Replace your BOV/Charge Relieve Valves
#1
Replace your BOV/Charge Relieve Valves
Well how unlucky am I? When was the last time anyone saw one of these fail?
The plastic fragments that came off the plunger resulted in damage to my brand new twins.
Just putting it out there, now may be the time to replace these as a precaution.
The plastic fragments that came off the plunger resulted in damage to my brand new twins.
Just putting it out there, now may be the time to replace these as a precaution.
#3
Rotary Enthusiast
Thanks for the heads up. I am sorry to see that happened to you.
#5
Sorry for the paranoia everyone.........I just do not want anyone else to be in this situation.
Perhaps if someone finds an all metal direct replacement for these, this modification might be one of the reliability mods along side replacing the stock plastic AST.
Perhaps if someone finds an all metal direct replacement for these, this modification might be one of the reliability mods along side replacing the stock plastic AST.
#6
Senior Member
iTrader: (2)
Pettit and a few other companies sell blow off valves for our cars, but I'm not privy to what materials they use internally.
I haven't seen any aftermarket relief valves yet. I just installed a new Mazda relief valve and the pettit bov and called it a day.
#7
That really sucks. I know I would be super po'd about that.
Pettit and a few other companies sell blow off valves for our cars, but I'm not privy to what materials they use internally.
I haven't seen any aftermarket relief valves yet. I just installed a new Mazda relief valve and the pettit bov and called it a day.
Pettit and a few other companies sell blow off valves for our cars, but I'm not privy to what materials they use internally.
I haven't seen any aftermarket relief valves yet. I just installed a new Mazda relief valve and the pettit bov and called it a day.
As for alternative BOV/CRV it looks like BLUE TII is investigating, if he finds a suitable substitute it will be great news for us all
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#8
Rx7 Wagon
iTrader: (16)
Pettit uses a 1" BOV, while our cars use something like a 19 or 20mm or 3/4 inch bov. So you'll need a hose adapter at least.
Options are pretty limited in the stock size. Maybe you could use a 90* Kompact Turbosource 1-way recirculation valve for the CRV.
Last I heard you could buy NOS OEM BOVs. You'll probably want to make double check some aftermarket CRV is working well with the stock sequential system.
And, there are some solid aftermarket options for the stock BOV from GReddy and HKS.
Options are pretty limited in the stock size. Maybe you could use a 90* Kompact Turbosource 1-way recirculation valve for the CRV.
Last I heard you could buy NOS OEM BOVs. You'll probably want to make double check some aftermarket CRV is working well with the stock sequential system.
And, there are some solid aftermarket options for the stock BOV from GReddy and HKS.
#9
half ass 2 or whole ass 1
iTrader: (114)
I feel this in my heart and I'm sorry this happened to you. Really, I feel this.
as far as the bov goes, you can always go with an aftermarket one and get a flange welded on to your pipe somewhere. No problem. As far as the crv, functionally is the same as the bov just in reverse. I don't see why replacing it with an aftermarket bov and then recirculating it wouldnt work. Or of course buy a new one if they're still available. I guess with our cars getting up there in age, stuff like this will keep happening with oem parts from when the cars were made. I'm sure everything is well past it's expected service life. I think we're all just waiting on the clock at this point
as far as the bov goes, you can always go with an aftermarket one and get a flange welded on to your pipe somewhere. No problem. As far as the crv, functionally is the same as the bov just in reverse. I don't see why replacing it with an aftermarket bov and then recirculating it wouldnt work. Or of course buy a new one if they're still available. I guess with our cars getting up there in age, stuff like this will keep happening with oem parts from when the cars were made. I'm sure everything is well past it's expected service life. I think we're all just waiting on the clock at this point
#10
43 yrs of driving My 7's
iTrader: (1)
There is a solution that is easy to do and will prevent any future problem with sucking debris into the turbos. I did this 15 years ago. You simply take the hose from the CRV to the airbox off and replace it with a smaller hose with a small air filter on the end. This prevents any of the broken pieces from getting to the turbos. No connection to the air intake. Also, if a new one should fail, the pieces would be blown into the short hose and against the small air filter. Easy to clean up and change. I put the air filter on the end just in case some air is sucked backwards into the turbo outlet during normal operation. I have I never understood why Mazda designed it this way anyway. Who would want to dump hot air into the airbox and suck it back into the engine to make the intake air even hotter for the turbos. Just dump the hot air under the hood.
Mike
Mike
#11
I feel this in my heart and I'm sorry this happened to you. Really, I feel this.
as far as the bov goes, you can always go with an aftermarket one and get a flange welded on to your pipe somewhere. No problem. As far as the crv, functionally is the same as the bov just in reverse. I don't see why replacing it with an aftermarket bov and then recirculating it wouldnt work. Or of course buy a new one if they're still available. I guess with our cars getting up there in age, stuff like this will keep happening with oem parts from when the cars were made. I'm sure everything is well past it's expected service life. I think we're all just waiting on the clock at this point
as far as the bov goes, you can always go with an aftermarket one and get a flange welded on to your pipe somewhere. No problem. As far as the crv, functionally is the same as the bov just in reverse. I don't see why replacing it with an aftermarket bov and then recirculating it wouldnt work. Or of course buy a new one if they're still available. I guess with our cars getting up there in age, stuff like this will keep happening with oem parts from when the cars were made. I'm sure everything is well past it's expected service life. I think we're all just waiting on the clock at this point
If I do keep the twins, I will for sure be deleting both the stock BOV and CRV (as I am non sequential) and just relying on my HKS SSQ IV....which I REALLY wish had been the case in the first place.
#13
RX-7 Bad Ass
iTrader: (55)
I think this was just good old bad luck. The stock BOV/CRV is very hardy and it's VERY rare I've ever seen one that has failed.
This isn't the plastic AST that's a time bomb, this is a VERY rare incident. Everyone doesn't need to panic and start replacing BOV's .
I would get with Bryan at BNR Supercars and see if he can fix those turbos for you. Very possible he can replace that damaged wheel, get them re-balanced, and good as new.
Dale
This isn't the plastic AST that's a time bomb, this is a VERY rare incident. Everyone doesn't need to panic and start replacing BOV's .
I would get with Bryan at BNR Supercars and see if he can fix those turbos for you. Very possible he can replace that damaged wheel, get them re-balanced, and good as new.
Dale
#15
I think this was just good old bad luck. The stock BOV/CRV is very hardy and it's VERY rare I've ever seen one that has failed.
This isn't the plastic AST that's a time bomb, this is a VERY rare incident. Everyone doesn't need to panic and start replacing BOV's .
I would get with Bryan at BNR Supercars and see if he can fix those turbos for you. Very possible he can replace that damaged wheel, get them re-balanced, and good as new.
Dale
This isn't the plastic AST that's a time bomb, this is a VERY rare incident. Everyone doesn't need to panic and start replacing BOV's .
I would get with Bryan at BNR Supercars and see if he can fix those turbos for you. Very possible he can replace that damaged wheel, get them re-balanced, and good as new.
Dale
Going single is an option I am currently costing out.........sucks if a brand new set of twins just became worthless though
#16
Rotary Freak
Originally Posted by mikejokich
I have I never understood why Mazda designed it this way anyway. Who would want to dump hot air into the airbox and suck it back into the engine to make the intake air even hotter for the turbos. Just dump the hot air under the hood.
I can see where the charge relief might be more of a problem, virtually operating continuously below 4k(?) and taking out you secondary turbo in this case with a downhill run straight into the compressor outlet.....I'd expect damage not just at the compressor face. Charge bypass has a more convoluted path and should see positive pressure most of the time. Can't see the diaphragm, is the spring still above the "washer" or has it fatigued too?
#18
Lives on the Forum
iTrader: (9)
Pettit makes a billet OEM replacement:
Blow Off Valve Upgrade Kit RX7 FD
Blow Off Valve Upgrade Kit RX7 FD
#19
Full Member
Did you happen to spray any silicone lube in the bov? I had a headset fall apart in my hands one day after spraying silicone on the plastic hinges. Apparently it’s not safe on all plastic parts.
#20
No, I did not, but who knows what the previous owner(s) might have done.
That's why I am replacing EVERYTHING in this car with new. Which is why I am so annoyed this happened, the BOV and CRV should not have been left on my car when the engine was rebuilt as they were redundant. However I did not realize that until I took the turbos out and understood the work that was done to convert them to non sequential.
Unfortunately the engine build got out of hand towards the end and I expect that these two parts where overlooked when they shop reassembled everything. I am chalking it all up to bad luck as they do really good work and have a great reputation, so I am sure it was an honest mistake.
#21
needs more track time
iTrader: (16)
Pettit makes a billet OEM replacement:
Blow Off Valve Upgrade Kit RX7 FD
Blow Off Valve Upgrade Kit RX7 FD
Forge Motorsport once offered a kit to replace both BOVs with their recirculating valves. That was a number of years ago though and no longer listed on their web site.
#22
Pettit BOV on both? CRV & ABV
Is it possible to replace both the ABV & CRV with 2 Pettit aluminum BOV kits???
One kit to replace each valve?
I replaced my ABV with a pettit BOV kit but not my CRV, thinking they are two different type of valves.
So my CRV is still plastic and brown and it bugs me how old and ugly it is.
My local rotary tech asked me why I didnt just replace both blow off valves. I was like uuuhhmm... lol
Are they functionally the same? Are they piped the same? Are the internals of the CRV and ABV exactly the same mechanically?
One kit to replace each valve?
I replaced my ABV with a pettit BOV kit but not my CRV, thinking they are two different type of valves.
So my CRV is still plastic and brown and it bugs me how old and ugly it is.
My local rotary tech asked me why I didnt just replace both blow off valves. I was like uuuhhmm... lol
Are they functionally the same? Are they piped the same? Are the internals of the CRV and ABV exactly the same mechanically?
#23
RX-7 Bad Ass
iTrader: (55)
The valves size and plumbing wise are identical. I believe the only actual difference is the spring pressure inside, I think one opens at a lower pressure differential than the other. They do have different part numbers as well.
I don't foresee any problems with using the Pettit valve to replace the CRV.
Also I believe Turbosmart has some BOV's that would probably work to replace the stock ones as well.
All that said, I have the original stock BOV's on my car at 132,000 miles. Zero problems. They work great and are super responsive and not obnoxious.
Dale
I don't foresee any problems with using the Pettit valve to replace the CRV.
Also I believe Turbosmart has some BOV's that would probably work to replace the stock ones as well.
All that said, I have the original stock BOV's on my car at 132,000 miles. Zero problems. They work great and are super responsive and not obnoxious.
Dale
#24
The valves size and plumbing wise are identical. I believe the only actual difference is the spring pressure inside, I think one opens at a lower pressure differential than the other. They do have different part numbers as well.
I don't foresee any problems with using the Pettit valve to replace the CRV.
Also I believe Turbosmart has some BOV's that would probably work to replace the stock ones as well.
All that said, I have the original stock BOV's on my car at 132,000 miles. Zero problems. They work great and are super responsive and not obnoxious.
Dale
I don't foresee any problems with using the Pettit valve to replace the CRV.
Also I believe Turbosmart has some BOV's that would probably work to replace the stock ones as well.
All that said, I have the original stock BOV's on my car at 132,000 miles. Zero problems. They work great and are super responsive and not obnoxious.
Dale
And I agree, as said in a previous comment, that these OEM valves are pretty durable. I think it was a rare failure that was experienced by the OP.
Personally, I just wanted to upgrade to a black and metal version for aesthetics and long term reliability, if at all possible.
Last edited by EREBUS; 05-14-20 at 05:58 PM.
#25