Pulley change on a Viper - Results?

[RX VIPER]

I've read that the new Cobra's with a pulley change off one of the Ford trucks makes it a more formidable opponent. I don't see this mod listed very often on a Viper. Does it make a difference on our cars? Any pros or cons? Thanks.

 

[Marv S]

that pulley change on the ford adds horsepower to the factory s/c mustangs(turns the supercharger faster and in turn produces more boost.)

Vipers don't have a factory supercharger so a pulley change doesn't "add" horsepower, just reduces the drag loss a bit from the accessories (under drives the ps pump, etc.)

 

[_Niz_]

Plus it voids the factory warrant on the s/c. I had one and it makes the s/c scream, a most awsome sound you can hear from a block away! The only thing about Ford that gives me goose bumps.

 

[SnakeBitten]

On an n/a motor like the Viper an underdrive pulley will only free up hp or parasitic drag loss by reducing the mass/weight of the pulley....I remember when I had my PGT I swapped out the stock pulley for an aluminum pulley...The weight and size difference was extremely noticible....Seat of the pants feel: the car felt a bit more snappy and rev happy especially 3rd gear....This was a car with 164hp in a relatively featherweight car. I later added a lightened flywheel and that really woke up the car...Used to chirp tires even in 3rd with quick up shifts....Really changed the feel of the car...


I can only imagine the felling on a 450hp car...Anyone run the 1/4 with just these mods. Gotta be worth at least .3 - .5 ...How about teh pulley/flywheel and some 3.55 gears header/catback/filter.....

 

[George Murray]

Could you be referring to the pulley for the block & tackle assembly used to crane drinks into the cup holder on the Gen III cars? Wrong forum...

 

[Nexus-6]

I swapped in a 4lb pully on my Lightning (4lb as in it adds another 4lbs of boost) about 4 months ago - talk about a screaming supercharger! Like ear splitting loud!

I had to go install long tubes and hi flow cats last week to drown it out a little...

 

[Marv S]

No, the mass/weight of the pulley itself is not the major benefit of using a smaller pulley.

They are not that much smaller in mass/weight and I doubt there would be any measurable benefit from saving that 1 pound (If even that) of pulley weight. The measurable benefit comes from spinning the accessories on a motor slower (the ps pump, the water pump, the alternator, etc.) That’s why they are a smaller diameter.

As for a lightweight flywheel, while it will allow the motor to rev quicker, a heavier flywheel can chirp the tires easier than a light one. The reason is that greater spinning mass resists change. Just hold the rpms steady at 4000 in first and shift to second with a quick clutch release and the tires will chirp. That’s due to the rotating mass not wanting to slow down as quick as the gear change wants it to.

On an n/a motor like the Viper an underdrive pulley will only free up hp or parasitic drag loss by reducing the mass/weight of the pulley.... I later added a lightened flywheel and that really woke up the car...Used to chirp tires even in 3rd with quick up shifts....Really changed the feel of the car...


I can only imagine the felling on a 450hp car...Anyone run the 1/4 with just these mods. Gotta be worth at least .3 - .5 ...How about teh pulley/flywheel and some 3.55 gears header/catback/filter.....