Overdrive with a manual

[Captain Ledd]

Kind of a specific to me post, but overall towing with a manual in overdrive info is appreciated. Warning - I'm expecting relatively in depth responses, you know, with reasons and all that.

So I could have sworn there was a wealth of into about towing with manuals and overdrives, maybe that was on the old forums? I searched here and in the transmission forum and couldn't find anything. Also tried plain old Google but all I got was automatic tranny related nonsense.

So a few of the topics in the "other engine swaps" forum have got me thinking yet again on a diesel swap. I researched a ton many, many months ago and decided against it. Now some recent curiosity and newer sources have peaked my interest again.

**Some background info: Actual questions are under the yellow text further down**

This swap would be the more economical one, a 1.9L VW TDI - likely chipped, no other mods - 02/03 and older. Quiet exhaust system (fairly low restriction though), driven responsibly, if anything hopefully easier to pay off by running on biodiesel (including paying taxes and being legal about it which should still be less than $1 a gallon). Chip is rated at 116HP and 195lb/ft of torque. Not exactly stellar, but I'm used to cruising around with the 2.3L so it's quite an increase in torque. I expect a bit of a learning curve with the new torque range (pun?)

Because I was amassing parts for a 4wd swap in the process I'm hesitant to change the overall plan. 2.3L/3.0L M5OD ratios / 4.10 gears / 31" tires. I'm willing to bet the M5OD will hold the torque, also It won't be jammed up against stumps and rocks, I have a built Ranger for wheeling. This Ranger is basically getting 4wd for low-range while backing up and other slow speed maneuvers, and because getting stuck in driveways/parking lots and the ever awesome traffic signal get's old quick. So... this would put me @ (roughly) 2150 RPM @ 60mph - 1970 RPM @ 55 MPH. I know the engine will be okay with this as this is at it's peak torque range and probably a little higher than the actual peak torque RPM, but these numbers are in OD - 4th would be 2720 / 2490 RPM @ comparable speed, which is a little high. It never bothered me before because I'd just leave it in 4th and let it rev a little.

I don't want to kill my new found torque through gearing up, nor then have my overdrive RPMs be ultra low. So depending on the feed back I receive I'm willing to re-do the gear ratios, and/or find a different transmission - though I'd really prefer not to.

I've towed a ton with my Ranger before, more than most ever should (and what many think the 2.3L ever could) so I feel I know my limits. Which happens to be about 4,500lbs or so. - this is the heaviest load the Ranger would be carrying for any moderate distance. Fancy trailer setup, brakes, controller, the whole 9 yards.

I'm confident the bulk of the M5OD will handle the torque (1st-4th), and the OD empty will take it. But I've never actually used 5th gear (OD) while towing anything. There really is no super science to my proposed gear/drivetrain combinations, basically stock equivalent from what I have now, just no letting the engine rev.

SO - what I'm wondering:

How will OD deal with a load for long periods of Interstate?
Are they're any other issues associated with the M5OD's 5th gear aside from a shifter issue? (not going into fifth, seen that one a bunch)
To those who have been around the insides of a M5OD, do you feel the 5th gear is well supported (bearing wise)?
Should I look into a heavy duty bearing retainer plate? (I've looked into T5's - and that is an issue with them) I haven't been into a M5OD yet.
The M5OD-R1/HD is supposedly stronger. Since I need 4wd parts for the back of the tranny, should I seek out one of these and swap over 5th gear parts as well?

*This is a STD. cab, short bed Ranger, so the lightest of all the body styles.

*The Tranny/Gear/Tire combo is only suggested as that it is the equivalent to what I'm currently running - I.E. bone stock. (225/70?R14 - 3.73 ;factory / 31x10.50R15 - 4.10). It's not based on some crazy equation, I just ran the numbers and it appeared to work moderately well with what I have.

*I'm not seeking comment on my choise of gearing and weather or not it will work out, just the strength of the M5OD-R1's 5th. I supplied that as background information that it won't be facing "normal" power. *Don't worry about it Bubba Bob. Just figured I should clarify things for others I'm not actually pissed or anything lol.

*A few edits, maybe clear some things up as to the information i'm seeking.

 

[Bubba Bob]

I cant find a stock 1.9l dyno chart, can you? Should give you a good idea about what gears you wanna run.

 

[Captain Ledd]

Not a stock one for a North American model, no.

The best I've found is this: A PDF on a tuning site. Kind of a mix-match of language, but it appears to have the the slightly older 90HP American based 1.9L engine. And everything is almost exactly where I thought it would be. It shows the graph down at the bottom, has almost the exact same specs to the chip I was looking at. I think the PDF is from a tuning shop they partnered with in Germany - or Germanic language based nation.

http://www.vividracing.com/catalog/productdocs/vag_1_9_tdi_90_115_ps_schalter_en.pdf

The Chip I was interested in:

http://www.upsolute.com/index.php?option=com_upsolute&task=car&id=362&id_marke=6&id_model=1116

(Bora is the European name for Jetta in the U.S.) The 90HP version is the only one sold to North American markets. Weather it's the same as a 90HP European version, I have no idea.

 

[fastpakr]

What's your plan on adapting the TDI engine to the Mazda trans?

 

[Will]

Towing in overdrive won't hurt anything unless you hurt it. If you keep a rule of thumb that if you are unable to accelerate in the gear you are in, you are in too high of a gear. This keeps you from damaging the transmission. Lots of semi tractors have more torque then their transmissions were designed for. They want the horsepower, not the torque, so they follow the rule I stated to make the transmissions live. Nobody is out there going up hills at 1,400rpm where the max torque is developed. They are going up hills at 2,100rpm where the max hp is made, in the proper gear. So if you keep that in mind, you will never put the max torque on your overdrive gear.

 

[Captain Ledd]

What's your plan on adapting the TDI engine to the Mazda trans?

Probably a plate with a spacer between the crank and flywheel. Though I don't currently know how much of a difference there is between the back of a Lima and a 1.9L TDI. I'd like to find a way to use the stock VW starter with the TDI's flywheel and possibly re-drill the TDI flywheel to accept a slightly upgraded Lima pressure plate (and thus Lima clutch disk) - IF it can fit. Similar approach with the pilot bearing, re-machine the flywheel to accept the stock Ranger bearing. Positioning the starter has alot of potential to be an issue, I don't know what kind of aluminum the M5OD is made out of. Hopefully something that can be welded (carefully) so we (me and a professional) can add/subtract metal to get the starter opening to line up and bolt on.

Thats the idea as it sits now, I wouldn't be too surprised if it changed though once I actually get my hands on a TDI and start taking measurements.

Towing in overdrive won't hurt anything unless you hurt it. If you keep a rule of thumb that if you are unable to accelerate in the gear you are in, you are in too high of a gear. This keeps you from damaging the transmission. Lots of semi tractors have more torque then their transmissions were designed for. They want the horsepower, not the torque, so they follow the rule I stated to make the transmissions live. Nobody is out there going up hills at 1,400rpm where the max torque is developed. They are going up hills at 2,100rpm where the max hp is made, in the proper gear. So if you keep that in mind, you will never put the max torque on your overdrive gear.

Yeah, I have no problems with down shifting a bit, I just didn't want to have the poor diesel rattling away at nearly 2,700 RPM. I'm much rather have it just cruise along at 2,000-2,100. I'd be willing to bet that the VW engine makes alot more HP at 2,100 than the Lima does.

Good to know that unless I'm pounding on the OD it should be relatively safe. Just have to keep that in my mind when I'm hitting hillier sections.

 

[Will]

I just drove my skoolie 1,500miles at it's load-governed 2,700rpm to South Carolina and back last week so we could all feed the mosquitos at the beach. The only regret I have is that it wasn't governed to 3,000rpm so I could have gone a few mph faster.

Towing up long grades I kick my overdrive out on my 6.2 to keep the EGTs below 1,000F and at 70mph it's spinning 3,000rpm for a few minutes sometimes. It's not a problem. If you don't downshift you will build up some serious heat. When you downshift the injection pump meters less fuel because the tranny is making more of the torque, and the turbo spins faster and blows the heat out the tailpipe. It's much better for the engine than to keeping making torque with the fuel--something like 70% of the fuel's energy is going right into the cooling system. A truck needs larger radiator hoses and such than a car because of that. In the VW that engine wasn't using much power on average and the little burst of pulling onto the freeway etc was quickly absorbed. But in your Ranger you will be using a higher duty-cycle and of every 3hp you take out of it beyond VW's car installation, you need 7hp more cooling system for it. And if you are planning to tow, you should plan for that. A VW might use 25hp to cruise at 70mph. You might use 50hp on the same road. On a hill, you may use all of the power for several minutes. In the mountains on I-26 between N and S Carolina, and on I-40 into Tennesse there are roads that will seriously kick your cooling systems butt. And even up into Kentucky. There were two places where my 20,000# bus was in 5th at 45mph and the tach pegged and my cooling system gained 25 degrees on the hill--going from 180 to 205. On a really long 7% grade--must have been 10 miles--I was at 37mph. Still to fast for 4th gear so I just let it ride to see what would happen. No way my pickup would have handled that load at that speed even though it has a lot more power. With a 14,000# trailer there's no way it could have blown off all that heat trying to keep up. The bus cooling system was built for it.

Long winded, but something I would think about when adapting a car engine into a truck.

 

[Captain Ledd]

Hmmm. Definitely should look into that, so to hijack my own topic...

Do cooling systems need to be larger for a diesel versus a comparitively sized gasoline engine? I was hoping to run the stock 2.3L radiator to just get it working, then depending on how rediculous the piping turned out to be either get a custom one made, or just replace the stock one (after 200,000 miles the fins are rather... bent). Going bigger I suppose was an option, though once I started getting really high numbers I probably (hopefully lol) would have noticed and gone bigger. Can I assume the 4.0L radiators are larger than the 2.3's? I'm trying to use OEM parts as much as possible. Then if I decide to go another route I can pawn off stock parts instead of one-off special ones, similar idea that if it ever needs replaced my options are much broader and cheaper.

Is there such thing as too large a radiator? If the coolant cools too much I don't want to cause issues with (mostly winter) air-temp coolant hitting the block causing a big enough temperature differential and maybe cause some cracking/warping over time (though I'd hope the engineers would have thought of this). I have no idea if this is an actual issue or not.



I've read alot about the VW engines, one thing that I've noticed and that I've seen in more than one place is that if left idling, the engines do-not-warm-up, at all, ever. Supposedly VW has worked some kind of voodoo and made these engines so thermally efficient that they absolutely have to be driven to warm up and if idled for longer periods after being driven, the temps will begin to fall back really low. Not sure if that is entirely true, or if it's common to all diesels, and by no means me justifying that I don't have to worry about engine temps and cooling, I just thought it was interesting.

Several of my firends have diesels and I rebuilt a D-Max for my engines class so I know a little bit about them, but this will be breaking my diesel cherry so to say (first one owned and driven). I can't say I'm expecting everything to go without a hitch, but I'm reading and planning as much as I can on on the subject and hopefully have at least one backup plan every step of the way. An expensive lesson for my '84 Ranger...

 

[Will]

Yes, a diesel needs a larger size radiator than a gas motor of similar size and power. For instance, with the 140hp 6.2 in light-duty tune in a 1/2 ton you got the heavy duty cooling package, and an oil cooler, where the 230hp 454 had a much smaller radiator, even with the heavy duty cooling package. I learned this recently when I had to replace my radiator. A 6.2 diesel radiator is $450 compared to $200 for a 454 radiator. I have a 454 radiator and was disappointed I couldn't use it when my radiator recently lost the whole bottom row.

All diesels are hell to warm up. It takes very little fuel to idle and drive around and unlike a gas motor, they only inject the fuel they need because there is no A/F ratio to maintain. My bus has a snap-on cover for the grill. My pickup does better because it has a smaller cooling system but it won't warm up sitting. It taked 3-4 miles for the thermostat to open.

You should not be able to have too large of radiator in theory. In theory the thermostat bypasses the radiator until its opening point. So the engine should warm up to the thermostat opening point. I've heard of people experiencing overcooling, but I've never first-hand seen it. I would err on the big side. If the radiator somehow keeps it from warming up I think you could just block off the thing with a cover.

I've never done a diesel swap so I haven't done much thinking or research about it. I think using a radiator from a gas motor twice as powerful as your diesel would be a good bet. Like a 4.0 SOHC radiator. Asking a radiator specialty place is a great idea. I would probably do that. If I ever do a 6.2 swap into my '83 Ranger it will be with a specially built radiator. Not that expensive.

 

[Frank The Tank]

If you idle a diesel too long without engaging (high idle) it can cause cylinder wash... where the diesel isn't burned and it washes the lubrication to the piston and can lead to scouring.
Me and my friends either, engaged high idle (about 1,100 rpms) or revved the accelerator every 10 minutes to burn the fuel during long periods of idle.

If you lug a diesel it will shake much more violently than a gasser and inevitably be harder on the trans.
Keeping the engine cool isn't really that big of a deal, gasoline engines usually run hotter anyways. Your main concern on a diesel is generally your EGT's exhuast gas temp, because turbo's tend to start melting at 1,200 degrees.

If you get a new model diesel, they have this new deal out called Blue-Tec is one example... it's an emissions deal that pumps this crap into it http://microsites.mbusa.com/microsite/bluetec/videos.jsp?open=1 (it's now the law, even semi's have a form of it)

Frank

 

[Will]

Frank, you aren't coming through coherently. Very patchy.

 

[Frank The Tank]

Frank, you aren't coming through coherently. Very patchy.

I've spent my life around diesels...... tractors, and trucks.
IDK, I have so many things to say, but I'm not %100 how each will concern him, and if you aren't as into them as me you won't get it anyways.

Well I apologize, but after re-reading what I wrote, I made sense, just on different issues in each abreviation lol
I sure as heck don't want to spill my guts on the diesel bit, and leave somebody further lost than if I just added my "toast" of a spill.

Frank

 

[Captain Ledd]

Well I did understand most of it, and yes, I already had every intention of installing a pyrometer. Through my readings I have also noted instances about lugging one of these engines, that if done either too low an RPM or at a low RPM for long periods it will do damage to the turbo. I don't really have any plans on hopping it up more than the chip mentioned.

I was hoping to stick to the previous generation of diesels (not the uber-duper squeaky clean ones currently out). 1st-ly because of cost, the super new engine is going to be an absolute fortune. 2nd-ly I believe there are more of the slightly older gen diesels around and they've had time to develop a good Tech following for diagnosing. 3rd-ly I do consider myself somewhat eco-conscious and would like some degree of equipment to protect the environment, catalytic converters and a "relatively" clean burning engine, even if it's not the latest and greatest, it's better than nothing.

Frank, while I theoretically could easily write for an entire day about questions on diesels, I unfortunately don't even know where to begin or what to ask. I've read for weeks on end about diesel engines and still feel I don't exactly know what I don't know (If that makes sense). I've got a pretty good idea on the basics, but that's about it. Now I know to keep an eye on it if I let it idle for very long, I didn't know that before, lord only knows what kind of damage I would have done. Just as Will has set me down a path about cooling I never expected, and has prevented me from creating a potential disaster by giving it too small a radiator. I thank you both immensely.

I knew even in the early stages of the project I was probably going to be on my own for many things. Just have to sit down and figure it all out. If I stuck to things I already knew how to do I wouldn't ever learn anything new right?

Frank, it's up to you if you feel like doing it, but your rambling on diesel engines certainly wouldn't fall on... blind eye's I guess? (as opposed to deaf ears lol) I'd gladly read all of it.

 

[Frank The Tank]

Well man, anything your in wonder about, ask away, if I don't know it, I will ask luke at L&L diesel, or research myself.

I don't know the specifics on the latest engines, but most diesel is closer to general principal.

Frank