Well I'm not sure if anybody has done this, but i thought i would try it out. eliminating the ac pulley to free up some more hp to the crank. I'm guessing everybody knows how to replace the serpentine belt...

I purchase this belt at oreilly's for $15 size is 630k6 works and fits perfect.


Just take the old belt off and put the new one on..just not over the ac pulley cause it won't reach anyways. Results faster acceleration...I was very impressed..woke up the v8 in a whole different way.....going to the track this july 19 so well see the results...


Too take the belt off and on only takes around 5-10 mins and would only do it when i need to. But lets say if your ac wasn't working anyways, great upgrade for only $15.

 

I really doubt that you will get 20% hp increase. Maybe more like 1-2%. I think if your AC is off, and the clutch for the AC is not engaged, then the parasitic drag of the AC unit wil almost negligible for a car with well over 280 hp at the crank. I would definitely like to see what your 1/4 mile times are with and without the AC attatched. BTW if you are gonna do a comparison, it would be better to do a couple of runs with the AC belt off, then with the AC belt on during the same race session.

keep us updated, the results should be interesting

 

You should eliminate power steering too, but I don't think it will work bacause of pulley location.

 

It's 97 degrees outside. I love my A/C right now. Haha

 

Bypassing the p/s pump on LS1 F-bodies has shown as much as .3 in the 1/4 mile.

 

Please forgive me for digging up an old thread, but I believe Fonzy on post #3 maybe on to something.

I don't have a GS400 to look at, but just from the pictures I have been able to find, it looks feasible to bypass the p/s pump as well. Bypassing the A/C and p/s could certainly be worth a few tenths at the track.

It appears to me that the belt could be routed from the crank pulley directly to the Alternator (bypassing the idler), then from the Alternator to the idler and back into the rotation. As long as there are no obstacles in between the crank and alternator, it seems that this may be possible.

Eric

 

I'm willing to sacrifice 0.3 off my 1/4th for some luxury

 

I might give this a shot next time I go to the track. I swap my wheels, might as well swap belt too.

 

Unless your AC compressor is seized...I very much doubt that you will gain that much power. The AC pulley has nearly zero resistance if you turn it by hand, in fact it has less resistance than both the alternator and PS pump with the engine off. Either way, keep us in the loop with your results. Your car might just react positively to it...who knows.

 

Well, I had a followup post just after my first one, but its not here? I suppose since it had an attached picture and/or I am new member, the post must be pending approval?

I don't have a GS400 to look at, but from what I can see in the picture above and the diagram that I found, the belt could be routed:
1. Crank to Alternator (bypassing the idler)
2. Alternator to Idler pulley
3. Resume normal route


-In response to teg and Fonzy. I bypass the p/s pump on my LS1 Z28 when at the track. It is a pain driving, especially at slow speeds. The flip side is, your just driving in the pits for a few moments and after you get the hang of changing the belt and knowing the routing, it just takes five minutes to swap. I admit, I do sometimes change at home though and drive to the track without p/s, simply because it is alot easier to change when the engine is cool.
-I agree with Jeff on the A/C, HP lost across the disengaged clutch is minimal. If your changing the belt though, you may as well bypass the A/C too.

Happy modding
Eric

 

stngh8r what you're saying is you can eliminate the p/s too..correct. what size belt? and diagram would be nice.

 

I tried again, but as stated in post #9, the forum is not letting me post a image or even a link? Sorry. Just google images (gs400, pulley, diagram)

I don't have a part # and I don't know if this mod is doable.

I was simply brainstorming and sharing idea's. It looks very possible.

 

let's see... 20 percent of 300...that's pretty hefty !

 

Sorry I was thinking of the good old days when i still had my honda civic @ 97hp. I was also over excited after it.

 

I'm just kiddn' LOL. Motor effiency equals usable power.