I have a Greddy supercharger on an 06 xB. It has given me minimal problems until recently, where it will periodically hold a vacuum under low RPM but not make any boost. I've isolated the problem to the rotating arm on the bypass valve vacuum actuator being stuck in the fully down (open I think) position. I've been oiling and excercising the bearing that goes into the metal bypas valve assembly connected to the throttle body and that helps for a day or two, but I would like to know what the problem is and if it needs replacement. Has anyone else had this problem?

I am unable to troubleshoot if it is a bad vacuum actuator (the little black cylinder on top) or the actual valve itself sticking since they are connected by the control arm. Any help would be greatly appreciated. It will be a little difficult getting Greddy to replace a part since I went through a "non-authorized" online dealer, thugh they will eventually honor it. I may go directly to Magnuson if it is the vacuum actuator, it's a $35 part for replacement.

FYI, Greddy uses an Eaton MP45 Roots-type blower and a Magnuson bypass assembly if you need OEM replacement parts or support.

 

that sucks, it sounds like it could be the actuator, have you tried removing the piece that connects the TB to the SC and see if you can clean the valve from there? just an idea.

 

I'll need to look, there's a spring inside the black can. These are modded in the Mini community for quicker throttle responce. The Mini has an MP45, P=water pump & the BPV is external making it accessable for calibration as well as modification. The Greddy is an Eaton M45, no pump.
Is the rod all the way in the can when stuck? If so it could be a broken spring. If it's the butterfly sticking, you'll need to remove the intake to re calibrate the BPV.
If you need more info email me & send a pic of the problem. This could be an easy fix........

 

Yeah, the rod is all the way in the actuator when it gets stuck. but if you move it ever so slightly it snaps back to being fully out when the engine is off. The butterfly valve is in an intake assembly that is cast metal, and sits between the stock throttle body and the blower on the intake side. I could pull off the throttle body to get a look at it, it is not easily removable from the blower though. What is your e-mail? Can you send it through a PM?

 

If you remove the actuator & make sure that it works without binding, you'll know it's the butterfly, although, if you just need to give it a little tap & the BPV opens, I think you're good to go.
Once the intake housing ( the assy that the TB is bolted to ) is removed from the SC, the screws will be accessable to re-allign the butterfly. The BPV closes when there is no vacume via the spring in the can. To remove the BPV butterfly shaft, after removing the bytterfly plate, there should be a "C" clip on the radiator side of the SC ( this may be missing, causing the butterfly to jam closed ). The shaft could also be bent, however unlikely. I'm assuming this just started happening & got worse. This sympton makes me think the plate has moved. You could readjust the stop, just a tad as the butterfly may close a little too tight ( there should be around .005, just enough to let some light thru, not that you can see any light thru the SC, just rule of thumb ).

You should have my email, I sent you an email about the "06 re-wire" yesterday.

 

the GReddy kit does use the MP45, the "P" stands for ported, as in S-Ported, heres a link i found on it...

http://www.capa.com.au/eaton_mp45_4th.htm

 

Yup, you're right, With the Mini the "P" was thought to mean pump, as in water pump drive, when it really means yhe next gen M45.
Thank you for your input,
Steve

 

no prob ;) great info on the valve by the way.

 

Oh, right, guess I forgot to mention it was fourth gen, thanks for the clarification. I'll pull the butterfly valve this weekend and hopefully get an answer. Might have to pull the whole blower assembly anyway to install a new injector and rail set.

 

Thank you Easybox.

Vettereddie,
TC injectors? You won't need to pull the SC. It's a little tricky but doable. New rail? Which brand? I'm thinking new rail, already have the TC injectors.

The BPV is right under the intake horn. It's quite easy to access & you will be able to see whether the butterfly is shutting too hard, causing the problem. This is not a difficult fix.

Off subject, I found the OE belt works somewhat better than the supplied Greddy belt, no slippage, no re-adjusting ( after 100 miles ), not much stretch.... And it fits just fine.

 

Wow, good to know I won't need to pullt he charger to get to the injectors. Going with a Perrin rail, 410cc injectors from http://www.deatschwerks.com. I'm up in the air about adding a new fuel pump, run about $100 from Deatschwerks. You mean the OE xB belt? I had a hell of a time getting the Greddy on, I don't know if I could fit the other one.

 

I don't have a new rail yet. I'm thinking OBX, they're around $100. Hey, you picked a great place to get the injectors.
And, the pump... In some cases you need the extra presure & volume. Dinan has a package for BMW that only uses a pump & regulator, along w/software, no new injectors. The duty cycle increases but not over 85%, which is plenty safe ( 80% is what most recomend ). Over 90% doesen't leave much headroom. Bottom line, I'm with you on the pump. Injectors - yes, pump??????
The OE belt went on both cars easily. Hmmm....
I wonder why the alternator pulley size was increased. An auto car has gearing that quite different from a standard - I can, maybe, understand why on a stick you may be in the higher rpm range but an auto?

Be sure to post the results,
Steve