Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster Racing Forum

Post Reply
 
LinkBack Thread Tools Display Modes
Old 03-23-2014, 05:24 PM   #1
Registered User
 
seningen's Avatar
 
Join Date: Jul 2008
Location: austin
Posts: 823
Which under drive pulley to buy/use?

Which under drive pulley to buy/use?

Have a Boxster S -- starting to warm up here in Texas -- I track it 2-3 times a month when I can. 90% track car.

Want to save the PS pump.

thanks,

Mike

__________________
Drivers: '15 Panamera Hybrid (wife's), ' 01 996 GT2, 00 Boxster S, '96 993 Çab/Tip (wife's)
Race Cars: '75 911 RSR Replica & '99 Spec Boxster
mike@lonestarrpm.com
seningen is offline   Reply With Quote
Old 03-23-2014, 06:27 PM   #2
Registered User
 
jsceash's Avatar
 
Join Date: Aug 2009
Posts: 1,466
Garage
RSS is not the lightest because it does not have all the lightening hole but it shouldn't break like those do. Running one now on the third season. Saw two of the ones with large lightening hole break out in the spokes. One was posted some where on here one at a DE.
__________________
2003 Black 986. modified for Advanced level HPDE and open track days.
* 3.6L LN block, 06 heads, Carrillo H rods, IDP with 987 intake, Oil mods, LN IMS. * Spec II Clutch, 3.2L S Spec P-P FW. * D2 shocks, GT3 arms & and links, Spacers front and rear * Weight reduced, No carpet, AC deleted, Remote PS pump, PS pump deleted. Recaro Pole position seats, Brey crouse ext. 5 point harness, NHP sport exhaust
jsceash is offline   Reply With Quote
Old 03-24-2014, 07:22 AM   #3
Registered User
 
Dlirium's Avatar
 
Join Date: Oct 2013
Location: San Jose, CA
Posts: 583
Garage
I installed the RSS after doing a bunch of reading and research on this forum. Seems to be generally accepted as the best, strongest solution. Also get the shorter belt...
__________________
2000 S - Borla Exhaust, TS Cat Deletes, RSS UDP, B&M Short Shift, T96 Steering Wheel, Potenza RE-71R's,
Mantis 2.0L Deep Sump, de-snorkeled, Bilstein PSS9 Coil-Overs, Rennline lug studs, and auto crossed regularly
.
Dlirium is offline   Reply With Quote
Old 03-24-2014, 07:53 AM   #4
Registered User
 
The Radium King's Avatar
 
Join Date: Apr 2010
Location: Canada
Posts: 3,121
I have the smaller one from tarett (ie, not the bbi one). seems to be the smallest available. might be an rss unit, dunno. works great. if it is 90% track car, pull out the ac and get a much shorter belt! reduces engine load and weight.
The Radium King is offline   Reply With Quote
Old 03-24-2014, 08:29 AM   #5
Registered User
 
Brad Roberts's Avatar
 
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
I'll send you a FREE RSS pulley!! No joke. We use a 4inch pulley in spec now, so I have a 5inch RSS sitting here. Had you posted BEFORE the PCA TWS race weekend before last?? I would have hand delivered to you while I brought out a Austin customer car

PM me your address!
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
Brad Roberts is offline   Reply With Quote
Old 03-24-2014, 11:31 AM   #6
Registered User
 
Brad Roberts's Avatar
 
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
and Mike.. if you have driven the white 911 in your pic for a couple of years? The small pulley wont help 911 drivers who transition into CaymanS and BoxsterS cannot STOP from sawing at the wheel it overheats the PS pump and melts the lines.

You will need a cooler in Texas heat for the PS
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
Brad Roberts is offline   Reply With Quote
Old 03-25-2014, 05:52 PM   #7
Registered User
 
seningen's Avatar
 
Join Date: Jul 2008
Location: austin
Posts: 823
Quote:
Originally Posted by Brad Roberts View Post
and Mike.. if you have driven the white 911 in your pic for a couple of years? The small pulley wont help 911 drivers who transition into CaymanS and BoxsterS cannot STOP from sawing at the wheel it overheats the PS pump and melts the lines.

You will need a cooler in Texas heat for the PS
Thanks, PM'd you.

Unfortunately for me my family Spring Break trip trumps the PCA TWS race :-(

I do get a hall pass most other times of the year tho!

The White 911 drives on rails -- not too much sawing (I think),
now in my 944 chump car -- call me mr lumberjack :-)

Mike
__________________
Drivers: '15 Panamera Hybrid (wife's), ' 01 996 GT2, 00 Boxster S, '96 993 Çab/Tip (wife's)
Race Cars: '75 911 RSR Replica & '99 Spec Boxster
mike@lonestarrpm.com
seningen is offline   Reply With Quote
Old 03-26-2014, 12:11 AM   #8
Registered User
 
danch's Avatar
 
Join Date: Feb 2014
Location: UK
Posts: 76
Garage
Just taken delivery of the RSS so hope to get it installed in the next month :-)
danch is offline   Reply With Quote
Old 03-26-2014, 09:59 AM   #9
Registered User
 
Brad Roberts's Avatar
 
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
They work great! and do not fail like the BBI pulleys!
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
Brad Roberts is offline   Reply With Quote
Old 03-26-2014, 11:28 AM   #10
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
Quote:
Originally Posted by jsceash View Post
Saw two of the ones with large lightening hole break out in the spokes. One was posted some where on here one at a DE.
Here is the link with the broken UDP: http://986forum.com/forums/performance-technical-chat/45527-underdrive-pulley-recommendation.html
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 03-26-2014, 09:51 PM   #11
Registered User
 
jb92563's Avatar
 
Join Date: Apr 2012
Location: Riverside, CA
Posts: 1,665
I just ordered a Tarret 4" UD pulley with belt and bolt.

You are supposed to replace the bolt after removal apparently.

The Pulleys come in different sizes, the RSS is 5" I think which would have more drag than a 4" because its turning the accessories faster, hence more hp consumed.

Still an improvement over stock in any case.
__________________
"It broke because it wants to be Upgraded "
2012 Porsche Performance Driving School - SanDiego region
2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP,
Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)

Last edited by jb92563; 03-27-2014 at 11:21 AM.
jb92563 is offline   Reply With Quote
Old 03-27-2014, 10:10 AM   #12
Registered User
 
Brad Roberts's Avatar
 
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
Listen carefully: The 4inch will not turn the AC compressor fast enough at idle to keep the car cool!! So sitting at stop lights.. NO AC. This can happen also with the 5inch if the AC system is not 100%
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
Brad Roberts is offline   Reply With Quote
Old 03-27-2014, 11:32 AM   #13
Registered User
 
jb92563's Avatar
 
Join Date: Apr 2012
Location: Riverside, CA
Posts: 1,665
Quote:
Originally Posted by Brad Roberts View Post
Listen carefully: The 4inch will not turn the AC compressor fast enough at idle to keep the car cool!! So sitting at stop lights.. NO AC. This can happen also with the 5inch if the AC system is not 100%
I never read that anywhere or perhaps I missed that point.

Fortunately the car is rarely stationary for long, no traffic jams on my local routes, so I guess I'll try it out and see if I can live with that.

Do you know what the original pulley diameter is by chance?

I'd be interested in calculating the rpm difference that the accessories will see.

No issues with water pump speed at idle I hope as that is the more important thing.

I did buy a lower temp Thermostat and a new water pump that I will install while I'm in there as well.
__________________
"It broke because it wants to be Upgraded "
2012 Porsche Performance Driving School - SanDiego region
2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP,
Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)
jb92563 is offline   Reply With Quote
Old 03-29-2014, 03:22 PM   #14
Registered User
 
jb92563's Avatar
 
Join Date: Apr 2012
Location: Riverside, CA
Posts: 1,665
Update

I installed my Tarret 4" under drive pulley and all went well and better than predicted.

Particularly, I am happy to report that a 2001 S with the 4" under drive pulley still allows full operation of the air conditioning at idle!

Here is the Proof below:

With the Tarret UDP installed and the engine up to full operating temperature,
Ambient temperature 70 F as shown on the guage, and ~750 rpm at idle for over 5 minutes, airconditioning set at full the temperature of the air leaving the vent is ~38 F.


No disrespect Brad, but your information seems to be incorrect for the 2001 S scenario at least.
What model did you have that experience with?
Maybe we can qualify that statement and limit it to certain models?

Tarret UDP and Original
__________________
"It broke because it wants to be Upgraded "
2012 Porsche Performance Driving School - SanDiego region
2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP,
Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)

Last edited by jb92563; 03-29-2014 at 03:34 PM.
jb92563 is offline   Reply With Quote
Old 03-29-2014, 04:40 PM   #15
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
[QUOTE=jb92563;393339]

This might be on of the most informative pic's I've ever seen on 986Forum - OAT, Tach, Eng Temp, and A/C air temp all in one! Very clever. Great job!

__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 03-30-2014, 02:38 AM   #16
Registered User
 
Join Date: Dec 2013
Location: Dahlonega , Georgia
Posts: 1,346
jb92563 no disrespect intended but you're kidding with just 70 degree ambient temp as your " test " correct ? Do a follow up when it's 90 + with lots of humidity sitting in traffic THAT is a test.
__________________
2002 Boxster S Arctic Silver with black top with glass window and black leather interior. Jake Raby 3.6 SS ( the beast ) with IMS Solution. 996 GT3 front bumper , GT3 rocker covers and GT3TEK rear diffuser and Joe Toth composites rear ducktail spoiler .
rfuerst911sc is offline   Reply With Quote
Old 03-30-2014, 08:26 AM   #17
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
I had the same concerns before I installed my UDP, there is a great discussion here: http://986forum.com/forums/general-discussions/37563-underdrive-pulley-questions.html

My experience is that the 4" pulley worked fine in all conditions including using the A/C while sitting on the grid for 20 mins while waiting for my turn to time trial during 105F days at the racetrack.

Your mileage may vary.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 03-30-2014, 09:43 PM   #18
Registered User
 
jb92563's Avatar
 
Join Date: Apr 2012
Location: Riverside, CA
Posts: 1,665
The point of my test was to prove the AC pump would work at idle rpms.

It created 30 degree temp difference so thats good enough to feel comfortable for a few minutes at the light.

Thats a lot better than no ac what so ever at idle.

I'll update in Aug for some higher temps if anyone cares to know, although I wont be able to produce humidity in CA.
__________________
"It broke because it wants to be Upgraded "
2012 Porsche Performance Driving School - SanDiego region
2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP,
Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)

Last edited by jb92563; 03-30-2014 at 09:45 PM.
jb92563 is offline   Reply With Quote
Old 03-30-2014, 10:28 PM   #19
Registered User
 
Porsche9's Avatar
 
Join Date: Sep 2013
Location: Chandler, AZ
Posts: 1,796
I've had a 4" pulley on the car for a few month and have been pleased with results so far. The real test will be when it hits 110 degrees in July and then throw in a monsoon for some humidity. I will report back then. So far the worst has been a 88 degree day and the car was parked in the sun for an hour so the interior may have hit 100. It cooled down in no time.
__________________
03 Carrera
02 Boxster S Guards Red, black interior with matching hardtop
89 Carrera 4
89 944 S2
78 911SC
Porsche9 is offline   Reply With Quote
Old 03-31-2014, 01:51 PM   #20
Registered User
 
Join Date: May 2011
Location: weehawken nj
Posts: 240
To the guy holding the temp gun directly at the vent and testing the AC at 70 degrees....

This test is a fail for several reasons.

#1. Holding the temp gun right in the stream of the cold AC makes the reading artificially lower.

#2. Its 70 degs, but what was the humidity?

#3. When its really hot at stop lights, I sometimes rev the engine to 1200 rpm to get some better AC.

Please revise your experiment and show us a AC manifold hooked up and before and after pic with the pressures.:dance:

Bigsmoothlee is offline   Reply With Quote
Post Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 11:08 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page