G/B for Underdrive pulley on CaymanClub
 

Just passing on what looks to be a decent deal on a bbi underdrive pulley kit on Cayman club.

http://www.caymanclub.net/cayman-chat/18986-bbi-under-drive-pulley-group-buy.html

I have no commercial interest etc. Participate at your own risk etc.


Looks to be for 987 and 996, 997 I'm not sure about 986's

Jason

I think there site is down, doesnt even come up with just the index page only and no path after ".com"

try .net
 

the homepage is at caymenclub.net

I just tried the link, and can't get it to go through either. All I did was copy the http.

I'll try again in a little bit.

Jason

yup
 

the site is currently down :confused:

Jason

Do they make a underdrive pulley for the 2.5?

I have never seen one for sale or tested on this engine?
Does anyone know??

If there is one made have you seen a dyno?

Afaik, it will work.

Before the site went down, there was a post about it being available (or compatible) with a 986.

Most h.p. figures were in the 12 to 15 at the wheels. Its underdriven by 16%

The main reason for 987's to change it is to slow down the power steering pump, to avoid overheating the p.s. fluid during extensive track time.

Jason

I tried an internet search to find the underdrive pulleys manufactures website but i could not find anything.

Does anyone have a link?

here you go....


http://www.bbiautosport.com/

BBI has a nice looking site but I did not see anything about the underdrive pulleys.

I must have in my back up brain.

I think its new
 

Its a new product, and I don't think the site has been updated yet.

Jason

Gary....Be Careful! The underdrive pully IIRC will give you more boost and if you are already at 6SI that may put you over the top. I will check with IA on my kit tomorrow

The pulley will effect the boost on the turbos??

No never mind just theSC unless the turbos are running on a belt system..... I honestly do not know much about the systm you are running. i would check with your guy first though on that.

Also have you done the plenum yet?

OH Yes, I would check with the turbo supplier first.
I am not into blowing anything up. I sent the shop an email today to see if they make these for the 2.5 and what sort of underdrive the pulley creates.

Ive looked around and can not seem to find the plenum for the 2.5

Do you know of a place that makes them. I dont think RSS is making them for my engine yet.

I'd be skeptical about buying from BBI.

I sent them an email about the compatibility with the 3.2L 986 S and the response was;

Thank you for your interest in our under-drive pulley,

It will work on your 986 boxter great.

I don't want any products in my car that were made by people who don't know how to properly spell my car.

They've had great reviews on the caymanclub forum though.

You know, the sad part is that we see Boxster spelled incorrectly so many times I almost did not catch it.

Gary,

Plenum for 2.5 :

http://www.************************************************************/productpage.aspx?pid=110901&cid=11&sid=51

Nick

Thanks,

I will look in to what it can do for my car.

Isnt the Crank pulley on the boxster as far as function, the same as other vehicles?

What i mean is usually the Crank Pulley turns belts which we all know, HOWEVER it also is a harmonic balancer for the crank... with my experience with bolt on mods on other vehicles, removing your Crank pulley/Harmonic Balancer will throw off some balance that the crank needs in order to prevent premature bearing failure... and by removing the Stock pulley and installing a lightweight Crank Pulley (which commonly do not have harmonic balancer atributes) can reduce the life of the bearings.


I would recommend performing an oil analysis before and after installing the new lightweight Crank Pulley to check for increased wear in the Crankshaft bearings.

On many cars the crank pulley is a harmonic balancer also, but not on the Boxster. The stock piece is a very lightweight item, and only used to turn the accessories. My custom-made one has been on my car without any problems, and can be seen here:

http://www.cheetahonline.com/products/n8039.html

This is a 20% reduction, has been tested, and it works great. A noticeable increase in power throughout the powerband. The voltage has been tested with all the accessories on during idle for extended time without any drop in voltage.

This also takes 2/3 the power to turn the pulley, as it was made as lightweight as possible. I have not been able to dyno it yet, but I hope to soon.

Paul

10 - 15HP at the wheels is BS. Mantis (they race a Cayman S in PCA) has an underdrive pulley that fits all boxsters / caymans at mantissport.ca. they're good for 6HP, but the primary use is to slow the power steering pump slightly so the PS couplings don't melt (a problem on C7's and 987's in particular).

Common problem on 986S too!

How hard was the install? What tools were required? How many miles have you had it installed for now?

http://www.caymanclub.net/reviews/showproduct.php?product=157

Should be the same concept on a 986.

The installation was not hard at all. The Cayman directions are very close to that of the Boxster.

Socket set for the various bolts to get to the pulley. To take the pulley off there are a few ways:

1. Screw a bolt through the hole in the pulley and into the area that needs to be ground down. This will hold the pulley still to take the bolt off. (this is what the Porsche book recommends)

2. Use the Porsche tool or equivalent to hold the pulley still

3. Use a strap-wrench to hold the pulley still.

I actually prefer #3 as it won't leave any marks and can be used to mount the new pulley easily.

Once the pulley is held still, a 24mm (I believe) socket will need to be cut down shorter. I was able to get the racket in this tight spot to take the bolt off, but the torque wrench to put it back on just wouldn't fit.

Grind the ridge as shown in the other installation. Put new pulley on and reverse instructions. The new belt that I listed is used as the stock one will be way too long.

I don't drive the car everyday (third car), but I have put it through every conceivable test to watch voltage, coolant temperature, and steering response. The voltage is good even with full load, the temperature stays the same, and steering feels exactly the same. I also monitored these driving with the Durametric logging all the sensors.

As stated, this is a 20% underdrive.

Any other questions, feel free to ask...

Paul

Has anyone installed an underdrive pulley on their 986 yet?

i just read the instructions for that install. FYI, that thing they grind off is actually kind of important during an engine rebuild. there's a pin that goes through the OEM pulley and that aluminum protrusion at six different positions required for proper reassembly of the motor.

Thats pretty cheap HP compared to other things that we do. 5 HP is not much but neither is $200 and there is some benefit on the power steering issue too (not that I've ever worried about that). The reviews that I have read report no problems. I've had these on other cars I've owned and have kind of wondered why I didn't hear anything about them in the Porsche world. I'm buying one.

Whooh! people are jumping around on this like crazy! This is my best at getting things straightened out. Ok of coarse a pulley kit won't increase boost do you know how a motor works? Pulleys have been known to throw off harmonics and wreck bearings. Pulleys also are very bad for people trying to run extra stuff electrically such as amps for stereos. Some one had checked their electrical current... was that also a load test? The fluctuation may be small but at higher revs becomes much greater. Over time wrecking your alternator. I'm almost certain the life of your alt. will be cut in half.... "but mine is fine." I know I'll here this yes I was guessing about half life or less more likely less. Say your alt. lasts 10 years normally 100k miles I'd almost put money on the fact that you will get another 30-50k on it now, not 100k. It is interesting about the power steering and I can see how it would help. Remember this is on track cars that this would benefit and they usually have less extra electrical stuff than you would have on the street other than af computers and things. 10-15hp that has to be an @ the crank "claim." You will feel more power in the throttle with pulleys thats not the argueement. Now lets look at the other side of the crank. I would hope everyone on here knows whats on the other side but if not... its your flywheel. I want to say its about 30 freaking lbs! I bet you can find one for 15lbs or less. Think that would be a better weight savings on your rotational mass? Best bet go all out get a light weight fly and pulley kit, strip your car down to a hyundai, track your car like a champ and buy alts. once every year. Oh and pray the part doesn't cause the dreaded gingivitis oops, I mean RMS. Know one worries about RMS do they. :cheers:

Could you be a little more specific? I understand problems about increased load on power amps and such but I do not understand this comment:

"The fluctuation may be small but at higher revs becomes much greater. Over time wrecking your alternator."

Is this assuming that one is powering additional power amps?

As insite points out, the installation of these pulleys requires grinding down a casting on the case. The one thing you may want to consider is if your motor ever requires replacement you run the risk of Porsche not accepting the old engine as a core in return for a Porsche reman unit as your core is now no longer acceptable as a rebuildable unit. You may get lucky and they won't notice it, but it could turn out to be a several thousand dollar mod down the road if they do.

As mn box s states, if you are simply looking to free up some HP, you are better off replacing the dual mass flywheel. If you are just looking to save the ps pump lines from failure at the track, simply reduce the pulley size on the ps pump.

Just something to consider.

Todd

Quote:

"As mn box s states, if you are simply looking to free up some HP, you are better off replacing the dual mass flywheel. If you are just looking to save the ps pump lines from failure at the track, simply reduce the pulley size on the ps pump."

Posted by tholyoak.

Uh, unless I'm mistaken you're going to need to increase the pulley size on the ps pump.

Sorry, my mistake, you are obviously correct.

Todd

Apology accepted.

Just don't let it happen again.

:D