I'm interested in tuning some gen4 LS1 camaro's, most guys just disable the maf in the computer and unplug it, then use just the VE tables to become a full speed density setup.

stock the ls1's have a maf sensor that gets 'blended' with the ve tables to make its fueling calculations

anyway... are there any speed density/gm tuners that hang around this forum if so post a reply.

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http://www.efidynotuning.com/ford/

anyone that disables a perfectly good MAF to tune in full time SD mode only is a "tooner", and not an engine calibrator. Unless you're making stupid boost, the GM MAFs have plenty of range, so no need to disable it.

Tune it as you would a Ford, get the MAF right first (under steady state conditions). Then if you want the tune perfect, go back and rework the VE tables in SD mode (temporarily disable the MAF) so the transitions are perfect. If you're skilled at tuning Fords, you'll find the GM stuff easy to tune.

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www.wolfperformance.com
Canadian TwEECer dealer

Hello Ed!!!

Yes, what he said, just drop the high rpm disable of the MAF (usually at 4000) to something below idle and tune as a Ford.

I do all the new GMs like this, FI or not.

What do you plan to use for tuning?

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MDS
http://www.tudyno.com
My car: http://www.youtube.com/watch?v=e_Ftc82mT7I

hpt mpvi pro

good news!

my first chance at speed density!

the new user here tbirdsc posted a thread about speed density tuning, since im trying to get into it i sent him a PM telling him that we can swap knowledge and perhaps help each other out.

well i gave him my cell number in the pm and he called me today, I didn't notice when he called because i was working but when I looked in my call log and called back I realized he had a local number!!!!

what is the chances of that? he actually lives right down the street from where i work, set for tomorrow hopefully i'll get my chance at speed density, should be fun.

anyway, any tips for speed density tuning? im searching for info but any tips would be helpful. I looked up the bin and it looks pretty simple, ve tables with pressure vs load, im guessing just adjusting those values will deliever more fuel and what not, seems pretty simple from a logic standpoint. Guess we'll find out tomorrow.

wish me luck

I think the HPT forum is your friend, good info there (some bad too, specially some PE table hackers still)

There are some tips on how to disable the MAF so you could tune VE and all.

But have you really seen the VE tables in some of the GenIV cars? (The ones with virtual VE)

Do a MAF only tune better first and then taste the waters of virtual VE.

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MDS
http://www.tudyno.com
My car: http://www.youtube.com/watch?v=e_Ftc82mT7I

will do lito thanks for the heads up

attempted to adjust some things on the speed density ecu today and couldn't get anywhere with it

88 thunderbird with DE ecu suppose to be the LUXO strategy but it doesn't want to communicate with it using the tweecer

checked out the def and theres no qhorse support in the def so that needs to be addressed

pulled the stock binary from the ecu using the tweecer though got the original DE bin file if anyone wants it

You'll find the GM stuff with HPT is extremely simple and histograms help TONS.... As was mentioned dial in the MAF first and then disable it and use the fuel trims/wide band to fill in the VE table and you'll have 80% of it. I also use the knock sensors as a tuning aid to dial in the spark tables.

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STLMustangs
Dealer and Tuning Support for DiabloSport,TwEECer, Moates, SCT & HPTuners

Don't forget to turn on lean cruise. From what I remember it's turned off by default on the Ls1. It's quite useful on the LS motors. Ah DFCO is another one to play with.

It's going to be interesting to see if you can debunk the Ford "Tooner" opinion that the only thing to do with a SD vehicle is fit an A9L ECU.

Tuning the VE table IS harder than tuning a MAF transfer function, simply because the VE table is the height of a 2 dimensional surface, and the MAF transfer function is the height of a 1 dimensional line. So in the MAF transfer function, and air mass value comes only from a single input voltage, but in the VE table, that same mass value can come from many N/MAP combinations.

I've never tuned a GM car, but I have done a SD truck. I imagine the histograms BobCat refers to are the same kind of tools I had to fabricate with spreadsheets. So here's some random tips from me. The pros are welcome to comment on the principles involved, but don't bother telling us all that it's better to use an HPT or other commercial program. I'm sure it is if you want to pay for it.

A Every cell you adjust adjusts the height of a surface. That surface should be smooth and not rippled as you
cross it in any direction.

B Every time I made a correction I would plot the VE table in a spreadsheet as a set of 8 lines (for Ford's
8 MAPOPE levels) versus RPM. These lines should all be smooth, should all be higher in the middle than
at the ends, ideally don't touch each other, although they sometimes do, and, (I believe) should NOT cross
each other.

C The corrections come from the same places as you get them when MAF tuning, basically measured WB
LAMBDA over commanded Lambda.

D However the Ford SD bins may have significant fuel contributions thatare not counted in the commanded
Lambda that you log. These are usually transient compensations, AE fuel and manifold wetting. If you have
a load absorbing dyno and are careful in finding steady state, these may not bother you. It was impractical
to put my 14,000# vehicle on a dyno (and any hill is a dyno :-)) and for me steady state turned out to be
an impossible thing to find. MY VE corrections never homed in on a solution, and this was the problem.

I'd suggest at least logging AE and EFTR fuel and computing them as a percentage of base fuel (the fuel
that does go to commanded Lambda) and discarding any sample in which they are too high. I ended up both
doing that and also removing their contributions to fueling.

E If you have a load absorbing dyno, you'll probably be able to use the VE table cells as steady state points
if you're careful. If you're tuning on the street, that will be impractical, and in that case, you'll need to invent
some method of combining the samples from the log that you do have, into contributors to a particular cell.

I used my spreadsheet to divide my log up into rpm bands and MAPOPE bands around the cells and averaged.
Probably the pro tools have their way of dealing with this. I'm sure it's better if you have it.

F If you're tuning an automatic transmission, with the converter unlocking, there will be places in the table that
can't be reached, so don't waste time looking for them. (these are the high load, low rpm cells)

Even with a manual, there will be cells that you won't reach, or won't stay in for long, probably the high RPM,
low load ones.

G When you get to enabling KAMs, remember that the VE table and the KAM table may have different
Y axis functions (if you decide to map the KAM corrections back in to the VE table.

Your DE.bin isn't the same strategy as a DA1.bin (which I gather is a LUX0 bin) It's similar, so many of the payload
addresses are the same, but not all. The VE table IS at the same address, so making changes to it should have made a difference. Have fun with it.

hey mpaton.. i posted this thread 2 years ago , i agree with you, speed density definitely has its place, in some aspects its much more practical than mass air, thats why i deemed it necessary to include speed density in the d.e.c.

i ended up loading a da1 cal on that vehicle, still had a problem with the map sensor reading full vac under boost, the owner had a spare A9L laying around so that went in as the only changes needed was adding a couple pins for the maf, that lasted a few weeks until he seen fit to drop a cbaza ecu in it :) in which its still rocketing down the straightaways terrorizing the streets with to this day

i really appreciate your tips though, i just thought of an idea that i'll implement when i really get into full swing beta testing

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http://www.efidynotuning.com/ford/