Air Temp and WOT PE tuning question.. with 7730 and $8D
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 33
Likes: 0
From: Connecticut
Car: 1991 Corvette
Engine: 406 NA Solid Rlr, Miniram Style Int
Transmission: 6 Speed
Axle/Gears: 3.73
Air Temp and WOT PE tuning question.. with 7730 and $8D
Do any of PE tables use the lookup from the MAT tables in its calculation for final PE or do they effect outcome in any way?? I know there is a function of AFR vs Coolant and AFR vs RPM, but wondered if final PE uses references from air temp in any way. I believe I read here PE calculation uses last VE reference just before entering final PE. I want to make sure somehow ambient air temps are compensated somehow.
Thank you in advance for any tips
Thank you in advance for any tips
Moderator
iTrader: (1)
Joined: Mar 2002
Posts: 18,432
Likes: 234
From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: Air Temp and WOT PE tuning question.. with 7730 and $8D
The MAT is used in the fuel calculations when calculating the mass of air that enters the cylinder. See the Tuning Guide Book sticky, chapter 5, '7730 ECM. There are a couple of threads on the use of the MAT tables. They will answer some of your questions.
RBob.
RBob.
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 33
Likes: 0
From: Connecticut
Car: 1991 Corvette
Engine: 406 NA Solid Rlr, Miniram Style Int
Transmission: 6 Speed
Axle/Gears: 3.73
Re: Air Temp and WOT PE tuning question.. with 7730 and $8D
Hello Rbob,
I have read through those stickies and I have only seen how the MAT tables effect the fuel calculations during normal operation, but I didn't see reference, in particular, to the PE calculation. If the BLM's get locked out to 128 in PE, does it look at MAT table values?? Perhaps seeing the actual calulation for PE and how the MAT table is in the formula would make some more sense to me..
Thanks
Sal
Thanks
I have read through those stickies and I have only seen how the MAT tables effect the fuel calculations during normal operation, but I didn't see reference, in particular, to the PE calculation. If the BLM's get locked out to 128 in PE, does it look at MAT table values?? Perhaps seeing the actual calulation for PE and how the MAT table is in the formula would make some more sense to me..
Thanks
Sal
Thanks
Moderator
iTrader: (1)
Joined: Mar 2002
Posts: 18,432
Likes: 234
From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: Air Temp and WOT PE tuning question.. with 7730 and $8D
The MAT tables are still in affect when in PE mode. There are only two changes (basically) when the ECM switches from closed, or even open loop into PE mode.
The commanded AFR is changed, which directly affects the injector PW. And the BLM value is used if it is at or greater then 128.
Even through the closed loop flag remains set in PE mode, it isn't really in closed loop. The INT is locked at 128, and the proportional gains are zeroed.
RBob.
The commanded AFR is changed, which directly affects the injector PW. And the BLM value is used if it is at or greater then 128.
Even through the closed loop flag remains set in PE mode, it isn't really in closed loop. The INT is locked at 128, and the proportional gains are zeroed.
RBob.
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 33
Likes: 0
From: Connecticut
Car: 1991 Corvette
Engine: 406 NA Solid Rlr, Miniram Style Int
Transmission: 6 Speed
Axle/Gears: 3.73
Re: Air Temp and WOT PE tuning question.. with 7730 and $8D
I'm guessing that explains why my car was leaner at WOT on a hot day rather than richer, because the MAT table was leaning mixture out. I've got some tuning there to do now. Is there anyone that has a MAT table worked out for a naturally aspirated miniram car? I saw two tables in the tuning section chapter 5 for a relocated MAT, one was Glenn's table for a traditional TPI car and the other was for supercharged miniram car from Ultm8Z.
Thanks again for your help,
Sal
Thanks again for your help,
Sal
Thread
Thread Starter
Forum
Replies
Last Post
mdtoren
Tech / General Engine
0
Aug 16, 2015 05:45 PM
