# Underdrive pulley, or light-weight crank pulley? ways to increase hp 2.5 jetta



## cdf2.5 (Jun 5, 2012)

What would be more beneficial? a 15% underdrive pulley or a lightweight crank pulley?

also what are some ways to get an increase in hp *besides* an air intake, exhaust, turbo, ecu chip.


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## 8V Fury (Jul 26, 2003)

Underdrive and lightweight pulley are not going to do much at all. To increase hp, you will need to do exhaust, intake, chip, and turbo, there is no way around it, unless there is some magical hp dust you can sprinkle on the engine.


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## Jade Wombat (Oct 20, 2004)

Just remember, all the power you can build up doesn't mean a hill of beans if you can't get all of to the ground. If you had two stock 2.5 jetta on a twisty track course, but one had limited slip, good tires, and improved aero. which would be faster?


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## cdf2.5 (Jun 5, 2012)

So far I have a carbonio intake, apr ecu flash, and a custom exhaust that's just two resonators from te cat back. It was a great power increase at first but now it's gotten kind of borig and my 0-60s are in the 7.5s range. 

I've read that motor/tranny mounts make a big difference in 0-60 is this true?


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## 8V Fury (Jul 26, 2003)

Anything that will help reduce or elimnate the movement of the motor and transmision wil help a little. Have you upgraded the clutch on your car, if it is a manual.


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## cdf2.5 (Jun 5, 2012)

yeah i was thinking about getting bfi's motor and tranny mounts will this decrease my 0-60 significantly? well actually my stock clutch went out because... i drive it hard.. we put a single mass flywheel conversion in.


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## pamatt (May 2, 2012)

*pulley*

Try the Neuspeed pulley. We have used them for years and they have worked well as advertised. The only other item might be a good cam. If you go to the track try VP street blaze 100. It will add some hp & torque. Are you using a premium synthetic oil?


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## paul610 (Oct 26, 2010)

i think underdrive pulleys only make a difference on supercharged cars if I'm not mistaken


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## clarksongli (Nov 4, 2003)

cdf2.5 said:


> What would be more beneficial? a 15% underdrive pulley or a lightweight crank pulley?
> 
> also what are some ways to get an increase in hp *besides* an air intake, exhaust, turbo, ecu chip.


 These are some crazy responses..... 

don't waste you time with underdrive or lightweight pulleys. i actually run a heavier dampener on my motors.....you want to avoid harmonics on the crank....with a 4cylinder crank, there can be multiple degrees of deflection under load.....add another cylinder in length and you have even more deflection.....stick with the stocker. 

in terms of power adders....you will not find anything that adds more power than forced induction....bang for the buck, it cannot be beat....my suggestion is to save or build(but i assume you are not that savvy yet, based on the fact you are asking the question in the first place) a turbo setup..... 

4 cylinder AEB 20VT makes about 150hp.....my motors make about 550BHP now.....and those would be considered mild by today's standards. 

You will never see large gains with natural aspiration bolt ons without major $ into motor work.


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## Gott ist gut (Jul 2, 2010)

You aren't gonna find any cheap HP with our motor. 
These are all average prices between good-best, used-new and estimated crank horsepower. 
Pulley ~ $150 arguably 5hp 
CAI or Ram Intake ~$150-$300 ~ 10hp 
SRI Manifold ~ $1000 ~ 30hp 
ITB's ~ $1000-$3000 ~ 50hp 
Headers ~ $350-$1000 ~ 20hp 
Full Exhaust (Headers+ highflow cat + race muffler)~$1000-$2000 ~35-45hp 
Turbo ~ $1500-$4000 ~ 100hp-200hp 
Chip ~$200-$400 ~ with intake and exhaust you will see about 50-75hp 

With everything above in crank horsepower estimates, it's all about getting that power down into the wheels. That's where the motor/tranny mounts come into play. Tires are also very important. And don't underestimate weight reduction, I believe the common fact is 100lb = 1/10 sec, so lay off the Krispy Kreme  
Oh yeah, a short throw shifter can help your trap times :thumbup: 
Light weight wheels and clutch help as well just not exactly sure how...Clarksongli may be able to tell us. 

And solid springs in the rear will help with a launch, it will prohibit the front from lifting therefore increasing grip on the front tires. Some people use wedges in the rear springs. 

And race fuel of course


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## cdf2.5 (Jun 5, 2012)

Gott ist gut said:


> You aren't gonna find any cheap HP with our motor.
> These are all average prices between good-best, used-new and estimated crank horsepower.
> Pulley ~ $150 arguably 5hp
> CAI or Ram Intake ~$150-$300 ~ 10hp
> ...


 thanks! most helpful response so far what's an ITB? never heard of it.


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## Gott ist gut (Jul 2, 2010)

http://www.google.com/#hl=en&safe=a...f.,cf.osb&fp=2ee01b6b490aafd&biw=1159&bih=747


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## Lella Autosport (Dec 12, 2010)

cdf2.5 said:


> What would be more beneficial? a 15% underdrive pulley or a lightweight crank pulley?


If you are saving the same amount of weight from each, the crank pulley will be more beneficial. Crank rotates twice for each time the cam turns once.


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