[WolfPlayer]

Originally Posted by daemon

I've finally started to get back to a place where I can play with these issues myself. And while looking at turbo dynamics vs. the AFR, I sort of started to wonder if there was any chance that maybe this is being caused by the fuel pressure regulator having some issues tracking the boost given how hard we are pushing things beyond stock. Silly idea?

I don't think that is a silly idea. However, considering that my AFRs were lowered by about 1.0 AFR point with just a FMIC install, I find it hard to believe that it would have just started to happen. I didn't change the boost or anything. I just went with a FMIC .

t

[daemon]

Hmmm... Yeah. True. I guess I'll temporarily stop shopping for a new FPR.

[04stiguy]

Originally Posted by 04stiguy

Thanks.

>>Wolfplayer, do you have the same intake cal. table values as you posted here on 6/15/06?

Bump. I think I may know what is going on with the rich spot...

[WolfPlayer]

Originally Posted by 04stiguy

Bump. I think I may know what is going on with the rich spot...

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

[TheLimitedProject]

After reading this entire thread, page 1 --> 4 (non-Noob settings), and seeing how much trouble it's taking to tune for a FMIC, I have to ask the people experiencing the issues (WolfP and Crystal, 04stiguy, daemon), what's the point of going FMIC if it can't be tuned for?

I'm a bit confused though, when it comes to people taking their car's to be protuned (as opposed to self-tuning). If these rich spikes are normal for a FMIC setup, how are tuners tuning it out? Or are they?

Is it easier to tune out the problem with a bigger turbo than the VF39 (or VF43 in my case)? Or are tuners band-aid'ing the problem by modifying the MAF tables?

I'm trying to ask questions for the people who run FMIC or want to, but don't have a clue about the actual tuning process (like me ). I have WBR's FMIC sitting in a box waiting to go on before I upgrade my turbo to a GT52 and intake to APS 70mm. After I've read this thread though, I have doubts about even going FMIC.

Would it be better to keep the length or tubing and volume of air to the max TMIC I can use, or will my tuner be able to tune out the rich spikes that I'll definitely see (as evidence from this thread) by installing the FMIC?

[daemon]

Almost every upgrade brings with it some form of compromise.

Why are you going to install a bigger turbo when you will lose a bit of low end spool? Because you like the advantage it provides despite the disadvantage that comes with it.

Why install a FMIC, even if we can't tune this rich spike out. Because there are still advantages to be had that can outweigh the momentary spool up rich spike. More consistency and cooler air temps, less pressure drop at higher air flow rates, etc.

BTW, nobody has said it absolutely can't be tuned out, it just might take a little while to find the right way to do it. As for the size of the turbo vs. the spike, I am running an SZ49 with an EWG and I currently spike into the 9s as well.

In the end, mod'ing is all about finding solutions that provide you with the advantages you want and whose disadvantages you can accept. Everyone has different goals, so the selection of components for "the perfect setup" will differ from person to person.

[jgheels2003]

Originally Posted by WhyteSTI

After reading this entire thread, page 1 --> 4 (non-Noob settings), and seeing how much trouble it's taking to tune for a FMIC, I have to ask the people experiencing the issues (WolfP and Crystal, 04stiguy, daemon), what's the point of going FMIC if it can't be tuned for?

I'm a bit confused though, when it comes to people taking their car's to be protuned (as opposed to self-tuning). If these rich spikes are normal for a FMIC setup, how are tuners tuning it out? Or are they?

Is it easier to tune out the problem with a bigger turbo than the VF39 (or VF43 in my case)? Or are tuners band-aid'ing the problem by modifying the MAF tables?

I'm trying to ask questions for the people who run FMIC or want to, but don't have a clue about the actual tuning process (like me ). I have WBR's FMIC sitting in a box waiting to go on before I upgrade my turbo to a GT52 and intake to APS 70mm. After I've read this thread though, I have doubts about even going FMIC.

Would it be better to keep the length or tubing and volume of air to the max TMIC I can use, or will my tuner be able to tune out the rich spikes that I'll definitely see (as evidence from this thread) by installing the FMIC?

Not everyone who tunes their own car is as skilled as the professionals who tune multiple vehicles on a daily basis. And, even those pros do variable work. Plenty of people run FMICs without a problem. Im sure some have issues that they just put up with, but plenty don't. If you are getting a GT52, it would be wise to run a FMIC. My opinion is that these guys here absolutely know what they are talking about, and what they are doing. They will get it straight.

[WolfPlayer]

Originally Posted by jgheels2003

Not everyone who tunes their own car is as skilled as the professionals who tune multiple vehicles on a daily basis. And, even those pros do variable work. Plenty of people run FMICs without a problem. Im sure some have issues that they just put up with, but plenty don't. If you are getting a GT52, it would be wise to run a FMIC. My opinion is that these guys here absolutely know what they are talking about, and what they are doing. They will get it straight.

I can EASILY produce a dyno curve like the 'pros'. I can easily turn the keys of my car over to another person and have them drive it and they will think it is fine. This is MORE than just about 'skill' . Scott from SOG already cleared that up in a different way. So did Christian.

Here's an example: Doug from TopSpeed tends to leave the MAF curves fairly stock when tuning a car with a Big MAF. Is that the correct way to do it? Absolutely not. However, it works - and the user will probably never notice it (until they log their car and wonder why it is only pulling 260g/s).

I don't like to fudge things. I like to do them properly. I could lean out the fuel curve enough to get rid of most of the rich spike. But, that doesn't makes sense to me ... and it doesn't make sense in terms of the tune. Some of the 'Pros' will do this though. They will use their skill to lean out the fuel curve and delay boost a tad. Leaning out the main fuel table in situations where that extra fuel is happening for another reason is NOT the correct way to fix this situation. However, I admit that it does have it's benefits.

t

[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

[crystal_Imprezav]

Ok so after playing around with MAF trying to fudge the results with the ecu, no success. It barely went leaner at all and then went really lean afterwards and when attempting to retune the after part my MAF curve looked like crap. Scratch that idea. I then went in to the engine bay to check for leaks. I found that my turbo inlet clamp looked a little loose and out of place. Moved that back and tightened down and went for some runs on the older MAF cal. RICHER afr's! craptastic! So I then said screw it and proceeded to reinstall my meth. Oh boy how do I love 24psi. I can pretty much mask the rich spike. On my meth tune where I used to hit a 10.9 afr at around 3000rpms I now hit a 10.0 to 10.4. Not too terribly bad but you can notice it. Feels almost like a slight 07 STi hesitation. What I did notice for the good side is that AFR's up top are way easier to predict and tune. I can tell there is a significant amount of extra airflow now and I am hitting 300g/s+ at 4.66+v now! At a stable 11.6~11.8:1 AFR I went in to tune timing. I was VERY surprised at my results. I was able to increase my timing down low by almost 4*, in the mid section (5000rpms) about 3*, and up top about 4-5*! Holding strong with 21~22* at 3000rpms and 23~24* at 5200! Sadly though no other significant discoveries on how to eliminate the delay. I've flashed more basemaps in the past few days than I ever have :O

[WolfPlayer]

Woo. I never imagined that this thread would get to 160+ posts. Now for something good.

Realization: I think the lazy tuning method is the reason why this issue is masked on big turbo setups tuned by a lot of the 'pros'. It all surrounds the MAF curve. If a tuner takes a shortcut and does not tune the MAF curve all the way through for the big MAF, then the change in load during a WOT pull is much lower. Do you see where I am going with this? The big-turbo car is getting a lot more air, but the load isn't changing that much because it is running a big MAF on a stock MAF curve. Thus, the change in MAF/LOAD isn't nearly as much as it should be with a properly scaled MAF curve. This supports what I have been saying all along - that if we could find an 'Enrichment vs. change (delta) MAF (or Load)', then we could get a better handle on this. As crystal pointed out to me, I was actually running a pseudo rich spike on my TMIC setup. It just wasn't nearly as bad.

This realization for me, is progress.

t

[crystal_Imprezav]

Dito, I pains me to looks at 'pro' tunes that are running 20G+ turbos and in datalogs only hit like 3.2 Load. For me stock turbo and all I am now hitting 4 load easily!?! Another progression: I have a very good intake calibration now, larger and smooth like stock. AFRs are pretty consistent. When I raised the timing to 22 at 3000rpms from 18 my afr's went from 10:1 to 10.6:1. Try this wolf, up the timing down there (I would try maybe 16-18*) and see if the car #1 likes it and #2 raises your afr's which it should unless it won't take it. Add it in the primary table so that the DA still has 10* of authority to pull what it doesn't like.

[RainMaker]

My AP cable broke. Perhaps a TACTRIX cable is in order (That lame "flex joint" right after the car-end of the ap cable end kept coming off of the connector and eventually, I guess, it pulled the red wire from the connection inside the connector. I can take it apart and fix it, but it doesnt seem all that well made and seems likely to break apart again.

We really need to understand from someone how the PCM figures out when to fuel what. Until then, an aftermarket ECM will always be superior.

Since this setup works fine for emmissions, I'm sorely tempted to plug in a Hydra and make it run *well*. I wish I was rich, I guess.

Chris

[WolfPlayer]

I have a Tactrix cable installed in my car 100% of the time. I never remove it. It runs into a USB hub with 4 ports in the glove box. I use 1 port for the Tactrix cable, 1 port for the StreetTUNER key, 1 port for the Wideband (from a serial to USB converter), and the last port is for my USB memory stick for carrying around logs, images, etc. Works like a charm. Whenever I tune, I simply plug one USB cable into my laptop. I love this setup. The cable is always there, everything is always plugged in, and it is easy to transfer stuff from my tuning laptop to other computers. Wonderful.

t

[WolfPlayer]

Originally Posted by crystal_Imprezav

Try this wolf, up the timing down there (I would try maybe 16-18*) and see if the car #1 likes it and #2 raises your afr's which it should unless it won't take it. Add it in the primary table so that the DA still has 10* of authority to pull what it doesn't like.

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