Slate993tt

I can't explain how it started but yesterday while on a drive I noticed the cur was only running at .8 bar while in 4th but the setting on the EBC was set where it normally run .9-.95bar. I though tit strange but then ignored it. Needless to say the condition hasn't gone away and yet the car is running perfectly...just limits itself to .8 bar If I turn the EBC to a level that would normally be 1.1 bar it will creep to .9 but nowhere near where it should be. If I turn the EBC down the max boost also goes down the way it should. So it seems the EBC is working perfectly.

My question to all you non-stock guy is it seems the car is bleeding boost somewhere. Has anyone else run into this and what was the cause.

Car has new 710N DV's and "new" Actuators when I did the 16/16G upgrade 3K miles ago. Those are the two areas is where I'm thinking could be the cause. Does anyone else have any ideas?

Again other than boost over .8 bar the car runs perfectly and acts no differently.

side note: I'm referencing the boost level on both the EBC's display as well as my mechanical boost gauge(clock replaced). Both gauges are in synch with each other so I don't think its a faulty gauge reading.

Thanks,
Chad

Slate993tt

Crickets....


On a side note I think I have a handle on the issue and will post results as soon as it is fixed.

Basal Skull

Sorry not much help, glad you've figured it out. I don't even know where the electronic boost control hooks up, I assume it takes place of the stock n75 valve? And with the external boost control, there's no 'limp mode'?

Spartan

If over boosting check the wastegate lines for cracks they usually show up around the clamps. If that doesn't do it then do a pressure test and see if there are any other small leaks

ScottMellor

Ask Schatz.
Isn't he your tech?

Slate993tt

Yes, replaces the N75 valve. Correct no Limp mode

Yep, that's the plan. The lines looked good but going to pressure test the system. Todd K also said there is a check valve to the oil tank that he has seen fail that can cause an issue. It's on the backside of the intake manifold so we'll look at that as well.

Correct, we've already game planned...just waiting on the new DV's and for him to get some free time.

It's just going to be one of those take your time and try to chase it down things. I will update the group as to the final resolution(though it may be a few weeks) just in-case someone else runs into an issue similar.

DiegoR

Well, from my own experience in the turbocharged world (not much and not expert) when I converted my old BMW e30 325is in a turbo little mosnter I had all sort of troubles along the way and one of them was loosing power from the nowhere, felt torqueless, yet the boost gauge was reading solid the target boost like always.

It took some time to figure it was leaking in some point of the entire "charged circuit" from the turbo to the throttle body. Even the smallest leak in my system the boost pressure wont' change in my gauge, but the engine did feel sluggish. Now you say your engine power/response is equal before you noticed this drop in boost? And supposed is boosting a tad less than before?

Slate993tt

Correct...under .8 Bar the system is holding boost fine...it's just not happy above that level...my prediction is the plastic DV's will be the culprit and are failing to hold the extra boost pressure. Billet ones from Todd K are on the way anyway. Will thoroughly check everything else however.

Spartan

Nothing wrong with plastic dv's lots of us big motor track guys run them for years with zero problems. The metal piston versions always end up sticking and cause the real problems. Don't switch

Pry

Make also sure the throttle cable is correctly adjusted.

Slate993tt

Out of curiosity why would this matter. The car would make full boost under not full throttle before. Maybe I am missing something but I don't quite understand this.

Pry

Ok, my stock car didn't make full boost when the throttle cable wasn't correctly adjusted. The stock boost control probably doesn't target full boost on partial throttle. Don't know about your tune though.

owen meany

I would add that my Greddy boost controller is not very accurate. My shop put gauges on the engine to test what I was really pushing. When I was set at 1. bar it was actually pushing 1.4
Not sure how this plays out with your problem, just wanted to add that. My shop guys car has the same set up and his is also incorrect.

Slate993tt

on my set-up the N75 unit is not used and the EBC is in full control of boost.

I have a mechanical boost guage that replaced the clock. Both it and the gauge on the profec-b are reading the same. The boost reference point for booth gauges are different however. So I'm fairly confident the boost reading is accurate.

Slate993tt

Just to give closure in-case anyone did care. My Tech ended up hooking a smoke machine up to the car and founds a few cracked hoses in and around the back of the motor(front of car). He replaced a few hoses and seems to have completely fixed the problem. So much so that I actually had to turn the EBC initial setting down a bit as the car now makes a bit more boost at previous settings.

We also replaced the BOV's aka Diverter Valves. Car runs as good or better than it ever has. Thanks to all that responded with ideas.

Chad