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Discussion Starter · #1 ·
Will a lightened TB pulley make a noticable performance difference with my current setup? I want to go with just a lightened crank pulley, instead of some underdrive pulleys and/or and alternator pull. My mods are only-
TurboBack TurboXS
Blitz Nur Spec Axle-back
Blitz SUS intake
TurboXS Unichip
Samco Hoses (woopdedoo!)

I did not want to get an up pipe because of the difficulty everyone was having getting theres to seal. I cant see spending 3+ hours trying to get a section of the manifold replaced..

Anyways will a lightened pulley do me some good for the Butt-Dyno??
Thanks
 

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Just a lightenned one I doubt it. An underdrive one will though. I've always gotten 4-6 whp gain on Hondas with the underdrive pulleys and the nice thing is that they work with any setup and require no tuning. Just bolt on and go.
 

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I know this is kind of bias however a lightweight pulley is SO much better than an underdriven one. Underdrive pullies main source of the extra power actually comes from the fact that you are making it lighter!!!.
You gain little in extra power from the smaller pulley itself and it in no way makes up for the fact that you are losing accessory power. I know it doesnt sound like a big deal right now, but I know in the peak of summer, my AC is a hell of a lot colder than stock even. Now imagine it in comparison to a car that has underdrive pullies.

Email me and I'll cut you a good deal on one.
 

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To address a few of the items mentions above. The GFB underdriven pulley kit is a crank and alternator kit. It doesn't touch the AC at all.

This lower weight yields a large reduction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range before the turbo spools up. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.

It is underdriven by about 15%, meaning that you get full charge at 1000 RPM instead of 850 RPM which will only cause problems if you plan to park your car at idle with the fan, high beams, air conditioning and stereo full blast for extended periods of time.

This is the reason for under driving, since from the factory the accessories (alternator, A/C, power steering) are designed to run 100% at idle, so at high RPM they are causing excessive and unnecessary drag. Reducing the drive ratio by 15% doesn't have a large impact at idle, but at say 5000-7000 RPM, 15% becomes a much larger proportion and the reduction in drag is much more noticeable.

My vote is for the GFB pulley kit.

Carlo
 

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I love my TB racing pulley! Do a search, please. I'm not alone. My A/C works great! My lights don't dim! The install is easy!

misterx
 

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I've measured the voltage on the UR pulleys and at idle they are 12.2 with 14.4 just off idle. Not a problem at all and actually the underdriving DOES make a big difference. I had absolutely no changes to AC peformance on any car I've ever done one on.
 

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God said:
I've measured the voltage on the UR pulleys and at idle they are 12.2 with 14.4 just off idle. Not a problem at all and actually the underdriving DOES make a big difference. I had absolutely no changes to AC peformance on any car I've ever done one on.
Which pulley did you use, Dan?
 

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Carlo said:
To address a few of the items mentions above. The GFB underdriven pulley kit is a crank and alternator kit. It doesn't touch the AC at all.

This lower weight yields a large reduction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range before the turbo spools up. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.

It is underdriven by about 15%, meaning that you get full charge at 1000 RPM instead of 850 RPM which will only cause problems if you plan to park your car at idle with the fan, high beams, air conditioning and stereo full blast for extended periods of time.

This is the reason for under driving, since from the factory the accessories (alternator, A/C, power steering) are designed to run 100% at idle, so at high RPM they are causing excessive and unnecessary drag. Reducing the drive ratio by 15% doesn't have a large impact at idle, but at say 5000-7000 RPM, 15% becomes a much larger proportion and the reduction in drag is much more noticeable.
well to each their own,

however the majority of us who dont 5-7000 rpm in daily traffic and unfortunately have to sit in traffic and such might care,

I dont see why you should degrade the luxury of a new car, when you can get just as much power from a lightweight pulley

its like arguing over getting 16inch 19lb wheels or 18 inch 15lb wheels

gfb makes a great kit too, and if you want underdrive I'd suggest getting it as well
 

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God said:
I've measured the voltage on the UR pulleys and at idle they are 12.2 with 14.4 just off idle. Not a problem at all and actually the underdriving DOES make a big difference. I had absolutely no changes to AC peformance on any car I've ever done one on.
where did you meter from and what kind of load did you put on it?
 

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the vishu power pulley is great....i have an autometer volt meter on my a pillar as well as my boost and there was absolutely no difference in alternator....just over 14 with my car running....and the ac is just as cold as before....as if i ever use it....robs gas and power:) ...oh and the pulley weighs so much less then the stocker...
 

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Discussion Starter · #12 ·
thanks for all the replies. I am still unsure wether to get the Go fast bit underdriven set, or the TB racing. I want to keep that luxory feel of my new car while still gaining a few horse power. From what you said God, it sounds like there is hardly any voltage drop at idle? How does this affect the idling of the car if any? Also are there any dyno carts of either or? The TB Racing would be perfect if there was actually a hp gain dynoed by someone.(no new belts, no alternator pulley to slap on, and throwing voltage drop out of the equation) Also, I saw Vishnu had a dyno of his underdriven pulley and he gained, what, like 7 or 8hp across the board? Thats pretty fair...
 

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TB RACING said:


where did you meter from and what kind of load did you put on it?
I measured using a Power FC ECU at the computer. I put no load. Just sitting in it revving it up and looking at the data screen. This was on a Type R which you may know has a pretty weak alternator from the factory.
 

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I have a Vishnu UD pully and love it. Installation takes less than an hour (don't even have to jack the car up! I surprised my wife by how fast I finished "this mod"). The car does drive better in traffic while off boost and in second gear at low speeds. It also helps in the high end, but just not as noticable.

I seriously doubt it effects my AC at all, and as Dan said, the alternator effect is only MINOR. Besides, if you have the AC on, then you're defeating the purpose of putting the pully on your car in the first place. Isn't this board about gaining HP not LOOSING it. Who drives with the AC on, that's what windows are for! :D

I would say the gain was about 1/2 of the power the Uppipe gave me according to my BUTTDYNO.

-Jason
 

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Discussion Starter · #20 ·
Ok lets get a little deeper! =)
For someone planning to get just a 5-channel amp to power all surround speakers a little better, and one 10" subwoofer, would this be considered a voltage hungry system? I do plan to upgrade my sound system later, but not to the extent of 1000watts pounding a couple of 12"s in the trunk! Does anyone else out there run a 5-channel (50x4, 200x1 or 50x4, 150x1) and have positive results from their underdriven crank and alternator pulley? Thanks guys!
 
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