Anyone have L31 speed density file? (Stock)

[Orion]

Searched, seemed like it pulled every thread with the "speed density" keywords. So pages, and pages of irrelevant info.

To have a simplified engine bay, looking to do a speed density tune on a bone stock L31 so i can do away with the MAF, and ducting.

Currently 1998 Tahoe PCM, can that black box even do an SD strategy?

I could swap an '0411 PCM if someone had that file, but since it's bone stock i saw no need to uprade the PCM.

And the mail order tuners all say "we don't do SD tunes", and i understand that SD tunes need a dyno, or road tune data logged.

But was hoping someone had a starting point i could dump in.

BTW, never tuned EFI before in my life.

Thanks.

[98vortecSilverado]

if you get unplug of the MAF you will be in SD. (You should keep your IAT sensor)

Under Engine Diag/Airflow/Mass Air Flow Sensor If you set those 2 values at 9 and 10 it should fail the MAF even with it plugged in.

You may want to set the MAF DTC's (P101, P102 & P103) to MIL on first error, and uncheck SES enable. That should allow the ECM to fail the MAF but not turn your service engine soon light on.

With the 0411 there is a custom OS that would let you use the main VE table in SD. That would be one of the biggest benefits of an 0411 if you engine is stock and you want to run SD. The black box (or 0411 without the custom OS) will run on the secondary VE table with the maf failed. It has half the resolution, but wasn't really a big deal when I was running like that.

One thing you probably will need to do right away is some calibration of the VE table. Mine hardly ran with gm's stock VE table.

[Orion]

That's definitely a start, thank you. It won't actually be me doing it, it'll be the tuner shop who also uses HP tuner.

They're a 45 minute drive away, and are going to charge me a lot more to start at square one converting to SD, than if they just need to dyno/road data log and tweak some values.

I see you're boosted, so i imagine you don't have a file with the VE tables already tweaked to make it at least drivable for the 45 minutes to the tuner's shop?

[98vortecSilverado]

Yeah I don't think I have anything that would be very close.

I would recommend setting up SD like I mentioned above and giving it a try. If it wants to surge and buck just select the entire secondary VE table and multiply by 1.05 or so until it smooths out. Might take several tries, but if it sounds good and runs smooth you should be good. It's very hard to actually do damage to your engine without going WO throttle or seriously messing with the timing. With SD you will want to have your intake setup totally finished before you go to the dyno. Any change in airflow will need to be calibrated for.

Also you should still have your fuel trims working so it will correct itself pretty well if you drive it a bit.

I just remembered I had the hotcam installed before I went SD. So you might actually be fairly close with the factory VE table.

[98vortecSilverado]

Also if you are at all interested in tuning and or more mods later on, I would recommend a $160 wideband instead of a dyno tune. But thats just me I guess.

http://www.ebay.com/itm/AEM-Digital-...1XKR6s&vxp=mtr

[Orion]

I'm going to try it tomorrow. Let's see what happens.

All this, just to have a functioning hood scoop, with a top-mounted air box lol. I know it's stupid. But hey, whatever.