Please list your voltage at idle and what underdrive/s you have. Also did it make a change in temps, or anything else? Also, what rpm does the charge go back to full if it drops off any at idle?

 

I have a set of Marh underdrive pullys on my car , and there great, well worth the money! If you want more info please e-mail me. I dont like answering questions, spending a half an hour typing for nothing. if you are serious, and really want to know, and arent just asking a retorical question, Ill be more than hapy to assist you. If you want pics, I have pics on this web site, under readers rides, 1Wickedss. thanks and Ill look forward to hearing from you.

 

If he's interested, and you're going to type it, can you cut and paste it here? I would really like to know as well

 

Yes, I am interested. If I wasn't I wouldn't have asked. I am going to be buying a few more things for my car this coming thursday and underdrive pulleys is one of them I was considering, but had some questions. Can you please just type a response here, not only for me, but others as well? Thanks.

 

crank pulley gave me no charging problems (same as stock) but the alternator pulley brings the voltage down to about 11-12 but only when in drive and at idle, even if you put the car in park or neutral the voltage goes back up to about 13-14.

 

I am also seriousally considering underdriving my pulley system. Im looking in my summit catalogue right now and see two kits. one is 2 pulleys crank and alternator (MCH-4000)$78, and the other has crank alternator and waterpump(MCH-4010)$163.

My question would be which sets (or similar sets) do you guys have (2or3 pulleys). How much performance increase or milage increase do you guys actually feel with these underdrive pulleys?

 

i just went with the ASP crank pulley, only $50. The only reason i later bought an alternator pulley is because summit gave me $35 in free money and $15 of it had to be spent by the end of the week, and that was the only thing i could think of to buy.

 

i got the march ALUMINUM SET... ver nice, it has 3 pulleys and it drops the voltage to around 9ish or so... but you could also get a higher current alternator. or increase your idle a little which is what i did. i popped out the little cap on the tb and turned the screw a little. i think it was a torx bit though??? last months chevy highperformance or one of those mags did the pulleys from march on a dyno and it showed a 17 hp rear wheel improvement. i can't remember how much torque though??? it is a very good mod!

 

This makes me re-think all previous thoughts I had on pulleys. I don't mind the voltage drop as long as my stereo and amp will stay powered however what about the water pump? Do you guys see in increase in temp at idle? Do only the three piece sets have the water pump pulley?

 

I contacted march about that and their 3 peice sets only underdrive the crank and alternator, or overdrive the alternator with the power and am series. The water pump pulley and optional power steering pulleys are stock diameter, but the crank being underdriven, still underdrives them slightly. I asked about the cooling issues on the cooling down board and the consensus was that it does not effect the cooling. To me, the 3 piece set is a waste unless you just want looks.

 

Hey thanks 25THRSS. So you would recomend going with a 2 piece set up? I think you can get both set-ups in two different materials and coatings right? I wonder how much less the aluminum ones weigh as compaired to the steel ones. If I remeber correctly the 2 piece stell set-up is pretty cheap. However, what serpentine belt would you use if you have your air pump removed and you go with the 2 piece set-up?

 

i actually think my wp pulley from the march set was bigger than the stock one... i will look when i get home and post tommorow... and the wp pulley is definatly for looks its the only one you can really see besides the alternator. but you must remember it is not just the size but the weight of the pulley . thats why you get all 3. and i have not noticed any cooling issues with the pulleys.

 

Your water pump pulley will be bigger. Bigger pulleys slow down what ever it is driving and it makes it easier to rotate. I really think the rotational mass difference between alum and steel is minimal for the sizes and rpms that we are dealing with.

 

First of all I am in mi, with no emission laws, well none that are inforced. I have the Macrh three peice power series I think they were like around $200, but that was quite some time ago, and yes there well worth the money. the pullys alone gave me 6 inches of underdrive, I now however have roughly 22.5 inches total underdrive. here is the the info as you all seemed to want/ need. I just hope I am not typing all of this in vein. With the power and amp series, all of the pulleys are smaller( Alt, W.P. and crank) the alt one as alot smaller, the w.p. one is just a bit smaller, and the new crank pully is so small that it would fit in the old crank pully. so thats where I got 6-6.5 inches of underdrive, where did I get the rest? I deleted the smog pump, and re ran the belt in my own configuration, it works, and works great, but took some time to find the right belt, first , take off the smog pump, and everything that it hooks to, and guess what , you wont through any codes either. take all of that emission **** and throw it away, plug up the 2 tubes coming out of the exhaust manifolds, and you are now smog delete. ( what about the ele plugs in the black box on the pass. side bank?) un plug em, and if you like the neet look, you can cut off the pig tails, and tuck the wires into the harness thats right there. ok, now for routing the belt. ( all of this is wirth about 20-25 hp, so yes it is worth it) well start with the alt, follow the stock configuration, go down to the powersteering pully, then it gets weird, go from the powersteering pully to the crank, across the bottom of the crank, and then up to the A.C. comp.around the a.c. pully , under the spring tensioner, and UN der the water pump, and then finally back to the alt, I dont recall the belt size I used, my car is in storage about 30 miles away, so I cant just walk outside and check it for you all. I do however HIGHLY recomend using a good year gatorback belt, there like 20-25 bucks, and the unique design helps the belt hold on to the pully's.This does work, I have had no prolblems with it, on the street, or the strip. the voltage at idle is the same as stock, or even better, and with a 160* stat, I never run hot, going down the road I run at like 140* and idle I guess 160, however I have a manual override electric fan, so I never run hot.I hope I have answered all of your questions, if you have any more feel free to ask, if you look at my pic, that is posted on readers rides you can see the belt sey up, well some of it, Hope I have helped a little, again if you have more questions feel free to e-mail me, or post someting for me.

 

Hmm, all I know is I emailed march, and asked them which pulleys were underdriven or overdriven. They responded by saying, "The water pump pulley and optional power steering pulley are stock diameter." The crank pulley and alternator pulley are underdriven, but the alternator pulley is overdriven on the power and amp series set. With this information I came to the conclusion that the only reason to get the 3 piece polished set would be for looks because the water pump pulley is stock sized. I think I'm just gonna go with the ASP crank pulley, that way I can get the underdriven effect without effecting the alternator too much.

 

and thats exactally why I dont like replying. I spent all that time giving ideas, and it dosent matter. WTF?

 

It does matter, and I appreciate you taking the time to reply. I wouldn't know which is true since I do not currently have underdrive pulleys, hence the reason for the thread. All I was saying is what March told me directly. BTW, if you say they are all smaller then that means the crank is the only underdrive pulley and the rest are overdrive pulleys. Doesn't that kind of defeat the purpose of underdrive pulleys in the first place?

 

ASP? What company is this? I don't want to have any charging probs either, so I too am only interested in an unerdriven crank pulley, I'll leave everything else stock. Does this CO. have a website?

 

http://www.aspracing.com/frame.htm

You can buy just the crank pulley from thunderracing for about $70

 

type the part number for the ASP crank pulley on summitracing.com , its only $62.39.

 

i also did the smog delete and there is a link on the tech section that tells you the part no. for the belt. also the weight diffrences do matter which is why people use aluminum rather than steel. every pound taken off a rotating assembly on the engine supposedly equals 8 pounds off the weight of the car. someone else may know about this equation. the alt pulley i have is way smaller than the stock one but i think the wp was bigger i will have to look again at the stock one i forgot to look because i was pulling out the cheap crap plastic center console and installing the 89 firebird heavyduty console... it looks nice in there. any way i will try to look again today. the march set is 170.00 now. that is a steal!!! for 3 pulleys. when i had the 90 300zx i had an asp pulley i bought it for 169.99 and it was just the crank. it made a big diffrence on the z because the stock pulley weighed 20 pounds and the asp one was 3. the dynoed one from the firechicken i refered to earlier was from the 3 peice aluminunumun set.
i just looked in chp mag and there is also an article on the asp's on an old nova. a few months back they did one on a fire bird.

 

yes, they( the W/P/ and the alt) are over driven, or rather kept at the stock speed, if all you do is under drive the crank, then you reduce the total rpm's of the w.p and the alt, hense the cooling and charging prolblems that many people experience when using the crank only method. and as earlier stated, going from solid steel pullys to billet aluminum reduces the total weight of the rotating assembly, thus incresing the total output of rear wheel horse power. I supose if you are on a buget, the crank only pullly may be a good investment, however , to experience true gains, with out affecting the performance of the water pump, and that of the alternator, a true three peice system must be used. BTW how fast is your car?

 

Only the crank gives the most power, huh? I've also seen some with 25% and some with 33%, the 33% would give the most power, huh? Thanks, Bobby

 

If you are gonna underdrive the crank pulley, then go back and overdrive the accessories it completely defeats the purpose of underdrive pulleys anyways so it makes no sense at all to me to overdrive anything.

 

THE MAIN POINT AS WELL IS weight reduction... also i found the other article with the firebird... it was 17 hp and 13 ftlbs torque at the wheels and this was the jet 3 peice steel set so i am sure the aluminum ones would show a 1 or 2 hp increase over the steel ones. and the other pulleys lookded a little bigger than the stock ones.
oh also not sure about my times... but i have out ran my freinds 87 iroc with tpi and headers with catback. his is an auto with 2.73 gears... i have t5 with 3.08

 

March power and Amp
13-14 V consistent at 500 rpm idle in gear
With A/C, head lights, turn signal, defroster, in gear 500 rpm and brakes, drops to around 11-12 V.

 

I have the same set up as yours, but experience none of the prolblems as you listed. I can have everything running, and the out put or the alt never drops below 13-13.5 volts. I dont know why, mabe because of the 22.5 inches of underdrive I have, mabe not I dont know.

 

Hey guys, I just copy/pasted this from summit since I couldn't get a link from their site. It is the ASP crank pulley. My only question is that my camaro is an '89, so will the pulley still fit? Thanks.

ASP-541300

Image is a representation of this part. Actual part may vary.

$64.69

Should Ship By: Today

Vendor: Auto Specialties
Product Line: Auto Specialties Underdrive Crankshaft Pulleys
Material: Billet Steel
Finish: Black Nitride

Get 15-plus extra horsepower in 30 minutes.

Chevrolet/GMC/Pontiac: 1982-85 305/350 Camaro/Firebird/C/K-series pickup/SUV, underdrive crank pulley

This Auto Specialties crank pulley turns your belt driven accessories 25 percent slower than stock and provides about 15 extra horses--for about 30 minutes work. You'll also get better mileage and accessory life in the bargain. This pulley is made from high quality billet steel and finished in black nitride.

 

its ALLOT smaller than stock, so one would think it speeds it up, but it doesnt.

I have a voltage drop @ idle with a load, I dont have a problem of any sort, but I really preferr for it to stay a constant voltage.

I think Im going to put the stock one back on and sell the SLP setup

 

Anyone?

 

I'm running the complete polished aluminum v-belt setup from March, ps/ac/alt,brackets, March everything and I couldn't be happier! Volts are at 12.7 idle in drive and 13.5 moving. My car does run hot but when it's 115 outside what do ya expect? It's the best looking and pain free setup I've ever had and well worth the money, not to mention picking up some horsepower along the way. And the gatorback belt is the way to go.

 

Since noone answered this simple question from Irocster, it's being brought back from a 4 day death..

The ASP pulley you posted is a multiple V belt pully.. you've got a single serpentine setup..

Use:

ASP-540800 --- Pulley 88-92 Camaro/Fierbird 305/350 25% crank full charge @800 rpm --- ships Today --- $62.39

 

Hey thanks man...I actually forgot about this, lol. Good thing you told me so I didn't order the wrong one.

 

Which is better between:


ASP-540800 Pulley 88-92 Camaro/Fierbird 305/350 25% crank full charge @800 rpm Today $62.39

AND

ASP-540801 Pulley set 88-92 camaro/Firebird 25% crank/23% alt full @950 rpm ???

So if the alternator doesn't get charged up until 800/950 rpm, what will happen when I'm sitting in traffic @ about 650 rpm?

 

The difference is that the first one comes with only a crank pulley and the second one comes with a crank pulley and alternator pulley. If it were me I would order the first and only use a crank pulley to avoid any charging issues. Your voltage would drop low at 600rpm, that's what would happen. To be on the safe side and prolong the life of that alternator I'd go with only a crank pulley.

 

What does it help to put these pulleys on the crank or the alternator? What would it help with both on or if you just put one on the crank or just one on the alternator?

 

Did you read any of the thread?

 

Yeah, I read it. I didn't read anything that explicitly explained what these features help do. All of these people already know what these things do and didn't explain the stuff that they were talking about to where a newbie would understand.

I don't know what all of those figures and stuff mean. I was wanting to get a direct answer instead of trying to figure out with percentages and figures and tech talk what these things do, and what the benefit of having an overdrive or underdrive pulley is.

 

accessories == added rotational mass on the engine. Added rotational mass == less spare torque being delivered to the flywheel/flexplate. underdriving accessories == less effective rotational mass == more spare torque being delivered to flywheel/flexplate

 

Jeez, I can't believe there is so much discussion and misinformation about something so simple.

The crank pulley slows all the accessories down to reduce the hp drag they create. The alt pulley in a "charging" series is smaller in diameter and speeds the alt back up to original or near original speed to keep it's output where it was intended to be. The water pump(and mechanical fan if present) create much more drag than the alt. Thus the movement to electric fans by even OEMs and the popularity of conversion to electric water pumps. An alternator's draw is a tiny fraction of 1 hp. Using the alt pulley to get normal voltage has negligible hp loss.

I don't know why anyone would not want to use a crank and alt set unless they don't want to spend the extra money and spend very little time idling.

 

also they are lighter and there is a formula that is summed up as every pound you take off of a rotational mass (on the engine) ypu take off equals 8 pounds off the weight of the car. so yes the diffrence would be minut but it does help! thats why it helps the 300zx so much the hbalancer is part of the pulley and it weighs about 20 pounds the asp aluminum pulley weighs a portly 3 pounds... the camaro cp and hb are seperate entities so it would not do alot.

 

Hey 25THRSS, for being a moderator, you sure are a jerk. It dosent matter what any one asks, or what is said; all you can say is something negitive. Mabe you shouldnt be a moderator, arent they supposed kind and willing to take time to help others? Rather than being shrewd, and arrogant? I hope you never need helo with anything, I seriously doubt that anyone would be there to help you, after all I helped you and you had nothing nice to say, and even told me that I was wrong. Think what you want , but there is a slight possibility that you might not know everythng that you think you do. Just my oppinion, and I know that I may be kicked off this site, or whatever, but someone had to say something. I think you need to check your self at the door, and leave the power trip at home!

 

yes i agree with the above statment!!!! you are an ***!

 

lol, you guys crack me up. i correct people all day long, no one calls me an ***, maybe its because i am so damn sexy

there is a certain amount of correcting that needs to be done, this board benifits no one if there is lots of misinformation, maybe our mods need to go to training on how to gracefully tell someone they are full of ****. Of course i get paid to go to work and tell people that everyday, maybe i have just gotten good at telling people they are wrong while not putting them down.

but yes i do agree sometimes 25th can be a little '*** like' but at the same time, remeber he is trying to keep the information on this site correct (or at least what he feels is correct) i am sure he has been caught giving some sort of inaccurate information at some point, we all have.

 

i am refering to another post on the v6 site where he told me to shut up... also he said i hated gm and should have kept my 300zx... now is that anyway for a mod to act??? if your a mod you need to be a little more tactful!

 

hey you should have kept the z32 i really liked mine.

 

well i got 2 kids with another on the way and a 2 seater is not feasable. that is also why i have the camry!

 

2+2 my friend. import a fairlady 2+2 turbo from across the pacific. problem solved.

either that, or sell the kids

 

i think the 2+2 tt would be cheaper in the long run than the kids!!! plus i like the newer look of the 99 models front nose clip!!!

 

Please don't even get me started on this guy!!!! He is great to talk to only if you agree with him, or if it's his way. lol

C'mon 25, I'm waitin for that PM