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Old 05-31-2003, 03:00 PM   #1
marioej18
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Default no A/C=more power?

some people have told me that if you take the belt off of the a/c that you will feel an increase in power. is this true? i doubt that it does anything, but im just curious.
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Old 05-31-2003, 03:56 PM   #2
DDMan
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For the most part...no

While the A/C is running, it takes no more than 5HP or so form your engine...and thats WHILE the A/C is on. If its not running, the belt is just going around on bearings...taking like .001 HP away.

Just keep the A/C off and you wont lose any power.
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Old 05-31-2003, 04:35 PM   #3
ciper
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The only thing you will get from disconnecting the AC is a damaged AC system when you finally reconnect it.
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Old 05-31-2003, 05:00 PM   #4
TheDonPerignon
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of course if you take out your entire A/C youll lose some weight though. make that power you already have more useful
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Old 05-31-2003, 05:20 PM   #5
Cujo31
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/unsolicited further advice.....


taking the belt off alone is pointless because if you look at the pulley, while the AC is off, the belt is just spinning freely on the hub of the AC pulley... its already almost like having the belt off anyway....

then when you actually push the AC button, a little clutch engages and the whole pulley spins and pumps the system.
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Old 05-31-2003, 11:56 PM   #6
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Quote:
Originally posted by TheDonPerignon
of course if you take out your entire A/C youll lose some weight though. make that power you already have more useful
except that will net you about 15 lbs in weight savings, not worth it for comfort IMHO.

jeremy
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Old 06-01-2003, 11:27 PM   #7
TheDonPerignon
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very true...all depends on what you want
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Old 06-02-2003, 05:58 PM   #8
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Look. It won't give you a lot of hp as what a lot of people are expecting it would and it won't allow you to use your AC/Defrost, but it will give you a bit better revving. If you look at it, you'd guess the pulley for the AC probably weighs 1-2 lbs (just the free turning side of the pulley), the supporting pulley is like .5-1 lb, and the belt is about .1 lb. I'd say it takes off around 2 lbs of rotating mass. It's worth a bit of free hp.

I have my AC belt off for almost 2 months now, and I am happy with it. I don't need AC or defrost right now... so I'm saying this 15 min. modification was worth the little power. When it gets hot, I won't mind spending another 15 min putting the AC belt back on. (It'll probably take about 30 min-1hr if you havn't taken off the belts before).

Take this as my 2 cents for you.
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Old 06-02-2003, 08:21 PM   #9
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Quote:
Originally posted by DDMan
For the most part...no

While the A/C is running, it takes no more than 5HP or so form your engine...

Man, you haven't driven my car. I swear it feels like I loose about 50% of my power when I have the AC blasting.
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Old 06-03-2003, 12:56 PM   #10
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Quote:
Originally posted by DoinkMobb



Man, you haven't driven my car. I swear it feels like I loose about 50% of my power when I have the AC blasting.
ueah... 50% for us = 5 hp
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Old 06-03-2003, 06:42 PM   #11
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Quote:
Originally posted by DoinkMobb



Man, you haven't driven my car. I swear it feels like I loose about 50% of my power when I have the AC blasting.
--------------------------------------------------------------------------------
its true! when i blast my a/c, it kills the car.... like instead of hitting the brakes, i could just leave it in gear and turn on the a/c to slow me down.... its really that bad! oh well, i guess you cant make a 1.8L any faster, time for a new car......
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Old 06-03-2003, 07:10 PM   #12
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kickin_81: You dont understand, the AC system needs to circulate once every once in a while to keep it in good shape. Removing the belt is only causing parts to be damaged. Why do you think some vehicles who have the AC basically permanently on still function many years later but the ones who sparingly used it have problems?

I would argue that the gains from removing the belt are so small you could NOT measure them, meaning I doubt you would ever feel them. The better alternative for all out speed would be to completely remove the system.
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Old 06-04-2003, 11:59 AM   #13
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The power gains are pretty insignificant really.
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Old 06-04-2003, 03:08 PM   #14
kickin_81
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Hey, guys! Well, I know that removing the AC belt will not gain me as much hp as a lightened pulley, but it does help. If you were to test a 40-70mph run in third gear, I think the most it will net you is .1 of a second. It won't make you any slower. I've read before that it's better to run your AC year round to keep the AC from rusting (for lack of better word). I agree with that, but I've never heard of AC reliability issues related to taking off the belt. I still think this is a good, free mod worth doing to release a bit more hp. Like I said, I can always spend another 15 min. of my life to put the belt back on. This modification/removal will not put you or your passengers at risk of anything (besides the whinning about no AC ). You just roll the window down if you need to cool off. I will put my belt back on when it gets too warm. For some of us, getting every ounce of hp from the $$ you have is worth it. Thanks for your concerned inputs, fellas. Always happy to hear the pros and cons of things.
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Old 06-04-2003, 10:03 PM   #15
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Umm.. removing the AC belt will net more gains than a lw ac pulley since there is less parisitic drag. I doubt I noticed much of a difference when I did it, but like everything else, its cumulative. If you can find 5 small mods to net you 1-2 HP, thats 5-10 extra HP that you have on tap. Not alot, but we have to work with what we have!
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Old 06-04-2003, 10:49 PM   #16
ciper
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joefocker20: Actually, you are wrong.
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Old 06-04-2003, 11:04 PM   #17
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Humor me. How would a belt routed around another pulley produce more power, unless its a S/C pulley?
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Old 06-04-2003, 11:24 PM   #18
ciper
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The lightened pulley is removing aproximatly 3.5 pounds of rotating weight. The portion of the AC pulley that spins might be .4 pounds. This weight is more important than non moving weight on the vehicle because you are accelerating it from 500rpm to 6500rpm. 3.5 pound "mini flywheel" with that much change in speed adds up.

The lightweight pulley has small gains to begin with. Having 1/8.75 of the gain from removing the AC is a joke. More gain in acceleration would be had by removing the two heat exchangers and leaving the pump attached!

The AC pulley has so little friction its not even funny. The power loss (which is near unmeasurable) from the resistance of the belt and additional mass is what you are dealing with.

Actually, Id even say your vehicle would be faster by getting some 400 treadwear tires, less forward rolling resisistance. I guarantee your gas mileage would increase

edit: I coudlnt figure out what S/C meant for a while! That doesnt count.

Last edited by ciper; 06-04-2003 at 11:30 PM.
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Old 06-05-2003, 12:43 AM   #19
kickin_81
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Ciper, are you speaking your words from experience? If not, then what you are saying about this mod being a waste of time is just your opinion. If you have not weighed the thing yourself, then I don't believe you. I don't mean to point fingers, but you are saying it like you went through extensive research on this matter, but you aren't showing proof. There's no hard evidence on the overall weight of the 1) free-play side of the AC pulley, 2) the belt, and 3) the tensioner pulley. With the belt off, I can play with the AC pulley and it feels like it weighs clost to 2 lbs. The tensioner pulley feels like it's .5-1 lb. This is my opinion.

I agree that the AC belt rotates two pullies that has no friction associated with them. If the pullies did have friction from the factory, I would prefer to leave it alone since it was designed to power something useful. ...But, if the crank pulley is rotating about 2lbs of mass that are just mass... why not? Who would have believed that exchanging the 5lb stock crank pulley to a 1.19 lb pulley would feel so good? No one did... until a market was created for them. The public liked it, so it became a performance modification. It was just lighter, yet it gave/freed more power in all the gears... about 2.7hp per lb of rotational mass to be exact.

Let me make myself clear... this will not net you gains as much as a CAI or an exhaust. In my honest opinion, I feel I freed an extra 1-4 hp. The choice is up to whoever wants to do it to their car. Besides, there are no known side effects other than the loss of using the AC (until you put the belt back on). The gains I got were small... barely noticable, but why not for that hint in power?



ps- Joe, you took off your AC belt, too? I thought I was the only one?
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Old 06-05-2003, 12:48 AM   #20
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Well, I already have a lw crank pulley, and the AC pulley is now just sitting there still, along with the tensioner. I don't know how much it will help, but it will help. I may just be nervous, but I did all kind of stuff that's debateable to free up a few ponies before I go to the drag strip on Friday. I put Royal Purple Oil in, Mobil-1 gearoil when I changed my clutch and flywheel, bypassed my TB, ripped out my rear seat, and I'm going to see how I can reduce more weight tomorrow. I want to get a 15.* @ 6000 ft above sea level this week
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