Aircon on effect tuning?

[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.

[flybobbie]

I think there is barely any load, at idle the rpm needle hardly budgies from normal tickover.
Cold air flowing out so pump clutch must have pulled in.
Only jumps a touch as you switch the air con off, probably as fan cuts out.
I'm quite sure in warmer climates folks would start a journey with the aircon on.

[mcbutler]

My point in a way, the higher fuel consumption brings the engine temperature up to it's optimum.
Normally my daily 7 mile drive to work never gets it up to ideal running temp., aircon on might speed that up, then switch off.

Let me get this right. You think that driving your 7 miles with the a/c on will help your engine? Seriously?
It will only put the engine under more load when it's cold and use more fuel.
There is a reason why BMW started fitting oil temp gauges instead of the normal water temp ones.

Thats odd, your post quotes me as making flybobbies statement!

[flybobbie]

Well can effect performance. If the aircon rad is in front of the engine rad. the engine rad will be warmed by air con rad.
By the time the engine thermostat opens to let cooler rad. water in it's already warmed up by the air con rad.
On a cool day with cabin heat on the engine might never reach it's optimum temp. on shortish journeys.
Shutting cabin heat off and running aircon might speed temp. rise up to optimum.

[Pbondar]

I think there is barely any load, at idle the rpm needle hardly budgies from normal tickover.
Cold air flowing out so pump clutch must have pulled in.
Only jumps a touch as you switch the air con off, probably as fan cuts out.
I'm quite sure in warmer climates folks would start a journey with the aircon on.

AFAIK the idle is controlled by the ECU..it maintains a constant rpm despite changing accessories loads..so a/c or alternator cycling shouldn’t affect idle speed

[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.

[Pbondar]

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