sgt

Unfortunately, without changing, at a minimum, Primary Fuel and Timing and DA scale values one cannot tune for a larger turbo, nor a highly tuned VF40 for that matter. Scale values are only saved in the base map.

That's interesting, as I did not experience any problems using rescaled rt maps.

Cobb's explanation to me was that any RT maps that were redundancies of base maps would override the base map unless the ecu was reset, at which point the rt would have to be reloaded.

Indeed, I have sat under the engine while running and someone revving while feeling everywhere for leaks. Havent found any.

Im really tempted to just unplug the o2 sensor and run in open loop.

Compression was near 150

Leakdown was near 0

All cylinder result s were near identical

You say nice and black, that does not describe a properly running cylinder, IMHO. And bright white certainly doesn't either. The 'correct' color is a very light tan approaching white, but certainly not bright white. A black plug is indicative of too much fuel or too cold a plug, along those lines. You seem to have multiple issues affecting different cylinders. Rough.

Well I was referring to the exhaust ports themselves which should be black. The last time I looked at the plugs they all looked alright.

While too much fuel, not burning correctly, will not immediately harm your engine a lean cylinder can definately ruin your day, quickly.

That I am well aware of.

My APS headers have an EGT port on each cylinder right off the head. I suggest you begin using yours to investigate your engine.

 

Something is wrong. Faced with this I would first begin with basics, a compression test. Then I would suspect an air leak, perhaps at the TGV or Intake, for the lean cylinder. Obviously, even though you seem to have it covered, I would get the injectors flow tested. And something is wrong, in general, with your fuel, be it Intake Calibration or whatever, as your plugs should not be black. Etc.

 

Headers simply do NOT cause these problems. Think about it; EL headers treat all the cylinders equally. Unless something is wrong with the installation, which I have to assume you have checked, look elsewhere... QUICKLY.

I was considering checking egts but I would first need to get my hands on one.

Compression test is good, leakdown test is good. Pressure tested the intake from the turbo to the engine and everything looks ok. Injectors are even, all three sets. Again, plugs were pretty much perfect, the exhaust ports were what I was referring to. Really Im rather surprised that the plug looks good but the port does not.

I don't see how a header, and especially the APS EL, could cause it either. Do you have a non-stock intake? And if so, what is your IC. FWIW, my IC for 1.64 is 8.74 and for 1.72 it is 10.22. LBGT's is 8.31 and 9.87 (IIRC). Both of us have the AEM CAI.

 

Do you have the APS Wrap Kit installed on your headers? I do.

 

What are you mods?

Well, I can say with near certainty that the surging is caused by the header. I have removed pretty much everything else with no effect. Mods are as follows:

AEM intake

VF34

APS Header - no wrap

ebay tmic

sti swap

tgv deletes

nismo injectors

avo pump

turboback exhaust

With a scalar of 3680 I have 9.38 and 11.04 in those two spots in the IC. It really doesnt matter much what I put there as the ecu still over-corrects in those blocks. FWIW, in open loop the car drives beautifully (I am tempted to just unplug the sensor and leave it there). I have tried other injectors in various combinations as well as testing the car with nearly all of the mods removed with the exception of the header and always end up with the same results.

I think it might also be worth noting that the front left exhaust port has always been a really bright white color while the rest were nice and black. I think that has something to do with my issue but right now I dont have any good ideas of how to correct it. That cylinder is #2 right? Isnt that the common failure point?

Maybe you all can help me with some insight into my problem.

Ever since I installed this APS equal length header, when I am in light throttle cruise I get +-25% correction which causes the car to surge. This happens only right around 1.6-1.7V on the maf. I am reasonably sure that the header has brought out this condition, but still not sure exactly what it is. On one of the other boards I saw someone that went to twin scroll had the exact same problem, but he never found a solution. Has anyone else seen or heard of this before?

The rear diff. will work, because it's 160,[same in the GT now] regeared to match the STi tranny's 3.90 final drive.

Where did the replacement gears come from? Are they factory or does somebody make them?

IIRC, the ecu will hit lower wgdc if it is having trouble controlling the boost.

What turbo are you using?

Will we be able to use the new software with the old AP?

The way I see it, the AP is solely to flash the ecu and nothing else. The rest I want to do with the laptop.

I was just trying to get a correlation between calculated load and maf voltage.

That sucks that it doesnt mark the cells as it goes along. I really liked that functionality in the other software that I use.

So you are scaled up to 3.4 and that only covers up to 4.9V? So 3.5 is the limit for the stock maf?

With a VF34 I was already seeing load of about 3.19. Im just trying to cover all of my bases.

What about the tracing function? IS there a way for it to mark the cells?

Currently, I rescaled my fuel/timing maps up to 3.25. However, I am thinking I may need to go up to 3.5.

At what point does our MAF run out?

While using the map tracing function, is there a way to have it mark the cells where it has been?