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Bypass / Cutoff valve question and who wants a cat bypass?
Posted this at bottom of another thread, but maybe it's buried. Replacing the bypass / cut-off valve yesterday I noticed a small 1.7 embossed on the inside, and the original unit (marked BOSCH) has a 1.2. Assuming that corresponds to the pressure - suppose it could mean the pressure at which it opens...I could have had the wrong unit installed? Maybe 1.7 means atmosphere 1bar plus .7 boost, which would be correct? Original (or old replaced prior to me) could be wrong? Boost pressure seems to climb more readily and I hear a new cute little turbo-related whine sound.
Also, this is available if anyone wants it, half price or whatever if you can arrange a pickup (LA). Fabspeed bought 3 years ago run for 3K miles or so:
The opening trigger for the diverter valve is not positive pressure but negative pressure. This is created in the intake area when the engine draws against the closed throttle valve at a relatively high speed in overrun mode.
If you have installed a Bosch valve, the part number 0 280 142 102 or 110 should be on it.
Oh right of course, thus the vacuum line. I'm thinking the original one may have been broken for a long time. Add to the list of parts that age out due to 30 year old rubber.
Yes simple testing using your finger and a socket to check diaphragm in the diverter valve.
however for an in-car test you can pop off the small vacuum line on top and use a hand-vacuum pump with gauge (mightyvac) and draw a vacuum. value holding = good valve.
Yes just checked the original one and it doesn't hold at all. Guess I've never driven the 965 with it working. Have to get used to the noise it makes when coming off throttle.
HI
Ist Joe Fabiani the president and founder of Fabspeed Motorsport USA.
I am still super mad at selling y 1994 white 3.6 Turbo 20 years ago. Knucklehead move.
Fabspeed Motorsport recently developed a 1991,1992, 1993, 1994 C2 TURBO 964 Turbo 965 HJS German super high flow racing 200 cell catalytic converter for these magnificent air-cooled cars.
A direct replacement ultra highflow OBD2 European certified European homologated Emitec HJS German trimetallic race cat huge massive that will flow 90% to 92% of a straight pipe. The HJS Fabspeed cat is EPA Compliant and a great upgrade for Old restrictive factory cats and or used cars that have NO cats and the owners want clean & green power with no stink and no pollution. 2024 state of the art HJS racing cats from Fabspeed for 34+ year old Porsche C2 Turbocharged masterpieces collectors items!
thanks for the thread hijack - maybe a 50% discount code?
Originally Posted by Joe@Fabspeed
HI
Ist Joe Fabiani the president and founder of Fabspeed Motorsport USA.
I am still super mad at selling y 1994 white 3.6 Turbo 20 years ago. Knucklehead move.
Fabspeed Motorsport recently developed a 1991,1992, 1993, 1994 C2 TURBO 964 Turbo 965 HJS German super high flow racing 200 cell catalytic converter for these magnificent air-cooled cars.
A direct replacement ultra highflow OBD2 European certified European homologated Emitec HJS German trimetallic race cat huge massive that will flow 90% to 92% of a straight pipe. The HJS Fabspeed cat is EPA Compliant and a great upgrade for Old restrictive factory cats and or used cars that have NO cats and the owners want clean & green power with no stink and no pollution. 2024 state of the art HJS racing cats from Fabspeed for 34+ year old Porsche C2 Turbocharged masterpieces collectors items!
I was simply trying to let people know that older cars can have maximum performance and sports car sound and be emissions compliant . If anyone wants highflow Hjs German cats and diverted valves i have them in stock will surely give rennlisters a discount. /
Joe, you could always build one like what I just did.
Add all sorts of fun stuff. Total write off for you.
.....Just that hybrid Diverter/blowoff valve made my day.
Buy that Rubystone one on Pcarmarket that needs your products.
06-16-2024, 09:27 AM
Bypass / Cutoff valve question and who wants a cat bypass?
