Rxmfn7

iTrader: (4)

Does anyone make an underdrive pulley kit that still allows the use of the airpump? I still need my car to pass emissions every year, so unfortunately I am stuck with it. Thanks..

rotaryracer1

iTrader: (1)

Unorthodox Racing does. i have one my 86 gxl. they run about $200.It will improve the throttle response and help the car rev quicker.

BDoty311

Damn $200. Thats ridiculous. Personally I dont think that an underdrive pulley is worth that much. Rxmfn7, maybe you could find one after a little scavenging at the junkyard.

NZConvertible

Don't waste your money on underdrive pulleys for a street car. You'd be better off spending that money on performance mods that don't compromise the performance of the water pump and alternator. Water pump cavitation is not a problem in street driving, and the charging system is already weak enough. If you still have power steering and A/C, you can expect reduced performance from them too. These belong on racecars only. A light flywheel will have more effect without the downsides.

jon88se

I've had my UR pulley on for years with no real problems...voltage does drop at idle at night with all accessories on but you can still keep it around 13.5 volts if you bump the idle up a bit. It helps to be friends w/ UR and be located around the corner hehe (i.e. didn't pay much). Under drive pulleys are good for NA's as it does help out power and response you can feel (not a ton but it's there) and the NA needs all it can get. They are fine for street cars just make sure your battery and alternator are healthy and add a few grounds for beter continuity...an NA with an full exhaust, pulley, aluminum flywheel and TB mod is one FAST responding and quick revving motor!!!

Rxmfn7

iTrader: (4)

Yea P/S and A/C are coming out, so that wont be a problem. My charging sytem is in tip top shape (new alt, grounds..) so charging should be ok. I have stock stereo (besides headunit.) I just want to extract every bit of power and response I can....

NZConvertible

You're still reducing the capacity of the charging and cooling systems by a significant amount. To me that's not worth the 3-5hp gain.

BDoty311

I have an underdriven crank pulley and an overdriven alt pulley and i am always at around 12 volts. I have stock stereo and a different head unit.Peformance increase yes, but nothing amazing.

Cooling is fine too, havent ever noticed overheating and this is with stock fan and radiator.

jon88se

u wont overheat at all...that BS. my NA has had this for years, summer, winter...its fine

NZConvertible

You're supposed to be over 14V...

Ryde _Or_Die

Thats why I need to ditch this S5 alternator and get an S6

jon88se

if you are driving around at 12 volts that means your alternator is toast and the battery isn't charging. any throttle input over idle should take an under drive equipped car right to 14 volts.

BDoty311

I think its around 12V, probably wrong though. My charging system is fine, never had any electrical power loss, unlike my dads old 5.0L with underdrive pullies, where his headlights would dim if you had the radio too loud or driving in too low of a gear. Ive had mine for about a year now too.

jon88se

gotta be above 12...below 12 things start shutting off like the radio and the idle gets rough hehe

Ryde _Or_Die

I get 14+ when driving, but it lowers at idle with the lights/brakes/ac on. And I don't even have a stereo. When idling sometimes it goes down to the 11.9 or so range. Maybe lower.