Exhaust Drone Fixed! Spoiler Alert another 3.21 vs 3.92 discussion

[Bmags]

Just curious, why not just use the gear selector to hold in 7 and instead of programmer ?

I could have done that, and in fact I used to (to get rid of MDS anyways)... but it's so much nicer to just be able to hop in, put the selector in D and mash the gas pedal.

I also frequently have to put the vehicle in park and reverse and pushing the steering wheel buttons every single time got old quick.

 

[Bmags]

Well, since it never gets into 8th gear. How would that help?

Fair enough, I forgot you mentioned you never get in to 8th compared to mine hunting

 

[rvance]

Fair enough, I forgot you mentioned you never get in to 8th compared to mine hunting

Yeah, mine doesn't even hunt. Also, V6, remember? That's why I thought the 3:73 gears would put it solidly in 8th at 80 mph.

 

[leftchevybehind]

Not recommended to outright flash out a gear like that, especially if you use the truck for truck stuff

 

[Bmags]

Why? Please elaborate…

I beg to differ based on two points:

1) There is no difference on the final drive train ratio going down the highway with this setup compared to a truck built with 3.92 gears.

2) This is no different than running the truck using the ERS limited to ‘7’ which is also used when doing “truck stuff”

How is this hard on anything or not ideal?

 

[leftchevybehind]

Why? Please elaborate…

I beg to differ based on two points:

1) There is no difference on the final drive train ratio going down the highway with this setup compared to a truck built with 3.92 gears.

2) This is no different than running the truck using the ERS limited to ‘7’ which is also used when doing “truck stuff”

How is this hard on anything or not ideal?

Could have transmission issues or cause unnecessary engine stress because your gear ratios were optimized for your initial vehicle configuration. Even if the ratio is the same, which does mitigate potential issues, your vehicle and its original configuration were optimized with the gear you removed. In other words, from a systems engineering perspective, all the components have a different output for a reason.

I would actually just swap to 3.92 gears and get things recalibrated

 

[Bmags]

Could have transmission issues or cause unnecessary engine stress because your gear ratios were optimized for your initial vehicle configuration. Even if the ratio is the same, which does mitigate potential issues, your vehicle and its original configuration were optimized with the gear you removed. In other words, from a systems engineering perspective, all the components have a different output for a reason.

I would actually just swap to 3.92 gears and get things recalibrated

There is nothing different between a 3.21 and a 3.92 truck besides the gears in the diffs. Even the transmission “tune” is the same for a stock vehicle in each configuration regardless of the gear ratio. The transmission gear shifting is soley based on input shaft speed (ie the engine RPM)

The swap provides only a marginal benefit getting a heavy load moving, but that’s it.

 

[leftchevybehind]

There is nothing different between a 3.21 and a 3.92 truck besides the gears in the diffs. Even the transmission “tune” is the same for a stock vehicle in each configuration regardless of the gear ratio. The transmission gear shifting is soley based on input shaft speed (ie the engine RPM)

The swap provides only a marginal benefit getting a heavy load moving, but that’s it.

I'm not saying it doesn't work, because workarounds keep old legacy architecture operationally stable in the IT space, I know the truck will do what you need it too by hiding one of its gears, but I personally wouldn't flash, I'd re-gear and recalibrate. I'm one of those people that will pay more to do something 100% of the way, than save a few bucks getting 80% there - even if both approaches result in the same outcome and I could save money.

But if the flash works like a charm, then it shouldn't matter either way. Just re-flash to stock before trade-in or sell. There should be a traceable fingerprint but most dealers aren't going to check that sort of thing unless it was like a diesel (even then).

 

[Bmags]

I'm not saying it doesn't work, because workarounds keep old legacy architecture operationally stable in the IT space, I know the truck will do what you need it too by hiding one of its gears, but I personally wouldn't flash, I'd re-gear and recalibrate. I'm one of those people that will pay more to do something 100% of the way, than save a few bucks getting 80% there - even if both approaches result in the same outcome and I could save money.

But if the flash works like a charm, then it shouldn't matter either way. Just re-flash to stock before trade-in or sell. There should be a traceable fingerprint but most dealers aren't going to check that sort of thing unless it was like a diesel (even then).

You’re talking nonsense. You keep saying recalibrate but that’s not a thing. Take the software from a 3.92 factory truck and a 3.21 factory truck and they are identical. The transmission code is EXACTLY the same between the two.

And I couldn’t care less about turning it back to stock. This truck will forever be a 7 speed…

 

[leftchevybehind]

You’re talking nonsense. You keep saying recalibrate but that’s not a thing. Take the software from a 3.92 factory truck and a 3.21 factory truck and they are identical. The transmission code is EXACTLY the same between the two.

Whatever you say bro, it's your truck, you do whatever you feel is best.

 

[Bmags]

Not recommended to outright flash out a gear like that, especially if you use the truck for truck stuff

There is a time and a place for opinions, and they begin with such things like… “I think that….” Or “I could be wrong but…” or “I was under the assumption…”

To make a statement such as yours that’s factually incorrect is damaging to the community at large. Contact GDE, or any other tuning company and they will tell you the same thing… and they are the ones that get paid for selling a tune!

If you brought your truck in for a gear change and a recalibrate the shop would just regear your truck and then take your recalibration money and add it to the nightly beer fund.

I will add to this thread as the miles go up on my truck. I pull car trailers, horse trailers, and campers. I am not worried about the longevity of this in the least.

I can say that other truck manufacturers do have different transmission software, as that can affect the speedometer and other sensors. Chevy is like that for instance… but Dodge does their setup differently.

 

[GeauxinUp]

I don't think there's 3.73's available for the 1500's,that's more 2500 territory.
You must of been driving an oddball 5.7 if it wouldn't go into 8th with 3.21's,when i had 3.21's in my truck,it'd go into 8th at 50 mph no problem.I switched to 3.55's and in hindsight i wished i'd never made the switch,i prefered the 3.21's over the 3.55's.I made the switch for the dragstrip,and the truck never gained anything at the track.
If i didn't have a $h!tload of money invested in the rear diff with 3.55's in it,the 3.21's would be going back under the truck,as i still have my basically new 3.21 front and rear diffs sitting in my storage shed

You'd go back to 3.21's over going down to 3.92's??

 

[Wild one]

You'd go back to 3.21's over going down to 3.92's??

In a heartbeat. I'm no fan of 3.92's,as my truck used to spend more time at 80+ mph then it does at 60mph,plus going from 3.21's to 3.55's didn't gain me squat at the track,but the truck lost a good 6 or 7 mph wide open,with 3.21's it pulled 155 mph,with 3.55's the best it's done is 149 mph

 

[GeauxinUp]

In a heartbeat. I'm no fan of 3.92's,as my truck used to spend more time at 80+ mph then it does at 60mph,plus going from 3.21's to 3.55's didn't gain me squat at the track,but the truck lost a good 6 or 7 mph wide open,with 3.21's it pulled 155 mph,with 3.55's the best it's done is 149 mph

Interesting...I'm in the middle of ordering parts (6.4 intake, long tubes, tuner), and was strongly considering switching from 3.21's to 3.92.

 

[Wild one]

Interesting...I'm in the middle of ordering parts (6.4 intake, long tubes, tuner), and was strongly considering switching from 3.21's to 3.92.

What's your average speed,if you run freeways at 70+ mph you might want to stick with the 3.21's.If the majority of your driving is stop-n-go city driving with very little time spent above 70 mph,then the 3.92's are okay.
If your truck is a 4X4 you also need a completely new 3.92 geared front diff.You have to factor in the cost to swap to 3.92's on a 4X4 as it's not a cheap swap,and whether it's justiable is up to you

 

[Bmags]

Just remove 7th gear from your tranny tune for a while and see how you like it. You effectively get the same thing as 3.92 gears. If you like it, either keep it like that or regear to make it official.

Easy peasy

For me, just tuning out 8th gear is awesome

 

[GeauxinUp]

What's your average speed,if you run freeways at 70+ mph you might want to stick with the 3.21's.If the majority of your driving is stop-n-go city driving with very little time spent above 70 mph,then the 3.92's are okay.
If your truck is a 4X4 you also need a completely new 3.92 geared front diff.You have to factor in the cost to swap to 3.92's on a 4X4 as it's not a cheap swap,and whether it's justiable is up to you

I don't drive a ton...only have 65k on it, but mostly driving 60-80mph. I'll probably just do a truetrac in the rear and call it good. I've been pretty happy with the stock setup for a while anyways (other than the one wheel peel). Never understood why they'd put an open diff in a 4x4.

 

[GeauxinUp]

Just remove 7th gear from your tranny tune for a while and see how you like it. You effectively get the same thing as 3.92 gears. If you like it, either keep it like that or regear to make it official.

Easy peasy

For me, just tuning out 8th gear is awesome

I'll try it on the gear selector and see how it goes. Thanks

 

[62Blazer]

I'll try it on the gear selector and see how it goes. Thanks

Just to clarify:
If you have 3.21 gears manually select 7th gear and do drive. Running 3.21 in 7th gear will give you real close to the same cruising RPM on the freeway as if you had 3.92 gears but let it run in 8th gear. Obviously won't give you the same feeling on initial take off or through the lower gears as going to 3.92, but for just cruising down the highway it will tell you what it is like.

 

[ramffml]

Just remove 7th gear from your tranny tune for a while and see how you like it. You effectively get the same thing as 3.92 gears. If you like it, either keep it like that or regear to make it official.

Easy peasy

For me, just tuning out 8th gear is awesome

I prefer to run around everywhere bouncing off the rev limiter.

Be a man, tune out everything after 4th. Overdrive is for grannies.