Like the others have said, the first step is to use a Durametric (cable that connects a PC to the car's computer) and log the items Jon listed. That way you can verify what the ECU is seeing and requesting. That will rule out the dash display being different than the ECU or that the flash is not asking for 1.3, etc.

Then do a boost leak check to be sure there are no leaks that may cause odd boost problems. Pressurize from the turbos - search boost leak test and you will find a DIY.

 

OK, got it (about the durametric)
There are no boost leaks. I just had the latest shop do a smoke test. Thanks.

 

Smoke test won't do it. Not enough pressure. I had a smoke test and it didn't find a vac hose off... Have to pressurize the system like the DIY to find them...

 

This shop said when they do a smoke test, they pressurize the system to 2 bars. Is that not normal procedure?

 

That's not normal from my experience. Do you know how and where they pressurized it?

 

At their shop in Plano Tx as far as I know. I've been out of the country, and still am, so I don't quite have all the details yet. Will get them next Wednesday.

 

I think that a little background might help. The ecu programs work by having a map of engine load vs rpm at full throttle. The ecu reads several sensors, especially the mass air flow and O2 sensor lambda values and gives a boost request to reach the desired load. However, there are going to be limits. Here's one example:

If the fueling isn't able to keep up with the air flow, which would be reflected in high lambda (lean condition), then the ecu will reduce ignition timing, and the boost request will be lowered to avoid detonation. This might be due to a weak fuel pump, or from running 91 octane fuel, which is what you have in Boulder, correct? That's one possibility. Another could be bad readings from the O2 sensors. Temperature and humidity make a difference too.

Loss of boost due to a leak is another, as Chad mentioned. Most shop smoke testers run at 7 psi, although my indy's machine runs at 15 psi. Maybe your shop runs at 30 psi, but that would be unusual.

The only chance you have to sort this out is to collect the data from the ecu during a boost run. When I did my turbo upgrade, the data showed the fuel injector duty cycle was running at 100% (bad!). Turned out to be a leaky fuel pump, which you can't see because the leak is inside the tank.

What we're trying to tell you is that there is no simple answer to your question. If there were, the shops you have been to would have found it already. As Markski said, collect the data and you'll have a much better chance to find the cause of the problem, if there really is one. It could be that the conditions when you tested weren't ok for 1.3 bar.

I hope this helps.

Jon

 

It looks like you have already been down this road and getting the same responses as 6 months ago. Nobody can tell you until you log the car with durametric and figure out what the ECU is requesting... It is all speculation.

https://www.6speedonline.com/forums/...ost-ideas.html

Plus, I doubt your tune is requesting 1.3bar since you don't have the supporting mods to do 1.3bar safely. With 5bar FPR and 18g's you will only get 1.0-1.1 before you run out of injector duty...

So here are the steps in order you should do:

1. Log with durametric values above Jon has listed
2. Post log here so we can tell you what it says
3. If boost requested does not match actual boost then there is an issue to look at such as WG, DV, boost leak, etc. - cross that bridge after #1,2 above

 

lol Yeah right...

here , when you do this then Ill believe that its boost free... ( smoke tests are not going to find leaks like pressure tests from the turbos.)

https://www.6speedonline.com/forums/...cs-inside.html

https://www.6speedonline.com/forums/...leak-test.html

 

The above experienced guys are right...You have to get it data logged...I am surprised that your shop which did all that other stuff for you are not familiar with data logging??....Good Luck

 

So you tuned it, what boost is it requesting?

 

Potato Potatoe, whatever you want to call it the ECU controls the boost and limits via the N75.

So he is seeing 1.1 and should be getting 1.1. What is the issue then? Someone hooked up another boost gauge and sees 1.3 at some unknown test point with some unknown gauge?

How did the OP get from .9bar 6 months ago to 1.1? Seems there are some details being withheld or something... Someone knows more than they are letting on IMO.

/wildgoosechase

 

Load is a calcuated figure too.

I don't get it. Two different methods of measuring boost, who knows how calibrated these devices are, etc... it is really that surprising to see a difference?

 

The same thing can be said about boost (and it has). I disagree that calculated load has nothing to do with pressure. Load is a fuction of MAF except when you run mafless then it becomes a function of MAP.

 

I think you're used to the 996tt DME. The 997tt will use MAP to calculate load on mafless tunes. It's done all the time. It's pretty straightforward correlating MAP to MAF simply by knowing a few inputs like rpm, IAT, etc...I don't really understand what you're saying but I can't see how the ECU would even try to guesstimate turbo airflow. I never heard of such a thing. That would be too complicated and cause major headaches when you replace turbos.