That would easily work as well. I have done that with both TPI and the old Edelbrock TBI to MPFI intake setup. The old MAFs are junk in my experience. The 7427 is absolutely capable of open loop psuedo highway mode and it works well.Originally Posted by steveo
I have also run both the TPI and a dual plane MPFI manifold. Under ~2,500 rpm the dual plane mpfi manifold eats the TPIs lunch in torque production.
Last edited by Fast355; 1 Week Ago at 02:58 AM.
on rigs like my big heavy jeep (no highway lean cruise) i just run open loop super lean with lots of timing in cruise range. great economy. just gotta read your plugs to see if you went too far and your combustion chamber temp is too high. no need for a special program for that
Well interesting ideas, running open loop..how?? Cut the O2 sensor?? tell me more.
I know that these lean burn cruse do not tell how lean, I have tested a 2000 Ford 4.6 step by step from 14.7 to 18.0 and found its MPG peeked ay16.5. Reading the Air Fuel Ratios.
My set up is a low torque 383 running in a second overdrive so at 75MPH it is running a 1500RPMs.
The 165 was good enough for for nearly 10 years in Camaros and Corvettes.
It had a true Highway Mode that will automatically fade into lean curse and fade out as needed.
Plus we are trying to stop the lean cruse from cycling in and out so its duty cycle will be as close to 100% rather that the factory setting around 50%.
So this month I hope to swap out the dead 350 and its 4L60e with my custom 383 and its 4L80e and dual range overdrive.
This dream and project has taken 26 years to do.
Frankly I am afraid to fire it up, and to have to wait until some 500 miles to break in a rebuilt engine, transmission and NOS (New) Dual Range Overdrive to start seeing if this is a great idea and the van gets 25MPG+ or a total waste of my dreams, time and money.
And the frustrating fact that when I started this quest, my ideas were still valuable for a fair number of Vans, trucks and cars might be able to use some of my ideas.
Vans, Trucks and cars have move so far from these systems that only 20+ older Vans, Trucks and cars might be able to use.
So I maybe one of the very few that can benefit from all of this.
As I am compiling the ECM (Engine Control Module) running the fueling systems and a PCM (Power Control Module) to control the transmission systems I am seeing how complex the control systems have become.
The ECM uses ONE O2 sensor, a throttle position sensor, a MAF air flow sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor.
A new car now have: 4 O2 sensors, a crankshaft position sensor, cam shaft position sensors (one per cam) fuel pressure, a throttle position sensor, a MAF air flow sensor, and a MAP sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor, and maybe more:
How many sensors are in a car engine?
There are around 15-30 sensors in a modern car engine if you don’t include the solenoids. You can find over 70 sensors in a modern car if you count every sensor in the whole car.
And ALL this stuff has barely made driving a car any better..not in MPG any way.
ALL this tech and cars still get about the same MPG.
And Trucks, Vans and SUVs still seem to get the same crappy MPG thay got with old carbs and no overdrive.
My 1974/78 Chevy G20 Vans running a 350s with 4 barrel carbs and simple 3 speed transmissions, and the same rear end a 3.43 gear: 14MPG.
My 1993 Chevy G20 Van, now with Fuel Injection, and a 4 speed transmission with a .70 overdrive into a 3.42 rear end gets…wait for it…14MPG…WTF??
Is this a fix?? Is my van PROGRAMED to get poor MPG??? Is this possible??
Well I have TWO Ford Explorers, one a 02 with a 4.0 V6, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.
And a 03 with a 4.6 V8, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.
Both get the about the same reported MPG, with the V6 getting 19MPG and the V8 18MPG at 65MPH.
As I have seen cars get great MPG at around 1500RPMs so I tested both SUVs at 1500MPH which is 50MPH.
And WOW both SUVs showed 28 to 32MPG at 1500RPMs…
But speed up to 60MPH and WTF now they are getting 18MPG…they both lose around 10MPG just going 10MPH faster.
But then things return to a normal loss of 1MPG per each 5MPH faster so they both get 16MPG at 75/80MPH…again WTF.
How odd is this?? My 2000 Grand Marques and 03 Crown Vic with a 4.6 V8 only does the normal loss of 1MPG per each 5MPH faster…so they have a steady loss of MPG with faster speeds.
There is NO drop of 10MPGs at any speed change of any 10MPH.
I believe instead of using the computers to make as much MPG in cars and Trucks, Vans and SUVs especially are using the computers against us.
I hope to show that we can get better MPG.
I rest my case.
Rich
that's where you're dead wrongAnd ALL this stuff has barely made driving a car any better..not in MPG any way.
modern vehicles with variable cam timing controlled by neural networks and precise spark and injection control make vastly more power and achieve incredible efficiency for a given displacement
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.The 165 was good enough for for nearly 10 years in Camaros and Corvettes.
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.
The 165' was also only used for about 3-4 years. 85 had a 1 year only ECM with a seperate maf burn off aka "burnout" module as I like to call it for its ability to commonly fail which then killed the MAFs by baking the sensing wires during a prolonged burnoff session and then in 1990 GM moved on to the far superior speed density 7730 ECM and the underhood 7727 equivalent.
'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
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.
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.
Last edited by Fast355; 1 Week Ago at 06:12 AM.
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
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