Assume its a normal summer day, your cars running fine, your on a flat deserted road and your in no rush to get anywhere.
1. Assuming you have some sort of speed measuring device in your T, at what speed do you shift from low to high ?
2. Can you lug a T or is it just not worth worrying about ?
I upshift at about 5 - 10 mph.
NEVER lug a T engine. Bad for crankshafts and high speed clutches.
You have to choose between lugging the engine and throwing something from centrifugal force! If I am going downhill, I can shift into high almost immediately, but on level between 5-10 mph. However when going uphill 10-15 mph or I shift to Ruckstell and just let her go about 15-20 mph up the hill. I know what hills I need Ruckstell from driving the T on them for over 20 years, so when I start out I shift immediately. Usually just before I stop I shift to Ruckstell. The Ruckstell likes to be shifted while the car is still moving and when shifting down the engine needs to be pulling, but when shifting up, the engine needs to be at idle or near idle. Same way with shifting the T transmission. When shifting down give it the gas, and when shifting up, let it idle.
Anyway, that's the way I do it.
I've been shifting at about 12 mph. Guess that's a little high?
When the valves float and it wont rev any higher, grab another gear and hang on. Ok just joking. Thats from my 4 speed Mustang days.
I have a TT Truck so its about 14-15 so it doesnt lug the heavy truck. Scott
I suppose a lot depends on your definition of "lugging." Assuming the benign conditions you described, Bud, I usually shift up early and accelerate gently, with a very light hand on the throttle, through that ungraceful, vibration-prone, low RPM section of the power curve. It's not really "lugging" unless you get aggressive with the throttle and ask the engine for significant torque. Seems to me that low RPM and high torque is the perfect recipe for a busted crankshaft.
I used to do it differently. Used to be, I'd accelerate fairly hard in low and really wind up the RPMs before quick-shifting in an effort to avoid that nasty low-RPM rumble. Problem with that technique is that the crankshaft isn't counterbalanced and high-frequency vibration is also destructive (though not quite as bad as the low-speed/high torque combo).
Unfortunately, it's not always possible to operate on a flat, smooth, deserted road with a tailwind, good looks, wealth and a full head of wavy hair, under a smiling, yellow sun. If you've got full seats and a full tank and the top up, and your right turn from a stop-sign is followed by a hill, you're pretty much going to have to make that engine sing a high note before up-shifting and then lugging it at least a little. It's that or keep her screaming in low—and from what I've been told, that's rough on the planetary gear bushings.
The unsatisfactory answer is, the crankshaft is delicate and needs to be treated accordingly (in my humble, newbie opinion).
As a mildly amusing aside, I might mention that when I bought the car, I immediately switched to a high-compression head and larger intake manifold in the interest of having more power available—which is kind of a laugh because now, having acquired a little knowledge and experience, I'm afraid to get aggressive with the throttle. Funny, huh?
When you shift is more in the feel and sound of the car than in a set speed. My T will only reach a certain speed in low gear, fairly rapidly and can go no faster without a lot of complainin', vibratin' and strain. If I hold down the low for too long it simply labors mightily and sounds as if it is going to explode, so I like to shift out of low into high as soon as possible, when I reach the optimum speed, before it starts complainin'. If you want a speed, I would guess 8 to 10 mph. Whenever I turn a corner, I reduce the throttle, to slow her down, press the clutch halfway down for neutral and brake slightly if needed, then coast into the turn in neutral, going fast enough to, continue in high when I release the clutch as soon as I make the turn and straighten out. I like to stay out of low and keep her in high as much as possible. Jim Patrick
As soon as possible
Flat level land, maybe 50 feet at the max for me, and I don't lug...but what I do do is both sticks up with the pinky's at a shift time, and then pull each accordingly with pinky's to keep the power building until they are set right...and yes I'm a "dumper" on the clutch.
Becomes 2nd nature after a bit...tho most say to me 'huh?'
19 mph was max with an NH on the Fronty. Switched to a Winfield and it went to 28. That was with standard rear gear.
28 MPH in low? Wow. It must have sounded and felt like you were just about to achieve lift-off.
Set the red-line on the tach at 5600. Do you have a REV limiter installed?
Using a Stewart 490 speedometer and a Ruckstell with a standard ring-and-pinion in a 27 tudor, I use the following top speeds. (Stock crankshaft with no balancing, cast iron pistons, stock ignition.):
Ruckstell low: 5 mph
Ford low: 10 mph
Ruckstell high: 20 mph
Ford high: 40 mph
It just sounds like it's due. Did I read somewhere to "get out of low as quickly as possible as all regular driving can be done in High".
Charlie I know Rob was talking about being about to drive around in high at 5 MPH with his K, but that's the only place I remember reading what you are talking about.
28 mph in low would be about 2,800 rpm, the same rpm in high would give 70 mph & that's what the Montana 500 riders reportedly reaches downhill at times - and for longer periods than just before upshift, so I would start worrying about flying magnetos through the hogshead.. Less risk for Ralph, he's got a disturbutor and slingers on the flywheel, I think.
I agree with Jim Patrick, it's more the feel and sound than the speed. Anyhow, my TT doesn't have a speedometer, so who knows how fast I'm going anyway?
Seriously, since I have a Muncie it varies a little. When first starting out and everything isn't fully warmed up I'll use 1/L, 1/H, 2/H, then 3H. After everything is warm it changes to 2/L, 2/H then 3/H, but it's all based on sound and performance.
Jim Patrick lives in Florida which is quite flat. He can stay in high most of the time. Where I live I am lucky to be able to drive in high. I am either going uphill or downhill. In high it will just stop going uphill and in high going downhill it won't stop! I shift the Ruckstell several times just to go to town and back. I have one hill where I use Ruckstell and low pedal together to go up just a bit faster than walking.
I shift as soon as I can while avoiding the bucking that smashes my head against the windshield.
When it do too early my head hurts.
When I do it too late the motor starts screaming obscenities at me.
When I do it just right it is like a perfect symphony.
It depends upon the terrain and weather - going uphill, downhill, with the wind, against the wind, synchronizing the left foot and right hand is part of the fun.
Making a smooth transition between low and high is an art!
You're right Norman. The only hill I experience is the slight incline from the street into my driveway which is barely perceptible so driving a T in Florida is a breeze. Jim Patrick
Me too, Norm. Living in the CA Central Valley everywhere I go is pretty flat. Like Jim, the steepest slope I have is my own driveway, which is not much of a slope.
I shift from low to high when 'Lizzie' feels like she wants me to shift from low to high. I don't have any idea how fast that is, probably around 10 MPH. I'm sure this is going to vary with coupes, sedans, touring cars, years and engines.
depends as mentioned above as to location, flat/hill.
How can you NOT lug a T?
Cripes.......with only 20 HP even when it's standing still it's lugging....... LOL
Pull both levers down and wind er up in low till it starts to knock, pop all the way out on the pedal,and when the clutch quits slipping and takes hold you are on your way. By the way turbo and watts clutches won't take it. Have fun, KB
Just like in a modern standard shift car, in which you let up on the accelerator to slow the engine (not the car) as you are shifting into a higher gear, in my T, as I am lifting my foot to shift into high, I pull up on the the throttle lever to reduce the speed of the engine. After it goes into high, I increase the throttle to the desired speed. This helps to prevent lugging. As for the spark lever, I keep it fully advanced at all times.
When approaching a stop sign I also lift up on the throttle to slow the engine, which reduces the stress on the bands and drums and helps to stop the car in a shorter span. You'd be surprised at how many forget to pull up on the throttle lever, before stopping. Jim Patrick
I'm with Jim, l back the throttle off when up changing.
Same here. I "take my foot off the gas" (so to speak) when shifting and then feather in the clutch real gently before coming back in with the throttle. Very smooth shifts that way—at least in my car. Not the way to do it when taking on a hill, though.
Be sure not to decrease the throttle while in low or the car will slow down. You want to maintain the forward momentum and speed of the car itself but reduce the rpms of the engine only, by pulling up on the throttle lever after lifting up on the pedal and going into neutral so the the car is coasting in neutral at the reduced engine speed and at the same forward speed it had at the peak of low gear as it is going into high. Jim Patrick
I "shift" the way Bob and Jim and a couple others describe the procedure. Done properly that way, you can usually almost ELIMINATE all clutch slipping! Nobody will convince me that leaving the throttle alone and "popping" the clutch is careless, lazyness, entirely unnecessary and downright abusive. I believe it's a good thing the original steel Ford clutch is really tough and will withstand such abuse better than "turbo" and "Watts" clutches as Keith describes.
I shift out of direct drive low pedal at about 23 miles an hour and go into high pedal under drive. Then shift into high direct at about 42 and go into overdrive on the Layne Warford at 63 miles an hour. I don't know our top speed. I shift at the maximum torque place rather than when wound out. We make 47.8 horsepower to the rear wheels at 3000 RPM and maximum foot pounds of torque is 100 measured at 1835 RPM which is where the dyno starts to measure. It was dropping dramatically at 1835. We make 85 foot pounds at 3000 RPM. They shut us off at 3000 RPM but we turn faster. The dyno folks did not expect that much power out of a Model T and thought we could only turn 2000. We don't have a tachometer and simply listen for sweet spot to shift. The Layne Warford is made with constant-mesh gears and using the clutch is not necessary. Simply pull both ears down and move the lever at full throttle, then listen for the chirp of the tires as you go along the path.