Question for the Engine Tuners

[sprintcup]

When you remove the AC, PAS etc how does this gain you more power? I understand it'll reduce the load the engine has to move, but does'nt this just mean this power is alowed to get to the wheels as you are reducing any losses, similar to fitting a lightened flywheel? so if it makes 170hp on the rollers with the above it'll still make the same with them removed?
Unless you have a remap or other mods.

Regards Russ........

 

[Fred@BTM]

ever tried running in a swimming pool?

 

[Tom@JMS]

It's the same measured effect as if you had the brakes on, it requires effort to rotate the various aux pumps etc, effort which is subtracted from the eventual output at the cars wheels.

 

[CuppyDean]

ever tried running in a swimming pool?

PMSL, nice reply Fred

 

[sprintcup]

ever tried running in a swimming pool?

LOL yes when I was younger, but do I produce any more power or is it just easier to do, I'm possibly looking at this wrong, but you still have the same rpm,air, fuel going in , so a lightened flywheel will produce more power? where does the extra 7 or 10 HP come from you see on some RR graphs?

Regards Russ........

 

[Tom@JMS]

'easier to do'

In theory nothing changes in terms of the engines potential output no matter how much aux looses you place on it. (although load does effect the engine in the real world.)

Look at it this way - the aux components 'consume' power, preventing it from reaching the wheels. Remove these parasitic looses and more of this effort reaches the wheels = more gogo on rolling road graphs.

 

[Fred@BTM]

my version is easier to understand, do a 100M sprint in a swimming pool, then do a 100M sprint on normal dry land, you have the same power, which is quickest?

 

[Daz.]

my version is easier to understand, do a 100M sprint in a swimming pool, then do a 100M sprint on normal dry land, you have the same power, which is quickest?

^^^ Like

 

[jack_kemp]

Example:

Engine 1: 170hp - 6hp lost in power steering pump - 6hp lost in aircon = 158hp
Engine 2: 170hp and without the losses above = 170hp

All of the auxiliaries require power to make them spin. This power is lost.

Pretty much the reason why few Clio's make stock power, losses through aux bits and drivetrain.

As you said yourself, the power the engine produces is the same (roughly) it's the power that is 'allowed to get to the wheels' that changes. Which is the figure that matters.

 

[daddycool]

i've recently changed my pas rack for a manual one, and back again. when driving with the manual rack, the car felt more instant and picked up quicker on acceleration due to the less work it has to do. i was going to post another scenario for you. so i will. you're in the gym, you pick up 10kg, then you put it down and pick up 20kg. it's the same arm doing the work, it just takes less effort to pick up 10kg. simples

 

[scotty2hotty81]

LOL yes when I was younger, but do I produce any more power or is it just easier to do, I'm possibly looking at this wrong, but you still have the same rpm,air, fuel going in , so a lightened flywheel will produce more power? where does the extra 7 or 10 HP come from you see on some RR graphs?

Regards Russ........

You could also say, fit exhaust/filter and bin the cat where does the extra power come from? You are looking at it wrong ;-) ever been told that running your air-con uses more fuel and effects your mpg?