What do you think of these ratio's (Viper tranny)

[747mopar]

Thinking about buying a Viper tranny for the Charger, I found a 2004 6 speed with 18,000 miles on it for $1,800. The gear ratio looks pretty darn nice for a cruiser which is what I want, 1st 2.66 2nd 1.78 3rd 1.30 4th being 1.00 5th .74 and .50 for 6th. Really thinking hard about buying this

 

[HT413]

Lol with that 0.50 OD, you can run 5.13 gears and terrorize the strip in 1st through 4th while cruising the highways in style like no 2.73 gear can.

 

[Hemi Rebel]

1800 for a viper t56. Lucky. I would be on that

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Lol with that 0.50 OD, you can run 5.13 gears and terrorize the strip in 1st through 4th while cruising the highways in style like no 2.73 gear can.

Yeah. Torque is a necessity with this gear box

 

[conv67bdere]

Nahhhh . . . you don't want that tranny 747Mopar . . . I'll take it and get it off your hands and eliminate that decision for you . . . what are friends for ! ! ! ( smile )

 

[747mopar]

Nahhhh . . . you don't want that tranny 747Mopar . . . I'll take it and get it off your hands and eliminate that decision for you . . . what are friends for ! ! ! ( smile )

Me thinking I just might make the phone call tomorrow haha.

 

[kb67mopar]

If it comes with the bell housing id say its an ok deal. Without it I'd call it pricey. I'd also factor in a set of 3.92 or 4.10 gears to run with it.

 

[benno440]

does this mean you will be cutting up your nice new floor and trans tunnel

 

[HT413]

I'd seriously get a 5.xx:1 gearing and just start off in 2nd most days. My 4:10's put me at 3000 rpm for about 65mph with my 1:1 3rd gear 727. Same setup puts you at 1500 rpm at 65. A 3:55 puts you way closer to 1000 rpm, and that's rv cam territory, so if you plan on putting any cam in that motor at all, that 6th gear may end up useless.

 

[benno440]

yeh agreed, I got 3:55 rear and a 4 speed OD, 1st is real low, 2nd and 3rd are a tad too high and 4th is .75 so I sit on 1900 rpm at 100kmh(60mph) good economy drove 600miles and only 1 fuel stops with my monster motor and still bags the tires haha

 

[747mopar]

I'd seriously get a 5.xx:1 gearing and just start off in 2nd most days. My 4:10's put me at 3000 rpm for about 65mph with my 1:1 3rd gear 727. Same setup puts you at 1500 rpm at 65. A 3:55 puts you way closer to 1000 rpm, and that's rv cam territory, so if you plan on putting any cam in that motor at all, that 6th gear may end up useless.

Yes, a gear change will happen if I go this route. I'm running 3:55s right now and am at 3,100 rpm @ 70 mph running 27" tall tires. I built the motor knowing that I would be overdriving it with everything built to start making power around 1,800 rpm but was planning on the T56 Magnums .64 overdrive.

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If it comes with the bell housing id say its an ok deal. Without it I'd call it pricey. I'd also factor in a set of 3.92 or 4.10 gears to run with it.

I can't find any cheaper.

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does this mean you will be cutting up your nice new floor and trans tunnel

I've got a whole winter to sit threw with nothing to do so why not, still thinking. Really would like the gearing of the T56 Magnum better buts it's $$$$$$.

 

[MT_Mopar]

Me thinking I just might make the phone call tomorrow haha.

Buy it... we want to look at the pictures. :headbang:

 

[cdr]

just a note,when running a low rear end gear ,say 4.10 with an overdrive trans your drive shaft rpm will be much higher than engine rpm.i got a 4 in diam alum shaft made & had it high speed balanced. otherwise you will have bad driveline vibration.just sayin

 

[747mopar]

Thanks Charlie, thar's a really good point.


O.K, here's my problem. After some figuring I'd have to run a 4.57 rear gear to put the rpms where I want it (1990 rpm @ 70 mph), 4.10s put me at 1785 which is a little below the rpm level of my motor so hmmmm. Here's the big question, I've never run anything higher than 3.89s so I don't know if 4.57s would be like a granny gear in a truck or just a hole hell of allot of fun. What do you guys think?

 

[HT413]

Thanks Charlie, thar's a really good point.


O.K, here's my problem. After some figuring I'd have to run a 4.57 rear gear to put the rpms where I want it (1990 rpm @ 70 mph), 4.10s put me at 1785 which is a little below the rpm level of my motor so hmmmm. Here's the big question, I've never run anything higher than 3.89s so I don't know if 4.57s would be like a granny gear in a truck or just a hole hell of allot of fun. What do you guys think?

4.57's will be awesome for acceleration and won't be a granny gear at all if you're really getting into it. But i could see it feeling like a granny gear during normal driving, so most times I'd do a 2nd gear start.

That's how I would build it - 4.57's or numerically bigger. This way you get the best of both worlds, and I would think this would maximize the value of the car as well, as it will satisfy about everyone.

 

[cdr]

i would go with 4.10 just to keep the pinion speed down,you might have to put a rear end cooler on it. i went 3.91 with .69 od

 

[Photon440]

Thanks Charlie, thar's a really good point.


O.K, here's my problem. After some figuring I'd have to run a 4.57 rear gear to put the rpms where I want it (1990 rpm @ 70 mph), 4.10s put me at 1785 which is a little below the rpm level of my motor so hmmmm. Here's the big question, I've never run anything higher than 3.89s so I don't know if 4.57s would be like a granny gear in a truck or just a hole hell of allot of fun. What do you guys think?

I wouldn't worry about the revs being too low at 70mph, nobody says you have to use 6th gear. It doesn't help performance on the Viper, more for emissions and gas mileage. Back in 2004, the year you're looking at, Dodge only used a 3.07 rear gear. The newer ones with closer ratios use a 3.55 rear.

 

[747mopar]

If it comes with the bell housing id say its an ok deal. Without it I'd call it pricey. I'd also factor in a set of 3.92 or 4.10 gears to run with it.

I'm glad you mentioned it being pricey even though I don't think it is because that lead me to more digging around. I called my local salvage yard which put me in touch with another yard that specializes in them and voila $1,500 for the same tranny (04 17,000 miles). I'M DOING IT, if all goes well with gathering parts I'm tearing the Charger back apart as soon as the first truck load of salt hits the road (which could be tomorrow in Ohio).

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I wouldn't worry about the revs being too low at 70mph, nobody says you have to use 6th gear. It doesn't help performance on the Viper, more for emissions and gas mileage. Back in 2004, the year you're looking at, Dodge only used a 3.07 rear gear. The newer ones with closer ratios use a 3.55 rear.

I was just talking to the guy I'll be buying it from and he said the same thing, I think I'll just leave my 3:55s in there long enough to see what I think. I have a spare 489 center so it won't be an issue to put a set together and swap gears at some point.

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i would go with 4.10 just to keep the pinion speed down,you might have to put a rear end cooler on it. i went 3.91 with .69 od

I like your thinking, 4.10s is what I wanted to run and it's pretty close to my rpm range even with the .50 overdrive (I think with 456 cubes it will be fine). I like the cooler suggestion because the high gear speeds had me concerned (another unchartered territory for me) so I'll look into that. Do you use a pump to circulate the oil?

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Buy it... we want to look at the pictures. :headbang:

I'm almost positive I'm going this route and if so I'll do a full thread on it. The plan will be simple "POOR MANS OVERDRIVE", I'll trim the absolute minimum amount of the tunnel, build my own crossmember reinforcement patch, build the trans crossmember, use old Mopar pedals, etc. The goal will be to do a tranny swap that most can afford without compromising the car in anyway. I'm getting excited already!!!!!!!!!!!!

 

[HYRDGOON]

There is a thread I look forward to following! It's funny our minds are in the same loop once again I just finished going back and forth with Jamie Passon about the A-855. I really like the idea of direct swap with no tunnel mods since mine is already a stick car (although it wasn't born that way)

 

[747mopar]

There is a thread I look forward to following! It's funny our minds are in the same loop once again I just finished going back and forth with Jamie Passon about the A-855. I really like the idea of direct swap with no tunnel mods since mine is already a stick car (although it wasn't born that way)

I was thinking about the TKO 600 because it will fit right in there and still has a great overdrive but my 2 reasons for a change in mind are #1 cost (I can't afford it and think it's ridiculous) #2 is the T56 6 speeds are a single rail shifter meaning really smooth shifts. When it comes right down to it I like cutting things up anyways so this should be fun. I should have just over the price of the trans alone ($3,000) in the whole thing, I'm thinking $3,500 I already snagged up a 130 tooth flywheel at a Summit scratch and dent sale since I knew I was going to do this eventually so that's one thing down.

 

[HT413]

Sounds like a great thread, can't wait. I like your thinking, fairly economical, some fab work and you end up with a bullet proof setup.