legacycentral bbs

Let me prepend this by asking you to be kind to me if I missed this in the search. I dont know what it is about the search feature in this forum but you really do have to word things just so to find what you need.

I FINALLY got the TMIC and 1G DSM BOV installed. (I think the guy I bought it from said it was VRG's at one time?). I did it tonight and did not pic up a hose yet to run the bov back to the intake. (ok, so I wanted to have a bit of fun first ) Anyway, the bov seems to be bad, near as I can tell, but seeing as I have never dealt with a turbo car before I thought I would ask you all for the lowdown first.

Im running the saab900, with the aforemeantioned 1g supposedly good up to 20 or 30lbs, NXS mbc, and an uncorked sti exhaust turbo back on the stock 5spd. What does not seem right to me is that the bov itself seems to be constantly releasing pressure. For example, when I finnaly felt good about the mbc adjustment I took it onto the highway, running about 10lbs of boost, in 5th gear if I held the throttle steady at about 70 mph, 5lbs of boost, 3000rpms, the bov will start to slowly leak pressure. It will continue to do this untill I either accelerate or release gass at which point it will do as it should and blow off or close up. Is this normal? Im concerned because it seems to mess with the power a bit. Do I need a new valve or can this one be adjusted? Any suggestions are welcome, thank you for your time and collective experience.

Ben

First for a 1g bov stock they should run 10psi or so, but what the guys do is they crush them to hold more boost. I think that the crush is your problem cause my friend ran 30psi on his 62-1 whith a 1g bov and it only leaked a little. I would look into how to crush the bov and it should cure your problem.

THANK YOU! I really did get that one wrong. Everything I read made it sound as though the unit would hit 30psi unmolested. I was wondering what the heck was going on in the Eclipse engine bay to cause so many of these to become so damaged. I appreciate your time.

Ben

1G DSM blow-off valves are great stock pieces. They've been known to hold 30+ psi of boost in semi-modded form. If interested, I can post up how to do this.

As for yours, there are some simple tests to do to see if it's still in functioning form.

Hook up a vacuum pump to the nipple and introduce vacuum to the upper chamber of the BOV. The BOV should just crack off its seat at ~16 inches of vacuum. If the valve doesn't move at all, or it takes much more vacuum to crack it off its seat then there's probably a leak in the diaphragm or housing somewhere. Also, make sure the valve is seating correctly and there aren't any nicks or dings in the valve seat or valve itself. It needs a good seal to function correctly.

Oh, and don't bother with "crushing" the BOV. It's a hack mod that only works marginally well. Here's the "correct" way to mod a 1G DSM BOV:

http://www.thedodgegarage.com/turbo_bov_mod.html

pisces_0

Thanks you for that great writeup! You'd think I would have gone back to my roots as a former mopar guy to figure this out. Dummy me, been going to the dsm forums and all Ive read is a whole lot of flam'n and angst.

Ill give the vacuum test a try. Ill keep you posted on the results. Im also gett "t-clamps" to replace my cheap ass band clamps. The reducer from IC to TB is suspect as well.

Ben