We can try my boost controller, hallman pro (steel ball)... Thought you had a pro not the rx.. Hmm
been reading about issues at high boost due to the light wieght of the ball with the stiff spring.. Worth a shot... Maybe we will get lucky today

 

I had a similar issue. Didn't really see much on a boost leak test.. I pulled my BOV off and noticed the o ring was damanged. I replaced the o ring and wow car is responding the way it should be. Just a thought. I did a smoke test on my car and that is when I noticed it.

 

^^^^ great info, thanks for the help... Surprised it wouldnt show on boost leak but would show on smoke test. Smoke is rather thick and normally wont show leaks thats are small... End result, this may be the issue and worth looking into... Thanks

 

How come no one even suggested the bov opening to early, or being forced open at x rpm?

 

The op and i talked about it yesterday, the bov was not suspected due to the fact that vacuum is what opens it when the throttle plate closes... When under full boost, the vacuum/boost line connected to the top of the bov is under boost and ic pipe is also under boost which cancels each other out meaning bov should be tight... I thought it could be an issue until i started thinking about how it could effect wot if its nkt leaking... That was my thought process on why bov shouldnt be an issue...

 

Yes but remember he is on a 2.3. On a standard 2.0 the pressure may not open it but you added displacement and that may cause it to open slighly. I mean its a shot in the dark ya know.

 

By your vid, is it true you're making like 25-30psi a 4k rpm in 5th gear? Do you know the exact peak boost vs rpm in 5th?

What is your spool like in 3rd and 4th? I'm curious on the comparison since it only "happens in that gear"..... I believe this is important to remember, if you had a bov issue, it doesn't matter what gear you're in, it see's the boost level no matter what

Are you on a stock head with stock TB?

 

I don't recall having the o-ring there. So ill fix that asap. (didnt think that would be such a issue)

Spool in 3rd is 30psi by 5400 holds fine to 28/29psi to 7500
Spool in 4th about the same, i can double check

According to the video, it shows i hit 30psi just around 4800rpm, which is about 500+rpm faster then in 3rd (according to that video which surprises me).

Do i know the exact peak boost vs rpm in 5th? max boost at what rpm in 5th? I can do a log and know 100%

Head with ARP studs/bolts and stock tb.

 

quick update

no store around had the o-ring for the bov, so i used rtv sealer(which should easily seal it 100%) since it sealed my turbo without issues, and i still get the "boost bounce" in 5th.

my o2 sensor crapped out, so as soon as i get a new on in, ill do some logs to compare 3rd, 4th, and 5th gear spool and boost levels.

any other suggestions on what might be causing this?

Also if this helps at all... if i go WOT in 4th, shift at 7k, put it into 5th, full boost, no problems.... so basically this only happens during boost spoolup in 5th until it settles.

 

That's exactly why I'm curious on your building boost threshold in each gear, and maybe while shifting..... In my mind, I'm almost all in on turbo surge, you're building too much too fast for your system to ingest..... for what ever which reason, which is why perhaps you don't see it in lower gears or while shifting because you're past that flow point.....

Cam change, intake manifold change, or TB upgrade could solve your issue... or lowering the boost in that gear by xxx rpm... (boost by gear vs rpm)

In my GTI, I get turbo surge on anything higher than 17-18psi... because my charge piping to the IC is 2" and its very long... it sounds EXACTLY what your car is doing. ( have virtually rebuilt my motor and changed every other part, still happens until I change the piping)

I'm not saying I'm correct, its just my feeling with some logical explanation.... so we need more info perhaps.

 

that's compressor surge


a wastegate doesn't flutter regardless of what you read about or hear on TV...whoever says that doesn't know what they are talking about

 

You have an AMS intercooler do you have the pipes with them as well specially the lower intercooler pipe?

do you have an upgraded Intake manifold? write down all of your mods

And you could get some more power from and upgraded throttle body with the mods you are running the buschur racing 65mm throttle body is pretty good.

 

He has 2.5" piping all around with a BR35R kit as already mentioned.

I'd look into a TB upgrade and ported Intake manifold maybe..... or does your 35R have a anti-surge cover?

 

I've always told my friend that... it never made any sense to me

 

Makes a lot of sense. Seems like its surge... building boost to fast for the system to ingest... like i said earlier, i build 30psi+ by around 5400+ in 3rd, but in 5th according to the video i hit 30+psi in under 4850.... so i belive you're right.

I'll probably upgrade the tb first, now dunno if i should go with 65mm or 75mm(suggestions?). Next in line after will be intake mani, and then exhaust mani last.

Stock intake mani. I most definitely would see more power from an upgraded tb. Gotta look into it, see if i should go for 65mm or 75mm.

I belive the holes are for anti surge?



---------

Im no expert, so if anyone can chime in plz do. Why is the boost spool so much quicker in 5th vs other gears? Hit full boost so much faster in 5th.

And big thanks for everyone helping out.

/dave

mods

Manley Crank 100mm
Manley Rods
CP Pistons 86.5mm
ACL Bearings
HKS 272/272 cams
ETS 2.5" Intercooler piping
AMS FMIC
Balance Shaft Delete Kit
FP 35R Turbo (BR35R)
Precision Racing 1000cc Injectors
MIL.Spec Throttle Body Seals
AEM EMS 13/13 Ecu
255 Walbro fuel pump
Koyo Radiator
Mishimoto lower radiator hose
Spoolin Up (COP) Kit
NGK One Step Colder Plugs
TiaL Bov 50mm
TiaL 44mm Wastegate
DC Downpipe
JGT 500 Exhaust
HKS Custom intake

wrote down what i thought may be important to help solve the issue. But i think GTIjoejoe is spot on. Now time to buy some parts ;D