Daily driven trucks with converters
03-03-2014, 10:23 PM
#1
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Daily driven trucks with converters
I'm about to add a 3000 rpm converter and a custom FTI cam/springs to my ls6 setup, that's destined for my 03 rcsb silverado. I'm hesitant on the tc because I've never modified an engine with an auto before. So I have no experience with converters.
I've driven in stalled automatics before, and it felt as if the clutch was slipping while we cruised around town slowly. Then at wot it yanks you back in the seat, which is great. But I don't want my truck to be a pig on light/part throttle.
I currently don't tow anything. Is a 3000-3200rpm stall going to drive me crazy in a daily driver? (It's actually just a weekend driver)
How will this effect gas mileage?
I've driven in stalled automatics before, and it felt as if the clutch was slipping while we cruised around town slowly. Then at wot it yanks you back in the seat, which is great. But I don't want my truck to be a pig on light/part throttle.
I currently don't tow anything. Is a 3000-3200rpm stall going to drive me crazy in a daily driver? (It's actually just a weekend driver)
How will this effect gas mileage?
03-03-2014, 11:59 PM
#2
On The Tree
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Convertors have came along way over the years. I think 3000-3200 is perfect for street use
Watch a couple youtube videos of trucks with stall convertors and i think you will get a better ideal of driveablity
Watch a couple youtube videos of trucks with stall convertors and i think you will get a better ideal of driveablity
03-04-2014, 12:57 AM
#3
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I have a 3200 stall in my '04 rcsb. I cant keep my foot off the floor lol, so I see about 13mpg average. But it will get 16+ if I drive like a normal person. You will regret not doing a stall especially with a cam. It will be a real pig from a dig and slow rolls with a stock one. It will be fine at part throttle also. I can still pull my Camaro with it too.
Stalled auto > stock stall
Stalled auto > stock stall
Last edited by Badlands; 03-05-2014 at 03:55 AM.
03-04-2014, 01:01 AM
#4
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3-4 low speed lockup - YouTube
4600 stall converter with a good tune.
http://youtu.be/gxQuwmuWXDM
This is a 5000lb truck with ~1000lbs of extra weight.
4600 stall converter with a good tune.
http://youtu.be/gxQuwmuWXDM
This is a 5000lb truck with ~1000lbs of extra weight.
03-04-2014, 08:28 AM
#5
A 3000 converter in the 278mm size will be great for a DD with those mods. If its a weekend warrior I may even go looser... and I don't like the way converters drive.
Gas mileage will suffer slightly, but on the highway with the TCC locked it wont change a damn thing.
Gas mileage will suffer slightly, but on the highway with the TCC locked it wont change a damn thing.
03-04-2014, 08:45 AM
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A 3000 converter in the 278mm size will be great for a DD with those mods. If its a weekend warrior I may even go looser... and I don't like the way converters drive.
Gas mileage will suffer slightly, but on the highway with the TCC locked it wont change a damn thing.
Gas mileage will suffer slightly, but on the highway with the TCC locked it wont change a damn thing.
I assume when you say the converter is locked, that means there is zero slippage, and gas mileage is not suffering, but what controls when the converter is locked up?
And does fluid from the trans flow into the converter to keep it cool? Or does the converter only see the quart of fluid that I add during install?
Should I look into getting a trans fluid cooler?
Does a higher stall put more stress on the trans?
03-04-2014, 08:54 AM
#7
Answers in red
Ok this leads me to my next set of questions. What do people mean when they say your tuner can "lock the converter" at a certain point?
That means that at a certain speed your PCM commands the torque converter to lock, and just as you said there is 0 slippage. Next time you are in the truck go from 0 to about 50 at light to medium throttle, i bet you cound 4 'shifts' and the last one you will notice as you slightly change the pedal position the RPM will no longer move.
I assume when you say the converter is locked, that means there is zero slippage, and gas mileage is not suffering, but what controls when the converter is locked up?
Your tuner can change characteristics of when is locks, and at what pressure it locks. Generally the factory settings arent too far off as far as speed, but you will want to increase the pressure in which it locks... thats very basic though and your tuner will have a handle on this.
And does fluid from the trans flow into the converter to keep it cool? Or does the converter only see the quart of fluid that I add during install?
Yes fluid flows in to keep it cool. You add fluid so that the first time you run it its nto dry and it wont take a while to fill. without fluid the converter won't function the way it should. It will be a LOT looser as fluid dynamics (the magic behind the way a converter works) for air and trans fluid are very different
Should I look into getting a trans fluid cooler?
Yup. Trucool 40k seems to be the most popular
Does a higher stall put more stress on the trans?
Yes and no. Heat is bad for a trans and the added slip will add heat. That said a looser converter is a bit of a pillow between shifts for your transmission clutches. It will allow them to grab and hold without as much pressure on them at light throttle without making you feel like the trans is rattling your bones.
That means that at a certain speed your PCM commands the torque converter to lock, and just as you said there is 0 slippage. Next time you are in the truck go from 0 to about 50 at light to medium throttle, i bet you cound 4 'shifts' and the last one you will notice as you slightly change the pedal position the RPM will no longer move.
I assume when you say the converter is locked, that means there is zero slippage, and gas mileage is not suffering, but what controls when the converter is locked up?
Your tuner can change characteristics of when is locks, and at what pressure it locks. Generally the factory settings arent too far off as far as speed, but you will want to increase the pressure in which it locks... thats very basic though and your tuner will have a handle on this.
And does fluid from the trans flow into the converter to keep it cool? Or does the converter only see the quart of fluid that I add during install?
Yes fluid flows in to keep it cool. You add fluid so that the first time you run it its nto dry and it wont take a while to fill. without fluid the converter won't function the way it should. It will be a LOT looser as fluid dynamics (the magic behind the way a converter works) for air and trans fluid are very different
Should I look into getting a trans fluid cooler?
Yup. Trucool 40k seems to be the most popular
Does a higher stall put more stress on the trans?
Yes and no. Heat is bad for a trans and the added slip will add heat. That said a looser converter is a bit of a pillow between shifts for your transmission clutches. It will allow them to grab and hold without as much pressure on them at light throttle without making you feel like the trans is rattling your bones.
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03-04-2014, 08:54 AM
#8
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yes locked = zero slip. My converter locks in 4th gear at 55mph. if I drop below 52mph in unlocks. Mine is a Circle D 3000 that is lose and flashes at 3200 + a tad with the weight of my rig.
1-2 back to 1 shift
https://www.youtube.com/watch?v=2vUDQYP2QPk
just normal driving. @55 you can hear converter fully lock
https://www.youtube.com/watch?v=5DFDCMqz2vU
Just normal driving. forgot the radio was on sorry
https://www.youtube.com/watch?v=I5CmcndFeqg
Just playing
https://www.youtube.com/watch?v=ldCOHR3v9WQ
1-2 back to 1 shift
https://www.youtube.com/watch?v=2vUDQYP2QPk
just normal driving. @55 you can hear converter fully lock
https://www.youtube.com/watch?v=5DFDCMqz2vU
Just normal driving. forgot the radio was on sorry
https://www.youtube.com/watch?v=I5CmcndFeqg
Just playing
https://www.youtube.com/watch?v=ldCOHR3v9WQ
03-04-2014, 08:55 AM
#9
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I have a 3200 stall in my '04 rcsb. I cant keep my foot off the floor lol, so I see about 13mpg average. But it will get 16+ if I drive like a normal person. You will regret not doing a stall especially with a cam. It will be a real pig from a dig and slow rolls. It will be fine at part throttle also. I can still pull my Camaro with it too.
Stalled auto > stock stall
Stalled auto > stock stall
