who here believes this
 

a good friend of mine didnt put AC in his iroc because he believes it 'reduces power'...is this fact or fiction?

ya thats true. plus its added weight. its more of a load on the engine, esp. with the a/c on.

how much of a horsepower loss are we talking here though, guesstimate

no idea but with the a/c on, i can seriously feel the difference in power. with it off, its tenths of seconds off your et.

On fourth gens its only a coupel hp.... but a big amount of weight and clutter.

and gas mileage.

Don't just take our word for it, I'll break it down.

The engine's internal combustion cycle makes power and moves the crankshaft

Any pulley-driven accesory is spun by this movement of the crankshaft

It takes energy to spin these other pulleys

Therefore, when you take away the resistance/drag of, say, the a/c pulley, you free up that much energy that the crank was using to turn it

Your A/C unit should have a magnetic clutch that allows it to free-wheel when it's not in use. So it may be 1-2 hp loss (I guess?).

Wooooo..that's cat like HP savings!

Race car - kill the AC - it's more about the ~50 pounds (if you get it all out) then the parasitic loss

Street car - save it if you can - and it helps resale.

JMO.

thats understandable...but it sucks because "my friend" is the dude that actually that car and that's the one that i bought. So its more of a "weekend warrior", so its half for driveability and have for racing. But i can live without ac, the only thing is my girlfriend hates it when her pretty hair gets all frizzy in the summer :-x

I hate using the a/c. ttops and windows is the way to go.....cept when ur sitting in traffic. waiting for some free time to rip mine out.

Only reason mine is out is because the core leaked and I was unable to re-charge it without it costing an arm & a leg. T-Tops rule anyway.

Two words, **** that.
;[

Seriously, have been down that road and done that with the 89. "ohhh saves horse power" "ohhh less weight". Well yeah.. All true facts..weight being the better of the two sattements.

Will you notice the difference in power with the ac ON? Yes. Will you notice the difference in power with the ac OFF and the pulley freewheeling? NO. I know you dont, since I went that route with my 89.

Also if you have a later model 3rd gen, or a 4th gen that has one belt you have two options for deleting the AC..buying a delete pulley OR trying to find a new belt routing to bypass the AC. Using stock accessories that may or may not be possible. If you go the delete pulley route it is the same as having AC and just not turning it on. Again the only true savings would be the weight

In the end IMO having no AC on a car that is anything but a all out race car is pointless. If it works, keep it. If you want to have it and it doesnt work,f ix it. T-tops ROCK, I wont lie. Windows down are fun too, its one thing i miss from my third gen, as the 93 is a hardtop. BUT..I dont care who you are..when your driving along on a 120 degree day with the tops off and windows down its ok to say the least..however once you stop..sayyyyyyyy sitting on the parkway in shore traffic..it SUCKS.

However if you still want to take out your AC for watever reason..(and remember..chicks dont likeeee ittttttt) do yourself a favor..pull it ALL out and bring it to the scrap yard, the price of alum is high enough right now that with the condens/evap/lines and the insides of the compressor if your crazy like me are all alum. Might get ya a few bucks. I use the guy on midland ave in garfield just as a suggestion.

+1 AC good for resale, too. If you don't remove it all then the 'savings' is nill. It's purely a weight thing. The EFI cars even shut off the AC at 80% TP (or something like that)

And old cars have big heavy brass condensors...the one out of my 77 must weigh 3x more then a 4th gen one. the little R4 compressor is probably the heaviest thing in the 4the gen AC system.

At highway speeds I think the A/C is more efficient than windows or t-tops on account of the drag that the open windows produce. Something to think about.

ive heard about that too...does anyone know if ac restricts gas mileage? i drove from my house to mountain creek yesterday with the windows up and ac blasting and i got terrible gas mileage

It is commonly accepted theory that at highway speeds AC on/windows up is more efficient than windows down/no AC due to aerodynamic drag. Of course windows up/AC off is the best bet!

Still though, the #1 roadblock to good MPG is the skinny pedal on the right.

I've heard that the best thing to go by is AC at 35-40+ and windows down at anything below that
but don't hold me to it

Didn't they do a test on mythbusters on this subject a while back?

Yes and they proved that the car with no AC and windows down got better gas mileage, by far. I suppose you could also take into factor that various cars/trucks may get different results. Another vote from me on keeping the A/C if it works... I pulled mine out because it didnt work right and I was frequently messing with the motor and it always got in the way.

I did a similar experiment last week with my power steering. Surely the pump robs HP, right? I bypassed it and the car ran exactly the same ET.

From what I've read, the pump doesn't have much of a load on it when you aren't turning the wheels, so for drag racing the parasitic loss is the pretty much nothing. But a manual box is lighter than the power setup ;)

- Justin

my SS will always have AC. currently it isnt charged and theres no belt for it. One of the idler pullies got wasted whn my balancer came off and i havent gotten around to replace it yet. but evetually i will and then put the belt on and recharge the system and enjoy ice cold air while violating other cars on the road

and I think manual steering in a race car gives you a much better feel of the track, and a slightly better chance of you not over correcting if the car gets a little loose.

I pretty much always use the a/c in my truck. I can feel a difference in power, but oh well. It restricts gas mileage as well. I think its worth it to be cool in the summer and not sweating. My r-12 system is very cold which I like. I almost removed a/c, but i realized it was worth maybe 1-2 mpg for not using it so its not worth the effort

hmmm my question is.... is keeping it on reg AC or MAX AC better for gas milage?