AOD 3:55's VS 4:10's?

[LilBerx]

I have a chance to swoop up on a rear axle with 4:10 gears in it.. i am currently running 3:55's in my 92 5.0 with an AOD transmission... I am pretty sure 4:10's will wake my car up, but what kind of rpms am i looking at freeway driving? around 65-70 MPH.
At around 65 right now i am around 1800 RPM

 

[1991notchbackLX]

I have a chance to swoop up on a rear axle

Must be Utah vernacular.

The 4.10 gear set is the typical recommendation for AOD cars. You're going to sacrifice fuel economy and some cruising RPM, though. Expect to see 2200-2500 RPM at highway speed.

 

[Jason 302]

What he said.

I say get the 4.10's and free that AOD up a bit. Don't forget to change your speedometer gear too.

 

[VibrantRedGT]

They say every gear up is 220rpm. So 3:55's to 4:10's should be and extra 660rpm. So say your at 2000rpm at 75MPH, expect 2660rpm at 75MPH now. However the performance should make up for the extra rpm in my opinion. They say an AOD with 4:10's is roughly the same as a T-5 with 3:73's. I remember reading that in a magazine many moons ago.

 

[Mustang5L5]

If oyu do a lot of highway driving, you may not like it.

I know when i had my AOD, i hated going on the highway with 3.73's. Crusing speed was about 70 and it felt like i was revving like crazy on the highway

 

[LilBerx]

Must be Utah vernacular.

The 4.10 gear set is the typical recommendation for AOD cars. You're going to sacrifice fuel economy and some cruising RPM, though. Expect to see 2200-2500 RPM at highway speed.

ha ha, must be! the only highway cruising i will be doing is going up to cdubbs in idaho, which is about 20 miles away... but how much fuel economy am i projected to suffer around town?


I'm tempted on 3:73's to be in between, but i want to be able to have that power when racing others...

 

[VibrantRedGT]

Motive makes a 3:90 gear if you want to get in between 73's and 10's.

 

[LilBerx]

Have a link by any chance Vibrant? thanks.

 

[LilBerx]

Nevermind... found them, but they have a price on them.

 

[Mustang5L5]

ha ha, must be! the only highway cruising i will be doing is going up to cdubbs in idaho, which is about 20 miles away... but how much fuel economy am i projected to suffer around town?

Depends on who you ask. You'll get numbers from 10-32 mpg highway every time a fuel economy thread pops up

 

[Mintsick]

I truthfully would not go through the time & money to move to 3.73 from a 3.55. A 3.90 gear isn't a bad suggestion.

 

[Codydubb]

Keep in mind that 4.10 rear end has a spool and will chew your tires up pretty bad....which is why i didnt want it, Drag Radials are expensive...

 

[1991notchbackLX]

Keep in mind that 4.10 rear end has a spool and will chew your tires up pretty bad....which is why i didnt want it, Drag Radials are expensive...

What has a spool?? I don't follow.

 

[Codydubb]

that 4.10 rear end he was looking at

 

[VibrantRedGT]

What has a spool?? I don't follow.

Me either, I'm still not following. The 4:10's spool? You talking about lots of tire spin due to the tall gear?

 

[Mustang5L5]

A spool is a axle that is pretty much solid all the way across. The two rear wheels don't spin independant of each other. Great for straight line drag racing, terrible for daily drivers because every time you turn, the inside wheel will chirp as it skips because it can only spin the same speed as the outside wheel. Chews up rear tires fast

 

[1991notchbackLX]

I understand what a spool is, I have one. I just didn't see anywhere in the post where anyone mentioned anything about having a spool. Must be some inside information or something.

 

[Codydubb]

I understand what a spool is, I have one. I just didn't see anywhere in the post where anyone mentioned anything about having a spool. Must be some inside information or something.

Keep in mind that 4.10 rear end has a spool and will chew your tires up pretty bad....which is why i didnt want it, Drag Radials are expensive...

Yes it was inside info lol