Have been having some issues holding boost. I mean no matter how hard I cranked the bc it always fell off hard. So I took off the outlet pipe and capped it. Then i did some pressure testing. IT WASNT GOOD, thats all I have to say. Leaked insanely bad after 12psi. It wouldnt hold over 14psi at all. I just figured I would pass on my findings. If you plan on holding more boost than 14psi , I recommend a aftermarket dv or bov. I ordered one weeks ago and still havent seen it. Ill do some testing on that once I get it. Its a forge of course. (nana)
STOCK BIPASS VALVE tested.
- Thread starter driver311
- Start date
subparpunk03
Member
If it is leaking after 12 psi.... doesn't that mean it will leak at STOCK boost levels? Thats probably why some people are noticing a bit of a difference when they upgrade their BPV. Since its running in recirc I doubt the difference is really all THAT noticeable, but I'm sure if it starts holding all of that boost there will be somewhat of a difference even at stock levels.
silverspd3
Member
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- 08 speed 3
I switched out my HKS SSQ yesterday for the stock bypass valve just to stop the stumbling etc.. I dont really think I could tell a difference other than its boring without the BOV. lol
Why not just recirculate the SSQV?
silverspd3
Member
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- 08 speed 3
I dont have the kit to do the recirc right now. Just changed it cause I kind of thought the hks was bleeding off boost at part throttle. Most of what I heard was the CAI, so I dont think I have any problems.
Ok Im being lazy and dont want to search... what is the stock boost... I thought it was 15 (prob wrong) which means a leaky ass valve and/or a bad test setup... how bad is a leaky valve in recirc mode (yes some of us are clueless when it comes to turbos...)
ill_eagle94
Member
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- 1990 Mazda Miata
I could FEEL a difference going back from the Forge to stock. I could feel the boost fall off when it started to leak. This only confirms my suspicion.
The boost tapers off really hard and therefore less power in the topend. Trust me you wanna replace it. Is part of the reason the mazda falls off so hard in the topend.
silverspd3
Member
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- 08 speed 3
I will take my stock one back off tomorrow and test it. I guess I really have not revved it past 5600 or so lately. I will tonight and compare tomorrow with the HKS on it. If I have time, I might dyno it tomorrow. Been wanting to before I add anything else to it.
Young Roids
Member
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- The pennies have been saved the MS3 is mine!
Stock=15.6
how did you test it. since its a BPV you have to equalize the pressure with the vac nipple. otherwise your just pushing the spring. when your in boost, the boost pressure in the vac line helps keep it closed during boost. if it was a bov then yea u can just cap off the end since its a different mechanism.
so in order to properly you have to make sure your vac lines are pressureized as well. it prolly holds 12 pounds cause its over that stock, so the spring is stiffer than a standard one.
just a fYI. cause i dont know your testing method. i had the same problem when i was testing my forge bpv, i didnt know you had to pressure the vac too cause mine wouldnt even hold 3 psi lol
so in order to properly you have to make sure your vac lines are pressureized as well. it prolly holds 12 pounds cause its over that stock, so the spring is stiffer than a standard one.
just a fYI. cause i dont know your testing method. i had the same problem when i was testing my forge bpv, i didnt know you had to pressure the vac too cause mine wouldnt even hold 3 psi lol
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I tested it on the dyno, wot pulls in 5th gear. capped off the return portion of the valve. I started with the bc all the way down and worked my way up. Worked pretty good it just took two people. Not to mention this way shows how it would be under normal driving conditions vs. you trying to manually do it.
builthatch
Member
subscribed.
certainly, i just wanted to point that out incase you did it off the car or while the engine was off. Its no fun replacing parts for no reason
I took the pipe off the car, sealed both ends, and added a port on one of the caps. the port went from the endcap to the vac port.
Powerslave
Banned
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- mps 3
maybe thats why the tach on the boost guage looks nervous as you approach and pass 15psi
