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FYI...anyone who has a bypass valve like this, which you probably all do, give them a quick check.
Mine is bad. I don't know how long it has been bad, but i always felt something was a bit off for a while.
The valve defaults closed..so under ALL driving conditions the SC is compressing air and not bypassing it back to the inlet side. Probably not good for mileage...heat build up..load on engine etc etc. It is will be a source of a vac leak also.
How is the rest of it holding up Tony? I think you must have one of the longest lived Supermodel installations going?
How is the rest of it holding up Tony? I think you must have one of the longest lived Supermodel installations going?
runs great. no complaints. I really need to do a fresh Sharktune and go to the dyno. I have never dyno'd it after i got a sharktuner. I had a bad/slow cooling fan that i fixed and that helped in the heat of the summer here.... transmission finally gave up the ghost 2 yrs ago...got a used one with LSD on it now Just keeping up with typical piddley 928 stuff that is not related to a SC'r install and thats it...HP steering line...sunroof switch...bad door jam switch..etc etc all minor. Tires...
I also had a an issue when the car wouldnt start periodically when warm. I have no idea what was causing it except that, ever since i installed a plug on the front of the car for a battery tender and plug it in each night, I have never had another issue since 2+years. Strong fresh battery all the time....and the battery has lasted 3 summers here now with out issue.
There must be some voltage/amperage at which the injectors will not fire but the rest of the "car" operates normally. ?? The root problem was no injector operation when cranking. Let it cool for a while and it was fine...i swapped relays..you name it. Never did find a precise cause.
The root problem was no injector operation when cranking. Let it cool for a while and it was fine...i swapped relays..you name it. Never did find a precise cause.
This is a symptom of bad Lh harness ground connections at the back of the block.
runs great. no complaints. I really need to do a fresh Sharktune and go to the dyno. I have never dyno'd it after i got a sharktuner. I had a bad/slow cooling fan that i fixed and that helped in the heat of the summer here.... transmission finally gave up the ghost 2 yrs ago...got a used one with LSD on it now Just keeping up with typical piddley 928 stuff that is not related to a SC'r install and thats it...HP steering line...sunroof switch...bad door jam switch..etc etc all minor. Tires...
I also had a an issue when the car wouldnt start periodically when warm. I have no idea what was causing it except that, ever since i installed a plug on the front of the car for a battery tender and plug it in each night, I have never had another issue since 2+years. Strong fresh battery all the time....and the battery has lasted 3 summers here now with out issue.
There must be some voltage/amperage at which the injectors will not fire but the rest of the "car" operates normally. ?? The root problem was no injector operation when cranking. Let it cool for a while and it was fine...i swapped relays..you name it. Never did find a precise cause.
daily driver!
I'm a firm believer that these cars prefer to be driven daily.
Thanks for the heads up on the diaphragm Tony. I checked mine last night, and all is good.
They have plenty of flow for use in a twinscrew application, and are completely rebuildable.
I am finishing the development of a dedicated boost controller as well that will allow control of any single-port actuator (such as the QRJ or any standard bypass valve) not just for bypass operation, but also for custom boost curves and cuts. I should have the prototype back next week to test the new software package. If anyone else is interested in helping with the testing, shoot me a PM.
The 928 needs a suprisingly high voltage to get the computers to run. I had many times more than enough juice to crank the engine over (although a bit on the slow side) and the injectors didn't get enough voltage to fire. With the same voltage other cars would have started but the 928 needs more than normal.
Tony, did you notice a change in vacuum/boost numbers on the gauge??
Originally Posted by Tony
FYI...anyone who has a bypass valve like this, which you probably all do, give them a quick check.
Mine is bad. I don't know how long it has been bad, but i always felt something was a bit off for a while.
The valve defaults closed..so under ALL driving conditions the SC is compressing air and not bypassing it back to the inlet side. Probably not good for mileage...heat build up..load on engine etc etc. It is will be a source of a vac leak also.
simple test is popping the hood and blipping the throttle and watching the valve. It should move at some point.
they are built in a very similar fashion as the vacuum pods in the HVAC system but are just a bit more durable for the environment they live in. They can be checked to see if they hold vac in the same way. Im going to cut mine apart and have a look as it seems to be a sealed unit. They don't appear to be serviceable AT ALL. I can see in side where the diaphragm is split by looking inside where the plunger passes.
for a 170 bucks for the pod...and 289 for the entire unit...i will attempt ti fix it my self.
HTH
as an after thought...skip about a minute into it..
Just a heads up for you guys looking for a decent bypass valve.
This is the OEM valve off a supercharged MINI...OEM quality is usually very good and the price is right. $111 here...maybe cheaper elsewhere.
Very similar to the one pictured above...
Just a heads up for you guys looking for a decent bypass valve.
This is the OEM valve off a supercharged MINI...OEM quality is usually very good and the price is right. $111 here...maybe cheaper elsewhere.
Very similar to the one pictured above...
I saw that also in my searches but my VALVE was fine, as was the assembly. It was just the Vac pod that was bad. As you can see, you can buy just the Vac pod. I didnt t want to deal with the chances of different hole spacing on the entire assembly when re.installing it. Some pods are clocked differently in reference to the valve/assembly etc.
as for Darriens Question. I'm putting out 476 rwhp now
The line that feeds the vac pod is no bigger than any other vac line on the car really, so a leak there really isn't that noticeable. Yes, there is a vac leak and a boost leak present but the integrity of the VAC pod/line is how the BYPASS VALVE is actuated....that is where the problem is.
The vacuum offsets the spring pressure. It is the spring pressure that drives the valve to a normal closed "on boost" position. This means the Sc'r is constantly pumping air and not recirculating it through the bypass.. Its the capacity of the engine to swallow this air that gives you boost or not (in simple terms) With a bad valve the Sc'r is working/ dragging the motor all the time...idle..putzing around in traffic etc. When i put my foot into it, it still made boost.. I felt my motor was a bit sluggish...akin to having another AC unit running is the analogy. Parasite drag on the engine ALL the time.
With the valve working properly the car is definitely more punchy! and you can feel it hit.
Hans ...do those valves have the rubber diaphragm ? Ive heard of some that actuallly have a tight fitting machined metal cylinder as an actuator.?
There is an aluminum actuator and a "rubber" diaphragm. There is also a valve guide as part of the assembly:
There Synapse BPV is a piston style with compact body, and what I was originally planning on using, but don't believe it will have enough flow for the 2.6L HPS. That is what I would look at for anything 2.2L or smaller.
There are a couple others out there, but the size of the body makes it really hard to work with.
09-14-2016, 04:40 PM
Just keeping up with typical piddley 928 stuff that is not related to a SC'r install and thats it...HP steering line...sunroof switch...bad door jam switch..etc etc all minor. Tires...
