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Discussion Starter #1
I was doing some internet pricing for lower rear end gears for my R/T and I was thinking about going for some where in the 3.50-3.70 range (current ones are 2.65). I am very new to this and my mechanic agreed to install them if I buy the stuff but I was wondering what all do I need to change out the gears. I think I remember seeing a full kit a while back that was around $2,000 but that came with the rear axle and everything. But if I only need to change out a few things than I may not need the whole kit. If anyone could provide some info I would greatly appreciate it because I am interested in doing this mod but I've been staying clear of it due to my lack of knowledge on what would need to be replaced and what would be ok to leave on. Also for what it is worth I am doing mainly city driving and sometimes on the weekends I'll do some highway driving (typically 60 MPH). I don't want anything too bad that will make it a nightmare if I want to get onto the interstate (sometimes I do some traveling in the Summer time). Also I will NOT be taking this car to the track or anything like that because it is my daily driver.
 

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First of all, what you are referring to is called shorter gears, not lower. Let's not confuse a transmission with a differential. If all you want to change is your final drive then you can buy a ring and pinion kit from someone like Richmond. It's going to take someone with real experience to install it though, so be sure before you hand it over.
 

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Discussion Starter #3
First of all, what you are referring to is called shorter gears, not lower. Let's not confuse a transmission with a differential. If all you want to change is your final drive then you can buy a ring and pinion kit from someone like Richmond. It's going to take someone with real experience to install it though, so be sure before you hand it over.
Like I said I am out of my expertise here lol. I am not sure what the proper term is I just know everyone always calls them lower gears. I know what they do and all I just don't know all of the components that goes into it. I am wanting to change my gear differentials (I think that is right) so basically I get more torque but I lose out on my top speed. the 2.65 gears right now is way to high IMO and I think it is just a MPG thing that Dodge is doing so these cars seem more appealing to the people that want good gas mileage, I'd rather have the power :driving: Anyways so all I need is the ring and pinion? Is there an article I can read to help me understand a little bit better? Like I said in my earlier post I don't want to change out a few things and have something else break only to find out it could have been avoided if I would have upgraded that part too.
 

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The nomenclature is a bit confusing! Tall or high final drives have a lower number, while short or low gears have a higher number. Check this article for a concise explanation: http://www.superchevy.com/how-to/148-0208-gear-ratio-calculating/

The R/T R&T and SRT have final drives of 3.06 and that would be a good choice. If you go to an even shorter final drive, say 3.55, 3.73, or 3.92 be aware you will be turning considerably more RPM at highways speeds. This not only consumes fuel, but is noisy.

Check with Speedlogix, they have complete kits available. You want to get a limited slip differential (LSD). Getrag is a popular brand with LX owners.
 

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Discussion Starter #5
The nomenclature is a bit confusing! Tall or high final drives have a lower number, while short or low gears have a higher number. Check this article for a concise explanation: http://www.superchevy.com/how-to/148-0208-gear-ratio-calculating/

The R/T R&T and SRT have final drives of 3.06 and that would be a good choice. If you go to an even shorter final drive, say 3.55, 3.73, or 3.92 be aware you will be turning considerably more RPM at highways speeds. This not only consumes fuel, but is noisy.

Check with Speedlogix, they have complete kits available. You want to get a limited slip differential (LSD). Getrag is a popular brand with LX owners.
I've heard 3.55 is the perfect blend of city and highway which is what I am looking for. I want some real results when I put all of this in and while I am sure the 3.06 would be noticeable I want more than just that lol. So out of curiosity excluding the labor how much does all of this normally run for the parts?
 

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Go big or go home.....3.92's are amazing and cheap...Mopar 11's came stock with that ratio. Getting traction takes skill, but worth the results
 

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Discussion Starter #9 (Edited)
Go big or go home.....3.92's are amazing and cheap...Mopar 11's came stock with that ratio. Getting traction takes skill, but worth the results
Lol this is my daily driver and I would like to be able to do some highway driving without hitting 3500 RPM's. Where would 3.73's put me at on RPM's doing around 60 MPH?
 

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Lol this is my daily driver and I would like to be able to do some highway driving without hitting 3500 RPM's. Where would 3.73's put me at on RPM's doing around 60 MPH?
You can figure this out with basic Algebra. This is the formula every racer uses to see what gear they need to cross the line in.

Final Drive Ratio x MPH x Trans Ratio / Tire Diameter = RPM

Trans Ratio is what gear you want to be in to see the RPM. If you are only talking about cruising on the highway then you'd be in 5th. If you were racing you'd most likely want to be at the top of 3rd. So you'd need to know what the NAG1 gears are to plug them into this forumla.
 

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Gear Ratios
1st 3.59
2nd 2.19
3rd 1.41
4th 1.00
5th 0.83
Reverse 3.16
Final Drive Ratio SE (RWD) — 2.65
R/T, R/T Plus and R/T Max (RWD) — 2.65
R/T Road & Track (RWD) — 3.06
R/T (AWD) — 3.06
 
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