Underdrive pulleys [ merged 1/6/07]

[larryd]

Worth it or not? I'm thinking of going with the AEM tru-power pulley kit. Anyone used them?

 

[doug]

A fact? No. Some people's strong belief? Yes. My belief? Not sure, but I want to avoid the two-piece pulley separating.

Also: 311GSX-- a one-piece dampened pulley? I didn't think that was possible.

 

[BoostinAWD]

As long as you dont overtighten your accessory belts. A dampened pulley will last well over 100k.


Mine lasted 178k to be exact.

 

[Kevin Jewer]

Before making your decision, consider this:

http://www.dinanbmw.com/html/danger_of_power_pulleys.htm

Some of you may have seen this, but I Think its worth repeating, especialy on crankwalk prone 2Gs.

 

[interceptor]

Does any one have it in their ride ? if so please let me know if its worth getting. I want to get it from Howell .

 

[DSM-ZERO]

Yes I think it is the BEST mod for an N\T for the price it gives you 10-15 hp and really makes a difference Iam pleased and have had no problems with it I say go for it you will not reget it.

 

[interceptor]

thanx i will ..

 

[totaleklipse97]

how long and hard is the install? cause i had to change my belts today after my major problem and it was a pain in the ass!!! just wondering if it is any harder than changing the belts??

 

[DSM-ZERO]

About the same, It just takes longer and getting the OEM pully off is a pain you have to remove your rim from your passanger side and take off the slpash guards to do it I say 2-3 hours with no problems.

 

[2FST4U]

If you could help me out here.....what will this do to A/C, Water pump, alternator, and do you have to run a different belt? Any over heating or charging problems? thanks a bunch

 

[interceptor]

GOOD ? . slows it all down to 30% working speed so it can give the rest of the power to the engine. NO over heating at all .got it on my ride works fine.. A/C works fine just slower blowing speed.But you will live..Just roll the windows down ..

 

[Eclipse96Ryder]

hey i want one too,


whats a good site to get one???? And I only need one right?

I heard this mid is the sickest mod in the world for the money, so thats what im doing next...YAAA, maybe my freak can hit the low 15's with this....WE'LL SEE!!!

 

[BlueMoonEclipse]

This is an awesome mod for you people who dont daly drive your car in the desert...... i dont know if i could survive with 30% less cold blast of air.....oh well time to find out soon

 

[interceptor]

http://www.howellautomotive.com/How...duct_info.php?cPath=142_38_84&products_id=298


I think you can get the Neon Pulley for $120 ..It should work on
all 420A engines ...Damn it .. !!!

 

[racerecks]

does anyone have pics of the udp installed?

 

[aero_ub]

Originally posted by DSM-ZERO
Yes I think it is the BEST mod for an N\T for the price it gives you 10-15 hp and really makes a difference Iam pleased and have had no problems with it I say go for it you will not reget it.

No offence but I don't see any way that you will get anywhere near a 10%+ gain from UD pulleys. I'm not real familiar with N/T DSM's but I am with some other cars...like my GP GT. That car turns out a fair amount more HP and turns much larger accessories. On the GP's I don't think that they get much more than 2-3HP at most.

unless for some crazy reason these are different from any other motor I've been familiar with? Has anyone done dyno runs on these?

 

[Big Bald]

10-15 is really reaching there. Maybe 5 if you have other supporting mods........

 

[DSM-ZERO]

Lots of people say 8-10 even more say 10-15 hp so I did not make that up I'll look for a DYNO result.

 

[The1Bill]

I think that 10HP is a fair estimation.
Meant about .15 seconds for me in the quarter. That winds up being 10-15HP.

As for the AC, it doesn't blow 30% slower, the compressor spins 30% slower. The fan maintains it's regular speed.

If you were driving at 3300RPM with an underdrive pulley, your accessories would be driven as if the motor was at 2200RPM with a stock pulley. I have not seen any isses with charging, no air conditioning issues, and no power steering issues.

As for the Neon pulley, it won't work. They use a V belt, not a ribbed serpentine belt. Their accessories are laid out completely differently.

And for the install, the following must be removed:
passenger side motor mount
crossmember
front motor mount
battery
battery tray
battery stay
washer reservoir
rear motor mount
wheel (passenger side front)
splashguard (same corner)
then you must use a 3 jaw puller with a 5 ton rating to pull off the stock pulley.
The new pulley should be cooked in an oven to 500 degrees or so
and then reassemble in reverse order. This install is a pain in the ass.


-=B=-

 

[Eclipse419]

is that true you cant drive your car in the highway with the pulley..someone told me if you drive too fast..the pulley belt slips off because there no support and can cause major problems

 

[The1Bill]

Not true. The belt moves at a slower speed with the underdrive pulley then it does with a stock pulley. The only time that belts skip off is if the pulley is not all of the way onto the crank. Just crank it down to 105 lb/ft, and the belts should stay right where you put them. There is a disclaimer on Gary's site saying that it is not intended for public roadway use. That's just BS to cover their asses, as the pulley is not CARB approved, and there is no guarantee that it is legal for use in your state.
-=B-=

 

[aero_ub]

Well, I think that UD pulleys would be a good thing to do if you have the money to spend. They at least look nice, I know for my GP they had some nice bright blue ones that would look cool but it's just not worth the money to me.

As far as using track times to determine what they are giving you for increases, it's not at all accurate. There are way to many variables to take into account to tell if they gave you anything at all. It's obvious that they do HAVE to give you at least something but I would be go as far as saying that they definitely do not give you even near 10-15hp. At the track you can have that much variance in your runs without changing anything at all. You have to take into account the Temp. outside, the Bar. pressure, Humidity, track temp., track prep on that day (how well they sprayed it), The temp of your car at that run (how heat soaked the block is), and that doesn't even account for ANYthing that you do yourself when launching or running down the track at all. And all these can and do change even if you did it all on the same day!

I'm not bashing anyone or trying to rain on your parade but it definitely is not logical or true that they give you that much gain. But, for every car that I’ve had and read on boards for, there are people are under this impression about pulleys...not sure how or why though. Even on a dyno it is somewhat tough to get accurate consistent results when you are only talking about less than 5hp.

But regardless of how much they gave you, if you could tell a difference after putting them on then that's great and worth it...and they can look nice too. I would get them myself if I could justify parting with the $$!

later
Ken

 

[The1Bill]

Actually, the average of a series of track times are a good indicator. It wasn't like I was dumb enough to run one night, install the pulley, and run again. This is the culmanation of about a year before installing the pulley, and several months afterwards. The average gain that I saw was .15 second. And regardless of the power gain, .15 seconds is .15 seconds.
-=B-=

 

[greyforestgst]

thinkin about buying this
http://www.machv.com/macvalpulkit.html
four piece, since its so cheap yet is solid aluminum

ive read around and searched for the droves of arguments over harmonic dampeners on the crank pulley, but both sides just seemed to speculate and never actually went anywhere, hence this poll.

 

[greyforestgst]

wow this thread is incredibly successful
im bout to just go for it, since i gotta change my belts anyway

 

[loreak]

when i had a 2g, i wouldnt have done it because of possible crankwalk, with the 6 bolt i dont worry so i would probably put that on a 6 bolt but not a 7