I thought the IAT was only sampled at startup and not referenced after that? Am I incorrect?

IAT works all the time, The Baro Reset used to update at crank and at WOT under 3600rpm, other than that I cant think of anything that monitors only once.

Somewhere in my posts I checked IAT against temp and fuel/timing. It had no affect on timing but it did weird things to fuel, wasnt a straight repeatable change in fueling, more like all over the map and not repeatable.

I see... I tried to locate where I got the idea but couldn't. I did find this on LJ's old site...
IAT: intake air temperature. This sensor, which measures the temperature of the air the engine is about to inhale, is located in the elbow that attaches to the throttle body, unless you moved it with an IAT relocation kit. If the MAF is broken, the PCM needs a backup method to measure how much air the engine is inhaling. This backup plan, called Speed Density, uses RPM, MAP, and IAT to estimate air flow. The IAT is also used to control ignition advance. Cold inlet air helps the engine resist detonation (a Bad Thing), so the engine can tolerate a bit more advance. Very hot inlet air is more likely to cause the engine to detonate, so less advance must be run to avoid that destructive detonation.

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Absolutely not. IAT in these cars does not affect timing. I beat it to death and timing did'nt budge, as crazy as that sounds. My setup was an electric seat motor spinning a spare opti, plugged into the wiring harness, a 20psi adjustable regulator hooked up to the MAP sensor, and the fuel injector and fuel pump fuses pulled so I don't fill the motor up with fuel. Then I dipped the IAT sensor into hot and cold water (and hovering between the two for awhile all while adjusting RPM and MAP pressure). Timing was dead on the preset 20 degrees I entered in all cells. Fuel was all over the place though, ramp 1 up would be a certain shape, ramp down would not follow the same path, ramp 2 up would be different, like shifted, then the down ramp shifted, so on except when I 0'd the IAT tables then it was consistent and the same no matter what the IAT temp.. but that's kinda pointless?

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

This thread has be a very good read to say the least.
I have Tuner Cat and I can't find the Baro reset that is required
to do the 2 bar swap. I see the Cat over temp Baro settings but not
the one I need to make this work.

Do I need to update my version of TC?
Are the update free?

Here's my version.

Attachment 9956

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

The Baro uppate RPM is the under the ECM Constant table

According to TC's site the current verisons are:
PCM_EE CY
PCM_EEB CE

Send him an email for updates

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Ok I've got my TC software updated and I'll be ready to do some tuning here shortly.
I have read this thread about a dozen times just to make sure I understand everything.

I seems that for the most part you guys have this 2 bar swap nailed down.
I have a question. can i keep my MAF meter and run the 2 bar setup if I scale the maf values?

It seems to me that it would give a guy one more tool to make drivability a little better.
I know that most of you don't like running a meter.
My goal is about 10 psi of boost on a smooth idle 383 that drives as smooth as stock.

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

The MAF will max out with boost, and fairly early, then your back to SD. So, start from the beginning with SD and you'll be a step ahead. I think the only problem there is with this tune is not the tune, but the limitation to the MAT fuel correction options. You can tune it a small amount, but it's not clear what the settings do.

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Can you run both? I understand the MAF has limits but if you run the 2bar and the MAF
wouldn't that give you one more thing to tune helping the drivability?

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Im not sure, never tried. I put all my energy into getting the base SD tables and TPS accel shot working.

Give it a shot!

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Fair enough, I'll try it to see how it works.
I read where you change the injector size and fixed your lean tip in.
Did you ever find a "table" for the accel pump shot?

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

The only known way to fix lean tip in is to reduce actual injector size.. as discussed in detail below. Then all you need to do is reduce your VE numbers to compensate.

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

just remove the MAF sensor and leave the plug to PCM hanging?
What is the best way to keep it out of the system when trying this tune?

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

I did not unplug my MAF. It seems to be using the VE table exclusively in speed density mode.

Re: 2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
 

Well guys I will try to chime in, as in the previous post I did, I ran a 2bar / MAF tune @ 12 and up to 15 lbs of boost with absolutely no problems, car made 648 RWHP on the pump and 722 RWHP on the good stuff. I believe it may have been Dookie that I mailed to and said I had did 10 years previous what he tried and finally nailed, he asked why I never posted before, and I said because someone will always try to prove you wrong, anyway back to the tuning, Like I said, I ran 2 bar with the maf, disconnected under SD mode and got the fueling spot on, then I plugged the maf back in and started tuning with the PE tables...YES PE and the Maf tables at the upper KPA areas..Results, My A/F was "ALWAYS" at the commanded setting. I would go to a dyno in different towns, different weather and the fueling was always there. I ran this setup for over 10 years. Everyone started bashing me saying PE was just a Hack job, well Hack or not, it worked for me. This is the way I tuned my car, I am not telling anyone to do the same, Good luck to all and keep the LT's Going!!!