Crank pulley...
 

Anyone install the Unorthodox pulley? It seems they have both an underdrive (S) and stock diameter (SC). As far as HP gains, does one give more over the other?

http://www.unorthodoxracing.com/Merc...e=maximaultraS

http://www.unorthodoxracing.com/Merc...=maximaultraSc

I think this will be my next upgrade in a couple of weeks. If anyone has installed either one, how was it? :)

if you have a system the SC would be the best route [so ive read/heard] with the S pulley, itll slow down the P/S and A/C which i do not want to do. you might get an 1-2hp more that way but IMO the SC would be a better choice b/c its OEM size but lighter. and also your oem belts would work too, lol.

I've also been researching the mod Oolatec, and I'm still undecided. If you have big aftermarket stereo then probably the stock pully is better. I've only got one amp and maybe eventually two I am thinking I could still get away with the UD pulley.

As far as HP gains.......no one has ever posted dyno numbers for this mod that I know of.

Yeah, I don't particularly want to underdrive. No aftermarket stereo or anything, but you know... My mechanic said you could get 10-15hp gain with this mod. The part isn't too expensive either for that much of a gain, and install shouldn't be too difficult either. Maybe someone will have a group deal on the Sc pulley... hint hint to anyone reading this... ;)

if you get 10-15 whp from this on a dyno then I will send you $20 through PayPal.......................

lol well if you want to say WHP... then... ;)

lol...so what do you mean by that, you will get that to the wheels or to the crank?

then it would be immeasureable basically, because the gains are so small...

LOL Couldn't tell ya, man. You do get most of the HP gain by weight loss alone, and these days, Nissan has been making the stock pulleys lighter anyway. My friend runs a Z shop, and with the previous gen Zs, the HP gains were quite significant because the pulleys were pretty damn heavy.

Now if I had spare change for a before/after dyno run... ;)

already been done. And like I said, the difference was so minimal that it's impossible to say you gained any power through dynos considering you almost never see the same dyno numbers back to back.

Cliffs: gain is 1-2 whp...difference is mainly in response.

whats the wieght diff between the oem one and the sc one? i remember back in the honda days it made a pretty decent improvement, but then again our oem crank pully had a harmonic damper built in bringing the weight to around 12-14lb i belive while the UR SC one was like 3lb

You are freeing up horsepower (from kinetic energy) normally needed by the engine to spin up a 5 lbs weight from 3K to 6K. Since the rpm acceleration is very slow in 3rd gear, the hp saving is small. The difference is primarily on the 1st and 2nd gear.

4-6hp - http://www.nissanperformancemag.com/...r02/altima_ur/

One function that, IMO, may be affected by a lighter pulley is the misfire detection logic. The input is the crankshaft position sensor, which senses microscopic crank speed changes. The ECU interprets such variations as misfiring. A lighter pulley may allow greater crank speed variation and over report misfiring. This is just a theory.

madmik, i would think that would be true if there was originally a harmonic damper in the crank pulley itself [like civics and tegs] but with our cars, the crank is internally balanced so i would think that wouldnt be an issue.