batman-matt

was watching horsepower tv and noticed they used an under drive pulley system with smaller pulleys to add hp to the engine by reducing the work load, sounds great, but why can't I find one for 5.7L 350? anyone know where to find some for my engine?

ckyfreak2010

here is a link to pulleys for your car, i dont mean to be a dik but how could you not find them
http://www.youngsfbody.com/8292pulleys

BulliTooth

try summit or jegs... BBK, March, and Jet makes them for our cars

hellz_wings

iTrader: (2)

Hey.

Yeah March makes really good ones I've heard... They are a bit pricey for what they do, the money could be better spent elsewhere.

Also I've heard of problems arising from using these (mainly the alternator not fully charging at idle... which would dim the lights and i guess if you have a large sound system then that would be affected as well...)

I would research these things more before putting down all that money on something you may regret buying... for that money you could get a new set of 1.6 RR or something I dunno! Or, invest a bit more and get a used LS1 aluminum driveshaft, less rotating mass and no vibration at high speeds!

Just my 0.02$!

rv1890

iTrader: (3)

anyone make them for a vbelt?

tshack

I just recieved a set on from a seller on ebay. For my 87 Z28. The alt wouldn't charge much until the RPM was over 1000. It worried me that when idleing if the fans came on the low voltage would smoke them. so I reinstalled the stock alt pulley. It's charging at idle agian.

Hawk92z-TDZ

Get the March power and Amp series and your fine, with the normal march set I was having low RPM troubles but soon as I upgraded to the Power and Amp ones mine works fine

UnderCover89TBI

iTrader: (25)

i got the bbk ones. i didnt really care about the more power i mostly like the look sof them. but it did affect my idle charging. so i bought an msd 1.65 inch alternator pulley. a lot smaller than stock.

tshack

undercover: where did you get the 1.65 pulley from?

RiggsLW81

iTrader: (4)

DO NOT BUY FROM YOUNGSFBODY.COM !!!!!!!!!!!! BUYER BEWARE !!!!!!!!!

that is FBODY MOTORSPORTS... do a search and ull see.

youve been warned! if you value your $$, do NOT purchase from them at any cost!! they are scammers/ rip off artists

UnderCover89TBI

iTrader: (25)

well your local kragens, schucks, oreilly whatever you have should be able to order it for you. summit sells them part #MSD-51901 is SUmmit part #. Krangens number would just be the the 5 digit number. You can go to summitracing.com type in that number and see it.

I H8 WWD

iTrader: (5)

I bought my water pump pulley part number #4012 from March mainly because I wanted a lighter but also a nice new pulley to go onto my nice new water pump. I plan to get the crank pulley and when I buy my new MSD alternator (160A) I will get the smaller 1.65in pulley for it. I am looking to upgrade my power steering box system for a lighter quick ratio box with remote reservoir so a new pulley will be used there as well. Finishing my pulley setup for my car. AC Delete Pulley, Smog Delete Pulley, Gatorback Timing Belt Tensioner, March Billet Water Pump and Crank Pullies, MSD 1.65" Pulley and either custom or replicated Billet PS Pulley.

hellz_wings

iTrader: (2)

Never have I seen some clear results on aluminum or underdrive pullies... Somebody must know... I know that underdriving pulleys is generally not recommended on the street because it will give the car trouble charging at idle... But it will make your car rev up quicker and possibly give the car a few horses (still, this has not been determined yet either).

If one would just want the same "size" pullies but in the form of alluminum (for lighter weight, not changing the speed of any accessories) would it give the same effect as underdriving? Or close to it? Would it give any horses or would it just make the engine rev up quicker? Or maybe they are just for the look at 100$ (or wtv they are)?

I for one would like to know if anyone on here has tried and really tested these products to know if they make any difference... At the price that some of these pullies come by i'm sure that a potential buyer would like to know what they 'actually' do, pros AND cons...

Thanks
-Marc

UnderCover89TBI

iTrader: (25)

the power is supposed to come from changing the accesory speed and drag on the engine. now im sure the aluminum allows the components to spool up a little quicker but enough to notice i highly doubt. I put the kit on my car and felt a increase in engine revving and off idle power. so they were worth it in that regards. I wasnt even after power. just after the clean looks

hellz_wings

iTrader: (2)

Hmm... Interesting facts... You have TBI though, anyone have any results from a LB9 or L98 TPI engine? Stock or not stock? Mine's a not stock LB9 (cam, heads, etc.)..

I just realised that lots of people were putting underdrive pullies and to make up for the loss of charging at idle would put smaller alternator pullies... Wouldn't this just cancel out the gains of the underdrive pullies? I also heard it's dangerous for the crank the under drive the pulley... Any thoughts?

thnx!
-Marc

I H8 WWD

iTrader: (5)

P.S. Remembered someone stating the #4012 water pump pulley is actually the same size as the stock pulley (I will verify this today). I plan to pick up a smaller alternator pulley as well as the underdrive crank pulley. All for looks more than for power.

I have found a few people gain around 3-10hp 3-10tq on other cars not ours. Some have even been close to 12hp and 12ft lbs.

Like I said though, as well as UC89TBI, we both bought ours for looks rather than a possible gain, but if there is, awesome.

For me I wanted all new pulleys when I put my new waterpump and gatorback tensioner as well as new gatobrack belt on for a fresh start. All new and clean.

Just search (on here or google) for dyno proven underdrive pulleys. Quick search on google brought up one that dynoed around a 7hp gain (no tq readings) just off the crank pulley, which I beleive is the only one that you can gain power from anyway.

hellz_wings

iTrader: (2)

Ok cool... I'm thinking I will do a dyno BEFORE and then AFTER putting these pullies on to get a straight up result. I can get flywheel and wheel horsepower differences so I'll let you guys know. Just to clarify, which set (don't care which company) will enable my car to retain its regular charging capabilities? I don't want to install these and then have to take them off because my lights are dimming or worse.

Thanks,
-Marc

I H8 WWD

iTrader: (5)

These will fit all 86 LB9 or 86 305's

March Power & Amp Series Part #4420
BBK Kit Part #1598
JET Pulley Set Part #90106
ASP Kit Part #ASP541101 (Nitride) ASP841101 (Black, Aluminum)

All STATE they will keep charging capabilities at idle (1,000rpm)

Transdapt DOES NOT make a kit for your year/motor (86 LB9)

91interceptorZ

iTrader: (3)

I have a trans adapt kit on my 91 serpentine system....I didn't really notice anything...but I took off the alternator pulley it came with and put the stock one back on so the alternator would charge below 1000rpm. I would spend the money if I found a cheap used one...but like some others have said....money could be better spent somewhere else. IMO.