My trans am is my daily driver but I am looking for all the horsepower mods to add on to it that aren't that bad of an install. The pulley seems like the easiest one on my list that I haven't purchased yet. I was curious to see if it would be a good choice with a stock waterpump and alternator. I do have an aftermarket stereo system with an amp.

I actually thought that I might just do the crank pulley because the alternator would kill my battery due to the stereo system. What do you guys think? Will the crank pulley do anything to mess with the waterpump or cooling of the vehicle?

 

You don't have to worry about the "stock water pump".... it isn't driven by the belt. It's gear driven off the timing set, so the U/D pulley would nave no affect at all on it.

As far as the alternator, March for example sells there "Power & Amp" series pulleys, that have an U/D crank pulley and an O/D alternator pulley, to support high amp loads. I know with a full ASP U/D pulley setup (crank and U/D alternator) my basically stock equipped electrical system would drop the volt meter into the red when sitting in heavy traffic, idling, with the brake lights on.

ws6.com tested an U/D pulley, and found a peak gain of 0.7 HP.... yes, that would be 7/10th's of 1 HP. He did see larger gains on average.

 

I have an underdrive system, and a 160 degree thermostat. Unless i am sitting at a light for 5 minutes, my needle barely comes off of 160. At idle i have into the yellow. At about 1,000 rpm i have about 13 volts, and 1200 rpm i have full voltage which is almost 14 volts. If you have a big stereo i wouldnt advise it.

The guy who had the car before me had 3 15's and 2 12's in the back, and over 3,000 watts of just bass. He broke the back window. The fuse in the system was 150A, and he didnt have any troubles with that system, and the under drive pulley, so It's safe. I still wouldnt reccomend it though.

At a stop light i am only getting like 10 volts anyway, my gauges and headlights dim, so i can only imgaine what kind of drain a system would have.

 

So will most of my gain be from the crank pulley anyway or is there gain to be made from the alternator also? Do they come in a set or can I actually purchase them individually?

I heard ASP has the best full replacement pulleys out there. If there is a gain from the alternator can you actually gain by using an OD pulley on it? Is there a certain percentage pulley that is reccommended for use on a daily driver?

Where can you purchase them for the best prices? As you can tell I am in a very inquisitive stage in my life....

 

Any comments on this kit I just found?

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

 

I only have the crank pulley. I am not sure of the percentage it is, but it's as low as i would want to go on a daily driver. Any lower and it would be draining the battery with 2.73s (i only see 1500rpm at 60mph).

With that kit you get the alternator pulley so that you dont see as much of a drop in voltage like i do. I would say it's a good kit, looks pretty expensive, but i honestly dont know. My car came with the under drive pulley so I dont know much about them. I only know how it drive with one

I'm very inquisitve at my age too (17) which is a good thing. The only stupid question is the one that goes unasked .

 

Well, you are in the same situation as me. I have the standard bolt-ons, and was looking at pulleys. After looking at them, they don't seem worth it. If I were you, I would look into a good set of 1.6RR's first. I would put them in before I would put pulleys in. While searching, I've seen gains of 7 rwhp minumum, and 25 rwhp max from the 1.6 RR's. You can do your 1.6 RR's, pushrods, and springs for less than $400. I have yet to dyno my car again with the 1.6 RR's.

Dan

 

i dont think roller rockers are gonna give you 25hps without a cam....as far as the pulley goes i have the mac underdrive and alt kit and have yet to install it..ill keep you guys updated

bubba

 

I totally agree, but it was dyno proven. The guy obviously had other issues that were fixed when he put the new valvetrain in. If the car is running correctly before the 1.6 RR install, I think 7-12 rwhp is more accurate.

I'm hoping for 10-12 rwhp from my new 1.6 RR's.

Dan

 

ive got a march underdrive pulley i notice the car revs a little faster but as for sotp nothing really but hey i put on a new belt because of it and now my lights Lope (for lack of a better term) lol
but i think it might help alittle just not an UBER mod but if your lookin to get the most outta just bolt ons then go for it

 

The ASP setup you linked on eBay is a 23% U/D integrated crank pulley/damper, and a 15% U/D alternator pulley. That will give you the max HP savings, but it will also drain your electrical system at idle, with a beefy stereo and a low idle speed A4. I had that setup with stock electrical loads, and the higher idle speed of the M6, and like I posted earlier, the dash voltmeter would go into the red sitting in heavy traffic. If you want to make power in an electronic fuel injection car, the last thing you want is a weak battery, or low system voltage.

The "fix" is to get an O/D alternator pulley, but that will not "save" any HP, it will give back some of the small amount of HP you saved by going to the U/D crank pulley.

Think about what the belt drives.... tensioner pulley, alternator, PS pump and A/C compressor. When you want max HP (at least if you're a straight line racer), you aren't likely to be using the A/C, aren't going to be steering around corners and aren't likely to be operating your stereo. To me the whole pulley thing is just an uneccesary complication, with very little to be gained.

 

I had a bolt on system on my previous lt1.I think it was asp and pretty sure also put on the overdrive alt pulley.I don't recall having any problems on that car but it was an m6.I did see what I thought was an increase in vibration or harshness from that bolt on pulley.

This time on the 96 I finally managed to buy a near brand new asp underdrive balancer and overdrive pulley off the board here.I am quite sure it will not kill the battery with the overdrive and think the balancer is not quite as much overdrive as the addon but forget.I don't have a big stereo in the vert.

I am hoping for a tenth and maybe 1mph out of the pulley.I also got
1.6 pro magnum nsa to install and have heard guys getting around 2mph and 2 tenths from them.See how it goes but 3 tenths off my current times will be nice if it happens.
Also I believe the underdrive balancer gains some power due to lighter weight than stock.

 

alot of guys on here will tell you they had no charging problems, Ive owned 2 LT1's and never felt it was worth the possible trouble for a few HP....I had 2 buddies one w/ a 93 and the other w/ a 94 and they had all kind of charging problems w/ them...both ended up taking them off

 

well, not to hijack the thread but would a bbk crank pulley be a good purchase for like 20$?
wondering if i should spend my money and time on it

 

You can buy just the crank pulley from ASP, and then if you have issues with the charging system you can get an overdrive alternator pulley from MBA.