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Hi People,
I'm new to Forums, and to the Charger. Haven't had a new Dodge since 1973. Wow, I'm really impressed. Maybe Dodge will keep the spirit alive. Any how, I see a lot of talk about Cold Air systems, Chips, exhaust, silencers,turbos, etc. What about the real performance add ons. LIKE GEAR RATIOS. Has anyone done or tried changing rear gears?
 

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there is little room in the axle for a bigger gear. Also there is noone yet that has based on computer programming for gear changes. If it could physically be done , the tranny, vss, abs, and t/c would all be affected by inaccurate readings from the vss.
 

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Hi People,
I'm new to Forums, and to the Charger. Haven't had a new Dodge since 1973. Wow, I'm really impressed. Maybe Dodge will keep the spirit alive. Any how, I see a lot of talk about Cold Air systems, Chips, exhaust, silencers,turbos, etc. What about the real performance add ons. LIKE GEAR RATIOS. Has anyone done or tried changing rear gears?
Yes. One guy went to the mat and dumped a ton of money into a new rear end ratio. He had a V6 and swapped in the 3.90 from a 2.7L if I remember correctly. At the end of the day, after investing a TON of money and working very closely with his dealership that was doing the work (and really trying to make it work), the patient rejected the donor organ. Even the Dodge service department was unable to get the computer to function with the new ratio.

Until Chrysler releases info on how to tweak the computer, we won't get to do gear ratios, and we'll get minimum gains from everything else. Personally, I'm holding out until that day, since it doesn't seem like it's worth screwing around with the small stuff. I want a cam and gears.
 

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there is little room in the axle for a bigger gear. Also there is noone yet that has based on computer programming for gear changes. If it could physically be done , the tranny, vss, abs, and t/c would all be affected by inaccurate readings from the vss.
When you swap to a different ratio, the gears are physically the same size, they just have different numbers of splines on them. You do have to use the same size gears, though. The SRT-8 has a larger rear end and does use physically larger gears.
 

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Changing the final drive gear ratio is easy.. put on different size rear tires... hehe...

On a serious note, Changing the rear ring & pinion in the rear diff will be easy, Just have to find the proper R&P that will fit... Im not sure what type of rear end we have, but I am sure it is used in some other car as well... Maybe even the R&P out of a V6 is different then in a V8 charger? Thats something to look into..

As far as changing actual transmission gears which will change shift points etc, that will be a much more in depth installation and probably not be nearly as cost affective as changing the R&P...
 

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CDK, this rear end is indeed used on other cars. The last generation Mercedes E-Class:) MB did make one or two other sets, but without programming, it wont work.

There are other, minor, but still there, mechanical problems to fitting an SRT unit into a non-SRT. SRT has a different diff case, since its 215 ring gear wont fit into the case the 5.7s 210 ring does. So you need the whole SRT unit.

Now you'll need an adapter or a new driveshaft, or a new trans ouptput shaft, since the SRT one is a four bolt, as is the driveshaft. The 5.7s use a three bolt.

Axles are different too, so you'll need to get the SRT rear hubs. Not sure if those are compatible with the 5.7 brakes.

The V6 cars do have different ratios, but as noted before, putting those in causes limp mode.
 

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I have only had my charger a week... so I dont really know all that much about it parts wise and whats swappable etc...

But, from what I can tell so far, if I wanted to change my final drive gearing, I would probably just get some 18" forged wheels rather than these 20" cast weights, and run a 1-2" shorter tire. Will be a great weight reduction, probably save close to 100lbs of unsprung weight, then reduce rotational mass... will make for greater acceleration and suspension response as well...

options options...
 

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there is little room in the axle for a bigger gear. QUOTE]

the overall gear ring gear size typically stays the same, the pitch the teeth are at changes, and the gear gets thicker, the diameter of the pinion head gets smaller as the gear ratio gets lower (numerically higher)do to less teeth on the pinion.
you can have a ring gear with 41 teeth on the ring and 10 on the pinion, which would give you a 4.10 ratio, or 41 & 9 for 4.56.

so as the ratio gets lower, the teeth tend to move closer to being at the centerline of the pinion.
 

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Right, and thats the case for the 5.7 and 3.5, different rings, different ratios, same case. But the 6.1 does have a different ring, and case.
 

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Right, and thats the case for the 5.7 and 3.5, different rings, different ratios, same case. But the 6.1 does have a different ring, and case.
I like the sound of that. Hopefully a kit will be available to install some lower gears and make our cars work with them. That will really make our Chargers run much better without really hurting our engines with major power increases.
Randy
 

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so, you all would prefer a lower final drive gear ratio for higher top speed and slower acceleration?

rather then a taller gear ratio for greater acceleration and a lower top speed?

this will also make up for the heavy 20-22" wheels most are putting on ...
 
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