Arite, what do u FI ppl think about the KJR crank pulley for a supercharger? The crank pulley is suppose to be liter and the same size as the oem crank and uses the same oem belt. Is this safe for sc and will I still see gains??


Site:
http://www.kjrperformance.com/products.htm

 

I have the HKS system, with this pulley. I know of at least one other person w/an HKS and the KJR, and between the 2 of us, we are "SAFE" thus far (knock, knock..). LOGICALY, you will gain power, as the SC will not have to use as much force to turn the crank. But, that's just my theory, and reason for use. Good luck.
-A.

 

I am still not convinced that these pullies are safe long term and I hope that this thread does not rehash that issue. There is a reason that Nissan included the rubber damper ring in the OEM pulley and I'll leave it at that.

For the little bit they gain, I am going to wait a few years to see if there are any issues.

 

Im putting my stock pulley back on .When they took my motor apart , the light Wt. pulley had a groove dug into it where it slides into the block . Might be from running the belt very tight

 

When I removed the UR pulley when I installed the SC, my pulley had a very slight groove.

My biggest concern was, IIRC, the fact that the OEM pulley is connected to the crank via this rubber damper. The stress the SC places on this piece of rubber has got be be WAY outside of what Nissan ever expected to be placed on it. At some point, I suspect that it will fail and I will be forced to replace it with either another OEM pulley assembly or a Fluiddampr pulley.

 

I was running the SC for 5000 miles before I put on the light wt. pulley . It didnt show signs of wear

 

I ordered one and will keep you guys informed when I get it installed

 

The stock pulley didnt show signs of wear....The light wt. showed signs of wear after 1000 miles

 

I haven't had the chance to look at both pulley's together, but if you are worried about the rubber damper, can't you just remove it from the stock pulley and put it on the lightweight pulley?

FYI, I ordered one and am going to give it a shot either way.

 

hey booger, did u see any gains with the liter pulley?

 

Changed it out with the blower upgrade , so I didnt do a before and after

 

would u recommand this over upgrading to the 3.12 pulley? If I was to stay with the 3.33 pulley, will I still see 8 psi with the liter crank pulley?

 

The stock size KJR lightweight crank will not effect your boost. An underdrive crank pulley like the UR will. Changing the 3.33 pulley to the 3.12 is completely different. Switching to a smaller pulley on the blower will give you more boost and more horsepower. You will have to retune the car for the 3.12 pulley. You will not have to retune the car after adding the KJR crank pulley.