without realising it until I see all the cars in my rearview mirror. That and the car generally feels smoother and the cabin feel from 60-110kmh feels no different.

This becomes especially so after a particularly long ride 100km+.

[titium]

Originally Posted by Testercles

Also a possibility for what you're noticing: Our cars are slower on hot days as the air isn't as dense so there may be a correlation between days you choose to crank the AC and external temperature.

this difference is marginal. the ecu targets a set load to determine boost. (stock tune or mhd V7 and up)

hotter days the ecu will target more boost to make up for the lower density air. the only time you'd notice a performance difference is at high altitudes.

[Testercles]

Originally Posted by titium

this difference is marginal. the ecu targets a set load to determine boost. (stock tune or mhd V7 and up)

hotter days the ecu will target more boost to make up for the lower density air. the only time you'd notice a performance difference is at high altitudes.

Good info, I didn't know that. Makes sense that they'd allow for it.

[Socket]

Originally Posted by titium

this difference is marginal. the ecu targets a set load to determine boost. (stock tune or mhd V7 and up)

hotter days the ecu will target more boost to make up for the lower density air. the only time you'd notice a performance difference is at high altitudes.

What? like in a hot air balloon ?

[DOCTOR.Y]

um...this is common in E90 320i as I have experienced, in 325 its not noticeable, in 335 AC can hardly affect the power.

[CashedUpBogan]

Originally Posted by Avex

This. Even on a n52, after a good warmup, boy does the car fly. I climb to 90kmh so quickly sometimes i tend to end up speeding on 70kmh streets without realising it until I see all the cars in my rearview mirror. That and the car generally feels smoother and the cabin feel from 60-110kmh feels no different.

This becomes especially so after a particularly long ride 100km+.

must be accelerating at a blistering rate to leave cars driving normally in your mirror :

[7smurfs]

Don't know if it's in my head or not but my car feels faster after my car has been driven any distance and then shut off and turned back on.

Could be because on cold start I baby it aka <3k revs and then let it loose once at 90 degrees.

Also, getting a FMIC gave the car more consistent results.