Question I'm afraid to ask heh
 

I've searched, and read just about every post, but I still don't think I got the info I wanted.

I have a completely stock L98 except for the exhaust. I was looking at the March underdrive pulley 3 pc set. What I wanted to know was, is it worth it to spend the money? If it got me 10 more hp I'd be happy. If it got me 3hp I wouldn't even bother with it. So far, I've read that they don't really have any cooling issues, and the alternator pulley is smaller to bring back up the rpms and not lose as much voltage. I don't want to strain the engine, and if the pulleys do that I again won't bother. The car isn't a daily driver, more of just to cruise and occasionally race.

This was tough to ask considering all the debate and hoopla I've seen these discussions about pulleys have.

Any information is appreciated.

I have no idea but I have read all the post too, Im going to be putting them on my car when I put my top end all back together. Heres a pic of the ones that Im putting on. They are not March they are BBK's, I got a good deal on the and couldnt pass them up. if I have any charging problem I'll just put the stock altenator pully back on and then just get a polished on from March.

An underdrive crank pulley paired with an underdrive alternator pulley could easily net 10 RWHP. I wouldn't be surprised if it netted b/w 15 & 20 RWHP.

The thing is, some people say they have charging issues with underdrive pulleys. Well - I think it is b/c most people don't make sure everything is in order before they decide to underdrive the system to free up HP.Also, if you decide to get them, consider also purchasing a grounding kit to make sure you aren't straining the system. The grounding kit will ensure efficient current travel and it also commonly frees up a few horse power.

I recall on the LPE website, they chassis dyno'ed with pully's, something like 3-5 RWHP gain max. Seems like a lot of money for so little gain, and potential charging problems that so many report.

UD pulleys are scary stuff.

Dont run em on the street.

I have polished aluminum March undrive 3pc set...
Looks great...Probably picked up 5 at the wheels....
You probably wouldn't feel a diffrence...but its the little mods that add up.

Btw,on mine I have had no charging/voltage problems.

I'm also running the Mach pulleys with my serpentine conversion on my '86. I love them and haev had no problems with charging. I can't speak about a Camaro specifically, but we installed underdrive pulleys on my friend's Lightening and it picked up a full tenth at the track, indicating at least a 10HP gain. The truck was running consistent 15.1s stock, and with the pulleys now runs consistent 15.0s. Fast as hell for a fullsize F150...

I had them on my daily driver for a year and had zero problems, ever. (Only using past tense because it threw a rod, but I doubt it was because of the pulleys).

I ran em and pulled em.

My charging system was taking a big hit at street rpm levels.

87 split belt system.

I'm currently running two pulleys of the March three piece set (Alternator would drop off at idle). I'm not sure if I picked up any performance, that little would be hard to tell without a dyno or track times. Re-installing the stock alternator pulley fixed the charging problem.

Anohter point worth mentioning is what alternator everyone is running. The pre-serpentine setups could only get up to 90 something amp unit, but the later ones go up to 130 or so. I am running the highest amperage one I could buy from NAPA. Even running the full March system and idling at 650 RPM I still get 14.2 volts.

I have them....I took the pulley off of the alt. As far as if they really give you any extra power or not....I'm sure they do some...but I can't tell.

I wouldn't buy them.

87-92 ran 105 amp alternators

According to NAPA there were several amperages offered each year. I'm not sure what determined what cars got what alternators, but I always get the highest amperage one available for my application. I checked my tag, and mine is a 130. Of course this could also be for a truck application, since they ran the same style alternator, so as long as the PN crosses they are looking at every amperage rating for that style alternator available.

Bottom line I think is, it COULD be worth it, and it COULDN'T as far as RWHP is concerned. It's all up to the individual. There really isn't any fear of losing amperage, or overheating the engine with the March's. In the end they make everything prettier. :D

I think I'll just save the money and get a bigger TB... like a 58mm, or a 52? hahaha theres another whole debate that ended with tons of posts reguarding other stuff, and me still confused. Oh brother. Sorry. :p

I've only got one thing to say: March Power & Amp Pulleys. Absolutely no charging problems. These pulleys are meant to keep the Alternator spinning the same speed as stock. They use a smaller crank pulley to slow down the accessories and then use a smaller alternator pulley to speed the alternator back up. Works great! I've never ever ever had a problem with these pulleys.

Tim

I run the March power and amp pullies (2 piece set - Crank / Alt )

I have absolutely no charging problems at all !

I run a short belt (forgot the size), but I have the march pullies and no smog pump.

Batt. voltage stays arround 13 and that's with a 105 amp alt. !

i would not waste the money on pulley's i would save up and run the bottle....

Bottles... ehhhh no. I like engines that are all motor. Not to mention my car is extremely clean, and extremely stock. I'm just looking to do small mods to help out a little, don't hurt anything, and can be easily replaced back with the stock parts.

Dammmit!

Friggin 87 the bastard year.

All you guys with your serp drive systems love those damn pulleys, wtf!

Well if yall know anyone who wants to buy a set for 87 just let me know, LOL!

My '86 had the bastard belt setup on it too. I hated it so much that I converted to the serpentine setup. It was a lot of work, but I feel it was well worth it. You have to repalce every accessory, bracket, and the water pump. Some minor rerouting of wiring is required, but nothing major. I gutted a stock smog pump, and run it as an idler pulley, so I can use the stock length belt.

Was it 100% V-belt or did it have the 5-rib alternator/waterpump drive with v-belt for the smog/power steering/AC?

It had v-belts for everything. My '87 K5 Blazer uses the semi-serpentine setup with the wide, ribbed belt and two or three other v-belts. I'm going to convert it too at some point. I think this setup is better than the all v-belt system, but nothing beats the serpentine setup for simplicity and ease of maintenance.

Thats what I got, the split setup.

However at this point I am cool with it. The smog pump is dropped and I run the power steering and AC off 1 v-belt, which I can easily drop for the track. That leaves only the serp belt to drive the alternator and water pump.

personally i feel its money better spent elsewhere.
however, if they were free or near free and i had no problems with them charging, id get them.

athough i would think a electric waterpump would be a better solution... i mean

your AC isnt taking any power at the track (and alot of people dont have it)
i dont have a smog pump.
the alt is going the same speed or very close.. and when it doesnt have a load on it, it doesnt take much power.
i normally bypass the PS pump at the track (the only place where a Tiny diff like pulleys would be helpful)


so what have we done? made it look nice (thoes pulleys look schweet) and driven our waterpump slower.. the water pump is the biggest drain of all the accessories...

anyhoo... thats my take on it..