I have a Winters quick change and three sets of gears for my Model A coupe. In the next week or so we will be mating it to the axle housings and setting the back lash, etc. We will also install the initial change gear set. I'd like your recommendations on what overall gear ratio I should start with. 31 Model A on 32 rails. About 2,500 pounds. Engine: Mild Chevy 283. About 225 HP if the calculator is correct. Transmission: WC T5 with .73 OD. Rear tires: 7.50x16 31" to 31.5" tall. Possible Ratios: 3.48/1 3.62/1 3.76/1 3.95/1 4.11/1 I want to start with a good all around ratio. Later on I can experiment to find the optimum ratio for around town and open road cruising. Where would you start?
I would start with the 3.95 or 3.75 first. At 75 you'll be taching about 2250-2360 or so, just about perfect.
I learned some quick-change gears lessons way back. 1st lesson, Know what ring and pinion you have as there are 2 choices 4:10 and 4:56. Next lesson is Big Gear on Top as when you install the gears with the small gear on top the ratio ends up being much higher >>>>.Oops I ment 4:86 !!!
My Winters V8 has a 3.76 R&P. I also have a Frankland "Champ" on the shelf with a 4.86 R&P. So yes, you do need to know what you are starting with. V8 style change gears come in two thicknesses; 1" and 1.375". The current production Winters V8 that I have uses the 1.375" gears (Series 45**). Two of the sets that I have are 1" (Series 44**). To make them work I will need two of the .375 spacers that Speedway Engineering offers (Part 85-051). Why is everything I touch so complicated?
My roadster has a 302 Ford, AOD (.67 high), 3.90 gears, and 30 inch tires. It is a fabulous setup. Great dig around town, and easy cruising on the highway. With 4.11 or 3.95 gears, you will be geared just a little lower than my setup. With the 3.76 gear, it would be just about identical, at least at cruise. This combination of tire size and gearing gives about 2600 rpm at 90 mph; I don't think I would go much taller. I think you will be happy with any of these three.
What ratio is your low gear in the T5? If it is too low, you might want to go to a higher rear end gear.
****, now I'm worried. I went for tall gears in mine (not here yet). I am currently running a stock banjo with 4.11s and it runs at about 2800 at 60mph. I wanted to get down below 2000 rpm at 60mph because I live in the country and everywhere I go is open road. I reckon a 401 should pull the little A model along OK. The great thing is I have 3 lower gears and if that doen't work I can just buy another set of change gears. That's what it's about, isn't it?
My car had a 3:48 In it with 31 " tires, No overdrive , turned 3000 Rpm At 70 Mph., Great around town, For long trips i put in a 3:00 and now it turns 2600 Rpm at 70 Mph.The 400 less Rpm doesn't sound like much ,but it sure sounds different in the car
Most quickchange customers with t-5 5 speeds have had good success with a final drive gear set giving a round a 3.78 ratio. In over drive gear this brings the overdrive ratio down around 25% so that means the highway speed ratio is less than 3.00 -1, should be some where around 2-2100 rpm. You can use anyone of the gear ratio calculators on the net to help you figure out the exact rpm or ratio. One note though for high speed driving the smaller of the gear sets goes on the upper of the QC drive spuds. If you put the bigger gear on top you spin up the engine rpm. deuce354 you might want to check your gear set position.
i run 3.50/3.75 with no o/d and 28" tires, 3.75/4.11 with o/d same tire. but my motor hums with no o/d
Start in the middle of your possible selections. Drive it, and see how it feels. Then change up or down and see if it's better or worse than what you want. That's the beauty of a quick change rear end! They were first built for circle track cars for that exact reason. Once you have done it a few times, it's shouldn't take more than 15 minutesto swap change gears. Pumping the 90 wt back in takes most of the time.
I have model A rear end with the old 10 bolt quick change . 3:27 gears , t5 with od , 22/25 gear set , 30" tires . 60-65 mph @1800-1900 rpm .
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