So I too the 854 for a test drive today after installing the OBX Exhaust Yesterday, and here is my issue.
Pulled out on to US1 and rolled into the throttle... Boost kept climbing, Hit 16psi, spiked to 18-19psi when it shifted. My jaw dropped..
I got on the the Turnpike an Nailed it, Spooled right up to 16-17psi and then it fell on its face. Backed off and rolled at 60mph then nailed it, dropped a gear and took the frig off, hit 16-17psi and again fuel cut off. I mean I knew a Open exhaust gave a small HP Gain but 3psi? Isnt that like 30 HP?

My multi-part question is.....
1.With the free flowing exhaust allowing more space to push out the exhaust is this a common situation for the boost to increase? or should I be looking for something else.

2. Will a MBC allow me to LOWER my Boost? Instead of increasing it.

3.What are the chances of burning up a valve or throwing a rod just because of the higher boost?

4. and Finally, Has anyone else experienced this?

I would really like to get to 500,000 miles before I blow the motor. I at least want to do My Miami to Portland trip to IPD before that happens..

 

your turbo control valve is not hooked up correctly. You shouldnt be getting more boost from the exhaust - your boost should just come on faster. Check your lines to make sure they are hooked up correctly.

 

Agreed check the lines just the exhaust will not increase it.
DO NOT keep hitting fuel cut!

 

Sure boost will increase if you decrease exhaust back pressure. A turbocharger works on pressure differential, high pressure exhaust gases want to go to a lower pressure area and to do this they must travel past the turbine wheel.
I got a solid 2psi increase in boost on my 740 just doing a cat back exhaust, no way anything was touched on the turbo.

 

there shouldnt be ANY boost increase. The CBV should be taking care of overboost.

 

Copy that... Going to check my bcs lines I may have swapped them or left one off..

I will report back with any findings of questions, thanks guys

 

So it looks like the Red line off of the BCS to the Compressor Housing decided to tear almost completely off.

Would that have been the cause of my problem from the start?
even before I did the exhaust I was getting 13psi out of nowhere.
Just one day started getting 13psi...

also what is this plate for?

Just holding up the factory exhaust in-case it fell or is it structural?

I was just wondering cause the new pipe seems to be vibrating against it occasionally..

 

I left mine off when I put my pipe on. No issues. And yeah the red line is the one that goes to your CBV, chich means it's not opening.

 

Yours was resting on that cross member also?
Im convinced, Im yanking mine out tomorrow..


So this is correct routing.
Blue to the intake
Yellow to wastegate
and the red to the bottom of the CBV.

I do really appreciate all your guys help with this..

 

thats what we're all here for Matty. While you're replacing lines anyway, why not go with the silicone hoses? Think about how old all those vacuum lines are, and how some of them might be brittle and seeping air through them. I did mine and am glad that now i KNOW im not losing anything through vacuum lines.

 

I removed my plate.

As for the boost, I agree it sounds like the wastegate is having trouble opening...which will cause the increase in PSI. Your probably spooling much faster now and there is some lag. Check or replace your Vacuum lines as stated by ibified. Another thought too, you could be having spark blow out.

Aside from all that...when are you going to get your ECU flashed so you dont have these issues with fuel cut off. I cannot express how nice it is to have that gone.

 

Spooling faster and now you have some lag? You do know faster spool means less lag?
And again with spark blowout, seriously. This is a near stock engine.....

 

And that would be? LOL, you lost me on that one.


Funny, I just boxed up my spare ECU this morning and Have Fed Ex picking it up tomorrow to send it over to IPD.

Who did you go with?

 

So just for clarification the red line goes from the BCS to the connection directly under the CBV cover and the line that goes from the nipple on the CBV cover goes to the manifold?

 

Well I replaced the Lines this morning and that was 100% my issue...

But now im back to the stock 10 psi
FedEx picked up the ECU today so it will be at least 2 weeks untill I can feel that gain safely again... wow the change from 14-16psi to 9-10 SUCKS.

 

Fantastic!

For Typhoon, I think you were thinking Lag as in Turbo Lag. I was thinking Wastegate as in Wastegate lag.

Lag Definition:
Lag is a common word meaning to fail to keep up or to fall behind.In real-time applications, the term is used when the application fails to respond in a timely fashion to inputs.

My thought was that the turbo was spooling faster now and the wastegate was lagging in response therefore overboosting.

As for Blow-out. I dont know how else to describe this. It means that the spark to the spark plugs cannot jump the gap due to high pressures in the combustion chamber. When running high boost it is a common practice to run a smaller gap. Larger gaps can cause missing (maybe a better word than blow-out) at higher rpms and boost. Stock engine yes, higher than normal boost, yes, has the car ever seen these high numbers, no. Could it be bad plugs, yes.

Obviously he is fixed now and it was none of these items so as with all troubleshooting issues that we all face and try to help with on this forum we chalk one up for the hoses.

 

So it did it again..
Split the Brand new Motion Pro Silicone hose..
What the hell?

Something rubbing or ??? Im Lost

 

HMM was the hose to tight on there and split when hot? When I had my BOV on and had to remove the hose to adjust it the hose broke.

 

No its weird... it split in the middle of the hose.
It was all fanned out like it built up pressure and just popped.

Is it possible that I am getting oil in the CBV and its clogging it?
For the passed 2 days She has been smoking a little at start up and a little while sitting at stop lights. I figured it was just valve seals But, now with the line off its smoking less, is there any connection?

Im am so confused..

 

How is the PCV system?
Could have also been a weak spot in the silicone hose.