Underdrive pulley recommendation
 

I'm wanting to get an underdrive pulley for my 2.5. I've been looking at a few but was wondering if anyone could make my mind up for me. I've looked at the precession chassis works pulley and Chetah online pulley. I've seen another pulley that looked a bit weak and for sure found pics of it broken. If there's any others people could recommend it would be most appreciated.

what type broke? I've done little research but RSS looked lightest to me. I'm probably going to try using 987 idler pulleys as well as I've read here that there aluminum.

RSS seems to be the popular pic here.

Beware of BBI pulleys. They have a tendency to do this:

http://www.planet-9.com/attachments/...lert-image.jpg

I've decided to go with tarett engineering. Looks strong and the price seems good at $175.

I would go with either Tarett or RSS, you can't go wrong with either one

I installed the RSS UDP. Worked great. You can also buy the smaller/correct size serpentine belt at the same time.

RSS Under Drive Pulley for Porsche Boxster, Cayman, Carrera, Targa

http://i1114.photobucket.com/albums/...isc/rssudp.jpg

I purchased the tarret. It came with a new bolt which is recommended regardless of which brand you choose. Also, I think the Tarret is a 4" pulley, whereas some of the others are 5". I am not sure what this means in terms of performance. Would be good to know .

Yikes ! I have the BBI LWUP !

I have just fitted this one, bbi.
http://986forum.com/forums/uploads01...1367925054.jpg

All the ones I saw when I did mine were 3". Didn't matter the brand, price, or what milling of the body looked like... They all had a 3" diameter.

Had to go with RSS because of it was too important to fail.

stupid question maybe, but how are UD pulleys not universal? I can see cam diameter varying in sizes, but there should be a lot of UDPs that fit the box, that does not make you pay the premium...

To those of you that have installed a UDP... What real difference have you seen.... and if one of you that trolls looking for an opportunity to scold me for not using the search function - please don't... If you have no other response - no need to respond.

I was just reading this an was interested.

Pup

Sorry guys, but sometimes that Use Search Function spanking , gets to me.

Pup.
They were first developed with the purpose/idea to simply slow down the accessories (power steering pump, alternator, AC compressor) on a car that spends a lot of time running high revs. 986/987 PS pumps are known to overheat and leak under heavy track use.

A side benefit is that the underdrive pulley reduces parasitic drag from these components and you can measure an increase in hp and torque at all rpms between 5-10 rwhp depending on the model.

Don't have one myself (yet) but only heard good things!

There are more variables than it may seem, besides diameter; bolt size, number of bolts, bolt circle diameter, pulley offset, center hole size, keyway/pin size & location, V-groove width/depth (this may be fairly standard?), etc.

Good monring gentlemen

Being that we are all having a nice friendly chat about UDP's - how easy is it to change/install.
Not looking for a full blow by blow account but can a fairly unskilled person do it or does it require a higher level of knowledge and does half of the interior need to be removed or can access be gained with seats and console in place.

don't worry chaps.
Done some searching and have my answers, just need to find the cash!

Thanks Essex for the info....

Pup

Anybody install Pedro's pulley? Most seem to recommend RSS. Any pluses or minuses for either one?

My Pedro UDP came in yesterday. As soon as get a minute to install this puppy I'll let everybody know what's up.

Install was done this weekend. I was going to it on Thursday, but I only had a 24mm deep socket, and you need a regular. Took me a while to get the pulley seated properly and tightened up so it didn't wobble. I cut the boss off with a sawzall, it only took about 15 minutes, no problem. Once I did this I put it all back together and went for a spin. You can definitely tell it has more grunt than it did before. I does accelerate better in all gears, and gets to 100mph in a more timely fashion. Not a bad mod at all!

Hello Essex,

The install is fairly straightforward and wasn't too difficult. I did mine with seats and console in place, just move them forward and you do it with the top down.

Is the sawzall step required for all makes of UDP? Will it be pretty obvious how much or where needs grinding?

Thanks.

Once you try and fit the new pulley it will be quite obvious which boss need to trimmed. I used a cutting wheel on a Dremel tool.

The sawzall seems like overkill, I only use mine for exhaust work.