Rear End Gears 101

[DjD]

Originally Posted by danhr

I don't know what you are talking about....

haha... it's fixed... I forgot to change that when I went back and changed the example. I am doing/did this write up at work... give me some slack here. lol

I'm not giving you a bad time, you asked!
...and you don't have to worry about me, I'm not telling your boss!

[lewylew]

I missed the link. Good thing I don't fish.

[CynAgain]

Great write-up!

:party0038:

[Bonemaro]

Yes most helpful thank you!

[HumanWiki]

Originally Posted by danhr

What can I say? I'm Asian.

And since I'm obviously not fulfilling the "driving a honda civic" stereotype, I gotta fill the void elsewhere.

I just had the Family Guy episode where Peter's taking a test, he pulls out that kid, pokes him and says "Come'on.... Do Math...."

[Apex Motorsports]

Originally Posted by HumanWiki

I just had the Family Guy episode where Peter's taking a test, he pulls out that kid, pokes him and says "Come'on.... Do Math...."

[GQ4Life]

i love family guy.. hilarious..

get write up.. been doing calculations to thinking about gears..

[calbert1999]

Strictly looking at the numbers then, if you want to go faster more quickly in a lowever gear; Why is the recommendation for an M6 to go with the 4.10's from the 4.33's. Wouldn't you want to upgrade to the 3.73 or 3.45's?

[Supercharged SS]

Hey Danhr, right now I'm trapping anywhere from 130-132 mph. I'm staring to wonder if some lower gears may be of signifigant help. Off the line and down the strip. 3.45's or 3.70's?

It seems that with any gear other than the stock 3.27's I will be shifting into 5th. With the 3.45's max speed in 4th is 133mph. Thats right where I am at currently and with the 3.73 the max speed in 4th is 123mph. Thats def not going to work.

[jagan323]

Thanks for the write up! I'm understanding gears a lot better now. In my Automatic V6, I don't have limited slip differential, does differential bushings still matter to me?

[DGthe3]

Originally Posted by calbert1999

Strictly looking at the numbers then, if you want to go faster more quickly in a lowever gear; Why is the recommendation for an M6 to go with the 4.10's from the 4.33's. Wouldn't you want to upgrade to the 3.73 or 3.45's?

While its true that the lower the number is, the faster you can ultimately go ... the reason why you go with a higher ratio is so that you accelerate quicker. Having a high top speed does you no good if you can't reach it before you run out of pavement.

Remember, these cars have 6 gears and they don't us all of them in the 1/4. A stock SS M6 will top out at about 110 mph in 3rd gear, which is about what they run in the 1/4. If you had a set of 4.10's it would max out at a little more than 90 mph in 3rd. But shift in to 4th and it can now go up to 130 mph.

[danhr]

Originally Posted by Supercharged SS

Hey Danhr, right now I'm trapping anywhere from 130-132 mph. I'm staring to wonder if some lower gears may be of signifigant help. Off the line and down the strip. 3.45's or 3.70's?

It seems that with any gear other than the stock 3.27's I will be shifting into 5th. With the 3.45's max speed in 4th is 133mph. Thats right where I am at currently and with the 3.73 the max speed in 4th is 123mph. Thats def not going to work.

ummm if I remember your dyno sheet correctly, you keep making power until 6700 or so rpm. That means you should be shifting/redlining around 7000 rpms.

So for you, the max trap speed of a 3.45 gear is 147 mph
3.73 gear is 136 mph.

A couple "special" things about your setup though

A) You are running a bias ply tire. Bias ply tires are known to "grow" on the top end of the track, since they have soft sidewalls and the higher speed. So your 28" tall tire, is going to be more like a 28.4ish tall tire by the time it crosses the traps. The faster your wheel goes, the taller it will get.

B) With most forced induction, they sometimes perform better with less gear, because the motor works better when it has more of a load on it. Well at least I know this to be true with turbochargers, I don't know about superchargers.

With that being said, I can't give an honest opinion on what should perform the best. That would be something to bring up with Ted... maybe he has a better answer than me. I know if it was me, I would be throwing a set of 3.73's in there, when you do the differential bushings. That's just me though...

[CamaroMiami]

danhr, you did a great write-up.

I'm going to save that as a pdf, so I can always refer back to an outstanding / excellent explanation of gears 101

[calbert1999]

Originally Posted by DGthe3

While its true that the lower the number is, the faster you can ultimately go ... the reason why you go with a higher ratio is so that you accelerate quicker. Having a high top speed does you no good if you can't reach it before you run out of pavement.

Remember, these cars have 6 gears and they don't us all of them in the 1/4. A stock SS M6 will top out at about 110 mph in 3rd gear, which is about what they run in the 1/4. If you had a set of 4.10's it would max out at a little more than 90 mph in 3rd. But shift in to 4th and it can now go up to 130 mph.

Not getting it.
Smaller gear ratio # the faster I can go in a lower gear, but, achieving that higher speed in a lower gear is going to take longer than with higher gear ratio.
So, the only reason why people spend big $$$ on these gears is to save themselves from shifting to a higher gear?
Hmmm...... I don't get it, everyone seems to freak out at how much qucker and more responsive the vehicle is when they change their gears to 4.10's or 3.73's, is it an illusion of the mind. What's the point?
If this is correct, shouldn't I just keep my stock gears?