I'm sure there is a simple answer to this, but it seems like the whole idea of the bypass valve recirculating the hot, already SC-ed air back into the intake leaves you with a higher intake temp, robbin you of some power. Is there anyway to make a system to vent to atmosphere. I just think gettin rid of all that extra hot air would help performance. can this be done?

 

Along the same lines as the question above...

I can just barely hear my bypass valve when driving. Is there anyway to amplify this noise, besides the obvious venting to atmosphere route?

 

From your sig, don't you have a blowoff valve already? How does it work?

 

On many cars vented to atmosphere (VTA) blow-off valves (BOV) cause an incorrect reading from the Mass Air-Flow Sensor (MAF). When the BOV vents the air off the MAF still thinks that air charge is going through the motor and a rich condition occurs. This can cause stumbling on de-accleration and between shifts. Some states also frown on VTA set-ups for emission testing. I'm not sure if the MINI would suffer from these problems or not as I'm not 100% familiar with the placement of all the sensors on the motor.

 

I would also like to know, and would like to see some pics too.

 

I do not believe they would suffer any problems from this at all since they are a MAP setup, only the air in the intake manifold is measured.

I had a vented BOV on my turbo dodge, which was also a MAP setup and it ran absolutely fine with it that way.

 

To me, it seems the hard part is a way to mount the BOV and then a way to block off the stock bypass valve.

 

thought the bypass closed under boost therebye not allowing recirculation. so prior to boost you're not makin' much power anyhow. ???

 

see while under vacuum you're getting fresh air right to the intake via the bypass . then the boost closes it ;to allow only boosted air . ???

 

That is the part I don't know. When it comes to turbos, air is never drawn through the BOV or bypass valve. The air still runs through the turbo and intercooler and all that stuff.

Sometime I'll look at the bypass vavle and figure out how it is routed.

 

All the air entering the cylinders passes through the SC--the BPV is not intended to allow fresh air to enter the intake manifold but to allow unneeded pressure created by the SC to vent back into the system.
My MAP readings would support this interpretation.
I stand to be corrected if necessary.

 

That sounds correct.

 

yeah you cant use a blow off valve on these cars, because you would be dumping metered air to the atmosphere, more or less making a huge leak. your check engine light would come on and your car will go into limp home mode. on turbo cars you are venting un-metered air, so it doesnt matter

 

Isn't the BOV on turbo cars plumbed into the charge pipe before the IC? In which case would also be before the throttle body.
On a MCS, if you were to remove the factory BPV, seal off the SC inlet tube, and mount a BOV to the IC outlet horn before the intake manifold, would that not have the same effect as if it were on a turbo car?
I'm just trying to learn here, because I believe there is a better solution to the stock MCS BPV.

 

That's not completely true. Metered air is only a problem when venting if the air is metered by a MAF or MAS. When using a a MAP sensor in conjuction with an IAT sensor, you get the same effect of metering but with the ability of being able to vent.

That is exactly how it was ran on my turbo dodge.

Also, where the BOV or bypass is mounted doesn't matter, as long as it is mounted on a pipe with positive pressure. A BOV can be put on either side of the intercooler and it will serve the same purpose.

So once again, since our cars run on MAP sensors the only forseeable problem with venting a BOV is where and how you are going to mount it.

 

I would tend to agree with rhubbard on this one.
http://en.wikipedia.org/wiki/Blowoff_valve

Thanks for the clarification on this.

I have thought about the mounting, and I think a good spot would be right above where the stock BPV is now. You could probably even use the port that the stock BPV clamps to with a 90 degree to the BOV. The only problem is that there are so many on the market, which one do you use?

minizeeg shows a Greddy BOV in his sig, hopefully he will chime back in here and elaborate, and maybe show some pics.

 

Think about what you're talking about. Venting the intake to atmosphere. For an N/A car, this would be more than floored!

A blow off valve and a by-pass valve are very, very different beasts.

Mattt

 

Furthermore read up on why you have a bypass valve;
http://www.magnusonproducts.com/bypass.htm
Works the same for your M45.

 

When it comes to BOV choices, pick whatever one you like. The only real difference is how they sound.

The HKS SSQV is a very popular choice.

The TiAl is probably the best one out there.

I don't know where you are coming from Dr. Obnxs. A blow off or bypass valve is not applicable to a N/A car.

 

As far as application to the MINI, I still feel I would need to physically check out how it all goes and also do more research.

 

I was looking at the SSQV this afternoon...
http://www.hksusa.com/products/more.asp?id=792
it appears to be a nice piece of hardware.
The only thing is that in the description they state that it has "complete closure during idle." The MCS should have bypass while idling, although Rick aka not-so-rednwhitecooper, has been running without a BPV for a while. I asked him about it once and he said his car lopes at idle.

 

so about that blowoff. I had the blow-off hooked up for a short period of time about a year ago. I forgot that was still on my sig. Neither my installation, or its performance were anything short of hilarious, and after about 20 miles my car felt like it was about to die. Just for the record, when i did this whole mod i knew nothing about how bypasses or blow-offs worked, I just thought, "hot air back into the intake....must take a little power away". Anyways I drilled, tapped and mounted it onto the driver side IC pipe with the help of a little JB weld, took the hose off the stock bypass valve, didn't even seal the stock one off, and just plugged it all together with no knowledge of how to adjust it or anything.(trust me its embarrasing just to say it) now that i have learned a bit more about how all this stuff works I do think it could work...if properly setup. I already have a gaping hole in the side of my intercooler pipe covered up by a aluminum plate and a gasket and a shitty greddy bypass valve sitting in my garage. If anyone in the NJ area that knows a thing or two about this stuff would want to come use my car as a lab rat i would be more than happy to try it one more time. I'll try to find a picture of how i had this set up...but due to pure embarrasment of my first try, i think i deleted them all, haha. Thanks for all the input tho guys, hearing all this I kinda want to give it another whirl.

 

I still would like to see the pics. Thanks for posting.

 

i looked everywhere n no pics, but as soon as i get the car back i'll throw it back on n take a couple pics so you can see how i did it. Its a shotty job but the idea behind it is good. I'll have them up as soon as i can

 

Why would anyone want a blow off valve on the Mini? Neither the M45 or the M62 are designed for a pop off, for that mater there is no SC that is designed for adjustable boost ( valve ) or presure release.
Minizeeg, "Anyways I drilled, tapped and mounted it onto the driver side IC pipe with the help of a little JB weld, took the hose off the stock bypass valve, didn't even seal the stock one off, and just plugged it all together with no knowledge of how to adjust it or anything.(trust me its embarrasing just to say it) now that i have learned a bit more about how all this stuff works I do think it could work...if properly setup. I already have a gaping hole in the side of my intercooler pipe covered up by a aluminum plate and a gasket and a shitty greddy bypass valve sitting in my garage."

I must admit this took some real courage to do. These valves are designed for a turbo to control boost presure release. With a blower there is no method of boost control other than the speed of the drive. On larger applications there is a blow off plate to prevent over boost ( adjusted with spring tension ).