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Discussion Starter · #21 ·
Looks like it hit the rev limiter but mine never went into limp mode. Happened when I first got the DD and was paying around with the paddle shifters. Otherwise that's a new one for me. Haven't seen it on the web.

Most hand held tuners have a way to raise the rev limit. I'd put it as high as you can go. I'd be careful
though till you contact the MAGs guys again.
so it does it before it hits rev limiter. Its like right at 6k it shuts off but new tune has rev limiter at 6100 for all gears. I emailed MAGs what is going on so I’ll update once i hear back and if we figure it out.
I wish there wasn’t an issue because then i could go get some runs in today! Pretty sure this will fix the issues on slow times and show actual improvement of the gears because i get 600 more rpm in 1st and 300 more rpm in 4th
 
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You’ll want a new tcm tune to take advantage of them. With the driveshafts spinning faster, the transmission is seeing its targeted shaft speed sooner and shifting sooner.
This is spot on when output shaft speed is hit, the trans will shift.

I’ll try post pics here tomorrow on how to simply change gear ratio in your handheld.
 
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I just went and filmed the speedo and tach for my 1/4 mile run and I think I figured out why my 1/4 mile didn't improve much with these.

It's shifting into 5th gear at 94mph before it hits the 1/4 mile at 99mph where as before the gears it would finish the 1/4 mile in 4th gear and not have that extra shift.

Here are shift points:

1st to 2nd: 5500rpm at 34mph
2nd to 3rd: 6000rpm at 54mph
3rd to 4th: 6100rpm at 77mph
4th to 5th: 5800rpm at 94mph

If I can get the tuner to make the 1st to 2nd shift point a higher rpm and the 4th to 5th a higher rpm I think I can shave time off. Especially if it doesn't shift into 5th gear before crossing the 1/4 mile.

Can’t wait to watch this…
 
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Discussion Starter · #24 · (Edited)
I don’t see anywhere in my tuner to change gear ratio or transmission stuff. There’s only tire size and rev limit.

So I had the tuner change rev limits to 6100rpm across the board. Went out for new runs and the car is slower than before the gears. Ran a 13.98 with a -180ft DA which before the gears I ran a 13.94 with a 270ft DA. Something is still off and doesn’t make sense…

i almost think that because all my car has is a tune and is stock otherwise that these gears actually hurt it. But that also doesn’t make sense at the same time. Getting kind of frustrating
 

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You get the limp mode thing taken care of? Another thing to take into account is your power curves and where your shifts drop into those. Is 6100rpm the ideal shift point? Dunno. If it shifts at 6100rpm and it only drops say a 1000rpm (hypothetical), then you are already at the top end of your power curve and aren’t going to gain anything. The ideal spot to be in with each gear change is just below the peak of your curve.
 

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Discussion Starter · #26 ·
You get the limp mode thing taken care of? Another thing to take into account is your power curves and where your shifts drop into those. Is 6100rpm the ideal shift point? Dunno. If it shifts at 6100rpm and it only drops say a 1000rpm (hypothetical), then you are already at the top end of your power curve and aren’t going to gain anything. The ideal spot to be in with each gear change is just below the peak of your curve.
Yeah so the limp mode issue is solved. I woke up middle of the night and thought about this exact thing. I watched my video again and when it shifts at 6100rpm from 2-3 it drops to 4900rpm. Shifting at 6100rpm From 3-4 it drops to 5200rpm. It varies by gear

when it was shifting at 5500rpm from 1st to 2nd it dropped to 5100rpm. All that is beyond me so hopefully my tuner can look at it all and figured out what the best shift point is in each gear. I sent him a data log of my 1/4 mile last night for him to look at

hopefully i can figure this out but as of now these gears are definitely not worth for my particular vehicle
 

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I just went and filmed the speedo and tach for my 1/4 mile run and I think I figured out why my 1/4 mile didn't improve much with these.

It's shifting into 5th gear at 94mph before it hits the 1/4 mile at 99mph where as before the gears it would finish the 1/4 mile in 4th gear and not have that extra shift.

Here are shift points:

1st to 2nd: 5500rpm at 34mph
2nd to 3rd: 6000rpm at 54mph
3rd to 4th: 6100rpm at 77mph
4th to 5th: 5800rpm at 94mph

If I can get the tuner to make the 1st to 2nd shift point a higher rpm and the 4th to 5th a higher rpm I think I can shave time off. Especially if it doesn't shift into 5th gear before crossing the 1/4 mile.

I’m sure you’ve figured it out and others have told you, but the shifts below 6000-6100 are killing power up top. I still think your going to get 5 shifts with stock cam, but your times will get better fine tuning those shift points.
 
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Discussion Starter · #28 ·
I’m sure you’ve figured it out and others have told you, but the shifts below 6000-6100 are killing power up top. I still think your going to get 5 shifts with stock cam, but your times will get better fine tuning those shift points.
yeah so he adjusted to redline at 6100 on all gears and it actually made my car slower so back to the drawing board. I may just have to go fbo to get the benefit of the gears
 

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I remember when I put the original tune in my '06 Daytona I was constantly going into limp mode after raising rev limiter and shift points. Stock rev was something like 5,700 rpm if I recall. I had to set rev limiter higher than shift points. Think I wound up with 6200 rpm rev, and 6,000 shift points. This was with the older NAG1 5-speed.

Curious to see what the solution is with the newer 8-speed, as your spread between gears isn't as dramatic as it was with only 5 speeds.
 

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My suggestion would be to keep adding mods. I think it'll do great once you open up the high end.
 
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I’d like to add something to this thread based upon my experience in tuning my 2016 RT with HPTuners software.

1. Changing the gear ratio in the software doesn’t automatically change the rest of the settings associated with it to make it run like should like it came from the factory. The parameters still think you are running your original differentials based upon other parameters that are not changed. To put it another way the PCM and TCM do not work like a trickle down effect…change one parameter and all the others automatically update.

2. The neural network platform that the PCM/TCM runs is very complicated to tune. You can’t just change one thing and expect it to work as such. It takes a lot of knowledge and trial and error otherwise something could really get messed up and you have some expensive repairs to make.

3. Changing your engine RPM limits only will not give you what you are looking for. I raised my cutoff to 6,400 and maximum to 6,500. It didn’t change anything. I even messed around with the RPM limits when using the paddle (autostick) since those are a separate parameter. The gears did not hold longer in all cases. It wasn’t until I went into the trans settings and played around with the different settings like the TCM RPM limit, shift scheduling and shift timing (up shift and down shift) did I start to see a change.

4. I even went as far as copying a 2018 DDSRT tune in some of the RPM limits and TCM parameters mentioned above and it did not take. When EVERYTHING talks to EVERYTHING in these neural network controlled vehicles it’s really difficult to get desired results.

I am currently on the hunt for a tune that I can compare from a DD V6 that was equipped with 3.45 gears to compare to 3.09 gears.

Food for thought. I hope you get it all sorted out because I am seriously contemplating doing this swap. Thanks for all your insight so far!!


Build thread: 2016 R/T - awehlage’s build
 

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Discussion Starter · #32 ·
We’re data logging again but this time data logging full 1/4 mile runs to dial in all the shift points.
The issue with the last runs was it was going to 6400rpm in the data log which was weird because on my tach it was shifting at 6100. Did a new tcm and pcm tune today and it ran better than yesterday but still not completely there i dont think. DA was -1777ft which is way lower (2000ft lower) than it is when I normally run. Ran a 1.99 60ft, 5.28 0-60, and a 13.72 1/4 mile
 
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We’re data logging again but this time data logging full 1/4 mile runs to dial in all the shift points.
The issue with the last runs was it was going to 6400rpm in the data log which was weird because on my tach it was shifting at 6100. Did a new tcm and pcm tune today and it ran better than yesterday but still not completely there i dont think. DA was -1777ft which is way lower (2000ft lower) than it is when I normally run. Ran a 1.99 60ft, 5.28 0-60, and a 13.72 1/4 mile
Well that'll do it. What kind of tuner do you have? I leave mine plugged in to the OBD port all the time. Has a lot of different pids which will show a ton of info, like on a diagnostic tool. The rpms on the tac versus the tuner reading is pretty dead on
till I see on video the needle doesn't go very far past the redline on WOT runs.

Thought that was only mine.
 
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yeah so he adjusted to redline at 6100 on all gears and it actually made my car slower so back to the drawing board. I may just have to go fbo to get the benefit of the gears
Damn!!! That’s wild….. Guess maybe that’s why there aren’t a lot with the kids out there.

I personally think with a more heavily modded truck they will pay dividends.
 
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Discussion Starter · #35 ·
Well that'll do it. What kind of tuner do you have? I leave mine plugged in to the OBD port all the time. Has a lot of different pids which will show a ton of info, like on a diagnostic tool. The rpms on the tac versus the tuner reading is pretty dead on
till I see on video the needle doesn't go very far past the redline on WOT runs.

Thought that was only mine.
I’ve got a diablo i3, I don’t like it its pretty cheap feeling but it logs the data needed
 

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Discussion Starter · #36 ·
Damn!!! That’s wild….. Guess maybe that’s why there aren’t a lot with the kids out there.

I personally think with a more heavily modded truck they will pay dividends.
That’s what I’m thinking. Full intake and exhaust with cam and tune would probably benefit way more than a bone stock r/t with a tune. Was going to get a fast man tb and intake and start going full “bolt on” but looks like fast man isn’t taking orders right now and I’d like to do the whole intake at once
 

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Discussion Starter · #38 ·
You could pull the air box out and make a quick run. Just to see if it’s limiting anything.
I’m thinking I’m just going to order an intake this week. Looking at voolant
 
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That’s what I’m thinking. Full intake and exhaust with cam and tune would probably benefit way more than a bone stock r/t with a tune. Was going to get a fast man tb and intake and start going full “bolt on” but looks like fast man isn’t taking orders right now and I’d like to do the whole intake at once
BBK is a bit more expensive but I got it quick, that was a while ago though.

Another thing, like I was saying in an earlier post, I don't think you'll benefit very much much from that higher rev right now anyway. I think that's part of why your times are hurting. From what I've seen on stock dyno sheets the power band is already dropping past 5300 to 5400. Think of a vacuum when you put your had over the nozzle, the motor starts yelling. That's kind of what the stock setup is doing it's working harder just to pull the air in.
 
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You could pull the air box out and make a quick run. Just to see if it’s limiting anything.
First thing I did was cut that little piece of plastic that sticks out from right in front of the scoop. It restricts the air coming in from the vents above the radiator. Cut that fucker off when I realized how restricted everything was. There was already a slight difference in throttle response. Then I cut off the rubber weather strip on the hood from the edge of the grill, basically everything right above the headlight. I also cut a big hole in the bottom of the air box. Did all that with just a drop in K&N. Throttle response was way better than stock.

I then managed to fit a 5.5 x 6.5 K&N cone filter inside the stock box by gutting the shit out of it and running a 4 in tube through the hole to another tube to the TB via a reducer. I was trying to use the stock box as a heat shield. By that point I had the custom tune.

I finally got to the point where I didn't think the K&N cone filter inside the stock air box was big enough, after my header install. So I upgraded to a 9 in. K&N cone. Made my own heat shield out of abs plastic so it lines with the hood at the top. I have pics in the gallery. I think all that helped a bit as I progressed.

I'm a bit of a tinkerer.
 
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