buttermantoast

i have a set of 3.73 i want to put in a a4 TA and was wondering what kind of top speed lose you guys experienced with them and about what rpms u turn at 70!!

bww3588

iTrader: (49)

http://www.f-body.org/gears/

Schweet97Z

iTrader: (35)

im not looking to go 200 mph in my car and neither should you. you dont need to kill yourself. but they make the car another beast. i say do it. at around 70 mph my car tach at about 2500 rpms oh yea the gas milage isnt that great either lol

donkey mule

I lost no top speed with mine, just get there faster. I have not topped the car out but back when I had 2.73's I went to 130 and seemed to take for ever. Now that I have 3.73's I have brought it to 130 and it was pulling much harder than when I had the 2.73's. I dont believe that you lose any top end at all, your rpms are just higher . I have talked to others about this and they have confirmed this as well.

extremez97

iTrader: (6)

you will lose top speed when raising your gear ratio, its a known fact. but in order to tach out a z28 on the highway your flyin-150-160, but with my six speed i still have plenty of rpm left just not enough room to keep it goin. but as long as your not tryin to set land speed records 3.73s are deff worth it

License2Ill

iTrader: (1)

The trick is to get a Ford 9 inch and 2 third members to swap between in case u want to go on a road trip.

I've heard for autos 3.73s is the max and for stick it's 4.11's .

I want to run 3.55s or 3.73s when I go Ford 9. Possibly 2.50's for road trips.

U lose some top end but what hurts most these days is the gas, but that's not the car's fault it's Bush's/shrub's .

blk94z28

As stated above im about 2500rpms at 70mph, i have not noticed a big difference in gas mileage with the gears either.

gapp94vert

iTrader: (15)

i have 3.73s in my 94 vert and i love them the car gets up to speed so quick last nite i was messing with a 2.0t and my car hit 100 mph so quick i didnt even have time to look at the speedo lol they are definetly worth it

bww3588

iTrader: (49)

not really, unless your pushing 1000 hp, a 12 bolt with 3.73 or 4.10 (depending on transmission) is the trick. you can put more power to the ground through a 12 bolt than you can a 9 inch.
edit: let me rephrase that, more power gets to the ground through a 12 bolt. it takes more power to turn the 9 inch pinion than the 8.875 inch pinon of the 12 bolt. plus, its GM not F***

Black99TransAm

iTrader: (16)

i have a 97 trans am... what kind of rpm do they turn stock at 70mph... my car at 70 turns 2500-2600... so im thinking it has 3.73s

LS1Silverado05

iTrader: (41)

Sounds like 3.73s to me. I have 4.10s and they push around 2,800 @ 70mph. A bit high if u do alot of highway....but if you dont...

License2Ill

iTrader: (1)

Yea I know u lose some HP to rotating weight, but they cost relatively the same and the "F***" can allow easy swaps of their pumpkins. I don't have a lift, so I have my driveway. For the money and the adaptability, plus the added strength(12 bolts have been known to pop sometimes under 1000hp) I prefer the 9 but it is just a preference, a 12 bolt will serve as well.

bww3588

iTrader: (49)

they do cost about the same, and yes 12 bolts have been known to pop under 1000 hp but, personally, id rather have GM under a GM car. and changind the center section on a 9 inch is easier, but all you need is jack stands and a jack under the rear subframe and crawl under and change them.

riodealz28

i went from 101 to 104 in the 1/4 mile going from 2.73's to 3.73's and at 60mph im going like 2300 rpms with 275/40/r17 tires

titter

iTrader: (5)

simple math ...

mph * rear gear ratio * trans gear ratio / tire diameter * 336 = rpm.
4L60E is 1st: 3.06 2nd: 1.63 3rd(D): 1.00 4th(OD): .70

right now my 26in radials in od at 90mph is 3,000rpm ... kind of sucks for highway driving lol.

License2Ill

iTrader: (1)

I know what u mean I was hung up like that for awhile too but I just got over it. There is sooooooooooo much support for the Ford 9 I cant say its incredible the right word is it's RIDICULOUS and im poor so this is all big money for me and then u add the work involved, which with me being lazy I like to keep at a minimum, I ended up going over to the dark side of the force, and the power handling levels is unimaginable just like the emperor promised.

not to mention the Ford has these funky gear ratios also availaible like 3.55 or I think even a 3.62 or 3.63, like I said the support is ridiculous, then u can also go pickup a pumpkin at your junkyard for like 100. And any stock dookie one is capable of about 425hp, which for me that spells releif better than rolaids. Yea I could never go back, there is a bit of blue oval blood here I guess, but dammit we modify chit so much it looses some GM branding, my car is more like my own Frankenstein as is. I'm a GM fan too but the less work the better.

BizZzatch350

iTrader: (33)

How are the autos from rolls with the 3.73s? Mines feels like a turd from a roll with 3.23s

donkey mule

The 3.73's woke mine up ! From a roll its great. I switched from 2.73's to 3.73's though. Right now I prefer to go from about a 15mph roll because my tires are not at optimum. I raced a guy with a bullitt mustang from a 15 mph roll and had 3 cars on him by 75. This was after I put on my 3.73's and before I put on my full exhaust. After having these gears I can not imagine having anything differant.

slagger

iTrader: (1)

to be honest, I went from a 2.73 - 3.42 and that woke it up alot it pulls good and with my stock motor before I rebuilt it. I got it up to 154mph (farm land in bakerfield)
I do really miss my 2.73 for the gas mileage but it is nice to have that power so its a toss power or mileage... BUT if I had to do it over again I would go with 3.73 from what I read they are great gears..