Stock Pulley or Underdirve Pulley? G37s

[ProjectMM]

What’s up guys, I'm just wondering if anyone is running a under drive pulley on there G37? The only one that I have found is from Stillen, all the other pulleys are stock size. Is there a problem with an under drive on the G37? Thanks for any info! I've always ran an underdrive and never had any problems!

[4drsleeper]

I bought the UR pulley from Stillen for my 08 G35 Sedan...and yes, it is the stock size. But, the stock pulley weighs 8 lbs and UR pulley weighed 2 lbs. It actually made quite a difference and you don't have to buy new belts.

[pfarmer]

What’s up guys, I'm just wondering if anyone is running a under drive pulley on there G37? The only one that I have found is from Stillen, all the other pulleys are stock size. Is there a problem with an under drive on the G37? Thanks for any info! I've always ran an underdrive and never had any problems!

Just keep this in mind. Regardless if the cause of event or not, it can be an issue:

http://forums.g35club.org/zerothread/433767

Perry

[audtatious]

I still find it weird that a pulley would cause such a catastrophic failure in a VQ. People have been putting them on VQ's for years and I have never heard of one having such an issue.

[pfarmer]

I still find it weird that a pulley would cause such a catastrophic failure in a VQ. People have been putting them on VQ's for years and I have never heard of one having such an issue.

That may be one very good reason to analyze the crank. He may have a case with Infiniti if it could be proven that the crank had a manufacturing defect in it that rendered it an issue in a unmodified state. Other rules other than the warranty may then play into the poor guys side.

Regardless without the mods I believe it would have been a no brainer as far as being covered under warranty, or at the minimum a heck of a lot less of an issue.

Perry

[AZhitman]

For the risk, it's not worth the couple hp gain.

There's plenty of other places to pick up a coule horses. Even if the crank doesn't fail, if the keyway gets "wallowed" out, that's a bad, bad thing.

If you MUST buy one, get a known quality unit from Stillen or UR. Cheap out at your own risk.

[Sentientbydesign]

I still find it weird that a pulley would cause such a catastrophic failure in a VQ. People have been putting them on VQ's for years and I have never heard of one having such an issue.

VQs have only been over 6500 RPMS recently. Could that be a contributing factor?

[pfarmer]

VQs have only been over 6500 RPMS recently. Could that be a contributing factor?

Or could the problem not be the pulley but some of the exhaust mods, maybe combined with the Cobb? I don't think I have yet to hear what was really found. That is did (or could) the crank fail due to external or internal forces (in relation to block).

While not as bad as a crank I have lost a timing gear due to a timing issue on a Mustang V6 once. I can easily understand how changes in harmonics from a pulley or from exhaust mods (or both together) could lead up to a crank failure. From what I have been reading it appears that there could be an issue with FOD brought on by exhaust modifications. It would be a good thing to know what was the root cause of the this particular event.

Perry