Under Pulley

[Jake Raby]

Its tested up and good to go.. I'd be happy to install one for you.
I am on the way to Florida as long as you are driving South..

Have you found anything to be concerning about this? Particularly, sitting in traffic in a hot climate?

[Jake Raby]

Nothing.. My Wife drove the 911 in July and August in traffic every afternoon and at low speeds with no issues. Those two months in Georgia are brutally hot, every day well over 90F.

That was with the A/C running continually.... While running the headlights as well.
Datalogged battery voltage was over 13.6volts all the time..

Battery voltage and charging at low speeds with the A/C on and running headlights was my biggest concern.

It's proven.

[Johnny Danger]

I had BBI's newest, light weight under drive pulley installed about a week ago. Unfortunately, because it coincided with the installation of a new set of headers and cats, it was difficult to discern what portion of the noticeable power increase could be attributed to the pulley alone. However, for what its worth, I can say that the part appeared to be beautifully made, and the installation was pretty simple and straightforward. Another thing worth mentioning, some astute members from the Planet Porsche site recommended that I should use a shorter drive belt to accommodate for the smaller pulley. They were indeed correct.

[Bob O]

Johnny, Can you tell us what year Boxster and what length belt you used? Did you get it from the dealer? Needing a shorter belt is my concern too and I'd like to have all the "goods" on hand when I do the change.

Thanks

Bob

[Jake Raby]

Mine comes with the belt.. :-)
Its not a "Dealer" item..

[Bob O]

Jake: I've been trying to get onto your site all day. Seems your parts section is DOA for the moment.

Bob

[Johnny Danger]

Originally Posted by Bob O

Johnny, Can you tell us what year Boxster and what length belt you used? Did you get it from the dealer? Needing a shorter belt is my concern too and I'd like to have all the "goods" on hand when I do the change.

Thanks

Bob

Bob,

It is my understanding that both the 986 and the 987 boxster all use the same size belt. With that said, after calculating the difference in circumference size between the two pulleys, the conclusion was that a belt which was 31 mm shorter than the stock one was the ideal choice. Therefore, the Gates #k060820 was determined to be the best choice.

Johnny

[Bob O]

Thank you for the info Johnny

Bob

[Jake Raby]

Originally Posted by Bob O

Jake: I've been trying to get onto your site all day. Seems your parts section is DOA for the moment.

Bob

Our server has had issues all week.. And my site has been bombarded with Excellence Magazine readers that saw the reference to our IMS development in the mag this month..

Sorry, it should be back up in a day or so..

[Cartel]

Originally Posted by Jake Raby

Mine comes with the belt.. :-)
Its not a "Dealer" item..

If I missed the memo, many a apologies before hand but when is your UDP set to be released?

[chaudanova]

The UDP doesn't require removal of the AC does it? Perhaps I am mistaken, but I read some other posts in the past about people that removed their AC also, and wasn't sure if that was a requirement for running the UDP... Please clarify...

[Topless]

Originally Posted by chaudanova

The UDP doesn't require removal of the AC does it? Perhaps I am mistaken, but I read some other posts in the past about people that removed their AC also, and wasn't sure if that was a requirement for running the UDP... Please clarify...

Nope. You simply replace the main drive pulley with a smaller one to slow down all the accessories. The guys removing the A/C pump are removing weight and setting up a race car. My car is still a street car and I like my A/C.

[chaudanova]

Originally Posted by Topless

Nope. You simply replace the main drive pulley with a smaller one to slow down all the accessories. The guys removing the A/C pump are removing weight and setting up a race car. My car is still a street car and I like my A/C.

Awesome, thanks for the info! Seriously considering getting the UDP...

[Bob O]

I got my under pulley from Brad Roberts last week and started to put it on. Should be a 2 on a scale of 1 - 10..right? BR's package comes with the wrench needed to hold the new pulley while you tighten it to the correct torque. The problem is......there's no similar tool (or rather I don't HAVE a similar tool) to hold the OLD pulley while you loosen it. And the holes in the old pulley vs the new pulley are not even close to being the same spacing. So unless I totally wreck the old one with some vise grips or some such makeshift arrangement that's either going to ruin the pulley or worse, I can't get off the nut from the old pulley. Porsche supposedly sells such a tool (special tool #9593) but the dealer gave me the shoulder shrug when I asked about it, Pelican doesn't carry it, Suncoast doesn't carry it, I can't find it anywhere and don't have the equipment necessary to make it from scratch. Any ideas??? You guys who have already done this job, what did you use to hold the old pulley while you loosened the nut?

Thanks

Bob

[Topless]

Brad lives in my town so he put mine on for me. Ask him what he used. Others have measured the hole spacing and just built a simple tool running two bolts through a piece of steel to hold the pulley.

[Sammy]

I put my car in 6th gear and had no problem removing/installing my pulley without the "special" wrench.

[23109VC]

where do I get the U/D pulley and how much does it cost??? sounds like a GREAT mod. it's not gonna make big power, but it will make something I can feel and it's not a $1000+

I'm in!

[Bob O]

This is what I got.

http://www.bradrobertsag.com/c=INAqeVpHZVT1bZMY0P4u1hPWa/product/POWERPULLEY/UnderdrivePower_Pulley.html

Bob

[Bob O]

Here's a few comments about the installation:

Its a relatively easy job but for a couple of things:

You need to grind down a stub on the engine in order for the pulley to fit (I knew that beforhand). BUT.. an angle grinder won't fit, there's not enough room. I suppose there might be one small enough to work but I didn't have one. You need a die grinder (straight shaft). Off to Harbor Freight....$29.00, plus grinding wheels...$9.00. No big deal but if you don't have one you might consider getting one or trying to borrow it. (Using the die grinder takes FOREVER! but it eventually gets the job done)

You don't necessarily NEED, but it would be helpful if you had, a stubby 24 mm socket. There isn't enough room for a standard socket to fit when attached to either the torque wrench or a standard socket wrench. I 'guessed" on the tightening torque using the box end of a combo 24mm wrench. Sears, Autozone, O'reilly and all the other auto stores I tried don't sell one but I didn't try the specialty tool shop in town to see if they had one. It was too late and I wanted to finish it up. Just a suggestion.

Removing the old pulley was a pain. No wrench available to hold it while loosening the bolt. So.....block the rear wheels, put it in gear and that should hold the car and not allow the engine to turn when you losen the bolt. (You're turning, or attempting to turn, the engine backwards when loosening the bolt so block the wheels in the rear, unless you put it in reverse )

I bought the shorter serp belt recommended above. Didn't need it. In fact, it wouldn't fit at all...too short. My original belt works just fine. Don't know if the shorter belt is needed on other MY"s but at least on my 01 it wasn't needed.

Other that those little burps it was a piece of cake.

Now on to the fun stuff, like driving it and seeing if there really is a noticeable difference in power. I haven't had time to get more than a few miles on it after the install to see if everything was put back together right!. More "butt dyno" info later.

Bob