Changing BOV Gains 30HP
 

The Bosch valves were probably leaking in boost, causing crappy AFR's and/or pushing the turbo out of it's efficiency range. That's right ladies and gents, boost leaks are bad.

Crappy valves are crappy valves. Most OEM DVs are complete garbage. Pretty much any descent aftermarket valve would see those same results, all you guys buying junkyard valves are doing yourselves a disservice. Just stay away from valves that can't in some way be tuned, there is no "one size fits all" sealing mechanism.

When I do get around to buying another bypass valve, it will be a synchronic, but as for all OEM valves being garbage, my 1g DSM valve works perfectly.

mmmmmmmmmmmmmmmmmmmmmm twin turbo vette *drool*

Actually I said "most". The problem is making a claim like that is similar to saying that a factory intercooler works perfectly, without trying something better you have nothing to compare it against.

I deal with people all the time that upgrade their OEM valves and have "drive-ability" problems that turn out to be caused by the new valve performing better and maxing out their injectors, MAFs, or fuel pumps.

DSM, Subaru, Mazda, VW, BMW, Toyota...

my daddy had a dual turbo c5z for a couple weeks. It was built just to run 1-liter bikes on the highway. It made something like 980whp on low boost. It was retarded.

I bet they just turned the boost up:giggle:

FM also noticed this on the MSM...and without switching to some BOV whose name sounds like a black womans dildo.

http://www.flyinmiata.com/tech/dyno_...boost_leak.pdf

Synchronic loves to boast on youtube.

I don't understand how adding a blow off valve can change output unless the wastegate is closed and the turbo is never spooled. If the BOV is bleeding off boost, the pressure will be compensated with the wastegate.

Oh, and that synchronic shit is fucking stupid. If it weren't so expensive then maybe I'd buy one...but this shit is retarded. Give me the one which lasts the longest v.forge

A leaking valve can put the turbo into a different part of the efficiency island, that's one way. That alone can effect power just by higher intake air temps. Those same temps can lead to timing retard, again less power. Spool will be slower, so everything below when peak boost is reached will be lower.

This can be very minor or it can be pretty significant, the turbo is drawing in more air to reach the same boost pressure so the bottleneck of the pre-turbo intake system becomes greater. And, this is a long shot, if recirculated back into the turbo intlet pipe, all that expanding air from the valve can create turbulence or cavitation or some otherwise undesirable phenomena which can lead to less power by interrupting the passage of air into the turbo.

Yeah I suppose. I have two 2g valves sitting in a box, one was so weak I could push it open with ease, the other was okay enough to use for a few thousand miles last year, so I guess it depends.

If they want to prove their claim, do a dyno run with out a BOV. The same gain should be achieved.

yep. the gain wasnt from a BOV, the gain was from fixing a leak.

bullshitin sob's...........reminds me of some of the ebay motherfuckers claiming "10-20hp gain" from their knock off bov's lol