I have read all of the "how to" write ups and everyone says to unplug the MAF sensor, reset your fuel trims, then drive to data log them as the PCM relearns the trims. I know this is Speed Density tuning, but what do you do after your fuel trims are all in line? Do you reconnect the MAF sensor and reenable it after you SD tune the car?

What happens if you leave the MAF connected, reset your fuel trims, and then data log the trims. Is it wrong to leave the MAF connected while mapping the fuel trims and adjusting them in the VE table?

I live in North Louisiana and the humidity is always 80% and higher year round, but the teperature can change 20 degrees overnight. Is SD tuning for me and would I have to do a weekly check to ensure the LTFTs were still inline.

Also, I don't have any add ons to my HPT package. (i.e. 1 bar speed density package) Is tuning SD without the 1 bar possible or is that just a useful tool to make SD tuning easier.

Mike

 

what mods do you have?

 

most tune the VE table then put it back into closed loop w/ maf...you should only have to tune your VE table once in that case.

 

99 TA

LS6 intake with 28 PSI injectors (upgraded to 01-02 specs)
LT Headers
224/227 114 LSA cam - Stock heads
True duals with H pipe dumped
Underdrive pulley
etc...

 

Anyone give me more specific information?

 

reconnect the maf so you get readings but keep it failed...this will basically give you the amount of error the maf is introducing into the system...from this you would tune your maf table not ve...this comes nearing the end.


yes its wrong to leave your maf connected...basically your trying to use & "fix" as many internal problems as possible...by leaving your maf in play its going to adjust for your trims as it is...you want to get your VE dialed in then your maf.


If you plan on leaving it in SD with no wideband then no its not for you...putting it into SD mode to get your VE table inline, dialing in your maf & then putting it back into closed loop maf would be what most do as I stated before.

 

you can set your MAF fail frequency to 0 and that puts the car into SD mode...
then tune your VE....
then change your MAF fail frequency back to its stock #'s
and do the same tuning process for the MAF(several methods to do this...Red supra's sheet...my sheet...wideband....)

 

you don't need to unplug the MAF... you can set the MAF fail frequency to zero... sometimes it'll set the SES right away other times it'll take a few mins

You do this, tune your VE table (there's a tuning doc in the stickies), then you reenable your MAF (set MAF Fail back to stock value) and you tune your MAF

For SD testing w/out the 1bar option you need to copy your low octane to high octane timing tables (it's explained in the tuning document in the stickies)

 

thats why i usually recommend just unplugging it in addition to...

 

something else to think about...
IF you tune your car in open loop to a wideband...
sometimes...ok...a lot of the time... when you put it back in closed loop..your o2's and your wideband dont exactly match up perfect.....usually because of their location because of longtubes...or because of similar things that relocate the o2...

I'm working on a fix for this...I have been playing around with something(with customers permission) and I have stumbled on to something that seems to work...but I need to develop a few things to make the whole process easier...and maybe need to build an excel sheet for the masses...unless keith or chris(hptuners) can find a PID that I need and include it in the next 2.0 release....er update...er...(I know its not officially released yet....)