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Just fyi these are not blow off valves. A P/D type blower does not need a bypass or a blow off valve. When you close the throttle you restrict air to the blower. It cannot overboost unless you put a bigger pulley on it and your foot is on the gas. The factory may limit boost at certain load conditions this way. But it is not needed. The very small light throttle efficiency from a bypass valve vacuum actuated or not is small. I think most of it is that the blower is not trying to run in a heavy vacuum. It can recirculate the air. But this actually causes it on these cars to be recirculating that air through the intercooler. So in effect you are just running hot air around and around throught the supercharger and intercooler. All be it very small amounts. Aftermarket blowers like an Eaton do this totally inside the supercharger case. It just reduces pumping losses when you are not using boost. That simple.
Besides noise the clutch is really doing the same it probably takes a few lb/ft of tq just to spin that thing at idle with no load on it. Maybe more.
Whipple Superchargers massive oversized intercooled air-bypass system for industry leading reduction of burst knock and incredible fuel economy, no ridiculous fabbed steel tubes or systems that circulate hot air
If Whipple includes on their units, I'm going to side with them.
I am not saying that it is bad thing it is just not necessary. You could easily run a vacuum actuated valve there instead. Or run the stock one as an on/off switch or PWM it for some basic ramp in if you want at a certain MAP value. But it seems not as a h-bridge controller like the factory setup with this controller. OP could look into some h bridge controllers that run from a simple pwm signal for degree determination. They are out there. It would simplify your control strategy a lot.
Another thing to consider when deciding on the bypass delete is how high the resolution for setting up the TB is in your ECU. OP’s going with the standalone system which will allow to dial in the cruising speeds with better precision than the OEM ECU. He will be able to set the TB’s position at say 100 rpm increments at low speeds (as opposed to 500s or 1000s). I don’t rely on factory or Weistec’s intake or cooling system (I made my own) so the combination of that and finer TB control allows to drive the car daily and have the power available instantly at the same time.
On a side note, very early SL55 didn’t have the bypass. CLK DTM didn’t come with one either. Two different cars for different markets. One with fuel economy in mind, another isn’t. Both drivable on the road daily.
PS: We've been discussing the same topic in another thread which may be beneficial to folks on here as it contains some input from the Whipple VP on the bypass valve subject in twin screw superchargers. Here
My ecu can handle a lot of extra inputs so Im thinking of maybe adding IAT sensors. I also have the haltech / racepak dash, so hopefully Ill be able to display the temps on there
Are you going to be wiring the ECU yourself? I’ve just finished mine not too long ago. If you get stuck, give me a shout.
I went with a 6 speed manual gearbox from Tremec. It was easier to do that than marry up the auto trans to the ECU. You get a choice of gear sets as well. Can recommend that although won’t be cheap.
Are you going to be wiring the ECU yourself? I’ve just finished mine not too long ago. If you get stuck, give me a shout.
I went with a 6 speed manual gearbox from Tremec. It was easier to do that than marry up the auto trans to the ECU. You get a choice of gear sets as well. Can recommend that although won’t be cheap.
Do you have schematics for each sensor? Ie which wire is 5v, ground, signal etc?
Last edited by h0tr0dder_uk; 03-30-2018 at 03:45 PM.
You cant just block it off or you will eat superchargers, you need a bypass valve or a recirculating BOV, we are trying both methods and will report back.
Check out this pulley we offer for this application (photo submitted by @autoperfection.utah)
As mentioned previously, there are cars that came from the factory with the bypass valve deleted. It is used mostly for better MPG. We offer a blockoff plate and have had no issues thus far on our test car.
Last edited by East Coast Euro; 07-19-2018 at 04:30 PM.
The M113k has a supercharger clutch. When the clutch disconnects, the supercharger spins freely. If you have one with a bypass valve deleted, do not get rid of the clutched supercharger pulley. As mentioned above, you will eat superchargers and, in addition, get crappy mileage, and suffer from more heat issues.
Another benefit of not using a bypass is your boost will be higher. Bypass butterfly is not designed to seal fully so some compressed air will be making its way back into the charger.
As mentioned previously, there are cars that came from the factory with the bypass valve deleted. It is used mostly for better MPG. We offer a blockoff plate and have had no issues thus far on our test car.
any updates info on BPV delete? Longevity? Was/is it in daily driver? Issues? Pics?
thanks
Mick
Last edited by AMG_55_cruiser; 04-10-2019 at 01:01 AM.
03-29-2018, 03:58 AM
