[crystal_Imprezav]

Originally Posted by WolfPlayer

Wordage. It's actually already on my list Right now I am experimenting with the MAF curve just a tad. I found some lean spots in the 2.5-2.9 region. Also seeing how much I can take out of the 3.5-3.9 region without ruining the curve and fudging it dangerously.

t

Been there done that, not worth it IMHO. I played with it for a few days (and I am talking about DAYS) and by fudging with that one very sensative area of the curve #1 your curve will end up looking like poo by the time your done with any noticable results and #2 makes you go stupid lean right after that spot no matter what (i.e. to smooth out the rest of the curve you lower/interpolate or have an ugly curve that hops a big difference). Im up to almost 22-24* of advance right now at the end of the day (rain) on 23psi @3000-4000rpms (METH) as opposed to my meth TMIC tune of 18-20* and my car is still taking it amazingly. AFR's have gone up to about a 10.8 from a starting point of 10.2 from some runs earlier this morning. Since I can't lean out my fuel tables anymore, have learned not to fudge with the intake calibration in that area, and have my progressive controller where I want it (limited by max boost setting), looks like I will be adding more timing til that DA drops at all then I am backing it off a degree. Hopefully by the time I am done, it will lean out or else I am going back into the AVCS to add a crap more timing. BTW my load has gone up to 4 (4.7v) at less boost than my TMIC tune (for right now) and a stock diameter/stock typhoon (no ru2800 filter)! I did advance my AVCS about 2* more from what you previously saw of mine though.
Check this bad boy out:

[Guest_1u53r]

nice fuel table. is that for testing purposes only?

[crystal_Imprezav]

Nope, thats really the only way you can tune meth/alky injection. That is unless you want to fudge severely with the intake calibration which will throw of loads and etc. For testing purposes i actually tested out a very similar fuel table with 14.7 up to 3600rpms and still no deal on getting the FMIC to lean out at all at that load/rpm site

[04stiguy]

Originally Posted by WolfPlayer

They are similar but not the same. The 2.5-2.9 area is richer. The 3.5-4.0 area is slightly leaner. The idle range is different.

What are your thoughts?

t

Look very closely at your load/rpm vs. commanded fuel numbers in the primary fuel table and compare them to your actuals (LM1 data logs) just before you hit full boost and in that whole area. Apparently with the TMIC you can mask an intake cal. that is not dead nuts on. With the FMIC (whether it is the "lag" or pressurization time), it uncovers this shortcoming, at least in my car. I modifed my MAF curve and smoothed it EVER SO SLIGHTLY in that area. MAF curve still looks like it should. No dips etc. I am finally on my way to an acceptable AFR curve. I will post more when I have some results worth posting.

I am still going to try out a blow through just for my own education after the draw thru is dialed.

[04stiguy]

Originally Posted by RainMaker

I should look, but Im under the impression that I dont have this issue.

I have a blow-through MAF.

MAF delay creates a different "big issue" with blow through, and that is around tip-in. I get terrible tip-in instability, and can't seem to make my tip-in work with ST. I have no issue when the boost finally hits.... Just when I hit the pedal.

Sadly, Im pretty sure that this issue you guys are seeing is all around the air it takes to fill a FMIC and piping with 2x+ atmosphere. Under vacuum, the car has the FMIC full of air at roughly atmosphere or slightly below. Under full boost, the thing goes to 2.5 times as much air in the FMIC. This air has to come through the MAF, adn when does it come through? Right when full boost "hits".

I tried to fix this a year ago with a blow-through.

Unfortunately, with ST, I brought a .45 pistol to combat. It "works" for the basics, but I havent had Christian or others mess with FIBTE. I hope the next ST will have it. Sadly, I've been waiting for ST to "have it" on a number of things for some time... I understand it takes more time than I thought.

So the "experts" have this figured out? I doubt it. Why do you think everyone is so excited about the MAP UTEC? MAF instability and delay are significantly lessened as issues with MAP at open loop.

I've moved to a smaller turbo, I like it, and I'll be moving back to a decently sized TMIC.

I want to have more fun with my car than I currently have with the FMIC and massive BT MAF. Unfortunately I did a very good job of cutting up my bumper for the FMIC

Chris

Could we get you to post some pics of the installed blow-thru MAF and orientation on the car? Thanks

[WolfPlayer]

Originally Posted by 04stiguy

Look very closely at your load/rpm vs. commanded fuel numbers in the primary fuel table and compare them to your actuals (LM1 data logs) just before you hit full boost and in that whole area. Apparently with the TMIC you can mask an intake cal. that is not dead nuts on. With the FMIC (whether it is the "lag" or pressurization time), it uncovers this shortcoming, at least in my car. I modifed my MAF curve and smoothed it EVER SO SLIGHTLY in that area. MAF curve still looks like it should. No dips etc. I am finally on my way to an acceptable AFR curve. I will post more when I have some results worth posting.

That is NOT the issue on my setup. Here is my latest 70mm cal ...




I lowered the area before 4v slightly. If I lower it any more then it won't make sense. Furthermore, I did some tests at part throttle so that I can keep the car in the 3-4v region. The AFR is on. IMHO, that is the key. Do some part throttle constant throttle logs of the 3-4v region (with no spoolup enrichment). THAT will tell you if that region is nuts on or not. You can't judge the MAF curve during spoolup because the lag can affect it. You have to judge it during constant throttle such that the motor can reach a steady state.

t

[RainMaker]

Originally Posted by 04stiguy

Could we get you to post some pics of the installed blow-thru MAF and orientation on the car? Thanks

Sure, it comes off the car this weekend as well. If you are interested, I'll even sell the whole setup to you for $150 including a worked-out intake calibration . The box prior to the MAF is a box of aluminum honeycomb for laminar flow conditioning.

[crystal_Imprezav]

^^ I knew you would end up messing with that curve Looks similar to the one I emailed you a few weeks back, lol where you said you wouldn't want to mess with it. So part throttle you said looks on point but what about WOT?

[04stiguy]

Originally Posted by WolfPlayer

That is NOT the issue on my setup. Here is my latest 70mm cal ...




I lowered the area before 4v slightly. If I lower it any more then it won't make sense. Furthermore, I did some tests at part throttle so that I can keep the car in the 3-4v region. The AFR is on. IMHO, that is the key. Do some part throttle constant throttle logs of the 3-4v region (with no spoolup enrichment). THAT will tell you if that region is nuts on or not. You can't judge the MAF curve during spoolup because the lag can affect it. You have to judge it during constant throttle such that the motor can reach a steady state.

t

Understood, BUT, this is also in an area (around 4V) where you cannot help but be in spoolup or in moderate/high boost. Not sure how you can be moving that kind of air and not be in boost or in the process of spooling....? Are you on an eddy current dyno when you have constant throttle and 4v MAF readings? My AFR was getting wacky right at the 3.75-4v readings, and your MAF numbers are almost spot on what mine were when I was having the 9:1 rich dip. Also, your maf v/gsec relationship above 4v looks too agressive for a 70mm opening.

Just my $.02. Seems to be helping my setup quite a bit.

[WolfPlayer]

Originally Posted by crystal_Imprezav

^^ I knew you would end up messing with that curve Looks similar to the one I emailed you a few weeks back, lol where you said you wouldn't want to mess with it. So part throttle you said looks on point but what about WOT?

In NO way does this look like the curve you sent me - rofl. I only decreased the area by like 2%. You had it WAY decreased (dangerously).

The curve is just on-point. I am testing steady state MAF V and comparing the fuel curve to the wideband.

t

[WolfPlayer]

Originally Posted by 04stiguy

Understood, BUT, this is also in an area (around 4V) where you cannot help but be in spoolup or in moderate/high boost. Not sure how you can be moving that kind of air and not be in boost or in the process of spooling....? Are you on an eddy current dyno when you have constant throttle and 4v MAF readings? My AFR was getting wacky right at the 3.75-4v readings, and your MAF numbers are almost spot on what mine were when I was having the 9:1 rich dip. Also, your maf v/gsec relationship above 4v looks too agressive for a 70mm opening.

Just my $.02. Seems to be helping my setup quite a bit.

You can hold low boost and produce the MAF V you want. Just takes some patience. However, it works. There's no way my 3-4v region is too rich in that curve. As to above 4v ... it is on the money up to 4.5v. 4.5v is the max voltage I have made and the AFRs were 11:1 with a 10.88 specified (so I guess it is a little high). Above 4.5v is totally speculative and is probably rich - but I don't know because my car doesn't pull that much air.

Don't get me wrong. I am sure that I could decrease that specific voltage area and get rid of a bunch of the dip. However, the intake calibration is not at fault. If anything, it is slightly too LOW in that area due to me fudging it a TINY bit (like 2%). Be careful about pulling that area down too low. You run the risk of part throttle lean fueling. You can run 3.7v at part throttle fairly easily in partial boost acclerating briskly.

t

[daemon]

I also double checked my intake calibration re: MAF voltage vs. AFR delta. The MAF areas where I logged a spike (~10+% delta) also tended to average less than a ~2% delta on a much more consistent basis. That is, the spike area of the intake calibration was more likely to produce the desired AFR then not (by a huge margin). Therefore, fudging the intake calibration would actually hurt me.

[04stiguy]

Originally Posted by RainMaker

Sure, it comes off the car this weekend as well. If you are interested, I'll even sell the whole setup to you for $150 including a worked-out intake calibration . The box prior to the MAF is a box of aluminum honeycomb for laminar flow conditioning.

Used 3" tube for the MAF?
Did the honeycomb help with the tip-in issues?

[RainMaker]

Originally Posted by 04stiguy

Used 3" tube for the MAF?
Did the honeycomb help with the tip-in issues?

The MAF is 3.125" ID.
The honeycomb fixed turbulence at the MAF sensor, and didnt have any effect on tip-in once tuned.

[RainMaker]

Oh... on a final note...

I successfully undid what Wolfplayer has done

Operation Remove Front Mount and Blowthrough has been a success.

I can stand on a boat and present Mission Accomplished because I *think* it went well, though Im not finished tuning yet.

These pull-throughs with TMICs sure are easier to tune