[91TurboFox]

Hello All,

I'm working on getting my 91 5.0L tuned using a Tweecer after installing a HP Performance Stage 3 Turbo Kit (76mm turbo). It has an A9P computer.

I did have the car running and driving using Tweecer/Calcon/Caledit with FPR 42# injectors, C&L 76mm MAF, and 255 lph fuel pump, and BBK AFPR (doesn't boost reference). I changed to Deatschworks 60# injectors, Pro-M 3" Slot-Style Pro Tube, 340 lph fuel pump, and Aeromotive AFPR (does boost reference). The car starts and idles roughly, but stumbles when trying to rev it at idle. The load at startup, idling, is around 100, with load percentage around 130, which makes no sense to me. How could this load be reading so high? The MAF voltage is around .8 which should be about 32 kg/hr.

It is also running very rich based on my LC-1 wideband. I'm using the supplied MAF curve for the new meter, and new injector settings, but so far haven't tried to adjust for it running so rich.

Would something mechanical instead of something in the tune account for such a high load value? I don't believe I have any vacuum leaks, but I did have the upper intake off and MAF tubing off to swap the injectors and MAF.

I attached my tune and my log file from it idling last night (forgot to connect WB and Boost sensor for this log). Thanks for any help!

[EDS50]

Upload your logs in .csv format. Upload your tune in .bin format.

[91TurboFox]

I've attached the log in .csv format and I'll work on getting the tune in .bin format this evening. Thanks!

[EDS50]

Cool.

[skunk]

Definitely need to see your tune......somethings not right. Your timing goes from 33 closed throttle 100 load to 60 at part throttle 190 load.....I cant imagine you set up to command that much timing. Aside from that your log doesn't say much since you never got out of OL cold start enrichment and there is no WB feedback.

Its possible you fat fingerd something related to column scaling or your tune is corrupt. I would start fresh with minimal changes just to make it run to see if the problem persists.

What I dont understand is your MAF voltages......it appears to be a 19# calibration. If your hitting 1.5 volts @ 1800 rpm with no load.......you will peg that meter before you even begin to spool the turbo.

John

Hey Ed.....long time no see.....hope all is well!!!

[91TurboFox]

Thanks for your reply skunk. As far as posting a tune in .bin format; it looks like I'm going to have a hard time until I have a registered version of Binary Editor. I've downloaded it but I can't save a .bin until it's registered. Sorry about that. Please let me know if there's a different way I could generate it.

I did upload my general Excel change log, which shows the stock A9P settings and every scalar/function/table that's been modified and their new values. I will take your advice and start again with A9P stock tune and change only the MAF function and injector slopes and offsets (not sea level scaling, timing or fuel tables). That sounds like a good place to start. I had re-scaled some of the tables to try to expand the load range that they reference.

The numbers for the MAF Transfer come straight from Pro-M, which shouldn't be calibrated to any particular injectors for their Pro Pipe.

Thanks for both of your feedback.

[skunk]

I highly recommend BE for use with the Tweecer but you can also use TunerPro to write, edit and save bin files. If you go that route....stick with Derek's GUFx definitions available on the TunerPro site. There is one small change in the xdf header you have to make to get your bin to display properly. There will be a check box to subtract a value.......enter 2000 and click the check box. The xdf is looking for 64k padded bin. The subtract 2000 aligns it to your 56k bin.

I mention the MAF Voltage looking like a 19# calibration because it will lack the range of measurement require based on the log uploaded. I would hate to hear your project came to an abrupt end due to lean-out. Take a good look at the flow numbers above 4 volts......if you data sheet doesn't start approaching 2000 kg/hr.....you will have issues.

John

[EDS50]

I'll comment when the tune is made available. Derek needs to update his personal windows XP based .cry defs because they will no longer be compatible with the current version of BE.

[91TurboFox]

As a quick reply; this morning I started with a fresh A9P tune and changed only the injector slopes, offset vs. battery voltage, and breakpoint, and then MAF curve. The load is back down to 20-30% and the car isn't stumbling like it was when revving it at idle. I don't know specifically what was wrong with the previous tune, but that's ok. I did log it, so I'll post it for posterity.

Thanks for the good suggestions, and now I can start tuning in earnest. Tonight I'll be looking into using BE with EEC Analyzer or Tunerpro. Thanks again; you've given be some renewed hope with this project.

FYI: At 5V, this MAF is reading 3480 kg/hr.

[EDS50]

20-30% load is still too high at idle. For reference mine is 8. Once I can look at your tune I can make my suggestions. Is your maf calibrated for the injectors and strategy your using?

[91TurboFox]

I don't think the MAF is calibrated for the injectors. Attached is the Transfer Curve shipped with the meter. I think that unlike Pro-M's bullet style MAFs, these aren't calibrated to an injector.

http://www.promracing.com/mass-air-mete ... -tube.html (Don't specify an injector size with the MAF)

By calibrated for the strategy, are you referring to different EEC clock speeds (which would use different transfer functions) or scaling because a strategy can only support a certain maximum kg/hr value (described about 1/3 of the way down this page as "Scaling AIRFLOW - SCALING PERCENTAGE", http://www.efidynotuning.com/scaling.htm)? These are new topics for me; I'm reading up on them now.

[EDS50]

I don't mess with any of that scaling nonsense but since you are you need to be fully committed to it and follow it to a T to make it work for what you are doing and make all the necessary tune related changes.

[skunk]

Good to hear you made progress!!!

Calibrated to the strategy and injectors simply means the voltage output will be a ratio of injector size difference based on specific ECU MAF data.

The advantage of a calibrated Maf is usually you won't have to scale airflow and can pretty much slap it in and make minimal changes or none in the tune. This is why Eds load at idle is around 8. His tune is scaled to fit the existing constraints but it's done with hardware instead of software. Nothing wrong with tis approach as it makes use of 0-100 load instead of needing to expand tables beyond 100.

Since your MAF is not calibrated and is capable of reading well above the clip limit.......you will need to scale your airflow to fit the ECU constraints.

John