Which 1st gear ratio is best in a T56 Magnum 6-speed?

Daryl

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Given my current set up (347 stroker with 3.55 rear gears), how do you decide if a 2.66 1st gear ratio or a 2.97 ratio is best?
 

J_lope82

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I would say it depends on the cars purpose and what your desires are. I would go to the manufacturer with your set up and what you want to accomplish. They should be able to guide you the best.
 

cobrajeff96

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+1 for intended purpose. A 3.55 final drive isn't all that aggressive, so the 2.97 1st might be the jam. A 347ci (all-motor I presume) is gonna be torquey compared to the 2vs and 4vs that most people use, so it could be kind of a toss up between the two ratios. Tire selection comes into factoring.

The two ratios aren't that far apart, but keep in mind that the 2.97 gearset has the first three or four gears in close ratio, where as the 2.66 gearset has the upper gears in close ratio. Therefore, the 2.97 gearset will be very aggressive at lower speeds, and the just the opposite for the 2.66 gearset being aggressive at higher speeds.

Just depends on what you want out of it.
 

ttocs

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I have 3.55s and went with the close ratio magnum myself. I was happy with where I was shifting.
 

joemomma

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+1 for intended purpose. A 3.55 final drive isn't all that aggressive, so the 2.97 1st might be the jam. A 347ci (all-motor I presume) is gonna be torquey compared to the 2vs and 4vs that most people use, so it could be kind of a toss up between the two ratios. Tire selection comes into factoring.

The two ratios aren't that far apart, but keep in mind that the 2.97 gearset has the first three or four gears in close ratio, where as the 2.66 gearset has the upper gears in close ratio. Therefore, the 2.97 gearset will be very aggressive at lower speeds, and the just the opposite for the 2.66 gearset being aggressive at higher speeds.

Just depends on what you want out of it.
Interesting, did not know that about the ratios being close at opposite ends.
I have 3.55s and went with the close ratio magnum myself. I was happy with where I was shifting.
Any idea what RPM you're turning at highway speeds (55, 75)?
 

cobrajeff96

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Interesting, did not know that about the ratios being close at opposite ends.
Yea, if you look at the ratios on either side of 4th gear which is the 1:1 gear, you'll see that the 2.97 gearset has the first three gears pretty close and from experience they make the car move like a bat outta hell from a dig, and my car has a 4:10 so it's particularly nuts in N/A Coyote trim. It's so much fun that I can't stop cheesin'.

And then the 2.66 config has the closer ratio in the higher gears (to include 4th because 5th is a bit close to it as well).

I think I would've rather gone with the 2.66 myself given the kind of high-speed/high-duration driving I do on the Autobahn. RPM calculator has my car topping out at somewhere around 285mph, lol. 6th winds up being a wasted gear for the most part.
 
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Daryl

Daryl

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I’m a pretty mellow driver. I tend to upshift between 2500-3500 rpm’s daily driving, chilling around town. But there are of course times when I enjoy reviving it out to 5000-5500 rpm’s to get that shit-eating grin OR toast some AH who’s F’g with me ;-)

On the freeway at 55, 65, 70+ I would love to be pulling fewer rpm’s. Wondering if that 6th gear would do it?? And based on the responses and feedback here, I’m thinking the 2.66 1st gear because I go through 1st & 2nd gear pretty quickly. Maybe with the 2.66 1st gear I could stay on it a bit longer.
 

r3dn3ck

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In my 02 I had 2.83 which really worked well with the much more powerful engine that it had, the 3.55's and the >8000rpm redline. If you have a bunch of torque then you don't need such a short first gear as they come with in 5spd GT's. 2.66 seems maybe a little long to me but if you have gobs of torque and drag racing isn't your jam then it might be nice to do 45mph in first gear.
 

white95

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…the 2.97 gearset will be very aggressive at lower speeds…

Sums how my car drives nicely with the 2.97 gear set and 4.10’s. It can feel a bit frantic at times I’ve been contemplating switching the final drive for something a bit higher to stretch it out some more.
 
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Daryl

Daryl

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I’ll recheck rpm’s at different speeds Wednesday when I have the car out. Post then…
 

Musturd

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My car has a 2.87 first gear and 3.55’s i don’t like it and will be going to a 4.10 or 3.90 . 45 mph in first is a little ridiculous even with a supercharged car
 
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Daryl

Daryl

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Yeah… 45 in 1st is not my style!
 
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Daryl

Daryl

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So the 2.97 1st gear ratio?
 

cobrajeff96

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Sums how my car drives nicely with the 2.97 gear set and 4.10’s. It can feel a bit frantic at times I’ve been contemplating switching the final drive for something a bit higher to stretch it out some more.
Yea, our cars are pretty much the same for power delivery and drivetrain. I absolutely love the T-56 Mag with 2.97 1st and a 4.10 gear. But I'll have to add that the car is N/A with not a lot of mods. If it ever goes 600hp to the ground and beyond that'll probably have to change (either the trans gear set or more likely the diff gear) because I doubt there'd still be reliable traction with WOT at low speeds then. And that's already with 315s on dry pavement.
 

joemomma

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What's the difference in the Magnum and Magnum XL?
 

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