I just installed the KJR pulley on my G35 (because I have a procharger normally on the car, therefore it cannot be underdriven).

So at the moment, I'm N/A with about 260 at the wheels with my current mods (UTEC, MREV+, Spacer, Headers, exhaust, HF cats, intake). that being said, I followed the "hint" in the technical forum for getting the crank bolt off without taking the radiator out, and it worked. My gripe (or the thing that scared me anyway) is that the OEM pulley goes right up against the front cover of the engine, but the KJR pulley does not because the ring closest to the engine is not as thick. (see pics below).






As far as performance, I think it's the placebo effect, but I notice a slight increase at higher RPM and it revs a hell of a lot faster, but that's about it. If I didn't buy it for $100 brand new, I probably would have left the stocker on.

...and for all you naysayers, it is perfectly balanced. I had it checked at Havanna Machine yesterday and it is 100% perfectly balanced to 10,000rpm. They didn't have to touch it one bit for balance.
There is no engine vibration or anything. I love that part of it.

 

Nice

 

Sweet! Sometimes I think I should've done the KJR pulley vs. the UR Underdrive. Oh well... I'm happy.

 

I have one of those things have not installed it, they got a LOT of bad threads about jacking up the crank oil seal.
I hope you don't have any issues with it.

 

Nope. Zero issues. Oil seal looked awesome when I removed the OEM pulley, and this one I checked with a digital caliper for thickness, and it is identical to the nearest thousandth of an inch. (around the outer edge where it fits against the seal)

 

I had one on my HKS SC, and took it off after 5K miles. It did cause a vibration, and became annoying and louder. I had installed by a local tuner shop, and had it removed at my friends shop, also local. We found that it was not well balanced and possibly warped with the high revs from the track and dyno tuning. Also no damper, I think NISSAN knew what they were doing when they built the OEM one..just my $.02. Hope you don't have the same problem.
GL!

 

That's why I had a machine shop check it for me. It is perfectly balanced up to 10,290rpm (I have the sheet in front of me)...it starts to show some vibration after that, but seeing as my VQ won't ever be past 7600rpm, no worries. That vibration is due to the soft metal most likely (aluminum).

 

Good deal man!