best gear ratio for 97 z28

[z28trick]

i have a 1997 z28 camaro thats all stock except for flowmaster exhaust. im going to purchase new rearend gears soon and i would like some input on what the best ratio would be. im leaning toward the 3.73:1 but im also considering a 3.42:1. i would also like to know how much a 3.73 gear will increase the rpm say at 55 mph. right now at 55 its turning 1500. with the 3.73 what would it be? and at 70?...and also what size carrier does it have?

[89IROC&RS]

what gears do you have right now?

If you have lower than a 3.08:1 then you have a serise II carrier.

To swap to a 3.23, 3.42, or 3.73, youll need a serise three carrier.

both are 7.5in ring gears for your ten bolt rear end. For your mostly stock setup, i would reccomend 3.23 gears and if you bild up more hp, then go with the 3.42's.

[Savage Messiah]

Right now you either have 3.42 or 3.23. Probably 3.42. Do you have an auto or manual? if auto 3.73... if manual you can manage 4.10...

[z28trick]

i think the gear in there now is a 2.73..it shifts out of second at 95 when its matted...i have performance upgrades in mind to do to it little by little..so i want to go on and get the rearend right..

[89IROC&RS]

well you have an automatic so there is a item you need to think about. when doing rear gears on an auto equipped car with a lockup converter you need to match the stall converter with the rear gears. if you are gonna be putting in really tall rear gears youll need a stall to take advantage of it. I have an 89 IROC with a 700R4, 2600rpm stall converter, and 2.77 gears. The stall is way to much for the gears, and it dosnt shift right. So i need to put in 3.27 gears at least to make it work together better. Just something to keep in mind. again, ill stress that if the car is for daily driving, you dont go higher than 3.73, and i reccomend 3.42 as a max. 4.10 gears are for drag racing in my opinion, not the street.

[Savage Messiah]

I know a few guys who drive their 4.10s around no problem (4th gens), just make sure you get tuned/reprogrammed... but they are a little extreme... 3.42 will make you very happy, 3.73 is prolly the highest you should go having an auto. (guys with manual and the extra gear [or 2] can get away with 4.10s easier, RPM wise)

[Morley]

For daily use the "rule of thumb" is: For an auto 3:42, for a standard 3:73. This is supposedly the "optimal" gearing to complement the gearing in the transmissions.

[z28trick]

how much will a 3.42 increase the rpm's by?..at 55 its turning 1500..what will it be turning with the 3.42?

[89IROC&RS]

depends on tire size, there is a formula to work that out, dont know it off of the top of my head.

[DVS LT1]

Originally Posted by z28trick

i think the gear in there now is a 2.73..it shifts out of second at 95 when its matted...

That sounds about right - I remember pulling near 2-gear quarter miles lol.

I switched out similar gears last summer for 3.73's in my auto. City and stop light to stop light driving is just halariously stupid fun now - damn car will rip into the tires SO loud when shifting into 2nd gear with just half throttle.

But I must say I really really mis the unlimited top end speed the old gears had.


I know a guy from the UK of all places who switched out his 2.73's for factory 3.42's while keeping his II series carrier - found inserts or something to hold them in there.

I can also recall that Strange makes 3.73's specifically for II series carriers (remember seeing that when I was shopping around).


If you do a lot of highway driving and are one of those guys who likes to race on the highway at really high speeds then I wouldn't go 3.73's. Most guys be happy with a 3.42 swap.

[PowerJunkie]

As was said...stay with 3.73s max for an auto and 4.10s max with a manual. These can easily be used on daily drivers. Many out there are running them.

[DVS LT1]

(lol) Well, if you LOVE hitting 150 Mph at the tail end of third gear and have got the power in 4th to pull beyond 160-170 Mph... then don't go as high as 3.73's cause you'll be sorry.

Otherwise 3.73's are totally streetable if you're a good little boy doing 100 Kph/60 Mph on the freeway - and you'll actually get better mpg in city driving with shorter gears. It's just a matter of how much top end speed you want to sacrifice for low end torque.

Unless you're totally into drag & red light to red light street racing and aren't afraid to watch Honda's blow by you at 260 Kph on the freeway... then go smoke them tires!!!!

[Mr. Luos]

I disagree with the above statement.
The race should be LONG over by 150 MPH. I have never had my car that fast, and I don't plan on it.

Gearing depends on power as well. Since you are mostly stock, I would recommend the norm. 3.73 for auto and 4.10 for manual.

I have an M6 car, but I am going to be making close to 600 crank horse, so 4.10's are too big for me. I will go with 3.73 when I break my rear end. Should be right at the end of 4th gear when I cross the traps.

[DVS LT1]

Originally Posted by Mr. Luos

I disagree with the above statement.
The race should be LONG over by 150 MPH. I have never had my car that fast, and I don't plan on it....

You actually do agree with the statement if you're saying you don't care for high speed racing and are only concerned with drag racing... but whatever, I can appreciate your opinion about not wanting to go too fast. It is dangerous.

Overall I love what the 3.73's did for my A4. The ONLY time I ever regret putting them in is during cottage runs up north. That's it. Now when I try to jump into a caravan of cars cruising at about 200 Kph, I'm buring so much freakin gas that it adds another stop to my trip. And then when one of the leaders decides to lean out the pack - guess what? Some of these Acura's and Honda's (even kids in their dad's Volvos!) have an easier time keeping up that I do.

I just miss the days when it would be me and a Porshce leaving everyone behind. Oh well, on the bright side I get less bugs splattered on the front when doing 120 Kph behind a minivan.

No more begging to have my ticket reducted to 149 Kph in a posted 100 Kph zone either, lol.