Forrest Gump 9

Can any tuners here in the US tune an E55 with the boost by-pass valve (the second tb that sandwich between the sc inlet and intercooler) deleted?

MBH motorsports

I have a little experienced with this. I'm sure all of them can, I would also think none of them mess with that function in the ECU. If thats the question you are asking.

If you are asking: if you delete the bypass valve will there be tune issues? That that answer is... Possibly. More so It could and is stress "could" cause some supercharger shock. As the boosted air has no place to go, once the TB is closed. Instead it backs up against the flow of the supercharger. that could cause some shock. Adding some stress to the bearings. In turn shortening there life.

under slow/easy driving the bypass valve is open. This helps with MPG, and its more efficient to get the air to the cylinders that way. Rather than pass it though a no engaged supercharger.

Granted some older 55k's did not have this bypass valve. and the CLK DTM does not, However it may have a more conventional bypass valve. As seen in Whipple supercharger kits. Hope that helps.

GT-ER

Bypasses in SC are actually to avoid having the engine build any kind of boost during idle/low rpms due to the fact that this would make the engine more inefficient due to heat. It also makes it easier to create a stable idle. The kind of supercharger shock MBH is talking about only applies to Centrifugal SC's when the throttle body is AFTER the charger. But in a roots/screw type setup this is not an issue due to the fact that when the throttle body closes, any air left inside the intake tract will be sucked by the engine and then there will be no air for the SC to build any boost with until the throttle body opens again whether it be for idle or for low rpm power. It's also for fuel economy as MBH stated.

The removal of the bypass isn't a big issue, and is great for oval track racing as it makes the engine even more responsive...but why do it in an E55? For drag racing it's meaningless and it'll take away some comfort for daily driving.