Underdrive Pulleys

[flyguy2618]

I was wonderin how much these pullys actually help, i dont think there are many variations of pulleys out for the Z right now but im looking at getting some pollished aluminum underdrive pulleys, does anyone else have these installed in there Z. If so how are they can you feel the difference in power? Also since they do underdrive the engine does it still get enough power to everything else that the pullys power? If anyone has any other information on these tell me what you think.

[flyguy2618]

No one knows about underdrive pulleys?

[AZhitman]

Not a fan.

There's a lot better ways to free up / make power, that aren't as dangerous.

Many of the pulleys for the VQ motors have created issues with the keyway, necessitating crank replacement.

If you need 3 hp that bad, take out your spare tire or floor mats.

[NSRsheets]

^

[flyguy2618]

Not a fan.

There's a lot better ways to free up / make power, that aren't as dangerous.

Many of the pulleys for the VQ motors have created issues with the keyway, necessitating crank replacement.

If you need 3 hp that bad, take out your spare tire or floor mats.

really? How or why is it dangerous?

[AZhitman]

Many of the pulleys for the VQ motors have created issues with the keyway, necessitating crank replacement.

[flyguy2618]

O sorry about that didnt quite get that but now i do, thanks for the info.

[modified350z]

Underdrive Pulley Set, Polished, 03-07 350Z Quantity in Basket:noneCode: 10-2195Price:$329.95

Quantity: Description:Unorthodox Racing Ultra Street lightened under drive crank pulleys are made of premium lightweight 6061-T6 billet aluminum to ensure consistency of the material's strength and balance. An average of 5 to 12 HP and 4 to 8 lbs.-ft. on normally aspirated engines and 8 to 16 HP and 8 to 18 lbs.-ft. on forced induction engines can be gained. Higher gains may be possible on certain set-ups. For example, tests on one Nissan 300ZX twin-turbo saw gains as high as 37 HP and 45 lbs.-ft. on the dyno. Power gains are obtained by weight loss and underdriving. Underdriving on Unorthodox pulleys is maximized for power, but not at too great a ratio in order to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving HOPE THAT HELPED OUT. I ADDED THESE TO MY Z AND YOU CANT TELL A CHANGE IN HORSEPOWER EXCEPT ON A DYNO, BUT YOU WILL GET THRU GEARS TWICE AS FAST. http://www.webspawner.com/users/drewh24/

[flyguy2618]

Hey thanks alot, ya those are the exact ones i was looking at getting. So you like them, would you recomend me getting them? Do you know anything about what "AZhitman" was talking about when he was talking about how they mess up peoples engines?

[modified350z]

Those pulleys are turned by belts. (now just throwing a number out) Lets say the three pulleys you want to swap out(stock) weigh 13 pounds total. The new pulleys you will be putting on weigh a total of 6 pounds. Those belt driven pulleys can suck up to 15% of your engines power, just by operating everything. With the new lighter pulleys and belt......it gives you most of that power back because they are so light and spin easier/faster. Also it will help with your revolutions. You will be in and out of a gear alot faster then stock pulleys. Im sure I said something wrong in hear and will be corrected, but thats it in a nutshell. Hurting the engine, I've never heard of that, but anything is possible.

[flyguy2618]

Hey that explains what i was wondering pretty well, it sounds like what i want for my Z so guess im going to have to look into that a little bit more. But thanks for everything modified.

[flyguy2618]

Hey Modified one more question about the pullys. How are they to install do you need to take out the engine to do it? How labor intensive is it and how long do you think it takes to do?

[modified350z]

You need take of the engine cove and take out your fans. YOu will have two hoses that you have to take off(and will lose some radiator fluid) once you get those fans out and free up the space. Its just a matter of taking your old belts off and have some wratches and wrenches and about 2 hours to do it wright and clean up. Loosen the bolts up on each pulley and take off and put the other one in its place. I dont work on cars but I had a buddy show me and it was quite simple

[StevieRaySTL]

I was also looking into doing it on my J/vg30 . I was advised not to for what seemed like the same reason as Azhitman says above.

[AZhitman]

"Get through gears twice as fast"?

No.

You're freeing up a few HP, that's all. It's not a lightened flywheel, and it's not going to reduce rotational inertia significantly.

[trev0006]

don't think they help much.

[joe603]

They are also a problem if you want to install an aftermarket stereo. The factory alt. can barely keep up with the normal pulley setup!

[flyguy2618]

Why is that? Not enough power to the alternator? Does it get enough power with underdrive pullys if there isnt any aftermarket sterio or big subs?

[PerfectApex]

Not a fan.

There's a lot better ways to free up / make power, that aren't as dangerous.

Many of the pulleys for the VQ motors have created issues with the keyway, necessitating crank replacement.

If you need 3 hp that bad, take out your spare tire or floor mats.

Great reply and very true!!! Total waist of money.

[NSRsheets]

I trust what Greg says.