Seventh Gear!

[Big Dave]

Finally got around to putting my money where my mouth is, and installed a Gear Vendors overdrive on the Red Baron. Just did a test drive and still have a couple of small installation issues to work out, but this is gonna be sweet.

1125 RPM @ 60 MPH EGT: 475 degrees pre-turbo.

I also did some other work - chamfered my swollen brake pads, set camber and toe-in dead on zero, and I'm trimming back the air dam, so I'll need a month to re-baseline the truck's MPG. Then I'll get a valid 1500 mile test on the MPG.

[Frank Lee]

Is the Baron ever heavily loaded/pulling?

[Big Dave]

Its loaded or pulling a trailer about as much as most pickups.

I'll do some loaded tests with this setup.

I saw that Ford had some folks test their new Super Duties with a 1,000 load. 25 bags of anthracite should nicely mimic that one.

[bgd73]

what is final drive?

60 @ 1150..nice.

[Frank Lee]

I asked because once upon a time I considered the GV OD too. I came to the conclusion that one would have to put on one hella lot of miles for it to pay off- as you well know they aren't cheap. And I thought unless the truck is really, really heavily loaded (of course this is from a flatlander's perspective) there is no need for more gears; just a desire for a taller cruise gear. AND I thought since the goal is efficiency, adding another set of gear meshes, shafts, bearings, oil sump, weight, and whatnot to the drivetrain actually decreases the drivetrain efficiency as far as friction losses go, but ODs show an fe gain due to the tall ratios... therefore, for the lightly loaded flatlander truck the best thing to do would be gear up with tall diff gears and/or tall tires.

Actually the notion that more gears i.e. 5, 6, 7, and ? speed transmissions increase efficiency is kind of lost on me... because even with a 5 speed stick, with my mostly lightly loaded driving conditions I end up skip-shifting almost all the time anyway... well if I'm ignoring 2 gears and treating the car like a 3 speed, I think an actual 3 speed trans would be more efficient because there would be two fewer gear meshes, and gear meshes take power even when they are transmitting none.

P.S. Back in the '80s Ford offered a 4 speed m/t in their High Efficiency version of the Tempo/Topaz, NOT the 5 speed...

[Christ]

In some cases, it's a bad idea to set toe-in to 0 on an idle truck because of "scrub angles" of the tires.

Not saying this is the case with your truck, but the proper way to dial in the toe for the least drag at a given speed would be to measure the average suspension height at that speed, and set it so that suspension travel and scrub angle sets the tire to 0 toe at the speed you want.

IE if you hold 75, figure out where your suspension is on average at 75 on a flat, smooth, level road (yeah, right), and determine 0 toe for that suspension load, and then (I have no idea how to do this part) calculate the angular load against the tires for that speed and set the toe inward enough to combat it at that speed.

However: This may not apply to your truck. I don't know if toe angles are changed with I-beam front suspension and a non-R/P steering setup. I don't think they are. Scrub angle still applies, though, for the record.

[Big Dave]

Actually zero is within the specified range for both toe-in and camber, so that is not all that radical a setting.

The idea of more speeds is to eventually get the engine RPM at a given road speed to a minimum without a big jolt in engine speeds.

Low engine speed at a given riad speed has long been effective for improving MPG because it minimizes engine frictional HP. This loss is protional to engine speed below 2000 RPM in the T444 and slightly hyperbolic above.

This mod is pricey, but in my view this truck is now a form of hot-rod and not just some weak "duct tape and coroplast" dabbling.

If I don't mess up my air dam, I expect 30 MPG. There is no EPA mileage for this truck but most guys report 14-16 MPG, so I'll have the average effectively doubled.

[RobertSmalls]

Originally Posted by Big Dave

This mod is pricey, but in my view this truck is now a form of hot-rod and not just some weak "duct tape and coroplast" dabbling.

I'm trying to get to that stage myself.



Btw, the Ford Fusion hybrid has no reverse gear, just electric reverse.

I can't remember the last time I used 4th gear on my car. When I'm PHEV'ing, I skip 2nd as well. It feels like I have enough torque to do a clutchless 3rd gear launch, if I had the right software, which would give me a 3-5 shift.

Yup, I could picture a really efficient car with a two speed tranny and no reverse gear.

[Frank Lee]

Originally Posted by Big Dave

The idea of more speeds is to eventually get the engine RPM at a given road speed to a minimum without a big jolt in engine speeds.

But you want to get in top gear a.s.a.p. Less shifting = top gear sooner.

Heavy loads + uphills = jolts.

Empty + flat = not so much.

[slowmover]

This mod is pricey, but in my view this truck is now a form of hot-rod and not just some weak "duct tape and coroplast" dabbling.


Yup . . braggin' rights ain't cheap. But that GV would sell overnight on Ebay, so it ain't much of a risk.

I'm all the time reaching for mystery seventh on the occasions I get past 60 mph entering the highway.

It would be a heckuva lot of fun on one of these light duty trucks to have a 10-speed that didn't weigh as much as the engine . . perfect gear choice at every posted speed.

So, even though this thing has a motor stolen from the special ed short bus . . we're looking forward to how it works out.

.