SL55 bypass valve v SRT6/SLK32 no bypass.....
03-26-2014, 04:28 PM
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R170 99SLK230 + SLK32
SL55 bypass valve v SRT6/SLK32 no bypass.....
Can someone explain (or post a link/s) as to the differences between the 2?
The bypass valve (2ndry throttle body) in the SL55 sits just after the primary throttle body and allows air to bypass the supercharger.
I presume it's open somewhat unless your under WOT or at least if the MAP pressure starts to go positive....
I've noticed from logging on on my SLK32, that my MAP (pressure) doesn't go +ve unless I'm over 3,000rpm and/or throttle position >25%.
Just wondering if there is any deficiency in not having a bypass on the supercharged 3.2L?
The bypass valve (2ndry throttle body) in the SL55 sits just after the primary throttle body and allows air to bypass the supercharger.
I presume it's open somewhat unless your under WOT or at least if the MAP pressure starts to go positive....
I've noticed from logging on on my SLK32, that my MAP (pressure) doesn't go +ve unless I'm over 3,000rpm and/or throttle position >25%.
Just wondering if there is any deficiency in not having a bypass on the supercharged 3.2L?
03-26-2014, 04:55 PM
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E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
There are a few threads that discuss the by-pass valve here on MBWorld, as I recall MB added it to reduce a "supercharger Lope". The first SL 55s had no bypass and suffered a harsh SC engagement and poor idle.
One member here did mod the by-pass valve to log/see the position of the BPV you can search for him under the name Finny "stock to awe"
I really dont think the V6K suffers any loss by not having a BPV.
One member here did mod the by-pass valve to log/see the position of the BPV you can search for him under the name Finny "stock to awe"
I really dont think the V6K suffers any loss by not having a BPV.
03-26-2014, 05:20 PM
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03-26-2014, 08:42 PM
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E55, GLS450, GL63, GLE350
The supercharged 55 engines use a bypass valve. It is very much necessary. It allows the car to run as if it was a NA car when you aren't on boost by allowing the air to bypass the supercharger. Without it, the car gets crappy mileage and runs hotter. The heat is much less since the car has an electronic supercharger clutch but the bypass valve really makes it a much nicer engine to live with on a daily basis. You can really feel when the bypass valve fails or the vacuum to it is lost.
