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Can someone give me a lesson on gear ratios?

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Old 07-19-2005, 02:13 AM
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Default Can someone give me a lesson on gear ratios?

I've learned a lot here and now I want to learn about gear ratios since theres a gear ratio converter kit out for bonnevilles.

Thank you
Old 07-19-2005, 02:15 AM
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Lower the number, the better top speed, but you sacrifice Acceleration.....Higher the number, you gain acceleration but sacrfice top seepd. And gas mileage to due to the increased engine speeds with the higher ratio.
Old 07-19-2005, 02:26 AM
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how much would a 3.69 improve accelration, decrese top speed if limiter is removed and how much more gas would my car chug.

Is that why a c5Zo6 has a worse top speed then the c5? Gearing?
Old 07-19-2005, 02:29 AM
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That could be.....I'm not sure what you're gearing is now......But you wanna try to keep a nice even ratio for a daily driver.
Old 07-19-2005, 12:32 PM
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I'm pretty sure your at 3.06 right now.
3.29 gears might be better then the 3.69'* in terms of getting somewhat good mileage while upping the performance.
I've read people go back and forth about the two. I've read that 3.69'* are too high and your at the top of 3rd by the end of the track and others say 3.69'* are prefect. So it could go either way.
Remember that when you raise the gear ratio, you are significantly increasing the stress on your tranny.
You'll need to either reprogram your pcm or get a vehicle speed calibrator cause your speedo will be off.
Another thing is the higher the ratio the higher your rpms will be while cruising on the highway. That'* where the bad gas mileage comes in along with slightly increased wear on your engine.
Old 07-19-2005, 01:12 PM
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Ya, you'd either have 3.06 or 2.89.

The 2.89 is quite rare.
Old 07-19-2005, 01:55 PM
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Default Re: Can someone give me a lesson on gear ratios?

Originally Posted by ComfyCar
I've learned a lot here and now I want to learn about gear ratios since theres a gear ratio converter kit out for bonnevilles.

Thank you

A what kit? You're looking at serious tranny/diff work for any of that to take place? You could always fiddle with wheel diameters to get the same desired effect, but that would screw with your speedometer.

Link to such a kit? (I'm confused, lol)
Old 07-19-2005, 10:11 PM
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I've always thought that somewhere between 3.20 and 3.40 was perfect for a street car. In our cars, going from 3.29'* to 3.69'* only improves your ET by .1 second, but reduces your gas mileage considerably and you'll never get any traction in first gear. My dad has 3.29'* in his GTP and its about perfect. Around town anytime you get on it, it will downshift into first and take off. On the freeway when you are merging or something like that it drops down into 2nd and is right in the powerband. With the stock 2.93 gearing if you are merging onto the freeway and you get on it at like 45 or so the car will be a dog...did this in the SSEi last week fully expecting it to drop down into the middle of the powerband like my Lumina does and it just sat there and didn't go very well. I just like where the 3.29'* put you in the powerband for street driving. Its all a matter of opinion, but I wouldn't go with 3.69'* thats for sure.

Shawn
Old 07-19-2005, 10:29 PM
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Originally Posted by dbtk2
I've always thought that somewhere between 3.20 and 3.40 was perfect for a street car. In our cars, going from 3.29'* to 3.69'* only improves your ET by .1 second, but reduces your gas mileage considerably and you'll never get any traction in first gear. My dad has 3.29'* in his GTP and its about perfect. Around town anytime you get on it, it will downshift into first and take off. On the freeway when you are merging or something like that it drops down into 2nd and is right in the powerband. With the stock 2.93 gearing if you are merging onto the freeway and you get on it at like 45 or so the car will be a dog...did this in the SSEi last week fully expecting it to drop down into the middle of the powerband like my Lumina does and it just sat there and didn't go very well. I just like where the 3.29'* put you in the powerband for street driving. Its all a matter of opinion, but I wouldn't go with 3.69'* thats for sure.

A 4.10 rear end didn't seem too bad (see sig), it did lead to 2500rpm @ 100km/h / 60mph, however.


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