Do I need a different blow off valve?
#1
Do I need a different blow off valve?
Just bought a 94 DIY turbo miata with a Borg warner efr 6258 (http://www.full-race.com/store/turbo...258-turbo.html) setup running 12 psi. The tuning seems to have been done very well, but I'm getting a pretty bad "chuffing" noise even when the bpv activates at higher boost pressures. I'm nearly certain that the noise is the compressor seeing the back pressure from the closed throttle plate like it's not _supposed_ to see. This also makes transitions between gears difficult because it immediately kills my turbo momentum and I have to respool.
The bov (actually I believe it's technically a bpv) is a flying miata unit that he bought used some time back. It has a little filter on it and I think instead of just using a proper bov he just venting a bpv to atmosphere.
FYI, additional details about the car can be found in my meet and greet thread. https://www.miataturbo.net/meet-greet-40/miata-noob-saying-hi-59080/
Any suggestions? I'm going to start by lowering the boost to 10 psi because I don't like what it's doing. I've heard the same noise on turbo cars with no bov or bpv, so I'm sure it can't be good.
The bov (actually I believe it's technically a bpv) is a flying miata unit that he bought used some time back. It has a little filter on it and I think instead of just using a proper bov he just venting a bpv to atmosphere.
FYI, additional details about the car can be found in my meet and greet thread. https://www.miataturbo.net/meet-greet-40/miata-noob-saying-hi-59080/
Any suggestions? I'm going to start by lowering the boost to 10 psi because I don't like what it's doing. I've heard the same noise on turbo cars with no bov or bpv, so I'm sure it can't be good.
#3
Well the po never set it up that way, but he did mention it as an option when I questioned him about what the block off plate on the compressor housing was. He gave me the associated parts to set it up, but as I've never seen a setup like it before, I wasn't comfortable just setting it up without more info. Would it be superior to the bpv that's on there now, you think?
#5
If it doesn't work as I hope, would I be better served with a beefy bov as opposed to the old bpv that I previously used?
#7
Those 'on turbo' BOVs have been around for a long time. The version the EFR turbo uses is the same as that run on Vauxhall/Opel engine in Europe. They have excellent repsonse, however they do fail regularly - the rubber diaphragm splits. Talk to Forge Motorsport about the FMDVK04D valve which is a bolt up replacement with an aluminium piston www.forgemotorsport.com (its not listed on their US website as its a part made for Europe only)
I should point out that i work for Forge so am biased, and that there are other aftermarket options available e.g. EVOMS.
I should point out that i work for Forge so am biased, and that there are other aftermarket options available e.g. EVOMS.
#8
Those 'on turbo' BOVs have been around for a long time. The version the EFR turbo uses is the same as that run on Vauxhall/Opel engine in Europe. They have excellent repsonse, however they do fail regularly - the rubber diaphragm splits. Talk to Forge Motorsport about the FMDVK04D valve which is a bolt up replacement with an aluminium piston www.forgemotorsport.com (its not listed on their US website as its a part made for Europe only)
I should point out that i work for Forge so am biased, and that there are other aftermarket options available e.g. EVOMS.
I should point out that i work for Forge so am biased, and that there are other aftermarket options available e.g. EVOMS.
I did install the built in unit the other day and the response is amazing. It's lightning fast and I experience none of the issue that I was getting before. I may sell the FM BPV and see if I can put the money toward an aftermarket built in solution like the one lloydie mentioned.
#9
Here it is on the Forge UK wesbite in case anyone searches in the future:
http://www.forgemotorsport.co.uk/con...oduct=FMDVK04D
If anything users have reported improved response over and above the OEM valve.
http://www.forgemotorsport.co.uk/con...oduct=FMDVK04D
If anything users have reported improved response over and above the OEM valve.
#10
Here it is on the Forge UK wesbite in case anyone searches in the future:
http://www.forgemotorsport.co.uk/con...oduct=FMDVK04D
If anything users have reported improved response over and above the OEM valve.
http://www.forgemotorsport.co.uk/con...oduct=FMDVK04D
If anything users have reported improved response over and above the OEM valve.
#11
Its good for mildly tuned engines as shipped - the springs are interchangable. But Forge can supply springs that will support 25psi static (i.e. with boost only acting on one side, which isnt how it works in the car) which would be 35~40psi on the car, with boost acting on the top port too. I cant say an exact figure as we've never shipped one of these springs!
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