just debating on a tranny now...I would prefer a toploader, but may go with a t5 if the engine speed at cruise is just too high, so if anyone knows offhand(or can direct me to a site I can calculate it at) I would appreciate it
engine speed w/toploader and 3.5ish gears @80mph?
- Thread starter wicked93gs
- Start date
ga289stocker
Member
I have a 4sp top loader in my 65 w/ 3.80 posi gears. @60 mph i'm turning 3050 rpm. Last trip to track i tripped the beams at 98.4 mph at about 5300 rpm. I have a t5 to go in it once i get the parts. If you not doing any and i do mean any highway driving the 3.55-3.80 gears w/ 4sp are ok but if you think you will be on the highway some I'd go w/ the t5. I think the top loader is stronger than the t5 i have but i do use the car and like driving it on highways. it just really needs that extra gear now for anything over 55 mph. my .02
thanks for the info...ah well, I was hoping for the lighter stronger tranny, but I will be on the highway enough I'll need to go with a T5
Multiply the tires diameter times Pi (3.1416) then divide that into 63,360 (inches per mile) that will give you the tire revolutions per mile. Multiply that times the rear gear ratio to get rpms @ 60 mph. To figure what it is at 80mph, divide 60 into 80 and multiply that times the rpms @60. For an example, your Stang likely has 26" diameter tires, a 3.5 gear ratio. (26 x 3.1416 = 81.68) Next we divide 81.68 (I'm going to round it off to 81.7) into 63,360 that gives you 776 (rounded off from 775.52) 776 X 3.5 = 2714. Thats the revs per mile and minute at 60 mph. You can use this figure to figure any rpms at any other speed by dividing the speed desired into 60 or vice versa. (90 divided by 60 is 1.5, multiply 1.5 times the rpms @60 to get rpms 90) To figure the rpms with overdrive, multiply rpms @60 times the OD ratio
grantur01
Founding Member
my father had 4.11's in his toploader and it was HORRIBLE even cruising. a few months ago he dropped to a 3.50 and it has really helped. It still a little harsh IMO. Especially since I'm getting out of a 2001 GT with 3.73's and a 3650 tranny, and then jumping in a 66 fastback with a 4-speed. I could definately see where highway would be worse. Driving it today I was thinking some day lord willing I'll just put and auto tranny of some type in there with a slap shifter. A T5 would be a very good upgrade as far as driveability is concerned. However, it is weaker. As far as I know the toploader is near indestructable with a normal guys muscle car.
3166 @70mph is perfectly acceptable to me...puts it at around 3600 for 80mph, which will actually inspire me to stay closer to 70, which will be fine...thanks! I think I will go with the toploader after all...for now...then if I choose I can get one of those custom gear ratio T5s somewhere down the line if I decide i dont like it
ultrastang
Founding Member
dennis112
15 Year Member
ultrastang said:
GREAT CHARTS!!!!!!!!!!!!!!
You can actually see what is going on with different height tires, various gear ratios, and can compare 1:1 trannies to O.D.'s.
ultrastang
Founding Member
D.Hearne said:If you're like me, who spends hours behind the wheel, a hand held calculator is a neat thing to keep you occupiedNever thought I'd use algebra that much.
I had to use the formula to individually calculate all 306 possiblities that are listed in these two charts; http://www.ultrastang.com/Rearinfo.asp?Page_ID=3. That took a while to come up with all the results before it could be put on my webpage.
