Stillen Air to Air setup

TopgunZ

So looking at Bypass valves. Seen Tial makes one now and I have always had great results with them. But they come in 1" and 1.5" outlets. Any suggestions or reasons for going with a certain size?

Also going with the 11lb spring based off my 17hg vacuum reading.

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silencedeyes

3lb spring would work better for low vac / bypass purposes. I don't think it will bypass enough with that heavy of a spring. Do you plan on plumbing it into the s/c intake for filtered air or adding another filter setup?

Im also starting Andrew's 370 this week end. Ive developed some safety systems on the scavenge system including a setup to use a turbo timer on both car and scavenge pump. I may ditch my electric pump and do a gear driven pump using the a/c compressor location.

TopgunZ

This is the one I am talking about. They don't even offer a 3lb spring. I can't find much information on how a bypass is different than a BOV. I know the difference in their intended purpose but as far as the mechanical construction of them, I am not sure. Besides the fact that it is a directed dump vs. 360* dump what is the difference? Can you use a BOV if you wanted?

http://www.treadstoneperformance.com...l+Bypass+Valve

I am dumping to atmosphere pre-intercooler. No filter since it will be blowing any debris away and can not ingest anything.

Good call on putting in a safety setup for that pump. I still have the oil pan spacer and a fitting for you.

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victorofhavoc

I think he was referring to something like the synchronic diverter valve, which actually open at vacuum so that air can have a shorter route for greater response. Genius actually, but for a supercharger i don't see the use. The annoying lag and slow response of a turbo I get though...

the only time you'd want recirc is to keep your car from leaning out too much when not on boost. Pre-intercooler, post, or even on it I don't see as making that much of a difference, except for maybe putting it post to make sure your pressure drop across the intercooler isn't as much of a factor in tuning...or at least that's what was explained to me before.

At 20 psi 1" diameter means there's 15.7 pounds of pressure on the valve, and at 1.5" there's 35.33 pounds. 1" and 11 lb spring is 14.013 psi. 1.5" and 11 lb spring is 6.227 psi. So when do you want it to vent is the question?

EDIT: This is all provided i didn't jack up my math somewhere...I've been paged out for work twice in the middle of the night this week so my math may not be trustworthy until the weekend

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silencedeyes

Aaron, youre thinking in terms of turbo. Yes a bov is similar to a bypass valve. But you need a smaller spring pressure to allow equalization of air pre and post s/c at off boost situations (cruise and idle) or you'll get cavitation.

Another thing with your air to air setup, be careful of psi drop across the board with the core and all that piping. Remember you s/c wont compensate for it like a waste gated turbo will (or well mask it to some degree). You say 14psi is that at the compressor? If it is, it will be less at the manifold. IMO, I would run a smaller pulley to compensate for the psi drop and a waste gate ( on the charge pipe) to control the amount of "boost" you want.

Check out this link for your bypass valve. http://tialsport.com/index.php/tial-...vs/47-tialbvqr