Anyone with a supercharger get the URD pulley?

ramsee1 · 04-14-2008, 06:40 PM

I've contacted URD about any specs on hp gains, but no answer. I know I spoke with someone from the board who was going to try it. So i thought I would post. Seems like it would be a nice compliment to the SC.

DocME · 04-15-2008, 09:21 AM

I'm assuming you are talking about the URD 2-7/8" pulley on the TRD supercharger? I think it supposed to up the boost by 3psi. That's enough to feel the difference, especially considering that the TRD s/c is like 3-6 psi boost to begin with. You might see a bit of perceived lag when you make the change from the TRD 3" pulley. I'm not sure if you're going to need a new fuel map programmed or if the new injectors that came with the kit are going to be enough. You might check with URD. For now I'm going to have to abstain from upgrading, I still have 4 years 11 months left on the drive train/supercharger warranty.
Good luck, please let us know if you try it. I'd like to know how well it works!

-Derek

ramsee1 · 04-15-2008, 07:17 PM

Hey Derek. Yeah that's the one. I believe they recommend having it remapped. I don't know enough about superchargers to know if boost is an accurate way to guage it's power, but if it is, 9psi total boost seems like it would really add some ooomph. I am surprised URD hasn't written back after two emails and they usually jump in these conversations.
What would cause lag by switching to a smaller size? Thanks for the info

DocME · 04-16-2008, 09:22 AM

Smaller pulley results in a smaller "torque arm" length, if you will. Thus it takes more force to turn the pulley, thus more parasitic drag on the engine. You would only "feel" this low in the RPM range, if you even feel it at all. Once the boost starts to come on you will really feel the added horsepower and the increase drag will be negligible. The "lag" or shift in power would only be noticeable if you are doing a lot of slow speed activities such as crawling or the like. I really wouldn't let the lag slow you down from purchasing it. I would totally put one on if my engine wasn't in the beginning stages of the warranty. I've only had the truck for a month now.

Hope this answers you question.

-D

Jordiggity · 04-18-2008, 11:12 AM

I have a URD pulley on my 2003 cobra. HUGE Difference!

ramsee1 · 04-18-2008, 03:59 PM

That's cool. Not that it's the same application, but I'd love to hear more

Jordiggity · 04-21-2008, 11:16 AM

It turns a belt driven supercharger faster because of the smaller diameter. It also wears the supercharger out faster though. I still say its worth it though. I know I dont plan on keeping my cobra forever so let the next owner of your vehicle worry about it. Thats my thinking atleast.

ramsee1 · 04-21-2008, 06:17 PM

Well I guess when I get the SC one of these days, I'll pick up the pulley too.

K_os · 04-22-2008, 11:19 PM

I had a underdrive pulley on my corolla XRS before I had the FJ and it was a huge difference if this is anything like it, I'd recommend it 100%

ramsee1 · 04-23-2008, 08:37 PM

Well hopefully someone on the board will get one soon. Thanks for everyone's input