Question about gears, rpm's and such.

[Doug_Guilds]

My friends car is very similar to mine in that it has a 2.3 Ford with a 2.14 second gear trans and a 7.5 rear end. I run a 3.73 rear gear and he runs a 3.43 (think that's the number it's a 3.4 something) and he has to run 80+inch tires to keep the car around 7k rpm while i can barely get mine over 6200 with 72-74 inch tires. Everything is the close to the same no lightweight items in rear end and driveshaft with the exception of the flywheel. He runs a 12lb unit while I run a 16lb unit. Would that make a near 1k rpm difference in the cars? My car is even lighter than his by about 70 lbs overall.

It's just something we have been trying to figure out all year. We run the same track and even the same line.

[car62]

its a 3.45 ratio...the flywheel difference is not going to be the rpm difference,my guess would be that he doesnt have the 2.14 transmission..if the cars are similar as you state...or perhaps the 3.73 gears you think you have could be 2.73...my money is its an error on the gearing.

[Doug_Guilds]

I bought the gear from Speedway so it should be a 3.73. It wasn't taken out of anything. The cars are very similar, but something sticks out at me. When we put my trans back in last week he told me my trans is a lot lighter than his. I am taking the gear out later this week so I will check the tooth count and make sure it's what it is supposed to be. BTW you have a PM car62.

[return to dirt]

it sounds like your friend may have a mustang 2 trans or a t5. are you sure your trans is a 2.14? what type of shifter does it have? spin in(lol) or does it use 3 bolts?

olin

[car62]

PM replied Doug..and hopefully i didnt come off as being rude..just dont want anyone thinking i am "that" idiot.

[Doug_Guilds]

Car62- Not rude at all. I rereplied (is that a word? rereplied?)...anyways n/p.

Olin- I did a spin test last week on my trans and it spins out as a 2.14 second gear. My case has the numbers 7006AA 77ET and from what information I found about it, it backs up what I found with my test. I will post what I find with my rear gear this weekend when I take it out.

EDIT- It is a 3 bolt shifter and so is my friends.