if i understand correctly you take your rear end ratio, and times it by your first gear ratio and that will give you a final drive ratio ? then what would be a decent ratio for street acceleration with a mild 350 ? 9.0 to 10 to1 ? example 3.73 rear x 2.52 first=9.39 i have a m-20 now with a 3.08 rear and it's a bit doggy (3.08x2.52=7.76) am i doing the math right?
what is a good final drive ratio ?
fnoblitt
1 - 11 of 11 Posts
Joined
·
104 Posts
if i understand correctly you take your rear end ratio, and times it by your first gear ratio and that will give you a final drive ratio ? then what would be a decent ratio for street acceleration with a mild 350 ? 9.0 to 10 to1 ? example 3.73 rear x 2.52 first=9.39 i have a m-20 now with a 3.08 rear and it's a bit doggy (3.08x2.52=7.76) am i doing the math right?
Joined
·
1,503 Posts
I read something in a magazine a few years ago, if I remember correctly the number is "10".....
Joined
·
390 Posts
I like 9.5 to 11 plus---high 8's is a decent compromise.
To 9.5 or more there you either have to deal with 3.73 +gears and high hiway rpm or have a trans with a low first gear.
Mine=3.28x3.31=10.8-I'm gettin some 3.08's this year and it'll still be at 10.1
To 9.5 or more there you either have to deal with 3.73 +gears and high hiway rpm or have a trans with a low first gear.
Mine=3.28x3.31=10.8-I'm gettin some 3.08's this year and it'll still be at 10.1
G
Guest
·I dearly LOVE my 1st Gen. Camaro M-20 car's 3.31's!
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
Joined
·
3,384 Posts
I like about 10:1 with a manual, an auto can go to about 8:1 and be good. The thing to watch is the compromise between first gear acceleration and final drive in top gear. A close ratio Muncie, 2.20 first needs 4.56 gears to get 10:1, but requires too much rpm on the highway for me. I ran 3.55s for a few years and they were ok, but not great at either. 2.73s are nice on the highway, but with a 6:1 final drive in 1st are wayyy too steep in town.
Devin
Devin
G
Guest
·AND DON'T FORGET YOUR REAR TIRE HEIGHT!!!
I say this b/c a tall tire will drop my 3.31's down to 3.07 easy!
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
I say this b/c a tall tire will drop my 3.31's down to 3.07 easy!
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
Joined
·
3,935 Posts
Yes, you are doing the math correctly.
Think about where you do most of your highway driving. Think about the maximum sustained RPMs you are comfortable doing while on that highway - and think about what is the slowest sustained speed you will be comfortable to drive on that same stretch. From this you can work backward to find the lowest (numerically highest) gear ratio you can use to optimize 1st gear fun factor with tolerable highway revs. On-line calculators can help you with this.
If you have Microsoft Excel, I can send you a spread sheet I made that lets you vary a number of different transmissions, rear gears, and tire sizes to see how that changes your revs in each gear. PM me your email addy if you want a copy.
This is good advice. :yes: 4.88s etc are gonna be super fun in 1st gear, but deathly awful cruising at 50mph. I had 2.56s which was awesome on the highway, I could cruise @ 70 all day. However, 1st gear was lack luster.
Think about where you do most of your highway driving. Think about the maximum sustained RPMs you are comfortable doing while on that highway - and think about what is the slowest sustained speed you will be comfortable to drive on that same stretch. From this you can work backward to find the lowest (numerically highest) gear ratio you can use to optimize 1st gear fun factor with tolerable highway revs. On-line calculators can help you with this.
If you have Microsoft Excel, I can send you a spread sheet I made that lets you vary a number of different transmissions, rear gears, and tire sizes to see how that changes your revs in each gear. PM me your email addy if you want a copy.
G
Guest
·I have to say that way back when I ordered my '67 350SS/RS Camaro car, I wanted to order the big 3-speed stick OD tranny BUT it wasn't offered back then!!
I doubt if there's a handful of guys around here that have driven a 3-speed stick OD and I have to say that one is great!
Lock it out of OD for serious tire spinning and then stop, "pull out/push in" the handle so she is in OD mode and then go tooling down the hwy in OD at a low rpm........
And what's cool about it is that while in OD, you can clutch-less shift EASY if you match your rpm's!!!
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
I doubt if there's a handful of guys around here that have driven a 3-speed stick OD and I have to say that one is great!
Lock it out of OD for serious tire spinning and then stop, "pull out/push in" the handle so she is in OD mode and then go tooling down the hwy in OD at a low rpm........
And what's cool about it is that while in OD, you can clutch-less shift EASY if you match your rpm's!!!
pdq67
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
Paul, I hardly ever used the clutch on a 69 Roadrunner I once had!.....I knew exactly the rpm to shift at!:yes:
1 - 11 of 11 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
