Just bought 02 Gt and not sure if it has underdrives on it yet or not, can someone please tell me the size of the stuck pullies so I can measure them please.

Thank you

 

Are they colored?

 

Look down at your crank pulley.... If it looks like there's two of them stuck together (larger one toward the front of the car, belt running on the smaller inside pulley closest to the engine), then yes; those are usually referred to as "piggyback" style. Or if it's by itself and has any little colored lines/marks on the outer edge of the face of it then probably yes, as well. A few of the more expensive brands, like Steeda, sell theirs with a new crankshaft dampener that replaces the factory one altogether. I have udp's on my car, so can't help you with the stock ones diameters.

 

If u look at themu can probably find a name on them somwhere... like on mine its said MARCH on it... take a look

 

does the car have any other noticeable mods done to it? if not, id bet it doesnt... seems like someone wouldnt do just pulleys on their car. although i could be wrong.

and ya, what all of the above have said.

 

The OEM harmonic dampener is 7" diameter, the actual pulley has a 6.5" working diameter. I have the Steeda UDPs on my '03, and the harmonic balancer is 5.25" diameter with a working pulley diameter of 4.875".

My brother has Steeda's UDPs for his '99 GT and the dampener is a bit larger than mine, perhaps 5.75" OD, they pulley seems about the same.

 

Thank you all for the info, I guess I should have been more specific so I will give a little detail about myself and the car.

This is my 4th mustang, my others were a 91 lx 5.0, 95 GT, 06 Gt and now this one. The 91 was for drag racing only, my ex wife made me sell it when we moved, the 95 I sold it and the 06 I sold do to the economy and my job. So now I have bought this one, it has only 39,000 miles on it and came out of florida, who ever had it installed a new throttle body and cold air kit, 4.10 gears and flow master exhaust.

Since I havent toyed around with mustangs in a while I dont know crap about this 2valve motor and have no idea if they had installed the underdrive pullies or not and didnt want to buy them if they were already on there.

So once again thank you all for the info and if there is anything else you would like to share with me about this motor as far as getting more bang for your buck and I dont want Nitrous (been there done that with 91) I would appreciate it. But I do plan on purchasing the Hellion twin turbo kit in the near future so if you would like to comment on that feel free.

 

If you are going with twin turbo's, i'd would definantly skip the bolt ons route then lol. How much power do you want to make? The stock internals are only good to 400-450 rwhp. With that said, and you want more, then doing some head and cam work along with forged internals will be a good investment.

 

hi cliffyk,could you tell me what i have,i think i have something other than
stock pulleys.my harmonic balancer is 4.75'' with a pulley diameter of 4.25''.
my water pump pulley is 6.25''.and alt. pulley is 2.5''.the pulleys were on
the car when i bought it.i dont see any markings on them.thanks in advance

 

Any photos, are they steel or aluminum?