Running a 165 ECM along side a 7427 PCM

[Fast355]

Manufacturers are not utilizing computers to deliver the best fuel mileage possible. They are using them to meet the emissions requirements for the length of the federally mandated emissions law requirements and warranties of those systems. It really surprises me that a modern drive by wire vehicle goes full throttle at all now. 15-20 years ago the EPA was talking about closing the WOT emissons loophole thus OEMs would be using the drive by wire to decrease engine load to a point that the system would never use wide open throttle enrichment, thus always operating at a stoichiometric air/fuel ratio for cleaner emissions. I feel like modern controllers are calibrated first and foremost for emissions and warranty requirements, secondary to that for CAFE fuel economy, with drivability and power a distant third and fourth to the first two requirements.

[steveo]

'good enough'

that's the only reason one should use an antique ECM

or because you're poor like me, or like a challenge

if you desire real control, upgrade

the 1980s and early 1990s ecms were a dark era in fuel injection

tuning mid 90s and up ecms is a very different experience

im not saying you can't make the car just fine with this dual ecm plan, in fact its something i might do if i had the parts laying around, it's just that it's really not optimal for what you're doing and your goals

[tayto]

have you spent the last 20 years playing with your current ECU and tuning it? are you planning on tuning this yourself? do you have a datalog cable, chip burner, emulator, etc? you are setting yourself up for heartache/failure if you think your gonna tune this thing solo. thats why I mentioned an LS PCM on gmt400.com so you can at least get someone local to help tune.

[dave w]

This thread has some interesting information and debates.

I often wonder if the debate about which is easier to tune 1227165 (MAF) vs. 1227730 (Speed Density) is factor for wanting to use the 1227165?

Back in time, before TunerPro RT, the debate winner was for MAF. Fast forward to now, with Tuner Pro RT, the Speed Density is the clear winner of the 1227165 vs. 1227730 which is easier to tune debate.

The internet is filled with information about how MAF is easier to tune than Speed Density. It's interesting to point out, NONE of the MAF supporters mentioned or even referenced the tuning software used for tuning the MAF system.

[Fast355]

This thread has some interesting information and debates.

I often wonder if the debate about which is easier to tune 1227165 (MAF) vs. 1227730 (Speed Density) is factor for wanting to use the 1227165?

Back in time, before TunerPro RT, the debate winner was for MAF. Fast forward to now, with Tuner Pro RT, the Speed Density is the clear winner of the 1227165 vs. 1227730 which is easier to tune debate.

The internet is filled with information about how MAF is easier to tune than Speed Density. It's interesting to point out, NONE of the MAF supporters mentioned or even referenced the tuning software used for tuning the MAF system.

The 165 can run $12P MAP code as well but that is code developed off the Australian Holden 308 V8 application 808 ECM which shares its back bones so to speak with the 165. I find speed density much more accurate than those early MAF setups.

[steveo]

yeah definitely. keep in mind while GM was doing their early MAF systems, the Japanese were still using vane airflow meters in a lot of their cars. for their time they were very advanced. the history of fuel injection is a long and crazy one. participating in it on a running vehicle is like playing nintendo video games on a tube tv while the rest of the world has an xbox

[steveo]

.... of course i still play nintendo games and have never seen an x box. so if you want to play with old car computers, you are in good company. but lets not live a lie that some antique lean cruise routine is going to out-do a modern ECM somehow

[Fast355]

.... of course i still play nintendo games and have never seen an x box. so if you want to play with old car computers, you are in good company. but lets not live a lie that some antique lean cruise routine is going to out-do a modern ECM somehow

Agreed, especially considering the modern PCM also has an even better version of the lean cruise. With 8 coil packs there is more spark energy available to more effectively fire the leaner mixture as well. Could easily run 0.060" gapped plugs and have all the spark energy needed for that lower compression engine.

[Racprops]

Well, you've just arrived at the heart of the issue. The 165 was "good enough" even though vehicles with a more recent design were getting a better ecm. OEM choices are based on economy and profit. That's what business is. But you're in a different space.

Think of it this way... the 5.7 / 350 was "good enough" until the LS engine was introduced. But you're using a 383 instead. Why? And if you're using a better version of the factory engine what is stopping you from using a better version of the factory ecm? The 7427 has more features and more tunable tables. The LS pcm has more tables and features than the 7427 and it has a faster processor.

If you want to run dual pcm's, follow the instructions in the pdf previously posted.

I am subject to a lot of bad reports of engine failures with the newer engines and car, seem the newer they become the faster and more costly repairs.

Lots of reports of major problems with every transmission from the Ford 5R55s on up.

I know a SBC can take beating and keep on Ticking, and the same for a 4L80...and my Doug Nash Dual Range Overdrive. I CAN tow in the 4L80 in 3rd and in the DN Overdrive so I will be in 3rd overdrive.

With the newer many gears you really need to be in the 1:1 gear to tow.

So as my 93 G20 Van came with a SBC I want as close to a 400 I could get, so a383, and as I wanted torque a longer stroke gives that.

So what can a newer super PCM do better in my set up??

The 165 has a adjustable Highway mode, and it fades in and out automatically...need to pass something, just put your foot in it return to cruising speed and it fades back into highway mode. As I may not be the driver on long trips my co drivers need to not blow up my engine is we hit a hill, I NEED the system to be automatic.

I have seen some grade that snick up on you...and that might harm a manual lean burn.

So two questions how would one kick a system out of Closed Loop??

And what PDF?? the one where your running a carb and using the PCM as a TCM??

Rich

[Racprops]

Agreed, especially considering the modern PCM also has an even better version of the lean cruise. With 8 coil packs there is more spark energy available to more effectively fire the leaner mixture as well. Could easily run 0.060" gapped plugs and have all the spark energy needed for that lower compression engine.

Or I can add a MSD coil....or captaincy discharge system and do Multisparks for a longer duration.

The main advantage to all the newer stuff it it might last longer...and keep the smog better controlled, almost all these improvments ina STOCK car is to keep smog control, after all why the hell are not getting 40 to 70MPG??

Rich

[dave w]

Often the best plan for a project is low cost and simplicity. How much budget combined with technical skills. Often low cost and simplicity is a tug-of-war of compromises. OBD1 vs. OBD2 is a huge factor low cost and simplicity. If it was my 93 Custom Van I would likely keep the OBD1 EFI with some low cost modifications. There is a huge gap between planning a project and getting many miles of smiles. First comes the miles of smiles, then get more smiles per gallon.

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