PDA

View Full Version : Underdrive Pulley question


v10tt
06-10-2015, 01:43 PM
I'm considering doing the UD pulley mod. I drive the car always with the AC on and Stereo On, and sometimes go for 1 hour long stop and go cruising.
Those of you that have done this mod have you noticed any issues with your charging system?

Mine still iddles at 1k rpms, I've read it is supposed to come down down after the 1k mile mark. Right now the charging system shows 14.2 volts steady.

Are there any measurable gains with this mod? Dyno or trap speed in the 1/4 mile?

Thanks for the input!
RoyV101621
06-10-2015, 02:00 PM
No measurable gains. You may notice the the engine rev easier off idle.
pdv25
06-10-2015, 02:13 PM
I'm considering doing the UD pulley mod. I drive the car always with the AC on and Stereo On, and sometimes go for 1 hour long stop and go cruising.
Those of you that have done this mod have you noticed any issues with your charging system?

Mine still iddles at 1k rpms, I've read it is supposed to come down down after the 1k mile mark. Right now the charging system shows 14.2 volts steady.

Are there any measurable gains with this mod? Dyno or trap speed in the 1/4 mile?
Thanks for the input!

Race me tonight and find out if my pulley made a difference! LOL!!
bogdan
06-10-2015, 02:29 PM
Which pulley do you run?

unrelated story... I installed one when I had my M3, and loved the results. Would like to repeat with the Viper. :)
pdv25
06-10-2015, 02:34 PM
Which pulley do you run?

unrelated story... I installed one when I had my M3, and loved the results. Would like to repeat with the Viper. :)

http://www.ipsco.org/Viper_files/Viper%20billet%20Pulleys.htm
viper04
06-10-2015, 02:40 PM
Race me tonight and find out if my pulley made a difference! LOL!!

LOL!!! be nice..
MtnBiker
06-10-2015, 02:55 PM
I'm considering doing the UD pulley mod. I drive the car always with the AC on and Stereo On, and sometimes go for 1 hour long stop and go cruising.
Those of you that have done this mod have you noticed any issues with your charging system?

Mine still iddles at 1k rpms, I've read it is supposed to come down down after the 1k mile mark. Right now the charging system shows 14.2 volts steady.

Are there any measurable gains with this mod? Dyno or trap speed in the 1/4 mile?

Thanks for the input!

Another thread has some answers you seek (well, for a Gen IV).

http://driveviper.com/forums/threads/9149-Gen-IV-Underdrive-Pulley
FLATOUT
06-10-2015, 03:07 PM
I ran one on my TA and now one on my 15 and have not had any issues. I would say the power gain is anywhere from 2-10 depending on day and dyno.