hey guys so im a little curious and i want more sounds from my mini. my question is how could i hook up a bovor a waste gate?, i already no its pointless and i wont gain hp or hold more boost i just want my car to scream a little more. if anyone has any ideas leme no.

current mods
milltek exhaust
2% alta crank pully
15% supercharger pully
sprint booster
jcw fuel injectors
afe cold air intake

 

Neither are functional or will make noise

 

The supercharger setup already has a bypass valve to divert excess pressurized air from the supercharger outlet back to the supercharger inlet in order to reduce parasitic losses from the supercharger when you come off the throttle.

In theory, you could dump the pressurized air to the atmosphere instead, but the problem is that the airflow sensor already "knows" that air is in the intake tract and the ECU has budgeted a certain amount of fuel for it. If you just dump it to the atmosphere instead, you'll mess up the air/fuel ratio and the engine will run poorly.

 

i uderstand how both work meaning bypass and bov. and i wouldnt get rid of the bypass valve wat i want to know is... is there a way to hook a bov up so when u relese throttle who get a swoosh sound its completly pointless i understand already i just want to no has anyone experimented if so post a vid or pics

 

That was the point I was making - the "swoosh" sound you're looking for comes from pressurized air being dumped *to the atmosphere*, which you can't do on the supercharged engine because it will mess up the fuel metering.

 

A blow off valve will BLOW the "unused" pressure into the atmosphere or into the filter side of the SC/Turbo.

The byp will feed the "unused" pressure into the INTAKE to keep it pressurized, this keeps cylinders filled with air helping push the exhaust out.

 

No. Read up the function of the bypass valve again. If you wanted to keep the pressure at the cylinders high, then a bypass valve would be the last thing you'd want, since its sole purpose is to lower the pressure at the supercharger outlet (which is what feeds the cylinders.)

When you come off the throttle, the pressure at the supercharger outlet goes way up. This means that the engine has to work harder to spin the supercharger against the high outlet pressure. The bypass valve takes some of the pressurized air from the outlet and redirects it to the supercharger inlet, helping to equalize the pressure between the inlet and the outlet. This makes the supercharger easier to spin, thus reducing parasitic drag on the engine. That's the whole reason for the bypass valve - to make the supercharger easier to turn when you come off the throttle and don't need the boost.

Because the supercharger inlet is downstream of the airflow sensor, the ECU still knows exactly how much air is in the intake tract, and it can supply the proper amount of fuel. If you dump the outlet air to the atmosphere instead, the airflow sensor will think there's more air in the intake tract than there really is and will make the mixture too rich. If you dump the pressurized air into the air box or any place else upstream of the airflow sensor, then the sensor will "double count" that air and think that there's even more air in the intake tract than there really is, and this will also give you too rich of a mixture.

Basically, any excess pressure that you dump from the supercharger outlet has to go back into the intake tract downstream of the airflow sensor (this is what the stock bypass valve does). I don't think you can do that while still getting any significant noise out of it.

 

Also, if you've seen a blow-off valve on a supercharger before, it was almost certainly a centrifugal supercharger (which behaves more like a turbocharger in terms of airflow versus engine speed.) A BOV isn't useful or appropriate on a positive-displacement supercharger like the Eaton unit in the MINI.

 

okok i understand now. so let me ask another question what if i just upgraded the bypase valve to a detroit tuned one or if u no anyother ones???

 

The DT bypass valve works the same way as the stock valve (in fact, it's just a modified OEM valve.) The difference is that it uses a stiffer spring so that it will build a little more boost before opening (about 1 extra psig on average). It's also adjusted to close more tightly and not leak when it's trying to build boost.

The DT bypass valve was developed mostly because there was a problem in the early MINIs where the valve would open too soon or not close fully, causing the boost to fluctuate wildly (the "yo-yo" effect). It's not as critical of an upgrade for the later supercharged cars, but you might notice an improvement in throttle response from the small amount of extra boost. No extra noise, though, since it still dumps the bypassed pressure to the same location as the stock unit.

 

Sounds like a candidate for the old M7 AGS product. Screamin' loud. Unfortunately, they don't make them anymore. Some say the Alta CAI provides a bit more noise.