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Hi All.
New MPS owner and new to the forum. Awesome site!!!:2thumb:
I just bought a Turbosmart BOV Dual Port and installed it myself. Whilst driving I feel I have had a loss in power.
Any ideas of whether to have the spring tension on hard or soft? Or is it just me being paranoid?
Thanks in Advance
Hi mate and welcome to ozMPSclub!
Plenty of info knocking around here!
Is the BOV currently VTA or is it blanked?
Thanks.
It has the trumpet, Is that VTA?
Yep, then it's set to VTA (Vent-to-atmosphere) Try blanking it and have a couple of runs through the gears and see how you go
FASN8D, Hi, wait a minute! It's not necessarily VTA. The Turbosmart BOV in 50:50 Bypass mode will vent initially to Bypass and under more aggressive relief will vent excess pressure to the atmosphere as the piston rises further in the barrel. The screw in-out cap setting determines at what point this transition takes place. I'd say it is most likely you are in 50:50 mode, not 100% VTA, unless you bought the blanking plug that shuts of the bypass. It doesn't come with it as standard.
The BOV will NOT vary your power, unless it is incorrectly fitted or leaks. Too many users assume that somehow the BOV can be a sort of "tuner" device. What it WILL enable you to do is set the point at which the retained pressure in the plumbing is sufficient to enable the engine to get back on-song fast after a gear-shift, and yet not so much as to cause compressor stall.
If you are setting yours up, then screw it all the way down until it won't screw in any further (don't force it), then all the way out which should be exactly 6 turns to reach the red limit line engraved on the body and visible at the bottom edge of the cap. Don't unscrew any further from this line. Then screw the cap in progressively, no more than 1/2 turn at a time (I did mine in 1/4 turns) and test drive the car after each adjustment until you reach a point where you have no spits and backfires. Doing it over several days of driving in all conditions is best. The instructions that come with it are pretty good anyway, but my notes will add something that will help.
Thanks for that post Doug, I have mine in VTA at the moment and frequently get misfires/backfires etc. I used to get them occasionally (but not as often) on the blanked set-up too. I have been told that is likely to be a tuning issue due to the mods I have and current stock tune. On a weekend I'll have a more comprehensive look at mine and see if I can eliminate those misfires (popping). Btw - pretty sure the blanking plate comes as standard with the Turbosmart Dual Port unit...mine did.
Doug, that is really helpful appreciate it. Will let you know how I go!
Btw mine came with the blanking plate.
The blanking plate that comes with it is the one usually used to close off the bell-mouth aperture, as when setting up for 100% Bypass.
If you want to set up for 100% VTA, this plate is used to close off the Bypass aperture.
If you are 100% VTA, then you will get popping, farting and backfires unless you program your ECU or Standback to cut fuel on throttle lift-off, because your MAF is telling the engine it needs fuel to match the air ingested, but because you send that air VTA, the engine doesn't see it and the mixture ends up rich and the excess fuel still being fed in isn't burned until it lights up in your exhaust as a backfire.
This excess fuel will also significantly dilute the oil on your cylinder walls.
50:50 Bypass or 100% Bypass is safest and easiest to deal with without a fuel re-tune to compensate for the above issues.
I used to have one. useless piece of kit really. I loved the sound and to be honest i liked the spit between shifts but the way the car felt with it wasn't great. the gearshifts became very rough and went back to stock and the shifts went back to smooth. must be something in the way the standard unit bleeds air rather than all at once.
Thats how I feel at the moment, that the car is not how it was with the OEM Bov! Now it does feel like a waste of money!Quote:
Originally Posted by TUFMPS
All BOV's are a waste of money
LUKE, I disagree. Firstly, and most fundamentally, all turbo engines need one. But if you buy an after-market one just for the sound on a stock engine then yes, I might agree, especially if you don't know what to do with it by way of adjustment. And on that note, considering that most folks don't seem to understand BOVs at all, then of course there are a lot of unhappy users out there.
But as I noted previously, and especially if you are running additional boost, a good tunable BOV enables you to adjust it to maintain maximum line pressure so that the maximum boost is available after dumping excess boost, as remanent line pressure on re-opening the throttle, and the turbo doesn't have to re-pressurize the lines from zero after every shift, and yet it is tuned to keep it just low enough so you don't get compressor stall.
In my case just the turbo outlet line to the FMIC is over 2m long. "Re-filling" that from scratch takes time. And that is without considering the volume of the FMIC itself or the FMIC outlet to the throttle body, another metre at least.