70,000 miles is not a lot, but a few thousand with a loose air filter...some dust gets in...boost can drop a bit....rotor wear...Try messing with the bpv...locked one way, zero boost, locked the other, full boost....simple enough to try.

 

I zip tied the bpv shut and didn't pick up any boost. I also hooked up a mechanical boost gauge and verified that my Torque app is accurate, only seeing 13.5 psi.

Only other thing I can think of is to take the bpv off and adjust it, maybe it's way out of adjustment causing it to leak boost.

 

My $ is on BPV.

If belt was slipping that much you would not only hear it somtimes, you would smell it too...

If you go in, may was well swap it for a Detroit Tuned version....

 

To be fair I do smell the belt but I'm pretty sure it's because it doesn't sit perfectly on the SC pulley. The pulley needs to be pushed out just a hair (kind of hard to get the pulley properly aligned when you are installing it with the SC off the car). The belt sits in the groves just fine but you can see it lip up ever so slightly on the pulley. I've been monitoring it and it's not wearing or tearing or anything.

Doubt that would cause any slipping issues though, it really is very minimal.

 

Then step 1 IMO, CHANGE THE BELT....
You might be surprised.....

 

With what though? Some people have said they think the belt WMW sent me is too long and I should get either the 535 or 532 belt.

 

If the belt is making enough heat that you can smell it....it is slowly cooking....
If it fails.... The tensioner will slam into you your crank damper....wrecking it....

 

I'll take a pic of it to see what you all think. Its so minimal I doubt its an issue but I'd like to be sure.

 

I tend to agree that going with the Detroit Tuned is a smart idea.

For myself, I had the idea that sometime this winter I may park the MINI, switch the insurance to my other car so I can work on the MINI for an extended period.

That being said, I would have plenty of time to attempt to adjust the full close stop in my bypass valve, all the while knowing that I might mess it up, and then get the Detroit Tuned one anyway.

I would put priority on moving the sc pulley on the shaft to the right place. Even if it's just the edge of the belt that is wearing, I could imagine that the weak spot could work its way in, affecting the integrity of the belt as a whole. I think you said you have "just" one hole showing... and while I believe that's enough, I think you have room to go a few mm smaller on the belt so you see one hole and a little more (like halfway between the two holes). -belts are cheap, then you'll KNOW that it's right, and not slipping.

 

Update:

So I lied, the belt was sitting perfectly on the pulley lol. What I was seeing is the white stitching on the side of the belt and it made it look like it was slightly overlapping the pulley.

I swapped it for the Gates 535 belt anyway. The tensioner hole is much higher now and the belt was a pain to get on so I know its not slipping. The bad news is I am still only seeing 13.5 psi :-/

Only thing left is to buy the DT bpv. I'll update the thread after I buy one and put it on.

Wish me luck...

 

I looked on my torque app and I hit 14.1 lbs of boost today with my mods. What year is your Mini btw? The 2006's didn't have BPV issues is why I asked.

 

I had my BPV go bad around 40K miles. I don't think it's that uncommon...

 

Mine is an '04 so chances are it's bad/out of adjustment. I figure it is either bad now or will go bad at some point down the road so I'll just buy the DT and be done with it. Hopefully it nets me some extra boost.

Has anyone swapped to the DT bpv and gained boost? Or is it mostly to get rid of the yoyo? I would assume you gain boost if your stock bpv is out of adjustment and leaking boost in the first place.

 

you will regain the lost boost, and you will lose a little mpg too.

 

I hope you're right cause I will gladly trade a little mileage for boost ;-)

 

I have done a lot of research recently since my '03 with 116,000 miles was only boosting 11.5 psi with a 16% supercharger pulley and a 2% crank pulley. Recently went to a shorter belt and new tensioner with no improvement.

From everything I read, the DT BPV should be more responsive and DT claims a possible 1 PSI gain at redline. I am sure you probably found the same information.

FYI - I just replaced my supercharger with a low mileage '06 one, swapped to a 17% pulley and put on the DT BPV...now seeing 16 PSI. Not really sure where I gained but replacing some older parts didn't hurt.

FYI

 

Good input, thanks. I do plan on buying the DT bpv but definitely not buying another SC lol. Hopefully the bpv does the trick. I know they say about 1 psi gain but I'm sure that all depends on how far out of adjustment the stock bpv is.

 

+1
The SC is nothing more than a big air compressor.....they WEAR OUT, even if the bearing and water pump PTO does not fail....clearances get bigger...and max boost drops.....
You can sometimes find 15,000 mile superchargers(give it take) for sale for about $600....about $100 more than the core value of a nonworking sc....
They are getting harder to find...not as many weekend, summer only cabrio's (gen1 S's ) are getting wrecked....but that's how I got my spare....cheaper than an overhaul or a exchange...heck new/mini branded rebuilt are about $1500-1600.
Also a bit of info on the DT tuned bypass valve...
It is a NEW stock bpv, with a stronger than stock spring installed...
Pre 2005 cars had a weak spring in the bpv....in 2005, mini made the spring stronger...
The DT bpv tends to SLAM shut...making finesse driving harder for some...some like it...some like the newer post 2005 version better....

 

Granted SC's wear and boost drops but I doubt that alone is where my 3-4 psi of lost boost is coming from, especially with only 70k miles on it. I would imagine maybe 1-2 psi loss tops from the SC.

Heck, if I can gain 2 psi from the bpv I'll be a happy camper sitting at close to 16 psi.

I am aware of the drive-ability issues with the DT bpv, from what I've read its a little more mild than the VGS mod (which I have done) so I'm not too worried about that end.

 

Have you had a chance to look around the edges of the sc...glance at where you replaced the gaskets.... Wonder of you have one pinched....maybe use a smokestick/innense while somebody is reving the motor...look for air movement.
I have to admit 70,000 miles is low for a sc missing boost...but anything is possible.

 

The only gaskets I replaced are the SC inlet pipe (the green one) and the water pump to block gasket, neither of which have to do with boost. I have also had the IC off multiple times and always make sure they are sealed properly.

I'll probably make a boost leak tester or see if one of my current testers (for other turbo cars I've owned) will fit. Just to rule out any boost leaks.