Engine Mods for the V10 Ford what have you done

[E350]

This is why I love this forum and am a supporter of it. Quite frankly, vans are the redheaded stepchildren of the other forums and I rarely get the van-specific information from them that I get here:

Originally Posted by carringb

The V10 probably could manage with 3.55 gears (with the 4R100) or maybe a little taller with the TorqueShift. But once you start increasing horsepower requirements (4x4, high roof, bigger tires etc) than the taller gearing may be a hindrance to good fuel economy, not a benefit, as lower RPM = less HP and that could end up just putting you in a lower transmission gear.

Also, if you are running too tall gears with your 4R100 you will spend more time with the torque-converter unlocked, which is what causes early death in that transmission. Excellent info! I am just learning about T.C. lockup and I planned on adding either a light or a gauge to indicate when the torque converter is locked.

There's probably good reasons why Ford gives much higher rating for lower gears, and doesn't even offer taller gears in the vans. The pickups only got taller gears when they got the 6-speed with the deep low gears. The V10 with 3.73 gears is only rated for 15,000 GCWR. It jumps to 18,500 with 4.10 and 22,000 with 4.56 gears. Likewise going from 3.55 to 4.10 gears gains an extra 4,000 pounds with the diesels. Going with gears taller than Ford offers could have some adverse affects you may not have considered. Now we are coming full circle, back to how can we put a 6-speed in our vans. Based on what mgmetalworks has said about the PCM/TCM computer control hurdles, it seems that the ZF-6 is the easiest route to go. And if I ever go there, it will only be when my 4R100 fails.

Thanks carringb, I cannot wait to get back into repair and mod mode with the van again.

[carringb]

I actually thought about the ZF6 also, however it has the same OD ratio as the 4R100. Nail in the coffin was driving through Portland into Vancouver in a Ram 2500/6-speed pulling the big car hauler, during rush hour on a Friday. I never disliked M/Ts until that afternoon. 2-hours of clutch-in and out and 1st and 2nd was enough for me. And you can't just crawl along in a low gear, because all the small cars seize onto that gap and jump right in.

BTW - I have the Banks TransCommand on my transmission, and that helps immensely with the T/C lockup strategy. Its extremely rare its unlocked now. It locks midway though 3rd gear during normal driving, and under heavy load will lock up mid-way through 1st gear. It didn't quite do what I wanted for shifting however, so I added the Predator tuner for that. Turns out they play well together.

I would like to add a T/C switch, but primarily for down-hill engine braking, along with a 6.0-PSD fan clutch. That should be enough to keep one gear higher while descending, while also giving better A/C performance in stop and go traffic on hot days.

[MrWicked]

Originally Posted by carringb

That thing looks great! 8k really isn't too bad. You could pull two of those and still be less than my Weekend Warrior weighed when loaded up.

I'm still shopping for my next one. I went in to order an Attitude on Sunday but walked out when the dealer started playing dealer games with the price (I guess having every option checked off and essentially cash in hand.... they thought they would try to wring me out for some extra...). Fast forward to today and I talked to a former Eclipse dealer, and learned why they no longer carry them. Let's just say it has raised some concerns, so I'm starting to look back into living-quarter car-haulers.

Thanks

i got a good deal on this trailer but needs alot of work...
we wil be adding alot of goodies or around a 1000 pounds before we start to put the race toys inside...
first i need to get it painted.... then we will start the up grades...

[Chance]

Originally Posted by E350

The Bible written by the 7.3L mileage god:

http://powerstrokenation.com/forums/sho ... p?t=119745

MPG = RPM in the 7.3L

"Gearing does not affect road load, but reduces the engine frictional HP and accessory parasitic load at a given road speed. Engine frictional HP is the power necessary to make the engine turn without making any net power to the flywheel. It is somewhat of a misnomer – most engine bearings are plain bearings which have very low mechanical friction. Most of this HP goes to pumping air through the engine. For International and Cummins engines (and most engines in this class, I’d bet) engine frictional HP goes up proportionally with RPM between 1000 and 2000 RPM and increases with the square of RPM above 2000. Looking at engine frictional HP curves I’ve seen for the International 444 engine, my engine need 12 HP less to make itself run at 1325 RPM than at 2000 RPM. That explains the 3.0 MPG improvement I got over a 3.73 R&P.

Gearing is tough to do. This involves changing the ring-and-pinion set to a numerically lower ratio. Most guys go up in ratio to compensate for big tires but lower ratio R&P sets are rare. I have a 3.08 gear set, but I don’t think they are commercially available anymore. 3.55s can be had, though. I’d expect a 1.0 MPG improvement for a truck that had 3.73s (the most common) and somewhere between 1.5 and 2.5 for a truck with 4.10s."

I am convinced that my higher rpms are inversely correlated to my lower mpgs due to gearing change.

Other things of course, conversion to 4x4, large top causing wind resistance. But I have driven on the flats slowly, and seen no significant mileage change.

Injectors could have also been slowly wearing out (or plugging up with delamination goo from fuel tank) which would result in poor atomization which could have a detrimental affect on mpg.

Only time and money for repair will tell.

I am intrigued by the V10. Does it have enough low end torque to push 3.55 or 3.08 gearing, thereby reducing rpms, and increasing mpg?

I suggest you stop analyzing this issue from the RPM side of the equation because it mostly addresses engine efficiency indirectly, and unfortunately that leads to a lot of confusion. Lowering RPMs may help, but may not. It's not as simple as assuming that lower RPMs will increase MPGs; although often it does, particularly with oversized engines and/or light loads.

[JWA]

Originally Posted by Chance

I suggest you stop analyzing this issue from the RPM side of the equation because it mostly addresses engine efficiency indirectly, and unfortunately that leads to a lot of confusion. Lowering RPMs may help, but may not. It's not as simple as assuming that lower RPMs will increase MPGs; although often it does, particularly with oversized engines and/or light loads.

I'm prone to agree here, maybe add something or take this mileage issue one step further: stop worrying about squeezing every last 1/100th gallon out of a rig intended to pull and handle large loads. Trying to compromise their intended duty by adding a daily driver component seems to begin the chase of spending mega-bux for scant tiny MPG improvements.

I completely get saving money---but at what cost in actual dollars or aggravation?

[Chance]

Originally Posted by JWA

......cut......

I completely get saving money---but at what cost in actual dollars or aggravation?

Agree saving money is important but not when it cost more than what it saves. As I mentioned in another thread, I looked at saving gas by replacing 6.8L V10 with 4.6L V8 that could save as much as 17 to 20 percent on fuel but I would not recover the cost for many many years at the rate I drive today. And that didn't even count the personal time I'd invest in the project. It's just not worth it.


By the way, regarding my point above that focusing on RPMs can be misleading, below are BSFC (brake specific fuel consumption) curves for two Ford engines that clearly show that efficiency doesn't vary all that much over wide RPM ranges. What sometimes makes engines run more efficient with taller gearing is not the lower RPMs themselves but the fact that it makes the engine run at higher torque, which "OFTEN" (but not always) improves engine efficiency.

Both RPMs and torque are important so looking at a BSFC engine map is best, but if we can only consider one variable, percent torque engine is working at is far more revealing than RPMs alone.

[Chance]

Here is curve for industrial V10

[E350]

Thanks Chance! Although this is a V10 thread, would you mind posting the same graph for the 7.3L Diesel?

[Chance]

Originally Posted by E350

Thanks Chance! Although this is a V10 thread, would you mind posting the same graph for the 7.3L Diesel?

Sorry E350, I have not seen a BSFC map for the 7.3L diesel. The simpler curves above are for Ford industrial engines where fuel consumption has to be disclosed or they wouldn't sell many engines.

For what it's worth, diesel and gasoline engines have fuel consumption maps that look similar in appearance but with different values. Like gasoline engines you don't want to run diesels at too low a torque, but also not too high either if you want to optimize fuel economy.

The practical limitation with optimizing gearing and thus engine speed and torque for fuel economy is that it would leave so little engine-torque reserve that the vehicle would need to downshift to climb even a minor hill or to accelerate to pass. And drivers generally don't like that even if it saves a little fuel.

[E350]

Dang Chance! I am pretty much only concerned with maximizing fuel economy on the flats heading North East across NV and Idaho or to UT or South towards L.A. where I really miss my overdrive and lower rpm. It is my understanding with stock AD split shot injectors and even with AC 160s single shot injectors with stock nozzles that the injection event (Pulse Width) is pretty long, resulting in lots of torque at low rpm which is what Dave Whtimer takes (and I would like to take) advantage of. BTW larger nozzle injectors dump more fuel into the cylinder with a shorter PW thereby increasing HP at higher rpms, of which I have no interest. I bought a diesel for low end torque (and because it has more energy per gallon and it was the cheapest of all fuels at the time!), and in my opinion (and as you mentioned) I am not using it since I am generally not towing. So, other than the other things which you guys have mentioned TC lockup etc. I think I really do want to focus on how tall a gearing I can push with the least rpm and still stay somewhat in my torque band. I only wish I could see a graph with the 7.3L torque band, rpm and HP. Thanks as always for your input.