[hooleyboy]

Originally Posted by silence

yeah, I understand. The car is way beyond what I can do with my current job/priorities and it will be very cool when complete.

I just sort of cringed when I read it- I spend a lot of time on bimmerforums browsing the FI forum just sort of for my own education and interest. We all need to keep some perspective even when it comes to builds like this one vs. what they are up to.




I actually have a tech question that some people here can likely help with (so, sorry for quick threadjack... but it's almost on topic)-

I have found that my supercharger bypass functions in a manner which negatively affects driveability. It is just the "stock" eaton bypass that functions off of manifold pressure. It does open and shut smoothly as the vacuum turns to boost, but it's function is a bit choppy. I have replaced the unit and still have same results. I have also tried a few different ways of giving it vacuum. Also, because of the simple (maybe ghetto) way I tune my car with just MAF scaling and adjustable fuel pressure the choppyness really makes it hard to get the tune just right. I have driven the car some without that bypass and it alleviates those problems, launches harder AND is easier to control off the line/alleviates driveability issues.

What would be a better setup? With my low boost how damaging can it be to run it with no bypass? I see what you are planning with this car, but my application is quite different. I spent some time researching on other forums, but most other applications utilize a throttle body downstream of the supercharger.

thanks for any help there...


again, looking forward to solid numbers on how this car performs! That, and I'd love to get all the info on how to do the LSD.

Is your blower a roots style?

Is your car always boosting? Even when the TB is closed?

If your answer is yes to these questions. Than once the you let off the gas and the car goes to vacuum all that compressed air gets rammed back into the blower from the wrong side and can shock the rotors. Thus casing stress and could toast the bearings. At least thats my theory

Here is a pic of my blown supercharger That I feel is from no bypass valves. My rule of thumb is.. If the blower is on it always needs something to eat"