In your opinion, what should I do?
I am hitting only 10 psi, where is my final 5?

My has just barely over 80k miles, should I try replacing the BPV first?
and if that doesnt work get my supercharger rebuilt/ buy a new one and have it rebuilt?

Thats what I am thinking, but I don't want to use money I don't have to.

but at 80k should I have it rebuilt anyway? since It might start wearing out anyway?

I just want your guys 2 cents.

Also, I think I will get the Detroit Tuned BPV over a new OEM one.
Only $25 more..


Edit: 15% Pulley installed.

 

Some love the DT BPV...it builds boost sooner...some say it is does not fit well with their driving style....it does impact your MPG a tiny bit. We chatted before.....but somebody will chime in. One tip....check for used DT BPV if you want, I know one guy in out local club took his DT valve out, and put a new stock one in...did not fit his driving style.

One thing....the real reason I chimed in, and I forgot to ask before...How high above sea-level are you? This will have a major impact on boost level too....unlike a turbo...a supercharger does not have the ability to compensate for higher altitude, and make more boost...so in a best case senairo, it is unlikely you will get 15 PSI of boost at 5000 MSL like much of Colorado, Wyoming, and Utah! Check with the denver guys...post and ask what type of boost thet get with a similar setup.!! That bit of info should be very telling!!

 

You need to do all the basic checks first. Check for boost leaks, sticking bypass or mis adjusted bypass valve.
Also do you have a known good boost gauge, I've seen many boost gauges fail.

 

Before you start throwing money at it, I recommend that you make sure that your intercooler boots are tight and if you're running a boost gauge that the connections are good there as well. The fix may be as close as a torx driver away.

I'm in Utah as well and am running a 15% pulley and a boost gauge. 10psi is low for that setup. I see about 14 at redline.

 

I didn't even think of the elevation!
5,627 ft is my elevation.

Do you really think the elevation would make me loose an entire 5 psi!?

someone from high elevations, also pipe in if you will =]

 

How do I check for sticking bypass or mis adjustment?
And what about leaks? Just make sure its all tight or what?

I checked the intercooler boots and stuff, it all seems solid.
I will try to make sure the boost guage connections are good.

More detail on how to check all these things for sure?
I really appreciate the help!

 

you gotta pull it off and hold it up to the light ; if you see light around it ;it's either sticking orhas broken spring or needs adjustment . dtbv is good but need smoother foot or tires will break loose when you dont want them to .

 

Pull exactly what off? the bpv? is it that easy to get out?

 

You know I swear I said this exact same thing at one point, and thinking about it has to be wrong. From a thermodynamics standpoint this is a mass flow rate problem, so analyzing it from that perspective may yeild an answer.

Consider a supercharged engine operating at steady state, in other words continuous speed. The engine has a mass of air it wants to take in, m1, and the supercharger flows a certain amount of air m2. By the conservation of mass law we acknowledge that in order for the system to maintain equilibrium m1=m2. In actuality m1>m2 at some or all phases of engine operation in order for the supercharger to build boost. In order for m1=m2 the supercharger would have to deliver the same amount of air mass as the engine wants at all engine speeds, which is impossible by nature of the design and would only result in boost if it was in a boosted condition when m1 became equal to m2.

So if m1>m2 what does that mean? At steady state the engine would continue to build boost, it would not level off at a specific point, ever. The implications of this are two fold. 1: It means that the supercharge has a means of bypassing the extra air it pumps. And 2: a supercharger is capable of compensating for changes in altitude.

 

Simplify =]

 

Basically, you should still being making more boost then you are, even at altitude.

 

Yeah might/should be making more boost than he is but a supercharger is limited by altitude because it is a fixed compression form of forced induction. With a turbo, the waste gate is operated at a fixed pressure regardless of air density.
In other words a supercharger is limited by its spinning speed so the denser the air the more boost/pressure it makes and vice versa. A turbo does not care since it is only limited by the wastegate which reacts to absolute pressure plus the pressure the spring is rated (without a boost controller that is, which increases the level when which the wastegate bypass is opened). Without the wastegate a big turbo will blow even a built block as it hits insane levels of boost.

 

Without getting way more technical....just post in the 5280 forum, and ask what the guys around 5500 feet are getting.....You will get a bit less than sea-level....especially on a warm day....during the winter, it will not be a huge difference, but still a factor. The suggestion to remove the BPV to look at it if you suspect an issue might be good....but a couple hours of work to check out a $65-85 part. You could just swap it out...not the cheapest way to go, but not a lot of BPV's seem to make it 80,000+, and it is likely coked up pretty good just like your intercooler....I would pull the intercooler off, and clean it out some afternoon....it is likely pretty filthy (allow it to dry thoroughly be reinstalling)....when you do this, it will give you a good chance to check the boots for cracking, and pull the BPV to look at it (it is not in the same spot...but if your tools are out...) Like I said, I'd just swap it as a preventive maintenance, Like doing a PCV valve. It sounds like you have a true concern that you are getting less boost than you should be....I will add that uncoated SC, dealer take-offs have popped up on E-Bay (they have been sitting on a few JCW owners shelves from when they did the upgrade and the mechanics that picked them up, now the cars are getting sold,and people need the $$) for 300ish, and coated for $500ish, like new with 100 to 7000 miles, so when it comes time, that might be an option!!
like mentioned before....the boost gauge could be sending you on a wild goose chase....before you do a bunch of work....are you happy with the performance you are seeing...or are you just trying to maximazie it? If someting seems lacking recently....then it is time to look....if all seems pretty good....and it seems to go up the same hills like before, chirp the tires the same, I'd be inclined to watch and wait!!

 

I really appreciate all of your guy's help,
and Yeah, I cleaned the intercooler like last week hoping to get some more psi, but this is simply according to my gauge.
My car still feels like its performing great, but I REALLY just want to make sure I have maximum performance that I can.
Without breaking the bank preferably haha.

I am just not entirely sure what a BPV looks like,
but I am sure I can look and find it if i try.
any hints?

Again, thanks everyone for piping in, I'm learning =]

 

BPV^^^

 

Okay, I will go looking for it once I am off work

Wish me luck!

 

Air pressure drops 3% per every 1,000' above sea level. So you may only have a 15% gain with your SC whereas at sea level others will have a 25% gain......

I think SC's were used in some high altiitude aircraft like the P-51 for this reason.

 

superchargers changed the face of dogfighting back in ww2 due to the fact that they could fly higher than na planes . so even though your boost is less than a dude at sea level ; it's way better than an na car .

 

Some WW2 aircraft engines pioneered the use of superchargers with Turbochargers!! So MINI's with both were not first! But they are in good company!

 

jirsty,
Where abouts in Utah are you? Maybe I can help.

 

I like that this turned into the history channel hahaha.

I will PM you Earl.

 

The following link is a how to install a Detroit tuned BYPASS valve...it should help you out!! You do need microsoft word or compatible reader to open it!! Enjoy!!


http://www.google.com/url?sa=t&sourc...bbJG96Bd0zTs0g

 

That is helpful.
But after messing around for a bit, we found this:



If I adjust that screw, the thing will open bigger,
is this the solution to my problems?
or is this bad news if I adjust it.

(click it to make it bigger)

 

you really want to be concerned in how it closes .(is light visible around butterfly etc.) opening is by vacuum say at idle and tooling around on partial throttle . it wont close till the throttle body goes way open and vacuum drops off. the spring then closes the bpv butterfly and the sc does 100% of the routing of air .(boost) . i think that screw will allow you to adjust the closing to be closed but not sticking closed .they do tend to stick closed if you relax that screw too much .

 

Personally. I would not touch it unless you know what you are doing. In the link you can see the pictures....I would pull it out, and look at it...and adjust it that way if it is indeed the issue.

Since the drop in boost was sudden, it sounds to me like something changed/broke on you....I think you said you fixed it onetime (for a short time) by uncolasping a vacuum line after doing the intake install or something right? To me, it sounds like I would be looking for more of the same.
One thing to look closely for....somewhat unrelated....the silicone intake tubes usually need to be trimmed to fit correctly, and sometimes they are misfit a bit, and the slip off the intake in the area you are working, letting in very dirty, unfiltered air. While you are in the area, I would check to make sure that the silicone intake tube is seated securely, with no leaks!!