Has anyone had experience with this item good or bad?
http://www.mailordercentral.com/928i...tem=1&mitem=51

It's the SS Rear Muffler Bypass from 928 intl.

 

Mike,
I put similar set up on my (previous) '87S4 and REALLY liked the way it sounded/looked. Not at all overbearing or intrusive - just right. Without it, the S4 just didn't sound like it's supposed to.
Will have a similar effect on your GTS (I've driven stock GTS' enough to know, IMHO).
Don't have it on my '89GT though - doesn't need it.....

 

I have one on my GT. Sound great, but you might not like it if you do a lot of highway driving

 

I have one on my S4 along with the Catbypass Test Tubes from 928 Specialists.

Gets abit loud above 4K rpm - but not too bad.

Much improvement over the stock exhaust IMHO - better flowing, more ummmmppphh, and a bit of a note to let others know ya mean business.

 

Installed it over the weekend. First time I got my hands dirty on my new shark. Took about an hour. Sheered a bolt, replaced all the hardware with stainless. Sounds great at start and idle, from 1-3K very nice a bit loud past 4K, but still nice. Don't really see too much change in performance. Too busy listening to the sweet sounds. I noticed that the RPMs drop much quicker when I let off the throttle. I stalled the car while waiting in line to get gas But after a few miles I'm a little more used to it. And I like it. By the way, the stock muffler weighs a ton.

Taking the car to Precision in Anaheim this morning to have the Timing belt and water pump replaced.

Thanks for the input guys.

 

The later the car, the more restrictive the exhaust system became to meet the EU drive-by noise standards (or maybe it was just Sweden).

Those GTS units do weigh a ton, and a the system is probably the most restrictive put on a 928. A GTS should probably be quieter than a GT with the same RMB. If all you did was the RMB, as the GTS also has more restrictive resonators (those mid mufflers) than the GT does.

Greg

 

Hi again Mike,

Don't know if you have seen my timing belt... document. There are many variables in that job. You may want to replace more stuff, and rebuild the tensioner. See below:

Timing Belt and Water Pump Replacement Essentials:

Removal:
You have to remove or loosen everything from the front of the engine including:
Fan and Throttle Linkage Console/Carrier
Alternator
Compressor
Smog Pump
Power Steering Pump
Front Main Timing Belt Cover
Distributors
Front Distributor Timing Belt Covers
Tensioner – Rebuild it
Tensioner Console
Rollers
Pulleys
Water Pump
Upper Fan Shroud/Cowling
Fan Belts
Hoses

You can easily break off water pump bolts by over-torquing or removing stuck ones. It would be nice to have the engine cleaned first – without losing any original factory stickers. However, I would not drive the car for that after receiving a belt tension warning. I heartily recommend that you or your mechanic replace everything on this list while you are in there. Rollers have bearings that will become fowled by anti-freeze or mileage.

Special Tools:
Buy the aftermarket belt tension tool for around $50, and the flywheel holding tool for around $20.
Socket for front main pulley
Metric Allen Wrenches with 3/8” drive fit
Breaker bar and cheater pipe for pulley socket (not really special tools)
Metric deep sockets (not really special tools)
Universal, ratchet, and extensions for sockets (not really special tools)

Tool, Part, & Manual Suppliers:
928 Specialists at 828-766-9280, Devek, and 928 International 800-634-6117. Those “Big 3” can hook you up with about anything for the 928. Tweeks, Pelican, Automotion, etc. can also help with your needs. See the Rennlist site for contact information. The other tools are available from Sears, and most auto parts stores.

Online Support:
Join the free Rennlist 928 Web Board. The web interface is the most effective that I have used. The email groups give an additional audience, but less sophisticated interface. See: http://www.rennlist.org/

New Parts & Supplies:
Water Pump – Porsche rebuilt will do, not necessarily new
Water Pump Gasket
Timing Belt
All other Belts
Rollers (3)
Aluminum Safe Antifreeze
Distilled water (to be used with antifreeze)
Thermostat
Thermostat sealing ring
Radiator Hoses (2)
Timing Belt Idler bushings (2)
Radiator Drain Plug
Engine Block Drain Plug Seal Washers – metal (2)
Tensioner needs:
O-ring
Gasket
Boot or rubber end cover – looks like a hollow half doughnut
Boot Clamp
90 weight gear oil
Optional Parts & Supplies:
Front Seals: Main, Oil Pump
Clutch (pulley driven) Fan Bearings
Silicon Fan Clutch Fluid – from Toyota

Timing Belt Tension Check:
You will need the belt tension tool to check tension after approximately 1,500 miles and 10-15k mile intervals afterwards. Remove the passenger side timing belt cover (at the cam gear, remove distributor first), and check the tension. Timing belt and/or water pump failure is common after 60k miles on the 928. Take belt tension very seriously. That is the Achilles heel.

Useful Manuals:
The Parts and Technical Reference Manual is a great source of diagrams, part numbers, etc. The factory manuals provide procedures that are very helpful. There are parts microfiches and CDs.

Optional Work:
While you have the pulley driven fan off, you may want to replenish the silicon with Toyota supplied fan clutch fluid. You may also wish to replace the front main seal, and the oil pump seal while they are relatively exposed. Those seals are tough to change. May replace the Clutch Fan Bearings.

Detailed Procedure & Photo Links:
Greg Nichols’ page has troubleshooting procedures for the timing belt light and more at: http://www.nichols.nu/tips.htm
Tony’s page has pictures and procedures: http://members.rennlist.com/v1uhoh/index.htm
John Pirtle’s site goes into great detail, with awesome pictures: http://members.rennlist.com/pirtle/svc.html
Link to Adobe Acrobat Reader document that has numerous service procedures. Download or open it here: http://www.jageng.com/sharkbit_2.htm


HTH,
Good luck,