Aircon on effect tuning?

[flybobbie]

Well having played around to day, don't think it makes much difference.
Mainly i think switching ignition on and letting what sounds like the valvetronic cycling has made it run better.

 

[Smartbear]

Well having played around to day, don't think it makes much difference.
Mainly i think switching ignition on and letting what sounds like the valvetronic cycling has made it run better.

I’m not sure the valvetronic system can cycle with the engine turned off as it relies on oil pressure to operate? :?
Rob

 

[Zed Baron]

I feel my cars have far more pep after I eat a can of beans. Even more if I add a couple of hard boiled eggs.

I guess you do a lot of roof down motoring then

 

[Marcoose]

I feel my cars have far more pep after I eat a can of beans. Even more if I add a couple of hard boiled eggs.

I guess you do a lot of roof down motoring then

No way! That would be a horrible waste of fuel. That's my ERS, mate.

I also have on good authority that a well-tuned E89 goes downhill far quicker than uphill.

 

[Anonymous]

Well having played around to day, don't think it makes much difference.
Mainly i think switching ignition on and letting what sounds like the valvetronic cycling has made it run better.

If you accept that the air con consumes about 10 bhp, then in a 200 bhp car that’s 5% variation..consensus from most tuners is that you will struggle to see that (outside of a dyno / highly structured test track ) unless it affects the shape of the torque / bhp curves…

 

[flybobbie]

Well having played around to day, don't think it makes much difference.
Mainly i think switching ignition on and letting what sounds like the valvetronic cycling has made it run better.

I’m not sure the valvetronic system can cycle with the engine turned off as it relies on oil pressure to operate? :?
Rob

Valvetronic motor changes the exhaust valve timing, bolted above exhaust on the N52 engine.
Someone on YT replaced their cars motor and did the 10 second ignition on to cycle it, i suppose so it can find the end stops.
I put ignition on can hear a motor winding in and out.
My car certainly received an instant tune up.

 

[abar121]

Doesn't the A/C compressor turn off when the car thinks it's wide open? Most cars do this as well as for heat management.

These days, your car would have to be pretty slow and gutless to notice it on part throttle.

Yonks ago I thought the A/C on my MX5 was faulty. I was crossing Germany at the time and without much traffic, was well above a ton. The car thought it was flat out (or close enough), so kept turning the A/C off. Glad I found out the reason, before submitting a warranty claim!

 

[Pondrew]

Doesn't the A/C compressor turn off when the car thinks it's wide open? Most cars do this as well as for heat management.

No they don't.

The car thought it was flat out (or close enough), so kept turning the A/C off.

No it didn't.
The a/c compressor is controlled by a) the a/c button and b) the pressures switches on the refrigerant lines. That is all.

 

[Smartbear]

Well having played around to day, don't think it makes much difference.
Mainly i think switching ignition on and letting what sounds like the valvetronic cycling has made it run better.

I’m not sure the valvetronic system can cycle with the engine turned off as it relies on oil pressure to operate? :?
Rob

Valvetronic motor changes the exhaust valve timing, bolted above exhaust on the N52 engine.
Someone on YT replaced their cars motor and did the 10 second ignition on to cycle it, i suppose so it can find the end stops.
I put ignition on can hear a motor winding in and out.
My car certainly received an instant tune up.

You’re right, I’m confusing valvetronic with vanos
Rob

 

[mcbutler]

If you've got the top down there's no need for aircon

The voice of sanity and climate protection, I salute you sir

 

[abar121]

Doesn't the A/C compressor turn off when the car thinks it's wide open? Most cars do this as well as for heat management.

No they don't.

The car thought it was flat out (or close enough), so kept turning the A/C off.

No it didn't.
The a/c compressor is controlled by a) the a/c button and b) the pressures switches on the refrigerant lines. That is all.

Here's some info on how the MX5 did indeed turn the AC on and off again, when wide open. Scroll down to post 6, where the A/C Compressor on / off signal is logged. Anyway, no bones to me either way

https://forum.miata.net/vb/showthread.php?t=512155

 

[Anonymous]

The IHKA unit ( heating and control unit ) fitted to the E89 can be commanded by the DME to switch the clutch on the compressor off for 10 seconds if full throttle is applied below 10 mph..

 

[abar121]

 

[Pondrew]

OK; I concede I may be wrong (again) . I know nothing about electronic wizardry, coding and the like.
I do, however, know a tiny bit about how car air conditioning works having earned a living from it (and other forms of the industry) for the past 36 years.

 

[Pondrew]

The IHKA unit ( heating and control unit ) fitted to the E89 can be commanded by the DME to switch the clutch on the compressor off for 10 seconds if full throttle is applied below 10 mph.

That makes no logical sense to my mechanical mind, apart from a stalling scenario. Please explain why

 

[Smartbear]

The IHKA unit ( heating and control unit ) fitted to the E89 can be commanded by the DME to switch the clutch on the compressor off for 10 seconds if full throttle is applied below 10 mph.

That makes no logical sense to my mechanical mind. Please explain why

Less mechanical drag for maximum engine performance i guess :?
Rob

 

[Pondrew]

Less mechanical drag for maximum engine performance i guess

OK. I can see the acceleration map, maybe, possibly

 

[Anonymous]

The IHKA unit ( heating and control unit ) fitted to the E89 can be commanded by the DME to switch the clutch on the compressor off for 10 seconds if full throttle is applied below 10 mph.

That makes no logical sense to my mechanical mind. Please explain why

I’m merely quoting from the hearing n cooling BMW technical training manual..

I assume the idea is like the alternator is to reduce ancillary loads to a minimum to add that extra few horse for acceleration and or reduce fuel burn on the acceleration part..

 

[Anonymous]

Less mechanical drag for maximum engine performance i guess

Under 10 mph?

You are correct you are dumb..

So ….

If it’s doing less than 10mph it’s stopped /slow

10 seconds buys you more than 0-60 to get you going…

Then you can chill..

 

[Pondrew]

You are correct you are dumb..

I thought about my response and changed it. Do you maybe want to do the same?