Mongo

An EFI system with sequential injection rather than a batch-fire style like the LH does would reduce gas consumption. It may not be a significant amount, but perhaps gain anywhere from 3-5 mpg depending on driving habit and how well it is tuned.

Tony

Manufactures wouldnt trust the general public adjusting their own mixture in a car "on the fly" during cruise...people would be burning holes in cylinders trying to get the most efficient fuel mileage. Besides...most people are too busy texting to mess with a mixture **** and there isn't an app for fuel mixture on the Iphone yet.

The ST'er is the best way we have of doing this.

123quattro

You won't get 3-5 mpg from sequential injection. The improvement is mainly just in driveability. Quite often fuel is shot on a closed intake valve to help with atomization and to not wash down the cylinder wall opposite of the valves. Shooting it just before the valve opens just give the fuel less of a chance to fly around the intake manifold and make less uniform A/F between cylinders.

Lizard928

I have done this a fair amount.

On a car with MSII, I was able to get 35mpg.

I have not calculated what I am getting on my 87 with using the STII. But I have it in forced cat mode, with ignoring the O2 adaption, and the CO Pot disabled too. I run at around 18:1AFR on the freeway at 62mph. As well up to 80MPH too. The LH is not nearly as quick in response time as the MSII with a MAP sensor is. However it is quick enough to compensate. I would also recommend turning up the low throttle increase enrichment slightly.

No issues with the engine when running like this. If you do this yourself (needs Sharktuner, or standalone EFI). Keep pulling fuel until you get a little buck or hesitation. Then add 5 points to that cell.
I havent been adding anymore advance to the brain yet, but that will come with time.
When done correctly it can be very safe, and give excellent increases in economy.
Yes the NOx do go up substantially when you do this. And it is a trade off. However when you look at the ratio of people who do this, the increase is so little it will have no real effect.

Roy928tt

What price is LPG (propane) in the US ? Here it is pegged at 1/2 the price of standard unleaded. Not bad for a high octane low pollutant fuel.

Just a thought.

It is what my twin turbo '79 runs on.

Cheers Roy

Jaeger

You only need a 5% hydrogen to 100% fuel ratio to get the engine to burn cleaner and convert more of the gas burn into kinetic energy instead of heat energy.

There is also a fairly simple device that allows you to change the incoming O2 sensor signal to something that would make the engine run leaner with a simple flip of the power switch, called an EFIE.

dr bob

1458 in a fancy potted package?

Pulease!

delisedesign

so the fuel mixture solution seems a bit complicated, to me at least.......what about cylinder shutoff?....GM uses it on their trucks and Chrysler has it on the 300....when you are running above 50 and there isnt strain on the engine, four shut off and then seamlessly turn back on when power is needed
I have been told that in 'limp home mode' when youre running on four its dangerous because there is still fuel being dumped in the chamber but what if there was a program that could safely cut off the firing and fuel by switch....i would think at highways cruising speeds on four cylinders we could see close to 28/30....i already get 24 on a good day
theres probably some blatantly obvious reason it wouldnt work, but thought id throw it out there

dr bob

The later S4+ cars (from 1989) have a protection function that shuts off fuel to four cylinders when it detects an ignition failure. The uneven firing generates torque pulses that the factory suspects will cause torque tube shaft failure. Pictures have been posted of shafts broken just behind the front splines, where the shaft necks down slightly.

With the fuel shut off to four cylinders, the engine is still pumping air. Friction stays the same. For sure there are wierd uneven heating issues with the block. The existing oxy sensor feedback system would get very confused with the flood of air passing through in 4-cyl mode. Lots to consider!

I'd rather have an oevrdrive unit that would let the engine spin at <1200 RPM's at 70 MPH low-load cruise, but keep all eight firing.

123quattro

Keep in mind those engines are all pushrod. Cylinder deactivation works by collapsing 4 sets of hydraulic lifters. It kills a pair of cylinders on each side of the engine during the combustion cycle. Mixture is combusted, but not exhausted. The burned charge acts like an air spring until those cylinders are brought back on. It can't be done on an engine that didn't have the cylinder heads designed for it and ETC. Well, I suppose it could be done, but it would cost more than what Sterling has in his whole car.

dprantl

Yes yes, like a Corvette transmission with 6 gears where that 6th gear is super long.

https://rennlist.com/forums/8398969-post64.html

Dan
'91 928GT S/C 475hp/460lb.ft

jthwan22

If it is so easy why won't the car companies do it. Hey I got some magnetic fuel saver to sell you. Just add to your gas line and save 25% instead of just 3-5% messing around with computer and wide band O2 sensor.

http://www.wholly-water.com/magnetiz...fuel.saver.htm

Good review on what is on the market
http://www.popularmechanics.com/cars...ileage/1802932

Tony

Next they will be putting nitrogen in gas to make an engine run cleaner and get better milegae...uh...oh wait a sec.

RKD in OKC

How about adding a low load switch that turns off half the injectors ala Cadillac NorthStar?

dprantl

If you have a dislike for your torque tube shaft, then it's just fine. Plus, as has been mentioned before, those cylinders will still be pumping air.

Dan
'91 928GT S/C 475hp/460lb.ft