Under Pulley
 

Does anyone have any experience using a light weight under pulley on a 986 boxster s
(e.g. Mantis Racing, BBI Tuning) ?

Yes I have data from 3 different units compared to stock on 4 different engines.

The one I tested on ly 911 saturday was good for a 10HP gain at the rear wheels, on my dyno.

Who's product did you use ? And what did the install entail ? Some "tuners" in my neck of the woods have suggested that it's a more involved install than one would think.

Johnny

The unit I installed this weekend was one of our products that I am gathering data from this weekend at an event.. It has not yet been released, ad it is the smallest on the market. I want to determine what temperatures I see with the coolant and power steering fluid and go from there.

The install isn't that hard.. The biggest pain is having to trim down the boss on the block that holds the engine lock, but I made a piloted end mill for this that works great in a drill and makes a 2 minute job out of it..

The other pain is holding the crank while torquing the crank pulley bolt to the specified value.

I can swap one in about 40 minutes start to finish, on a test car in about 25 minutes with the engine hot on the dyno.

"Tuners" generally aren't very good wrenches...

would a pulley make a noticeable power gain on a 2000 2.7?

More than about any other bolt on that we have done so far... Certainly more than a 2K exhaust system.

If things go well this weekend, when do you think your pulley will become available ?

It'll take more time than that.. I want to do some studies in low speed applications with my Wife driving the car daily and monitor battery voltage and coolant temps Vs the stock arrangement.

I am running a Mantis pulley......at the moment

Our 4" version is now fully tested on the street.. After a DE, 4,500 street miles (and a lot at low speeds and in traffic with the A/C and head lights on) and coming within 1/2 of 1 MPH from a Land Speed Record the unit has proven it's self.

I've seen a minimum of 5HP gain (at the rear wheels) with this unit along with LOWER coolant and power steering fluid temps. One engine has seen 8 HP, but it was one of my high revving 3.2>>3.6 modified engines.

Absolutely.. Thats one of the biggest benefits...
We also offer a power steering cooler and modified power steering pumps to eliminate this issue.

Great, when I get the 4 o2 sensors replaced, new tires, a new top, and replace a burnt headlight, replace the window regulartor, I will be all over a pulley. I'm begining to not enjoy my Boxster. Not due to expense, but I do all my own wrenching and I'm sore from the 10 hour H&R coilover install today and the 6 hour 60,000 mile service I did. This car is killing my back. :ah:

With the help of Marc Gamora from Joe Rizza Porsche, we have an inline power steering cooler that seems to pretty much eliminate any power steering pump issues. When I get around to it, I have a self-install guide and it's very inexpensive to do. Cheap insurance.

To answer the original poster's question on under drive pulleys, our 2.9 has had one since day one and has clocked close to 10,000 miles since May with no issues whatsoever. If you see a lot of low speed driving in traffic in warmer climates, that's about the one time I wouldn't recommend going that route.

Then it seems like the modified pump may be your best course of action...

the under drive pulley for boxsters were designed to reduce power steering pump speed at track type engine speeds as far as I know. this would be your primary line of defence. power gain is just a by-product

Does anyone recommend changing power steering fluid?

I had an SVT Contour that had quieter & smoother steering after switching to a synthetic fluid. Was a slow process though, used a turkey baster and changed about 10oz a day. The old fluid also had a strong burnt smell to it.

-james

I run Redline power steering fluid in our car.

The Contour just wasn't the best built car in the world. :-) Mine was not for this world after about 60,000 very hard (yet very well maintained) miles. Rod knock and bad tranny. Too bad cash for clunkers didn't exist then, I could have gotten more for it! Loved that car anyways!

power steering
 

Did you burn the pump or just melted the plastic clip on the reservoir?. I had that happen to me the firs time I took the car to the track, I just modifed the clip to use AN fittings instead of the clip and I haven't had any more problems I have had 5 DE's since

Mine threw at rod at 48k. I've decided that "hand built in the USA" is not a good thing when it comes to domestic brand engines. I have a machine built duratec 3.0 in my Mazda 6, 50k+ and runs great. :)

"I can swap one in about 40 minutes start to finish, on a test car in about 25 minutes with the engine hot on the dyno."


Cool Jake, you could be like, the Jiffy Lube of the Boxster under pulley world. Seriously, when you come up with an under pulley that works well with our cars, I think I would like to have one installed. I will be doing a couple of trips down to Florida this year and your shop looks like it is sorta on the way.

Ed

:)

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?

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.

Under Drive Pulley
 

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.

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

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

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

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

Thank you for the info Johnny

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..

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

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.

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

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

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.

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

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!

This is what I got.

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

Bob

Installed BR Underpulley yesterday
 

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 :eek: 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