I need the FAST tuners to weigh in and help me out.

[disco stu]

I've always had problems with this and would like to figure out what I'm doing once and for all. I don't know if it;s more of an issue of AE, 02 gain, or what. Maybe I should go ahead and choke down on the correction limits since the tune is getting close but scared to since it's adding fuel.

As the bubble transitions around I see alot of correction. Around and under 100 KPA it's an issue of me needing to play around with MAP vs AE and TPS vs AE I'm sure. I mess with it, and usually don't correct my problem but create new ones. It drives fine for now, but I'd like to get it nailed later.

But what I'm concerned about is when I'm building boost. I tuned the table pound for pound from about 6 psi up. But as it's going through those same cells it adds alot. This is not the way I wanted to do it but I jacked up the VE numbers in those cells the amount it was correction and about the same amount of correction.

How much does MAP vs AE affect this? Any? The rate of manifold pressure change is slow when boost is rising compared to the change going from closed to open or partially open and under vacuum to open and almost instantaneaously rasing manifold pressure.



I cannot seem to upload these attachments. It gives me invalid file errors. If you would like to offer your input I can email my GCT and log files to you. I would appreciate it.

 

[disco stu]

Pay no attention to the fuel press, it's a little off and I need to recalibrate.

 

[disco stu]

Can someone tell me how to attach the files or how to post them for download? Like I said, it gives me "invalid file". I could have sworn I've seen people attach GCT's and logs on here.

 

[Blazer406]

IMHO.....most of the meat of the tuning gets done on the base VE table. I always make a little full throttle snort in the boost range I want to tune..... look at the datalog..... and tweak the VE table accordingly based off the full throttle snort I just did.

In just a few iterations.... you should be able to tune the boost range you are working on so correction amounts are no more than +/- 5% IMHO.

Note: When you first start to tune... and you are significantly "off" on the VE table..... I open up the correction limits..... so it can go where it wants to go.... then tune the VE table accordingly. I tighten up the correction limits on the - side (pulling fuel) when I get the VE table tuned in.......

Maybe that helps?

 

[S2V6RACER]

Double post

 

[S2V6RACER]

I spool in open loop and have the map vs. AE cutoff set at 100kpa.

If you can log BPW and GPW you should see when and if it is adding AE fuel.

 

[disco stu]

Blazer, Thanks, but not really. I kinda know how the ve table works, and I don't wanna bandaid this problem by jacking numbers up to 80-100% at 3500 and 150kpa. This is about swinging corrections in cells ive gone through or are close.

I've tried moving 02 gain numbers up in those areas
of the table but it seems to not do much.

Need real tuning help.

 

[disco stu]

That's interesting S2. Maybe I should start choking down the corrections in these areas and see if it's preemptively (sp) adding fuel. Do gain increases show as correction percentage? Maybe that's the problem

 

[disco stu]

I had my ae cutoff at 100, kicked it up to 190 to see. Didn't get me any closer

 

[S2V6RACER]

You can zero out the correction (positive and negative) in the VE table affected at spoolup and get it dialed in that way also. When you let go of the brake it's going to go back to your regular correction you want.


I think you will find it very consistent this way.

 

[disco stu]

I guess that will be the next step. I was scared to limit corrections as it was adding up to 20% fuel as it is spooling. Even though it was way richer than target. I wonder if the o2 gain is indicated in correction factor, ie higher than necessary correction due to higher than necessary gain numbers.

 

[norbs]

You will need to use winzip to upload the files. Be interesting your logs. If you want you can email them to me and I will post them on the board for you.

 

[Eticket]

This is a good threads Stu. I've found myself retuning the same cells and not really making much difference in those same cells (I think).

 

[Blazer406]

You can zero out the correction (positive and negative) in the VE table affected at spoolup and get it dialed in that way also. When you let go of the brake it's going to go back to your regular correction you want.


I think you will find it very consistent this way.

Sounds like good advice to me.....

Cal had told me when I first started tinkering that it was a good idea to zero out the positive and negative correction in the region of the table (a few cells) where the two step was sputtering so it couldn't correct when it was on the two step....... seems to reason that this would also be of benefit in the spoolup portion of the correction tables....

 

[disco stu]

No, different deal. But thanks.

 

[disco stu]

C'mon guys. Non Buick people come here for FAST help because there are badass FAST tuners here. Anyone else have any theory they wanna add? I'd also like to talk about AE tuning for around town driving. Don't have that nailed either, seems like guesswork and is impossible to log. I've started a similiar thread to this with little imput.

My laptop crashed, so I can't try your suggestions S2. But I'd still like to see
some input.

 

[UR50SLO]

Sounds like your target AFR table and Main VE Table are off.

What is your target AFR's?

What your seeing in correction is the difference between your Target AFR and your VE table.

You'll have to send my your tune file and build info.
UR50SLO@aol.com
~Scott

 

[Turbo Loyd]

As the bubble transitions around I see alot of correction. Around and under 100 KPA it's an issue of me needing to play around with MAP vs AE and TPS vs AE I'm sure. I mess with it, and usually don't correct my problem but create new ones. It drives fine for now, but I'd like to get it nailed later.

When I first installed the XFI in the blue Turbo Regal it had a decent start up program that I promptly messed up trying to correct. In my case the CTS and ATS correction tables were adding fuel at the engine operating temperature. Make sure all other correction tables are zeroed out at your normal engine operating temperature. Otherwise they will be making adjustments so the corrections you make to the VE table by hitting the "L" key when the blue oval is hovering over a cell will be inaccurate.

Really had the table messed up. So review all the table and zero out most until you get the VE table where it needs to be. I even have limited the mentioned MAP change versus AE and TPS change versus AE to limit their effects on the base VE table tuning. Once you have the VE table nailed down then go back and fine tune these.

Better to start out with a good reliable base, to keep tuning simple at least for this rookie.

Hope this helps

 

[Turbo Loyd]

Two more areas to investigate:

Low voltage causes an enrichment. You should add both the voltage itself and the enrichment for voltage to your dashboard I had an alternator that would not keep up with the some of the loads so in the middle of making adjustments the computer would try to correct for low voltage. I happened to notice the enrichment and had to fix this problem, before trying to get the combination dialed in.

Another area to check is consistent fuel pressure. Had a fuel pump that was under performing, so would show 42 psi at idle, but when you hit the throttle would fall short. I really messed up the fuel map, before I discovered that problem.

Seems I have had my share of goofing up the fuel maps with outside conditions. I do keep files of past benchmarks so it is usually easy to go back to an earlier version.

Hope this helps

 

[disco stu]

Thanks Lloyd. Think I got the fuel map pretty alright. To within 1 percent or less for the most part. Like I said, I started at 6 psi and tuned every part of the map the bubble touches. And it's fine once the bubble stabilizes.

Logging FP, good. Need to calibrate transducer but it correlates to a mechanical that reads actual.

Voltage is solid going into the FAST. Just reads a volt lower coming out. Told it was normal. Voltage, grounds good.

ETC ETC ETC

What I should of said was "what do you do when you have swinging corrections through a tuned VE table and have covered all the basic stuff?"

Got some good info here though. Not gonna mess with it much until I get my new laptop that crashed back from computor jail.