STILLEN lightweight crank pulley

Crash · 05-30-2009, 09:19 PM

Cool... Looks like if the U/D pulley is gaining 5+whp, the lightened wheel would gain maybe 2-3. Doesn't seem worth it.

Thanks. Hadn't seen that thread.

KingDavid · 05-31-2009, 02:39 AM

Quote:

Originally Posted by Crash

Cool... Looks like if the U/D pulley is gaining 5+whp, the lightened wheel would gain maybe 2-3. Doesn't seem worth it.

Thanks. Hadn't seen that thread.

Power isn't everything and that isn't the function of a flywheel.

semtex · 05-31-2009, 12:49 PM

Quote:

Originally Posted by KingDavid

Power isn't everything and that isn't the function of a flywheel.

We're talking about pulleys in this thread, not flywheels.

black09Z · 05-31-2009, 12:06 PM

true dat!

Crash · 05-31-2009, 03:54 PM

HAHA... Exactly. I was thinking, "I didn't say Flywheel, did I?"

Believe me, a lightweight flywheel makes a big difference. If you're making serious power though, it becomes the weak link in the chain. For 450BHP and down, lightweight flywheels are great.

But as far as the pulley goes, it's not going to make enough difference when you're still close to stock power. Spinning mass is serious business, but when you're only gaining 2-3 HP to the wheels, it's not worth it. An underdrive pulley is different, though.

black09Z · 06-07-2009, 10:24 AM

so what are the pros and cons of the underdrive?

travisjb · 06-07-2009, 12:27 PM

pros - more hp, possible faster rev climb (not sure this is confirmed)
cons - none we know of except potential dispute with nissan next time you bring it in for warranty... or extra work to swap back before you bring in for warranty

imag · 06-07-2009, 12:52 PM

Quote:

Originally Posted by travisjb

pros - more hp, possible faster rev climb (not sure this is confirmed)
cons - none we know of except potential dispute with nissan next time you bring it in for warranty... or extra work to swap back before you bring in for warranty

One other con that should be mentioned - you won't get as much current to your battery through the alternator (underdrive means lower belt speed). This is probably only an issue if you have a high-current audio system. I assume the lower speed to the power steering pump doesn't make any difference...

wstar · 06-08-2009, 12:41 PM

Quote:

Originally Posted by imag

One other con that should be mentioned - you won't get as much current to your battery through the alternator (underdrive means lower belt speed). This is probably only an issue if you have a high-current audio system.

This is only true at idle though. Once you bring the revs up to driving speed the alternator is still getting more RPMs than it needs (which is why they have clutches) to maintain the proper output. Even at idle, I don't think you're actively draining your battery or anything, just not charging it as fast

Perhaps if you have a truly monster audio system it might be a concern. I don't, and I haven't had any issues with the UD pulley as far as voltage is concerned though, and I've had mine on for quite a while now. I also switched to a tiny PC680 battery mounted in the trunk via a long cable run. Even then, I still haven't had any problems starting the car, or any other electrical issues.

Quote:

I assume the lower speed to the power steering pump doesn't make any difference...

Right, the other two minor points for potential concern for the UD pulley are the AC and the Power Steering. I haven't had any issues with either. The change to the power steering isn't really noticeable, and again even if it were, it would only be at low rpm rolling around a parking lot. AC is fine too, still blasting ice cold air in the Houston heat.

In short, there really are no cons, unless maybe you have very demanding electrical needs at idle.

semtex · 06-07-2009, 04:02 PM

It should also be mentioned that if you intend to install a supercharger in the future, you don't want an UD pulley, as superchargers are belt driven. Although you could swap it back out if you install a supercharger down the road.

black09Z · 06-08-2009, 11:20 AM

no i meant as like compared to the light weight pulley

semtex · 06-08-2009, 11:30 AM

Those ARE the cons compared to the lightweight pulley.

Crash · 06-08-2009, 08:41 PM

^^ So no vacuuming the house on the car's power parked in the driveway?

RCZ · 08-02-2009, 10:34 PM

by virtue of being underdriven, the underdrive pulley is smaller and lighter than the normal lightweight pulley. So no, they replace the same part and the underdriven one is smaller and lighter.

FairLadyZee · 08-01-2011, 09:33 PM

Got my stillen lightweight crank pulley put on and was wondering if n e one would kno why the engine makes noise now when it down shifts at times goin downhill and a little bit when i get high rpm's??...its kinda like a hissing sound..sounds like the belt but its suppose 2 use the stock still..thanks

05-30-2009, 09:19 PM	#1 (permalink)
Crash A True Z Fanatic Join Date: Dec 2008 Location: Los Angeles Posts: 1,853 Drives: 02 Corvette Z06 Rep Power: 590	Cool... Looks like if the U/D pulley is gaining 5+whp, the lightened wheel would gain maybe 2-3. Doesn't seem worth it. Thanks. Hadn't seen that thread. __________________ 2002 Corvette Z06 - Totaled 2003 Corvette Z06 50th Anniversary

05-31-2009, 03:54 PM	#5 (permalink)
Crash A True Z Fanatic Join Date: Dec 2008 Location: Los Angeles Posts: 1,853 Drives: 02 Corvette Z06 Rep Power: 590	HAHA... Exactly. I was thinking, "I didn't say Flywheel, did I?" Believe me, a lightweight flywheel makes a big difference. If you're making serious power though, it becomes the weak link in the chain. For 450BHP and down, lightweight flywheels are great. But as far as the pulley goes, it's not going to make enough difference when you're still close to stock power. Spinning mass is serious business, but when you're only gaining 2-3 HP to the wheels, it's not worth it. An underdrive pulley is different, though. __________________ 2002 Corvette Z06 - Totaled 2003 Corvette Z06 50th Anniversary

06-07-2009, 12:27 PM	#7 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	pros - more hp, possible faster rev climb (not sure this is confirmed) cons - none we know of except potential dispute with nissan next time you bring it in for warranty... or extra work to swap back before you bring in for warranty __________________ 2009 370Z #104 For Sale

06-07-2009, 04:02 PM	#10 (permalink)
semtex A True Z Fanatic Join Date: Jan 2009 Location: Behind enemy lines Age: 54 Posts: 5,995 Drives: People to drink Rep Power: 33	It should also be mentioned that if you intend to install a supercharger in the future, you don't want an UD pulley, as superchargers are belt driven. Although you could swap it back out if you install a supercharger down the road. __________________ "There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) \| 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf.

06-08-2009, 11:30 AM	#12 (permalink)
semtex A True Z Fanatic Join Date: Jan 2009 Location: Behind enemy lines Age: 54 Posts: 5,995 Drives: People to drink Rep Power: 33	Those ARE the cons compared to the lightweight pulley. __________________ "There are no small accidents on this circuit." -- Ayrton Senna 316.8whp & 248 ft/lbs (Dyno Dynamics) \| 319whp & 256 ft/lbs (DynoJet) (04/23/10) Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf.

05-31-2009, 12:06 PM	#4 (permalink)
black09Z Base Member Join Date: Mar 2009 Location: killeen tx Posts: 202 Drives: black 09 370Z 6spd Rep Power: 17	true dat!

06-07-2009, 10:24 AM	#6 (permalink)
black09Z Base Member Join Date: Mar 2009 Location: killeen tx Posts: 202 Drives: black 09 370Z 6spd Rep Power: 17	so what are the pros and cons of the underdrive?

06-08-2009, 11:20 AM	#11 (permalink)
black09Z Base Member Join Date: Mar 2009 Location: killeen tx Posts: 202 Drives: black 09 370Z 6spd Rep Power: 17	no i meant as like compared to the light weight pulley

06-08-2009, 08:41 PM	#13 (permalink)
Crash A True Z Fanatic Join Date: Dec 2008 Location: Los Angeles Posts: 1,853 Drives: 02 Corvette Z06 Rep Power: 590	^^ So no vacuuming the house on the car's power parked in the driveway? __________________ 2002 Corvette Z06 - Totaled 2003 Corvette Z06 50th Anniversary

08-02-2009, 10:34 PM	#14 (permalink)
RCZ A True Z Fanatic Join Date: Nov 2008 Location: Miami Posts: 6,403 Drives: '09 370Z Rep Power: 1119	by virtue of being underdriven, the underdrive pulley is smaller and lighter than the normal lightweight pulley. So no, they replace the same part and the underdriven one is smaller and lighter.

08-01-2011, 09:33 PM	#15 (permalink)
FairLadyZee Enthusiast Member Join Date: Jun 2011 Location: Connecticut Posts: 281 Drives: 09'-370z-Silver-SP Rep Power: 14	Got my stillen lightweight crank pulley put on and was wondering if n e one would kno why the engine makes noise now when it down shifts at times goin downhill and a little bit when i get high rpm's??...its kinda like a hissing sound..sounds like the belt but its suppose 2 use the stock still..thanks

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