I get flutter with my JDM MR BOV. It only happens at very low boost, like when I let off the gas in third gear while I'm just putting around. Nonetheless, I don't like it and want it gone.

I just installed a Helix i/c pipe kit. I also have an HKS RS intake. I got the MR BOV because I wanted it to work correctly with no issues. For a while I thought the valve was installed backwards, but it's not. I'm thinking it's likely compressor surge. What are my options?

On another note, my autometer gauge will jump to 24 psi and then almost instantly drop to 22 psi, where it holds steady. Is this normal? I thought the ECU could be pulling timing or something. Maybe it's related to the BOV issue I mentioned above?

Thanks.

 

That's a boost spike. You only see it when rolling into boost from low rpm, right? If you downshift to a lower gear while at speed, you won't see a spike like that, unless you're saying that you see this 24psi spike at any rpm in any gear when going WOT.

 

I had surging and stalling issues with mine too. So have many others. But I'm sure you will get people posting about how theirs works great and that there must be something wrong your evo or the install. Obviously the mr valve works for some but not all.

As far as your boost needle dropping sharply, I will give you my experiences with that which may or may not pertain to you. When I was using the bov line as a boost source for my MBC, my needle would do the same thing. Now I use the nipple on the turbo compressor as a boost source, the needle drops very slowly approaching redline, which I think is normal with the stock turbo.

 

Warrtalon - I'm getting the 24psi spike at any rpm in any gear when going WOT.

GSXtoEvo8 - I never thought about that. I'll look into it tomorrow. I'm pretty sure I have it tied into the turbo compressor though. I don't remember right now and it's too cold out to go look!

Any thoughts on that flutter? I've heard it's most likely compressor surge and that there are a few things that could affect it, but mainly it's the intercooler pipe & BOV. This sound right to you? Perhaps I could get a Greddy Type S and adjust the spring? The MR is not adjustable, correct?

 

Oh, I've never heard of being able to make the boost spike at any rpm other than where you hit peak torque (~3800). That's definitely a strange problem. I see much lower boost when I downshift and hammer it from around 5500rpm as opposed to rolling into boost from 3000-3500 or so.

No, the MR DV is not adjustable. Did this problem occur before the intake and pipes? It's strange that it flutters at all, and even stranger that it does it in 3rd. If anything, it should only show up in higher gears when letting off the gas after light throttle (low boost). I haven't ever encountered a problem with the MR DV, but I also haven't bothered with intakes or IC pipes.

 

for some reason i've always found that the 03 evo's are the only ones with problems running the JDM MR valve. Any thoughts on that?

 

could be possible.. there seems to be a general concensus that the 05s run alot better VTA than the other years do, maybe this holds true with the JDM MR unit too

 

flutter and compressor surge are two different things. flutter should be when rolling on the gas or cruising, and surge would be when letting off the gas..

what are you using for boost control?

Im also wondering about your comment, "... pretty sure i have it tied into the turbo compressor.."

If you have a MBC, and have it connected to the turbo outlet, it shouldnt be T'd in or anything like that. did you remove all the stock lines? the stock lines have those restrictor pills in them, make sure those are all gone.

 

There is no difference between the 03 & 04. The 05 has a few minor differences, but how the BOV affects the car shouldn't be one of them.


Warrtalon, I thought perhaps it was just a faulty gauge or maybe some sort of boost leak. I'll probably fiddle around with it for a while, get pissed, then take it to the tuners and say, "Here, fix this!".

I got the BOV after I already had the intake. The pipes didn't really seem to affect it too much. When I ran some high octane fuel and turned the boost up a bit, the flutter seemed to stop. I'm currently running 91 water right now and I have the boost turned back down.

 

This is good to know. By your definition I'm definitely getting surge. I'm using a Hallman MBC. I do have the MCB tied into the turbo outlet and wastegate actuator.

What are some ways to combat the surge?

 

that autometer boost gauge is known to read wrong boost. change your boost guage to nice ones(dang expensive though).

 

yes that noise is surge, happens on low boost and quickly lifting the throttle. I didn't like that bov from the start. I found the type S to work well using the single spring mod. Adjust it relatively tight so you have surge on low boost like on the MR, then keep loosening the spring tension and testing it until the noise is eliminated.

Personally I didn't like the high pitched chirping noise the type S had so I switched to an old school forge DV. This valve gave some slight flutter in 5th gear when letting off slightly, even on the weakest spring (green). I have sinced modified that valve to open up further, which seems to have helped.

I would probably by a forge type rs if I was looking. It looks like a good unit. I wouldn't buy an aps because it's not 100% recirc and I don't like any vta, my opinion of course.

 

umm good question. I don't know. compressor surge is when you cut the throttle, which closes the throttle plate. however, all this pressure is still being pushed through the turbo, but now it has nowhere to go, this is the purpose for the BOV, to let out all this pressure. if your BOV doesnt do a good job of letting it out, it bounces back against the turbo, causing it to slow and the car to jerk, or whatever you are feeling.

so, this could mean that the BOV you are using is too tight.

do a search for 'compressor surge' you will get lots of info. i just pulled up a couple interesting threads, most bringing up the fact that compressor surge is something you might just have to deal with.

larger turbos, or folks that really cant deal with it (road racers) can get a turbo with surge ports in it, or have the stock one modded with surge ports.. i just found that in another thread, kinda neet.

 

THis is the second time you've said this. Are you trying to say "tee'd" or "T'd," or do you really mean to say "tied"? NOthing is tied, but maybe it's just your choice of words? There should be a separate vaccuum hose for both the turbo nipple and wastegate nipple.

 

That's quite possible. It seemed to be more of an issue a year or two ago than it is now.