Gear question

[Sgt_Rattlehead]

So i bought a used 2014 laramie 1500 with the 8 speed tranny I downloaded the build sheet from dodge/ram website and it says it came with 3.21 gears.... so here is my question, Ive been around quite a few muscle cars, before this truck it was a challenger, ever since i bought this truck i have been very impressed with the acceleration on this truck, it just doesnt feel like 3.21 gears, it really doesnt , so is there a stamp or something on the diff that will tell me for sure or any other way to find out???


fyi this is what it says on the build sheet:
3.21 Rear Axle Ratio
235MM REAR AXLE
Conventional Differential Rear Axle

 

[Burla]

That is a very common feeling, it is the transmission shift points that makes that puppy so impressive.

 

[Ratket]

Easy to belive that with just a few mods that thing can run 12"s in the quarter uh.

 

[Sgt_Rattlehead]

Easy to belive that with just a few mods that thing can run 12"s in the quarter uh.

i live less than3 miles from a track, when i get some time im gonna go run it to get a base line and see what happens after a few mods.

 

[Wild one]

On the bottom of the drivers side axle tube there should be a sticker listing the axle ratio.Depending on the condition of the sticker though,it might not be all that readable anymore.If it is,it'll have the ratio in small print,so you might have to look hard for the number.Conventional diff,means you have no posi/limited slip,she's a 1 wheel peeler, 235MM axle is generally referred to as the later model 9.25 ZF diff,differant then the earlier 9.25,but seems to be a fairly decent diff,except for lack of good aftermarlet limited slip units.You can put a Tru Trac posi in them,but it's not cheap,as you need the earlier 9.25 gears and one extra pass side axle,plus the posi unit.The factory limited slip is the cheapest one you can put in,it'll hold up for most guys,but doesn't care much for horsepower and water box burnouts, if you're going to modify the truck,and run at the track fairly often.The clutches in the factory limited slip are usually the weak link

 

[Skubasteve!]

Easy to belive that with just a few mods that thing can run 12"s in the quarter uh.

What few mods are these?

 

[69GWC]

The 8sp makes all the difference on these trucks. I would have never bought 3:21s with a older stlye trans and was not going to buy one even with thr 8sp untill I drove it and was surprised at how well it runs out.
Still going to put 3:92s in mine but really just because I am going to 35s.

 

[Pull Ya]

Other than off the line the gearing really doesn't make a huge difference with the 8 speed. Now all the 3.92 guys will jump in and start hooting and hollering but with the 8 speed once you get through 1st gear the 3.92's advantage disappears.

Time slips would greatly enhance your theory. Other mod's might also enhance acceleration ie; the Pedal Commander.
Jay

 

[Pull Ya]

I guess my question would be, can the off the line advantage(3.92) be made up by the end of the 1/4 mile, given everything else is identical. Not taking traction(or lack of it) into account. My personal experience has shown that even in passing mph range----50-65mph, the 3.92 gearing has the advantage.
Jay

 

[Sgt_Rattlehead]

On the bottom of the drivers side axle tube there should be a sticker listing the axle ratio.Depending on the condition of the sticker though,it might not be all that readable anymore.If it is,it'll have the ratio in small print,so you might have to look hard for the number.Conventional diff,means you have no posi/limited slip,she's a 1 wheel peeler, 235MM axle is generally referred to as the later model 9.25 ZF diff,differant then the earlier 9.25,but seems to be a fairly decent diff,except for lack of good aftermarlet limited slip units.You can put a Tru Trac posi in them,but it's not cheap,as you need the earlier 9.25 gears and one extra pass side axle,plus the posi unit.The factory limited slip is the cheapest one you can put in,it'll hold up for most guys,but doesn't care much for horsepower and water box burnouts, if you're going to modify the truck,and run at the track fairly often.The clutches in the factory limited slip are usually the weak link

great info! thank you!!!

 

[Sgt_Rattlehead]

Time slips wouldn't prove this as its about passing speeds not off the line speeds.

You have to look at the ratios in the transmission and rear. Although the 3.21 guy will be a gear lower through a running start but if you look at the shift points and ratios it will prove that difference once you are out of 1st is mathmatically made up on the transmission side. So again passing on a road or highway of both trucks were the same minus the differential they would yield nearly identical results with limited variables.

And do not get me started on the pedal commander.

3.92s make the truck a beast off the line I'm not disputing that. Once the transmission starts moving through gears is where the 3.21s will match it. Gears do not add power, they are a mechainical advantage that allows the engine to spin up faster to get to the power band.

Sent from my LG-H872 using Tapatalk

what are your thoughts on the pedal commander? i believe tunes will definately improve your performance but I always thought (and i may be wrong) throttle response mods are ussually a letdown.

 

[Sgt_Rattlehead]

Placebo. It only adjusts the throttle curve to be exponential vs linear. For example you push the pedal 20% down we will say for education, it will request 20% throttle and power from the motor. Well it's actually a request for a torque amount. The commander makes it so that we say 20% throttle on the pedal is 50% request of torque by altering the signal. This is how every BMW and Mercedes are programmed.


It does make it "feel" faster, but at the end of the day side by side full throttle is full throttle. It just makes it seem like it has more power because youve barely pushed the pedal and you are whisked away.

Sent from my LG-H872 using Tapatalk

i figured it was something like that, u used to be able to do that with throttle cables by putting some sort of spacer (cut hose works well) between the pedal and the throttle cable so the cable starts pulling faster, u dont get the exponential effect but your car was at full throttle without having to have the pedal all the way down.

 

[Chief_6.7]

Could be a dumb question but are 392s a must if your running 35 inch tires? Also if your 4x4 and you just upgrade the rear to 392s is there anything wrong with that? Or can it even be done?

 

[Rockit]

gosh I love the interweb

 

[69GWC]

I honestly dont see how anyone can drive with the throttle being more touchy, when I am on a gravel road or wet road its hard to get my truck to even move as it just spins the tires with a light throttle. The weight of my topper has helped alot with that though.
The 8sp was the best thing Ram did that transmission is allways in the right gear with the close ratios it has.
Too bad they dont have a 8sp for the 2500s it would make them twice the trucks as the competition but that 6sp thats in them hurts them alot imo.

 

[69GWC]

Could be a dumb question but are 392s a must if your running 35 inch tires? Also if your 4x4 and you just upgrade the rear to 392s is there anything wrong with that? Or can it even be done?

You dont haft to switch to 392s but you would be better off you will lose lowend punch, but it really depends on how much lowend or take off power you want to have.

you also haft to do front and back when doing so.

I will be going to 35s at some point and then I will upgrade to 392s .

 

[Pull Ya]

OP--you need to realize that "WilliamS" is in the small minority regarding his thoughts on the Pedal Commander. You can read the thread regarding the Pedal Commander. Everyone has there own opinion, however his opinion on the Pedal Commander runs contrary to hundreds of other members who believe the Pedal Commander is in fact a worthwhile investment.
Jay

 

[Sgt_Rattlehead]

OP--you need to realize that "WilliamS" is in the small minority regarding his thoughts on the Pedal Commander. You can read the thread regarding the Pedal Commander. Everyone has there own opinion, however his opinion on the Pedal Commander runs contrary to hundreds of other members who believe the Pedal Commander is in fact a worthwhile investment.
Jay

i understand, my train of though is if your going to do any serious upgrades youre gonna need a tuner right? dont most tuners adjust throttle sensitivity nowadays, so to buy a pedal commander as well thats another like 300 bucks (i think)

so to me its a cost vs performance type thing

 

[Pull Ya]

I have both a tuner with a custom tune by Hemifever and also a Pedal Commander. Most tuners do adjust the throttle response however I think that the Pedal Commander gives you more choice as to throttle response. A tune and the Pedal Commander work very well together. A tuner is one of the so called "basic" mod's. The Pedal Commander is one of the additional mods that can be added. It DOES NOT increase the horsepower or torque of the truck, it increases the speed at which the throttle responds. It has 32 optional settings and can be adjusted on the fly, unlike many tuners that can not be adjusted on the fly. It also is a true plug and play and it does not leave a footprint on the ECU.
Jay

 

[Pull Ya]

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