Thanks sd_boxster! - 986 Forum - The Community for Porsche Boxster & Cayman Owners

backman_z · 07-30-2010, 11:41 PM

I would like to publicly thank sd_boxster for his write up on installing an underdrive pulley. Great write up.

Underdrive Pulley Install Guide

My pulley arrived today. After an evening with some friends (watching Gladiator and drinking a couple beers), once they left, I ended up starting the project at 1:00 AM. It only took me about 1 hour 40 minutes thanks to sd_boxster.

The only thing I did differently was to use a screw driver head instead of his leverage contraption. I put the screw head through a hole in the stock pulley, and into the boss (see pics). This held the stock pulley in place while I loosened it.

http://www.flickr.com/photos/backman_z/4845265417/
http://www.flickr.com/photos/backman_z/4845884042/

My pics do not seam to be showing up, so I will post the pic url.

lbrown2009 · 07-31-2010, 06:37 AM

post install have you noticed any difference in responsiveness?

backman_z · 07-31-2010, 09:00 AM

I'll have to get back to you on that. I am home with 2 kids, while my wife is away. I can't really take both kids (4 years old- both) for a ride in a boxster.... Another reason to do the install at night while they are asleep,

lbrown2009 · 07-31-2010, 12:05 PM

bought mine from brad roberts a few months ago and never got around to installing it, I notice 3 things on mine 1) the car is seems quieter(eerily quiet) 2) the responsiveness has diminished 3) battery is charging exactly the same as it was prior to install high 13.8- 14.0 range. not sure what to think about this part but we followed the install directions to a T(grinded that nub on the block down real good) I didn't change the belt as it looks in very good condition with almost no wear. I need to put this car on a dyno and see what it has or doesn't have. 2.7 50k miles

AndyA6 · 07-31-2010, 01:23 PM

Responsiveness diminished?? I don't understand this point.... should be the other way round.

I have underdrive pulleys on my other cars and it always improved.

backman_z · 07-31-2010, 02:42 PM

Sorry lbrown2009, if forgot to answer your question.

I got a 4" pulley from amondc who is a member of this forum. The soonest I expect to be able to give feedback is Monday. Unfortunately, I doubt that I will get a chance to drive it before then.

Boxtaboy · 07-31-2010, 03:15 PM

Quote:

Originally Posted by lbrown2009

bought mine from brad roberts a few months ago and never got around to installing it, I notice 3 things on mine 1) the car is seems quieter(eerily quiet) 2) the responsiveness has diminished 3) battery is charging exactly the same as it was prior to install high 13.8- 14.0 range. not sure what to think about this part but we followed the install directions to a T(grinded that nub on the block down real good) I didn't change the belt as it looks in very good condition with almost no wear. I need to put this car on a dyno and see what it has or doesn't have. 2.7 50k miles

I thought that you had to use a smaller belt due to the size differential of the pulley.

lbrown2009 · 07-31-2010, 07:16 PM

when I originally bought the pulley I asked the manufacturer about changing the belt and they said no it doesnt need to be changed, I have read many threads on it while waiting to install it and some people said they used a slightly shorter belt and someone said they bought a shorter belt and it didn't fit so I left well enough alone and kept the original. It is working fine, spins without a problem as we started the car without the firewall on just to make sure. I can't say 100% if it's gained or lost power, but from the feel of it and I've been driving it for 9 months now ... I think I lost something yesterday. Would a shorter belt make a difference? anyone?

lbrown2009 · 08-01-2010, 06:08 AM

took it for a spin this morning, I figured it out... those damn flip flops were throwing me off lolol the car felt good... gave it a little juice up to 95 in 3rd gear on the parkway.... also today the batt is reading 13.00 in the driveway with the air cond, lights and radio on.

backman_z · 08-02-2010, 07:12 AM

Left for work early today and put my Boxster through some “tests.” Let me qualify this a little by saying that I have only had Boxster for about 1 year. Prior to this I have had small SUV’s and economy cars, so my “butt dyno” is not as well calibrated as some others may be. I drove both a highway and a curving road with some hills. Yes, I would say that there is more power to the wheels.

Getting onto the highway, I came to a complete stop at the on-ramp before launching onto the road. Several car kindly moved to the left lane to let me on the road. Maybe it is me, but I have never spun my wheels before, never really tried. On this morning, I did not try, but spin they did. Maybe there was some graved, who knows, but once the tires gripped, I shot onto the road and quickly passed all the cars that had pulled over into the left lane. On the back road, as I was coming out of the curves, I could feel a little more power when giving it gas. I only have a dummy light for the battery, so I cannot really comment on the electrical stuff.

Did this mod turn my Boxster into a Carrera GT? No, and I didn’t expect it to. I actually wondered if, due to my lack of experience in performance machines, I would be able to feel a difference. But in the end, I am pretty sure I did. All in all, a nice sunny drive, with just a little extra adrenalin for this mornings commute, and many other drives to come.

I am happy about the results of the mod. This is also a return to tinkering with my cars, after a long hiatus. In the past it was more out of necessity, this time it was pure fun. I’ll have to let your know if I have any electrical problems.

Next project… maybe secondary cat bypass pipes?

lbrown2009 · 08-02-2010, 05:33 PM

i have cat bypass pipes on order from FVD, am I addicted to mods?

The Radium King · 08-03-2010, 10:49 AM

ot, but on-topic wrt bypass pipes -

i think, from a flow turbulence reduction point of view, that it is best to have the restriction as far down-stream as possible. in the case of the boxster, this means deleting the pre-cats (the ones on the headers) and keeping the secondary cats (the ones on the mid pipes).

so, it would be less expensive, and provide more power, to get a set of those cheap Chinese headers on ebay (they come without pre-cats and are designed to connect direct to the mid-pipes) and keep your current mid pipes. this will require some post-cat o2 sensor kung-fu, however, as you have to either (a) extend the sensors to after the secondary cats (and perhaps add a bung) (b) get a ROW flash so that your car doesn't throw an emmissions code, or (c) get one of the many o2 sensor simulators or 'foolers' such as sold by fvd (or fab your own).