LT1Falcon

iTrader: (3)

i need help from anybody that has changed their rear to a 3.73. im thinking of putting one in mine but im worried about drivablility. how much does it hurt gas milage? im getting about 19 right now and i have an automatic and everything is stock 1993 except flowmasters. what milage should i expect to get? also, about what rpm's will i be turning at 70 miles an our? is this change worth it? mine is street driven with an occasional trip to the drags. basically, is it worth it? thanks

Formula350

iTrader: (3)

Well at 70 in OD you should probably push around 1800rpms I'd estimate. I'm not sure what I have for gears, but I'll assume 3.23's, and at 70-80 I'm around 1200rpms. I doubt you'll notice much mpg change. If ANYTHING I would think you would go up, since the motor isn't working as hard to move the car. That's my uneducated guess though, so don't hold me to it

ZFan88

iTrader: (4)

Do a search. No point in buying an fbody, doing mods, and then worrying about gas mileage. You'll like the gears though, that's for sure

the_merv

iTrader: (88)

I have 3.73's.. 75mph in OD gets me about 2500RPM's. They pull real good from 50 and up. You will notice a nice gain, even being stock.

LT1Falcon

iTrader: (3)

actually, my LT1 and z28 drivetrain are in a 1962 ford falcon ( sorry chevy guys), so i didnt buy an fbody, and for the first reply, i dont see how you could be doin 1200 rpms at 70 with 323s. thats what i have and im at 2100. thanks for the help tho

the_merv

iTrader: (88)

Add about 400-500 RPM on your current readings, and that's what you will get with 3.73's.

LT1Falcon

iTrader: (3)

thanks. it looks like you have much more of a performance setup so it is probably not relavent, but did you notice a change in gas milage?

ZFan88

iTrader: (4)

He gets about 0mpg right now

LT1Falcon

iTrader: (3)

lol thats probably pretty close

the_merv

iTrader: (88)

Hey clowns, easy...lol
It got about 17 city, 23 highway. You will notice a change, but keep your foot out of it, and it won't be so bad.
As far as the Car's situation.. It's going back together soon with the same stuff, and some better stuff on top of that.
Break it and build it better...

LT1Falcon

iTrader: (3)

wow, that is better than i would have expected. i recently completed my swap into the falcon and im only getting about 19 highway. i expected better than that. would you have any idea what would make it that bad. its not bad really but i thought it would be better since it is virtually all stock. and now im really wondering since you get 23 with those mods. any ideas?

the_merv

iTrader: (88)

Probably the weight of the cars.. that Ford weighs in at 4000k+, mine is at 3235lbs, and then my 150lb fat *** in it with some gas. When you get the Engine modded, it will use more gas, but it takes less effort to move, expecially with Gears.

LT1Falcon

iTrader: (3)

thanks for the suggestion, but i dont think you are familar with falcons. they are small economy cars and i havent had it on a scale yet but im pretty sure it weighs less than a camaro. i dont have, power steering, airconditioning, power brakes, spare tire.....
lots of things i dont have that a camaro or fbody does. im pretty sure it weighs less but even if it weighed the same or a little more, i dont think it would effect mpg much. aerodynamics might not be great tho, but i cant see that hurting much. i sometimes wonder if my canister purge is working right, or maybe injectors are getting old. i really am just guessing on things. my lt1 has 71000 miles on it so probably not injectors. anyways, thanks for the suggestion