[Illusive]

does the st, use 2d maps or 3d maps for airfuel/vvt/ign ?

what I mean is,
is there a 2d map with a correction factor, that allows you to easily tune the a/f, variable valve timing (avcs), and ignition tables?

or is it the traditional 3d map with rpm / fuel or ignition / airflow.

I've been seeing quite a few guys who have been "tuned" run at a different elevation track or in different conditions who are not trapping what they should be with their dyno sheet #'s. I think it may be due to only being tuned for wot and certain load points and at the location they are racing they are using load cells that are untuned.....But I dont know for sure if it uses 3d maps or not. Its kinda tough to tune all the load points in a 3d map on the dyno unless you can alter the load (like mustang dynos can) or tune for each psi of boost up to max, or each psi reference on the map.

[Nixlimited]

There is a Big MAF log in this thread (post #49):
http://forums.nasioc.com/forums/showthread.php?t=865041

One of the interesting things is that the MAF voltage is not peaked, but the g/s stops going up after 300/s

check out the bottom of the log

[RainMaker]

I may be late to the party, but we are moving to a blow-through setup on my car because we had so many difficulties with low-load turbulence in the bigMAF. A constant throttle angle, accelerating rpm, and the MAF info would actually go up and down through the troublesome RPM. When not in the toublesome RPM, the MAF was nice and constantly rising. This of course played havoc with the LTFTs, and my XD-1 wideband showed me going exceptionally lean (16:1). Thankfully, it was nowhere near significant boost.
The idle also was troublesome. EcuTEK didnt give us the tables to work on idle.

I use PDXTuning for all my tuning stuff, and they are currently (as we speak) doing the basic EcuTEK tuning for the blow-through with a custom aluminum MAF housing.

I'd prefer to have Cobb ST, as I would like to iron out the tune better than PDXT has time for. (Im capable). But I bought EcuTEK license before 06 STI Cobb AccessPorts were out. I may find a way to give my PCM to another 06 car and have the security codes reprogrammed. Then I can buy an AP and ST.

Anyways, PDX will tell you that you are not alone. Some tuners have worked out how to tune around the bigMAF, but it involves alot of bandaids (setting the target AFR such that the turbulence sends it into the 14-15 area) This of course fudges up the mileage and efficiency at other part throttle rpms.

Chris

[Siegel Racing]

g/s always maxes at 300...

it's likely a serious rich stumble. Anything under 9.6:1 or so the car just doesn't run.

It's good that you are not bashing the shop, but have you told them you are having this issue? The tuner may know immediately how to fix it, as soon as you tell him what the issue is.

I've had customers that have my cell number programmed in their phones, and I still don't know they have an issue until they post a problem on a forum (if you go from a stock TMIC to a BIG TMIC without telling your tuner you will get over-boosts )

SS

[STirish]

Originally Posted by Subaru of Gwinnett

g/s always maxes at 300...

This can be changed 8^ )

[RainMaker]

We put a "flow-straightner" from an Audi in the Perrin BogMAF and I have to say we fixed about 95% of the issues. The transitional fueling is still wonky, but Im using a real BOV post-MAF, so it is likely to be off until I get the blow-through completely data-logged.

[nathansvt]

Originally Posted by RainMaker

We put a "flow-straightner" from an Audi in the Perrin BogMAF and I have to say we fixed about 95% of the issues. The transitional fueling is still wonky, but Im using a real BOV post-MAF, so it is likely to be off until I get the blow-through completely data-logged.

Got a part number? I'm finally back from the holidays and ready to take a fresh run at the problem.

[RainMaker]

hrm... I don't. I'll know quite a bit more next week. I also did the "ground mod" and found a smoother idle and a slightly stronger spark up top. I did it with some 10 guage multi-strand wire, some crimp-on eyelets, and alot of solder.

I need to look more into getting ahold of some aluminum honeycomb. They sell it in sheets, and that is all that the Audi peice is.

On a side note, it changed my MAF readings significantly, and now the car runs *very* rich at WOT and at RPM. My WB is showing 9.2-9.5:1 Needless to say, it hesitates alot up there, and I'd need to re-dyno-tune it if I was going to keep this solution.

chris

[WolfPlayer]

Edited at the request of nathansvt.

t