80% rule?

[Been Here Before]

From following some comments and post there appears to be a few new to the Model T posting. The trend is to achieve speed, speed that at the time the Model T was constructed could only be achiever on a Board Track. That is 40 mph plus. Today it is easy to achieve 40 on smooth highways. But at the time of the T's introduction the speeds were much lower. Say 15 to 20 MPH.

40 MPH is about 1600 RPM. Certainly not what Henry was expecting to deliver the the average car owner up to the late 1920's.

Do any drivers and owners follow the 80% rule? Rather than use the full potential of the early Ford motor at 100%, only operate the motor at 80% power and speed. Use the motor at 1280 rpm and achieve a road speed of 30-32 MPH?


https://driving.ca/auto-news/news/on-th ... -kit-racer

[Art M]

I drive at about 30 mph. Maybe 36 downhill. Also I shift from low to high at about 10 to 12 mph. Some shift at 6 to 8 mph. This seems awfully low for the high gear without a Ruxtell or other gearing.
Art Mirtes

[DHort]

I have a new engine with a Scat crank in my 1920 Touring. The engine was balanced at Bill Stipes shop. I know I can probably do 40mph, but I keep the car at 25-30mph. I am not in a rush to get anywhere and I can smell the roses along the way.

[Steve Jelf]

I once got my 1915 up to 50 mph briefly, just to see if I could. But that is much too scary and dangerous to be a regular practice, not to mention wear and tear. A Model T will cruise at 40 mph, and I have sometimes maintained 37-38 mph when I was in a hurry, but I believe it is happier and will last a lot longer at 30-35 mph. And yes, I really can hear and feel the difference between 35 mph and 40 mph.

[Loftfield]

In a great HCCA video the owner of a 1909 Pierce Arrow was asked how fast the car would go? He replied, "It will go 60 or 65, but I only have brakes for 30". Need we say more about speed?!?!?

[zdillinger]

In a great HCCA video the owner of a 1909 Pierce Arrow was asked how fast the car would go? He replied, "It will go 60 or 65, but I only have brakes for 30". Need we say more about speed?!?!?

I say pretty much the same thing about my 1939 Packard when asked about how fast it will go. I say "she'll go 80 but the brakes don't like much more than 55".

[Norman Kling]

The engine will last much longer if it is not pushed to the limit. I personally like to drive the surface streets and not on the freeway. Most places are either stop and go traffic where it is impossible to go over 20 or 30. I also take the old highways which usually parallel the freeways. Less traffic there and room to pull over to let faster cars pass.

Another reason for not pushing the car to the limit is the brakes on narrow tires. Even when the brakes are strong enough to lock the wheels, they will just slide. It is difficult to install front brakes and with the original configuration of the front axle, brakes on the front could cause loss of steering control.

So It's best to drive a T the way it was made to go. Remember, it is much faster than a horse and it only eats when it is used.
Norm

[John Codman]

I agree with Steve Jelf. I too can really feel the difference between 35 and 40. It's much happier at 35.

[Will_Vanderburg]

The fastest I’ve ever driven my T in the 25 years I’ve owned it was 46 miles an hour. It doesn’t like it.

That’s with a slightly milled head and .030 over aluminum pistons.

[babychadwick]

I like my speedsters to be able to drive at 55 (Doesn't mean you do) as it simply opens up more territory when you dont have surface roads. To do this there is naturally things done to the engine, brakes, and steering. Of course I'm talking about speedsters. The most overlooked aspect is gearing and I always figure out a way to get some taller gearing whether its changing the ring and pinion or some form of overdrive. With this even when you are cruising thru a neighboorhood at 20-25 you can shift up and the motor is so much happier.

[Rich Eagle]

Over the years 80% of my engine, tire and driveline problems happened at over 45 mph.
I'm contented now with 33-35. It certainly was fun going fast though.
Do what you need to do. You can always fix things.
Been driving Ts since 1964.
Rich

[John Heaman]

I feel comfortable at 30 MPH tops. Pushing the car to its limits ends up in pushing the car.

[Mustang1964s]

The touring really likes running between 30-35, depending on the load.
I have ran faster and slower. She really will let you and the passengers know when she has reach her happy speed.

The speedster is still a mystery. It's scary fast and quick, I am in the planning phase to slow her down a little.

[KMcoldcars]

When I was young and dumb, in the early 1970s I had a 23 T roadster that was stock except for the Frontenac overhead valve head on it. The car had 30 X 3 1/2 inch tires, stock steering and brakes. The speed limit on the freeway was 70 MPH. I used to get out on the freeway and pass people in their cars. Now I would never do such a thing . 35 MPH is fast enough for me.

[jiminbartow]

My 1926 coupe will go 40, but after 35, the vibration and noise gets so bad, it feels like it’s coming apart. At 30 to 33, she runs smooth and quiet. Jim Patrick