2 weeks ago when I ran 12.2 @111 I recorded my boost during that pass, I peaked 24.something psi and it holds steady, but after 5.6k rpms or maybe a little more up top I start loosing boost and at 7500 rpms my boost is down to like 20.something psi.
VTA vs Recirc
Right now Im using Greddy Type RS VTA but I think that might be causing the problem, I was suggested the HKS if I VTA because it wont leak boost, or the Forge to recirc, but what will it do if I recirc instead of VTA? Also the Tial BOV is awesome for VTA since it wont hold boost, give me your opinion people, I have checked everything in hoses, clamps, everything and no leaks what so ever. And my car is brand new so Im guessing the BOV has something to do with it. Maybe an external wastegate will fix this? I can use a Tial 38mm and put the spring combination for 22 psi with the MBC fully closed and at the track give it 2 turns with race gas and buala

Let me know people
Thanks

 

Hello Randy...


Hey man, you know, could be the BOV, cause I was using the Greddy Type-S and the boost use to hold just fine, but now, I'm using a Tial type and my boost drops just as you just said. I can switch back to the Greddy to do some testing and check if this is the problem.

We can talk later,

Miguel

 

Yeah If its the BOV then I'll just buy a Forge those never give problems, put it back like stock recirc and buala problem fixed.

 

i have used 7 diff bov's, stock works best.. i vta, but i have a stand-alone ecu.. 23 psi and the valve stays closed... the only bov that comes close is the greedy type-s with the single spring mod... i have discussed this with many evo tuners and they have pretty much came to the same conclusion... other vendors dont talk about cause they have to sell product so there not going to talk about this prob with bov's and our cars..

 

Well, there is a post floating around saying that the 05's act different with the VTA's, which I think is true, I am now venting a greddy type s and not a single chance of stalling, no engine management. I poppped my utec in the other day but it is set on stock still.

My friend I just sold my TXS H-34 too on his 03 and he tried venting and had problems with stalling. The other part of your dropping psi is the turbo, it still drops in boost even with the 10.5 housing. Not as much but way up there it is too small to hold the boost. Btw, did I not look at your sig or something but how are you running 24ish psi without a problem, I saw the flahs which would eliminate boost and fuelcut and raise rpms but what else are you doing on it to run it effient.

Also I am not saying VTA is a benefit cause it isn't just cause it doesn't have stall problems doesn't mean it is a benefit, it still would run rich inbetween shifts and a recirc would be better.

And the other guy who posted, stock is not the best, it still leaks no matter how you look at it. You should not be able to blow into the valve and feel it on the other end. the JDM MR Divertor is a different story.

My .02, if I am totally wrong let me know
Tim

 

click my car pics thread and you shall see, go to bottom of pics.... sorry ot.. i didnt think about the 05's, but that does end one thing in my mind and something alot of us were trying to figure out.. the 05 metal bov has caused the same probs as other bov's on 03-04 cars but not 05... so that gives me the conclusion that with just a small revisoin in the turbo design, it eliminates the turbo flutter- bov prob... we dont ever see anyone complaining of probs with a bigger turbo ( 3037, 35r, etc. ) and bov probs.. there is no gain in vta or recirc.. just noise.. the stocker is designed to stay open most of the time for the maf sensor.. as long as you floor it and the valve stays shut the valve is working properly... as far as an 05 stalling i dont know i dont own one... almost wish i did..

 

Well to add to the issue, as posted before, I had no problem with dropping boost with the Greddy Type-S, but... BUT, the car stall with it, curious, the car is NOT stallting now with the BOV VTA, idles OK and runs fine, but is not holding boost pass the 1.5 bar mark..!!!
What I don't want to see is that, if I change back to the Greddy Type-S, my car will start stallting again.. cause it was a pain in the *** trying to keep it at idle with the AC on when I stop at a red light...

 

THe 05's don't come with a metal bov. It is the same one as the 03 and 04's.

 

Well with 93 octane and I have a Hallman MBC I spikes to 24 psi, drops down to 23 but like I said after 5.6k rpms til redline boost drops down to 20.XXX psi. I can get the boost up all the way with race gas, C16 but problem is with that much boost my car spins the tires way much and like that I will never get the 60ft I need to run 11's.

I will try maybe a Forge BOV which Al recommends a lot

 

And yeah 05's dont have a metal BOV we have the plastic BOV