Gear ratio choice

[PhillipsLT5]

4.10's came in car from previous owner & gave me 3.45 in box
Marc did replce 3.91 speedo gear with his 4.10 gear, similar but not the same amount of teeth

[mgg]

Charlie, now that you have gotten new tires, opting for the 410's will be a good option. Phil and I have them and I would never go back. The Zr-1s are not exactly torque monsters with minor mods so the 410's are a great addition if you ask me. As what everyone has said , 6th gear is really usable. I was worried that 1st gear would be useless but this is not the case at all. The trans ratio makes the 410s a great addition. I thinks Dave has them in his as well. If you would ever like to try them you are welcome to drive my car to see for yourself. I have the black 90 and met you at Mason Dixon and at Cars & Coffee when Mclellan visited. Anyway I don't think you would be disappointed. I have 373's in my race car and I would suggest 410s all day with the ZR-1 with its lack of lowend and 7000 rpms it is a perfect fit.

[Corbusa]

Is there a big difference in fuel mileage b/t 3:73 and 4:10's , how about driving at 70 mph .I always likes 3:73's in my cars but never drove one with a 6 speed 3:73 combo...

[Meanmyz]

Originally Posted by Corbusa

Is there a big difference in fuel mileage b/t 3:73 and 4:10's , how about driving at 70 mph .I always likes 3:73's in my cars but never drove one with a 6 speed 3:73 combo...

I am also interested in answers to this question.

also:

Does 4:10 really hamper your top end? What about 3:73?

I worry about 4:10's hampering the fuel mileage too much. Out here in the rural, most is highway driving. I also don't care for the idea of turning a 180 mph car into a 160 mph car. -Even if you would hardly ever go there.

To me 3:73 would maybe be the best of both worlds, but I have never had them, so I don't know.????

[cvette98pacecar]

If you have a stock LT5 engine and have no intentions on increasing the horsepower above 500 the 4.10 gear set will help you get out of the hole faster.
If you have greater than 500 hp you will have an additional shift threw the traps. If you do the math the 3.45 gear set going threw the traps in 4th gear has a higher ratio 1.0 to 1 for forth gear and 3.45 gear set, than 5th gear .75 to 1 and a 4.10 gear set.
I do believe most of the big cube motors are running 3.90, 3.73 and 3.45 for this reason.

[WVZR-1]

There's not a "single" gear set that can be said to be "best". NONE! Serious thought should be put into a gear set and NOT just because he said, he has or what ever. Tire size, fly-wheel weight, engine modifications and the topography of where the car sees the majority of use are all equally important. John has 4.10's, but John has 315/35,s, Dick says John has 4.10's I need them but Dick has 345/19's, John has a 14# fly-wheel, Dick has the stock 40# fly-wheel, John's a "flat-lander" in Ohio or Indiana, Dick's in NW PA in the hills and his car sees an Interstate twice a year. There's "no similarity" in what could be considered a "good choice". 6th gear creates I believe the most heat of any of the transmission gears and I don't believe you'll often see O/D ratio's calculated into a power-band of a drive-train. I'm not a "flat-lander" and my car has seen 6th maybe less than a dozen times, way less.

There's an RPM and a gear that you're comfortable with and that RPM is one that you know the car will accelerate to suite "you" from. A gear selection should I believe be based on that.

3500 RPM in 4th gear with a 315/35 tire and a 3.45 gear should be something near 78 MPH, a 3.73 takes that MPH to 71, a 3.91 takes it to 68 MPH and a 4.10 to 65 MPH regardless of mods.

If your intentions are drag racing often/frequently that's a different conversation, ORR really different conversation and I don't believe you'll see an ORR guy discussing 6th gear either.

[Meanmyz]

Originally Posted by WVZR-1

John has 4.10's, but John has 315/35,s, Dick says John has 4.10's I need them but Dick has 345/19's, John has a 14# fly-wheel, Dick has the stock 40# fly-wheel, John's a "flat-lander" in Ohio or Indiana, Dick's in NW PA in the hills and his car sees an Interstate twice a year.

Let's really make this interesting and add a "Jane" to the equation!

Sorry. I couldn't resist. That was a good post with valid points though.

[WVZR-1]

Originally Posted by Meanmyz

Let's really make this interesting and add a "Jane" to the equation!

Sorry. I couldn't resist. That was a good post with valid points though.

Would it make a difference where Jane lived?

You asked about a 3.73 and @ 7K 4th gear that's nearly 144 MPH and that would make a 7K 5th 191 MPH both with a 315 tire, a 4.10 @ 7K 4th is 130 MPH and a 7K 5th 173 MPH.

6th adds absolutely no value or relevance when calculating generally MPH and RPM's, the additional stress and heat are killers to the transmission. Are there differing opinions? Likely so but I don't believe the additional stress and heat can be argued.

[mike100]

I had a former 95 ZR owner tell me that he was totally thrilled how his car ran after going to 3.73's. plus there's a proper gear that drops onto the speed sensor making correction super easy.

[RICKYRJ1]

I,m running 3:73 but I have 325/19" tires which I believe puts me back close to the stock 3:45 I also have a 500+hp engine. I like but would not hesitate to go to 4:10. I enjoy them from cars I have driven