ZCHondaCRX91

Is there any way to determine if a BOV will be too small for a particular setup? The BOV I have says 10-25 PSI, but 10-25PSI on a 1.6L I4 is much different than 10-25PSI on a 3.0L V6. I know the old saying "bigger is better" but I don't really want to spend that much if I don't have to. Maybe someway to determine BOV opening size from boost level and displacement? Thanks.

TheShodan

iTrader: (14)

BOV size opening and "cost" have nothing to do with one another. Displacement of the engine and BOV opening is not relevant. what IS relevant is whether or not the size of the turbo with the amount of boost pressure you're using is relevant to size of the opening of the BOV.

So if you're trying to save cost by using a smaller valve size, save your breath. If using a larger than mid-frame sized turbocharger, 40mm and larger is optimal. If keeping it to the standard "T3/T04E" 45lbs/min-60lbs/min, get whatever you want and drive it.

ZCHondaCRX91

So for example if I'm using the same turbo on a 3.0L V6 as my 1.6L, then it shouldn't matter the engine displacement, what works on my 1.6L will work on the V6 at the same boost levels? By work I mean it's not undersize and causes flutter. It's a 60lbs/min turbo by the way.

It's not so much I want to save cost, as much as just work with what I have. I have another BOV (about 38mm) which is the same as my 1.6L, at 12 PSI it holds fine and has no flutter. Thank you for the response by the way.

OneBadTurboCRV

The BOV is ONLY for the turbo. The engine couldn't possibly care less about the size but the turbo sure does. Read the FAQs for how a BOV and turbocharger system actually works.

The existence flutter of the BOV is directly related to the design and setup. Most people have no clue how to properly setup a BOV and this is where the problems come in. BOV spring pressure is set by vacuum and vacuum alone. The transition between vacuum and boost is sometimes a trouble area where you have to fudge a bit on the spring pressure.

I am not sure where you got engine size matters but if you are comparing two engines with different idle vacuums, then there is your problem. Undersized BOV is hard on the turbo and where compressor surge can come into play.

ZCHondaCRX91

Your right, I don't know why I was thinking of displacement for the BOV, I think it was if they were at the same boost level power output would be different. The BOV on my 1.6L is adjustable, but some cheap ones aren't and I see that being the problem with compressor surging. I think I will try the 38mm I have, if that isn't adequate then I will just have to go bigger.

OneBadTurboCRV

Actually one of the better designs is non-adjustable as well - TiAL. You must change springs out for the engines specific vacuum range. The only downside is for the price they don't include all the springs like they do with their wastegates. IMHO you are on the right track. Use what you have and if it winds up not working then go bigger. Just make for certain it is adjusted right.

ZCHondaCRX91

Okay, thank you for the advise.