It's funny if you read everything you will see that the gains are shitty for a small motor but pretty good for a bigger one, but the excess crankshaft wobble gets worse the longer the crank so you're fucked either way.
Do your research people! If you see something that is like 80 bux and promisses 8HP at the wheels then there's gotta be a downside or it's just a straight lie...
It seems to me that the minnimal power gains aren't worth loosing your harmonic dampener. Get a CAI instead, you'll get more gains anyway
Since when did you start visiting xceedspeed? Especially since you live in Cali and it's a Michigan board?
As far as the underdrive pulley, I have heard all the rumors and warnings. I never could find anything concrete though so I put one on my car and I like it.
Originally posted by Chris Corolla S It's funny if you read everything you will see that the gains are shitty for a small motor but pretty good for a bigger one, but the excess crankshaft wobble gets worse the longer the crank so you're fucked either way.
Do your research people! If you see something that is like 80 bux and promisses 8HP at the wheels then there's gotta be a downside or it's just a straight lie...
Its all about percentages man. CAI on a 5.7L LS1, around 30HP. CAI on a 1.8L 1ZZ, around 7HP.
i wont deny the fact that it does cause premature wear on the crank...but really think about this: almost every performance modification causes some kind of premature wear
i had an underdrive on my corolla. they said 10 to the ground was the gain. sent me a dyno sheet from a corolla. 1zz has a pretty decent bearing design as far as mains go. i thought it to be a fair risk.
as for the s2k, there is no way i would change that crank pulley
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93 toyota mark II tourer V
1jz-gte twin turbo goodness!
93 toyota scepter turbo stored back in the states!
*in loving memory rapeacivic*
Here are our tried and true crank pulleys, the ones we’re all familiar with. In this series, additional power gains are seen from the underdriving of all the accessories (which accounts for about 15% additional gain). However, we do not push the amount of underdrive for two main reasons. First, it is important to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving. Second, not much horsepower is gained from extreme underdriving. In most applications all of our underdriving is done with the crank pulley, not the accessory pulleys. This is done so maximum weight loss can be achieved at the crank where most of the horsepower gains are found. Most Ultra Series underdrive crank pulleys are available in natural polished aluminum as well as black, red, and blue anodizing.
I think the underlined part should be read clearly.
This is from unorthodox.
I'm curious though, if the harmonic balance is in fact a problem to be reckoned with, then how would the ultra SS fair, which supposedly is just a lightened replacement crank pulley?
Originally posted by Talisman18 Since when did you start visiting xceedspeed? Especially since you live in Cali and it's a Michigan board?
As far as the underdrive pulley, I have heard all the rumors and warnings. I never could find anything concrete though so I put one on my car and I like it.
I've been visiting xceed a bit since you joined TN! Your first sig here labled you as an xceed junkie so I checked it out
I mainly just lurk and read drag racing stories and the tech articles... There are some very serious modders/racers there (as you know) so the random info is very good....
Nothing Concrete??? I think the information provided through the above links is very concrete. (See the Toyota engineering book in the link on the xceed article) The Harmonic Dampener is there for a reason and you can't expect to replace it with a solid piece of alluminum without any adverse affects... Besides with even a small doubt why do it when the gains are so minnimal...
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Last edited by Chris Corolla S; 04-02-2004 at 11:56 AM.
Originally posted by CrawlingEye I think the underlined part should be read clearly.
This is from unorthodox.
I'm curious though, if the harmonic balance is in fact a problem to be reckoned with, then how would the ultra SS fair, which supposedly is just a lightened replacement crank pulley?
CRANK PULLEY = HARMONIC DAMPER
Look at a picture of it... if it has a rubber inner ring great, if it replaces it with a solid piece, not so great.
fyi if you are looking for unbiased info on a product, don't get it from that product's manufacturer
Originally posted by silverstreakin i wont deny the fact that it does cause premature wear on the crank...but really think about this: almost every performance modification causes some kind of premature wear
i had an underdrive on my corolla. they said 10 to the ground was the gain. sent me a dyno sheet from a corolla. 1zz has a pretty decent bearing design as far as mains go. i thought it to be a fair risk.
as for the s2k, there is no way i would change that crank pulley
Now here is a good point. It's a CALCULATED RISK. If you do your homework and still think it's worth it, then do it up.
But don't be blind to the truth because you already did it then found out later the full story
Originally posted by Chris Corolla S CRANK PULLEY = HARMONIC DAMPER
Look at a picture of it... if it has a rubber inner ring great, if it replaces it with a solid piece, not so great.
fyi if you are looking for unbiased info on a product, don't get it from that product's manufacturer
I'm not arguing with you. I was simply citing one of the more credible UD pulley manufacturers. I'm still in limbo myself if I want a UD pulley.
From the article though, it seemed to talk about Honda more than Toyota; does Toyota use the same mechanical layout as a Honda?
Originally posted by Chris Corolla S Now here is a good point. It's a CALCULATED RISK. If you do your homework and still think it's worth it, then do it up.
But don't be blind to the truth because you already did it then found out later the full story
absolutely, i knew the risks of it, yet i still did it. i was wanting the engine to go out of warrenty, so i could rebuild it to my specs. had that of been the case, i would have done my majic on the 1zz. now the dealer i traded it in to is begging for my stock airbox. they havent realized that i have the harmonic balancer
__________________
93 toyota mark II tourer V
1jz-gte twin turbo goodness!
93 toyota scepter turbo stored back in the states!
*in loving memory rapeacivic*
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Underdrive Pulley
Your first sig here labled you as an xceed junkie so I checked it out
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