durtysc300

So my Power steering pulley is seeing it's final days..and I know the others can't be far behind..but is there any REAL gain in these unorthodox underdrives? In theory it should work..less load on the engine..but has anyone actually used them?

Wicked SC

iTrader: (3)

That's the theory I've been told. I am currently running the Unorthodox PW, WP, and Alternator pulleys but I am running them more for cosmetics versus performance.

durtysc300

How was the install? Just remove them and install with a puller? I think that the biggest gains would come from the crank pulley.

blk&blu*j

iTrader: (1)

Do not use the crank pulley from UR it will cost you a motor as the pulley has no way to balance the motor like stock or IE: ATI / Fluid damper etc. set Do your research and you will see, not trying to tell u what to do just warn you of the outcome.

jgilk1

i honestly don't really understand the purpose of running underdrive pulleys unless the vehicle is specifically tracked... 3hp (15hp in the top end really not useable imho) max that it frees up really imho not worth it (yes i under drove a 95 240sx (sr20 de n/a-tt) but it spent 90% of its time at the track and loosing power steering and voltage dive at lower engine speeds but it wasn't an issue)

i would idle at 13.2v and top out at 14.1v (figure you under drive 25% your loosing your charging capability 100amp alternator
factory charging of an alternator is about 35-50% duity load you reduce the speed your putting out ~75amps)

it would loose almost all the power steering benefit at idle-1000 rpm
if left idling for more then 20 minutes the car would start over heating

on throttle/and moving everything worked fine no over heating, voltage was low but useable and engine temp maintained 145-155*f (lower then stock thermostat)

durtysc300

Hmm...maybe I should just look into stock diameter lightweight pulleys instead..Does anyone know if the PS pulley itself has a bearing in it? or is the bearing separate? On sewells parts diagram they look separate, but maybe come off as one unit? I can hear it grinding and it makes my engine sound like ****!

2jznosht

look into a turbo, or gte swap if you want power

durtysc300

turbo will eventually be in the works, but the idea of a lighter resistance on the crankshaft is an intriguing idea to me..i would love to blueprint a 2jzge with an aluminum crank, aluminum rods and dished pistons, a **** ton of headwork and a full race mani with a medium sized turbo and make 800 horsepower starting at 2500 RPM, but right now i'm looking at smaller ways to build power without having to tear my motor out.

blk&blu*j

iTrader: (1)

This subject is so talked out, but just to entertain you an aluminum crank may spin like a monster but there is no rotational mass to Create the torque to get our tanks rolling from 0 to wherever!!!

Just 1 of manyyyyyyyyyyyyyyyyy examples

1JZPWRD

iTrader: (59)

I will be installing the DM underdrive pullies, only the fan, power steering, and the alternator. These were only to clean up my motor and the appearance. The HP gains are minimum in my opinion. Agreed on the use of the underdrive pulley for the crank, thats a NO GO !!!!

marshall2j

As others have said, be careful on use of underdrive pulleys... esp for the crank