Camarojohn82

ok guys, i need some help here, i dont underatand gear ratios, will someone please explain them to me in a way i can understand?
thanx
john

atc3434

iTrader: (4)

I'll take a stab at this one... I assume your talking about rear-end gear ratios. Well, the numbers that are associated with gear ratios, such as 4.11's or 2.73's. These numbers are refering to a ratio, the number of times that the driveshaft has to turn to produce one turn of the rear axle. So the higher the number, the more turns the driveshaft makes to turn the rear axle once. This is important, because changing the rear-end gears can add a lot of acceleration to your vehicle. By making the engine make more turns in comparison with the rear axle, it will let the motor get into the power sooner. Really makes a difference off the line. Plus, for a quarter mile setup, you can setup your gear ratio so that when you cross the line your just passing the rpm where you make maximum power in top gear. That way you can make full use of all the gears in the tranny, and have maximum acceleration.

Another thing I should clear up, a lot of times a novice will get confused when he hear somebody say "Lower gears" This may make you think lower gears would be like 2.73's vs. 4.11's, where the 2.73 is the "lower gear" Most likely they are refering to a higher number, like a 4.11. The "lower gear" part comes in because higher gear ratios such as a 4.11 will yeild a slower speed at the same rpm as the old gears. This can be confusing... but "lower" (ie 4.11's) and "higher" (ie 2.73) gears are almost always refered to in this manner.

Hope that clears it up some.... did I miss anything anybody???

joshp14

pretty much got it covered....now i have a question...what is the best rear end for the LB9 auto?? as far as best 1/4 times, top end, and off-the-line? i currently have 2.73's.

Camarojohn82

wow, that was so incredibly simple...i feel stupid now.
thanx a lot!
john

atc3434

iTrader: (4)

joshp14


Well, top speed and off the line are really going to fight each other. For a high top speed, your 2.73's are the way to go... but they are hurting your off the line and 1/4 times. I don't have a ton of Camaro experience yet, but I would guess with a fairly stock 305 something like 3.27's or maybe even 3.42's would be the route to go. 3.73's might be a little extreme... depend on how hard you want to go after the best times. Some of these more experienced guys on the boards probalby have a better idea of what would work well for you.

Camarojohn82

ok well, i have an 82 cam sc, and i may be getting rid of it for an 86 IROC, can you tell me what kinda rearend thos came with, what are they like?
thanx
john

Camarojohn82

well, you just answered that...nevr mind

atc3434

iTrader: (4)

Heres a link to the Tech specs here at Third Gen
www.thirdgen.org/newdesign/tech/techdb.shtml

joshp14

so if my 0-60 time right now is 6.5 seconds, and top-end of 135-140...what could i expect for those times with say a 3.23, 3.27, or 3.73?

atc3434

iTrader: (4)

Like I said... I'm not terribly farmilar with the particularities of F-bodies yet... I just got my first Camaro this week. But I do know that if you bring your gear ratio up to like a 3.73, your top speed will be signifigantly lower (Maybe around 115) and your 0 to 60 times will be faster... how much faster depends on how well you can launch the car.