Later MPH on 5TC lock up?

Twinturbostroker · Sep 15, 2015

Soooo long story short.........H&S single kit on my 6.4, took some fighting to get it on with a aftermarket DP, but she's in and sitting pretty. Have custom H&S tuning obviously, but there seems to be an issue with the 5TC coming on at 65MPH, I've had 3 tranny tunes sent and 65 seems to be the magic number. I need it to hold out to 75MPH at least, tuner seems to be having an issue getting around it???.......I have 37" and come to find out 3:55 gears, which I loved the pull with the stock set up, and 1st thru 4th are amazing under light to medium throttle with the single, but Jesus Christ does it fall on its face when it hits 65 to about 75-80, 1400RPMs just aint gonna cut it......I've been getting around it for the time being by hitting tow/haul and that will kick it down to 4TC and hold it, but that's a little much for just regular driving......if I could get 5th to about 75-78 and then TC lock, that would be perfect or at least a great starting point.....thanks fellas!!!

JMart · Sep 15, 2015

Twinturbostroker said:
.I've been getting around it for the time being by hitting tow/haul and that will kick it down to 4TC and hold it, but that's a little much for just regular driving.....

I have to do that too. I know its not related but my TC locks up at 60 and stays if I slow down, which happens all the time on my trip, down to 50. I can't get back up to 65 without hitting the tow/haul or blacking out the highway.

bigrpowr · Sep 15, 2015

Twinturbostroker said:
Soooo long story short.........H&S single kit on my 6.4, took some fighting to get it on with a aftermarket DP, but she's in and sitting pretty. Have custom H&S tuning obviously, but there seems to be an issue with the 5TC coming on at 65MPH, I've had 3 tranny tunes sent and 65 seems to be the magic number. I need it to hold out to 75MPH at least, tuner seems to be having an issue getting around it???.......I have 37" and come to find out 3:55 gears, which I loved the pull with the stock set up, and 1st thru 4th are amazing under light to medium throttle with the single, but Jesus Christ does it fall on its face when it hits 65 to about 75-80, 1400RPMs just aint gonna cut it......I've been getting around it for the time being by hitting tow/haul and that will kick it down to 4TC and hold it, but that's a little much for just regular driving......if I could get 5th to about 75-78 and then TC lock, that would be perfect or at least a great starting point.....thanks fellas!!!

text me.

Twinturbostroker · Sep 15, 2015

JMart said:
I have to do that too. I know its not related but my TC locks up at 60 and stays if I slow down, which happens all the time on my trip, down to 50. I can't get back up to 65 without hitting the tow/haul or blacking out the highway.

Exactly.....if rollin coal was still cool, I'd be the coolest guy I know LOL.......its damn game of cat and mouse when I roll up on a cop or trooper on the highway

bigrpowr said:
text me.

Gracias amigo

JMart · Sep 16, 2015

Twinturbostroker said:
Exactly.....if rollin coal was still cool, I'd be the coolest guy I know LOL.......its damn game of cat and mouse when I roll up on a cop or trooper on the highway

Got any 4" exhaust laying around your shop? I need to reroute mine to behind the truck just for this reason. Even if I just barely roll into it on the highway I get a good puff on smoke painting my bedside. Stupid me dumped it in front of the rear tire to be cheap. :doh:

SEABEE08FX4 · Sep 16, 2015

That tire / gear combo is a buzz kill with a single. Regear that hoe.

Twinturbostroker · Sep 16, 2015

JMart said:
Got any 4" exhaust laying around your shop? I need to reroute mine to behind the truck just for this reason. Even if I just barely roll into it on the highway I get a good puff on smoke painting my bedside. Stupid me dumped it in front of the rear tire to be cheap. :doh:

I got a few pieces laying around, let me see what I can come up with, you going to finals?

SEABEE08FX4 said:
That tire / gear combo is a buzz kill with a single. Regear that hoe.

Just got a new tranny tune, can't wait to try it......it's really not the gearing that's the problem, truck pulls great, better than before.....it just goes from 4tc to 5tc way too quick

JMart · Sep 16, 2015

Twinturbostroker said:
I got a few pieces laying around, let me see what I can come up with, you going to finals?

I'm trying to. I found a catback set up on summit for around $200. I am just trying to find something for less. Don't want to buy a full kit when I really just need to get over the axle. I just ordered some fox shocks and would like to keep the soot off of them. LOL

SEABEE08FX4 · Sep 17, 2015

With your set up ( 3.55 / 37's ) your final drive ratio in 5th is a 2.48 thats why I was saying you should regear. A 3.73 would help a ton, but a 4.10 / 4.11 would be even better with that tire size. Not sure how accurate the calculator I used is but shows your at about 1600 RPM at 70 MPH.

drunk on diesel · Sep 17, 2015

why don't you download the H&S single turbo tune? you can modify it to your liking too!

Twinturbostroker · Sep 17, 2015

SEABEE08FX4 said:
With your set up ( 3.55 / 37's ) your final drive ratio in 5th is a 2.48 thats why I was saying you should regear. A 3.73 would help a ton, but a 4.10 / 4.11 would be even better with that tire size. Not sure how accurate the calculator I used is but shows your at about 1600 RPM at 70 MPH.

I hear ya man......but I did get a good revision of the tranny tune, 5th gear is now unlocked and the truck runs amazing, still some bugs to workout but it's getting there, just gotta dial it in...

drunk on diesel said:
why don't you download the H&S single turbo tune? you can modify it to your liking too!

I've been seriously thinking about it, but with this time of year, the shop, events like finals and SEMA trying to get ready for those, not to mention personal stuff....just haven't had good quality time to just sit down and mess with it for a few hours

drunk on diesel · Sep 17, 2015

man, I understand being busy... sending you a PM

Sahrens0202 · Sep 25, 2015

How are you liking the single? Any issues or install tricks? I have it just hesitating putting it on as I just moved to 7200'

Twinturbostroker · Sep 29, 2015

Slowly but surely it's getting there.....who would've thought just moving up MPH for lockup would be so hard......but I love the way it drives in the city and getting in the freeway....not to mention it sounds amazing

ckrueg · Sep 30, 2015

Twinturbostroker said:
Slowly but surely it's getting there.....who would've thought just moving up MPH for lockup would be so hard......but I love the way it drives in the city and getting in the freeway....not to mention it sounds amazing

Are you doing the tuning yourself or having buying tunes?

Powerstroke Man 6.4 · Sep 30, 2015

Moving the shifts up helped out a ton on my truck with 366.

Twinturbostroker · Oct 2, 2015

ckrueg said:
Are you doing the tuning yourself or having buying tunes?

I was going to attempt it.....but if the pros are having a hard time with it, I doubt I could figure it out......plus to don't really feel like jacking up the tranny.

Powerstroke Man 6.4 said:
Moving the shifts up helped out a ton on my truck with 366.

Dude.....it would so wake up this truck on the highway. When in tow/haul the truck comes alive but it won't come out of 4TC at highway speed and the down shifts are really harsh.

I'm toying with the idea of a SCT Livewire TS as apparently there are more parameters to mess with among other things :naughty:

ckrueg · Oct 2, 2015

Twinturbostroker said:
I was going to attempt it.....but if the pros are having a hard time with it, I doubt I could figure it out......plus to don't really feel like jacking up the tranny.

Dude.....it would so wake up this truck on the highway. When in tow/haul the truck comes alive but it won't come out of 4TC at highway speed and the down shifts are really harsh.

I'm toying with the idea of a SCT Livewire TS as apparently there are more parameters to mess with among other things :naughty:

You could always use the base h&s tranny tunes and move the shift points around. That wouldn't mess anything up