Have you ever heard about deleting the MP62 Magnuson supercharger OEM bypass actuator to improve Lotus Exige 2ZZ-GE engine performance ?
The supercharger boost bypass actuator controller is an OEM Eaton part. This factory vacuum system, designed to fit all Lotus Exige MP62 supercharged cars (240R, S, Cup...) and 2-eleven models, occasionally fails and can be improved...
The Magnuson/Eaton MP62 supercharger is the 4th generation supercharger from Eaton. It differed from the earlier versions by the addition of the internal bypass valve.
"This bypass system incorporated in the supercharger reduces air handling losses when boost is not required, resulting in better fuel economy. Typical applications are on engines with displacements of 1.8L to 5.3L.
The MP62 was engineered for midsized fuel injected engines, ranging in displacement from 2.0 to 4.0 liters. Although it may be tempting, to install the largest possible blower that will fit under your hood, Magnuson's engineers recommend selecting the smallest supercharger that will provide your desired boost level. Remember, proper supercharger sizing ensures that your car will achieve boost at the lowest possible RPM, thus maintaining the responsiveness and street-ability of your engine’s power band."
What's the supercharger boost bypass actuator ?
Strangely and contrary to 2005 Lotus 240R engine pictures than you can see above (easily found on the web), the MP62 Lotus bypass actuator is a single port and no dual port !?
The picture on the right illustrates two kinds of bypass actuators but not exactly the one used on Lotus 2ZZ-GE supercharged cars.
Concretely, dual port would have been better since bypass is controlled, on the one hand, by the depression hose and, on the other hand, by the ECU (Electronic Computer Unit). You will understand why after reading this article.
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| 42_9.14 : Bypass Actuator Valve, vacuum [Part number: A128E6017S] |
The picture bellow shows the exact OEM part :
which control the internal supercharger bypass valve:
Schematic view :
Each owner of Lotus 2ZZ supercharged car knows the problem of cooling air intake temperature...
There are many reasons for that :
1/ intercooler just overhead the engine
2/ poor airflow through the intercooler due to the insufficient roof scoop
3/ lack of settings for superchager bypass (that's precisely the subject of this article)
The first two points can totaly or almost be solved by differents aftermarkets products (uprated intercooler, heat dispersant tray, big roof scoop, auxillary air feed kit...).
For the last point, I achieved tests and researches to find how to optimize bypass operation...
And finally, have a look at my 2ZZ-GE Lotus Exige 310RWB (Red Water Belgium) with my propre home made plug & play bypass actuator :
As you can see thanks to the video above, beware this system works only with CABLE THROTTLE BODY ! So, it's not compatible with DBW (Drive By Wire) throttle body.
How does it works ?
The MP62 supercharger internal bypass is now directly linked to the throttle body butterfly to follow exactly the same movement, at the same time.
Because opening internal supercharger bypass valve doesn't need anymore sufficient intake depression, the response is as progressive as your foot on the accelerator pedal. Furthermore, the supercharger is under boost only on driver's demand (boost-on-demand), decreasing supercharger parasitic.
When you foot off the pedal (for example to slown down or stop the car), the throttle body suddently closes and the supercharger doesn't need anymore waiting until intake depression strong enough to the OEM bypass actuator controller command to stop compressing air into combustion chambers.
What improvements does it make ?
+ Better throttle response in slow driving conditions = idle like Naturally Aspirated (NA) engine
+ Less stress to supercharger and serpentine belt = more reliable mechanic
+ Fresher intercooler = better performance
+ Parasitic losses reduction = better mileage
If you want this "plug and play kit", it's easy to install (1 hour), just let me know :
Nicolas F.
Tél.: +33 (0) 6 62 26 19 19
njb.fournier[arobase]gmail.com
FRANCE