what are your rpm's @ 70mph?

[CDQICKGT]

Just outta curiosity what rpms is everyone turning @ 70mph? when i bought my 89 hatch i was told it had 4:10's in it.( havent pulled the cover of to check yet)... at cruising speed im pulling around 3k. i have never had 4:anything in the gear dept as ive always been partial to 3:73. how much MPG could i gain from a geat swap with my T5?Right now im not gettin crap for mpg.

 

[87GT Drop Top]

Sounds about right for 410s. I have 373 and I'm around 2700-2800 rpms. I just put in a new trans will a .58 5th instead of a stock .68, but haven't been on the highway yet. You don't have to pull the cover to check the gear ratio. Just jack up the rear of the car. Then mark the drive shaft so you can count how many times it goes around. Spin the rear wheels by hand 1 revolution and count how many time the driveshaft goes around. If it's 410s it shound go around just over 4 times.

 

[MAC'n89Blckstng]

your mileage is going to suck regardless. With my z spec trans and my 4.10s I'm at about 2300 at 70.

 

[aar0s]

heh, im at about 1800 with my 2.73's and auto trans. I guess that about the only good thing about 2.73's is the low rpms at highway speeds.
I have some 3.55's that im waiting to get put in. if i have to wait much longer im going to do it myself and that will surely end badly!

 

[CDQICKGT]

Sounds about right for 410s. I have 373 and I'm around 2700-2800 rpms. I just put in a new trans will a .58 5th instead of a stock .68, but haven't been on the highway yet. You don't have to pull the cover to check the gear ratio. Just jack up the rear of the car. Then mark the drive shaft so you can count how many times it goes around. Spin the rear wheels by hand 1 revolution and count how many time the driveshaft goes around. If it's 410s it shound go around just over 4 times.

Guess you relly do learn something everyday.... thanks

 

[CDQICKGT]

heh, im at about 1800 with my 2.73's and auto trans. I guess that about the only good thing about 2.73's is the low rpms at highway speeds.
I have some 3.55's that im waiting to get put in. if i have to wait much longer im going to do it myself and that will surely end badly!

Its not that bad....Ive done plenty and the only thing that sucks about doing it at home is torqing that pain in the A** crush sleeve.

 

[Kerpal]

I'd like to know what RPM people are running at 70 with 3.55's or 3.73's too...

 

[SScott]

your mileage is going to suck regardless. With my z spec trans and my 4.10s I'm at about 2300 at 70.

me 2

 

[CDQICKGT]

me 2

Hey man, where is millbrook at? i grew up and lived in dothan before i joined the army.

 

[SScott]

About 10 miles north of Montgomery. Been through Dothan many times! I also used to live outside Fort Worth... I've been stalking you =)

 

[NIKwoaC]

Off the top of my head, my T5 + 3.73 equipped car runs 2200~2300 at 70.

Keep in mind that you can easily estimate RPMs just by doing a little math. For example, lets say my car runs exactly 2250rpm @ 70mph with 3.73s, and I want to know what it would be with 3.55s. 3.55/3.73=0.952. 2250*0.952=2141rpm. Ta-da!

 

[Shaolin Crane]

Off the top of my head, my T5 + 3.73 equipped car runs 2200~2300 at 70.

Keep in mind that you can easily estimate RPMs just by doing a little math. For example, lets say my car runs exactly 2250rpm @ 70mph with 3.73s, and I want to know what it would be with 3.55s. 3.55/3.73=0.952. 2250*0.952=2141rpm. Ta-da!

DUDE! you're hurting the reupation of fox owners, we're supposed to be uneducated hicks that think that "stang is a gratest evar"

 

[NIKwoaC]

DUDE! you're hurting the reupation of fox owners, we're supposed to be uneducated hicks that think that "stang is a gratest evar"

Haha, sorry, sorry, I will try to dumb down my posts in the future.

 

[lancec2c30]

Gear Ratio Calc

 

[1987LXragtop]

70 mph is speeding here

that and my speedometer isnt plugged in.

 

[65coupe408w]

around 2000rpm with 3.70 gear (9inch) and a Gforce T5 .58 OD

 

[CDQICKGT]

These 4.10's are just irritating the piss outta me. Ive never had them in ANYTHING before, and as soon as i can get them out i will never look back. I start off from a light and it seems like i shift 3 times before i clear the other side of the intersection. I do love the second gear effortless starts though. Ive always ran 3.73's but im thinking about doing some 3.55's in this one(never had them figure ill give them a try.) Im about to drive from ft hood,tx to ft jackson south carolina round trip and i dont wanna turn 3k+ there and back.

 

[bentley429isBAC]

3200 rpm

 

[aar0s]

noob question but whats the OD gearing on an AOD?

 

[KENS89LX]

In my 89 with stock tranny and 3.55 its 1900-2000 rpms.