Effect of AC on engine output?

[andygtt]

Adrian W said:

I'm sure that Sundance offered to pay to prove a point, but unless i am completely nuts, some posts have been deleted in this thread.

Im going with completely nuts

[wessexrfc]

andygtt said:

Well to find out what the power loss really is (and for absolutelly no other reason at all ) I have booked my car for a RR session next week... so Im taking donations to help with the cost

Any refrigeration/ac system will increase duty as pressure and tempreture rise, and so therefore the % of power taken will rise accordingly. Just to throw a theoretical spanner in the works, doing a RR with a/c on/off will tell you the power taken to drive the a/c at a specific temp, ie the cabin and outside temp. If you were to then move all the kit outside on a hot day, lets say 28 degrees with the car in direct sunlight etc, the duty on the compressor will be higher, pedantic I know, but if an experiment is worth doing.

[andygtt]

last time i was on the RR the dyno air temp reading was 30deg so pretty realistic for a UK hot summer day lol

[FUNKSTER UK]

Getting bored with this!

If it's hot I turn it on.
If it's not I don't.

[TuxMan]

FUNKSTER UK said:

Getting bored with this!

If it's hot I turn it on.
If it's not I don't.

[hoyin]

I don't give a monkeys about performance ... I prefer comfort and not looking like a sweaty pig when I step out from the car!

[andygtt]

TuxMan said:

FUNKSTER UK said:

Getting bored with this!

If it's hot I turn it on.
If it's not I don't.

you cant get bored yet i havn't had any donations

[wessexrfc]

TuxMan said:

FUNKSTER UK said:

Getting bored with this!

If it's hot I turn it on.
If it's not I don't.

Thats not the sprite, these thing need to be known, so you can calculate just how much fuel it is costing you to stay slightly less sweaty than you would be without, now where was I, that’s right, % of power X heat-soak, divide by temp....blar, blar , blarrrrrr (quite right)

[Adrian W]

wessexrfc said:

TuxMan said:

FUNKSTER UK said:

Getting bored with this!

If it's hot I turn it on.
If it's not I don't.

Thats not the sprite, these thing need to be known, so you can calculate just how much fuel it is costing you to stay slightly less sweaty than you would be without, now where was I, that’s right, % of power X heat-soak, divide by temp....blar, blar , blarrrrrr (quite right)

and the two kilowatt heaters sitting in the seats

[daddysumo]

hoyin said:

I don't give a monkeys about performance ... I prefer comfort and not looking like a sweaty pig when I step out from the car!

So you obviously did not have it switched on then, when driving the 'ring ???

[Vrsgang norfolk]

Been speaking to a few people about this someone was telling me when he dynoed his 1.8t golf he got 188 with the air con on with the air con deleted he got 210. I'm now curious to know how badly effected the pd130 is

[thebraketester]

The issue with some turbocharged cars is that the intercooler is sandwiched between the ac condenser and radiator. Once you turn on the ac the condenser gets hot and reduces the efficiency of the intercooler and air intake temps will rise. Higher intake temps mean reduced performance.

[Adrian W]

thebraketester said:

The issue with some turbocharged cars is that the intercooler is sandwiched between the ac condenser and radiator. Once you turn on the ac the condenser gets hot and reduces the efficiency of the intercooler and air intake temps will rise. Higher intake temps mean reduced performance.

You haven't seen a Noble...…………………………………..have you!





cor nine years between posts!

[thebraketester]

I was responding to the post above.

[paulcundy]

jamie g said:

If you talk in percentage terms it makes no sense. Running high or low turbo boost setting has no effect on the amount of power the ac pump uses. A definite power figure is more useful. I'm going with 4bhp

correct

[AMG Merc]

I see no noticeable loss of power, of a dip in revs, with the a/c on - only ever go up to position 2 though.