The 6R80 has a maximum torque input of 590 lb ft. so it would handle the torque. Main issue might be finding a torque converter compatible with a 4bt. Destroked probably already had an adapter plate that should work and may have a flex plate as well. Their adapters use the Ford 6.0 diesel starter. You'd need to check with them on that. That transmission comes mated to small diesels in the Ranger truck line but doubt those have torque peaks the same as Cummins 4bt.
4bt to 6r80 trans
I've decided to go another route on my 07 expedition. I've been rolling with a m5r2 trans for the last 5 years and 35k miles and something in the clutch system is not good. I also haven't been able to get 4x4, or cruise control working. So its time to change it up. I'm going with a 6r80 trans which is quite proven in the gasser world. So I have a few questions, I doubt the trans has been put behind a 4bt yet. Ill be machining the adapter plate myself. My current power is probably 225hp...assuming 450tq. The trans is easily rated for this from the 5.4.
Should I use a stock converter to get a baseline for how it will run? Will a stock HD flexplate be good for this application? Will a 5.4 starter start a 4bt?
Trans will be tuned with hp tuner.
Sent from my SM-G970U using Tapatalk
Should I use a stock converter to get a baseline for how it will run? Will a stock HD flexplate be good for this application? Will a 5.4 starter start a 4bt?
Trans will be tuned with hp tuner.
Sent from my SM-G970U using Tapatalk
1 - 5 of 36 Posts
On the stall speed for a torque converter, most guys shoot for 1300 RPM. Full torque for a 4bt come on around 1700-1800 RPM.
That a very serious looking adapter you made. Nice workmanship. See you have twin turbos. If you're only putting out 225 HP you must have the fuel turned down or are using stock injectors. With a set of 5x.012 injectors that can easily do 300 HP even with a VE injection pump. With a P pump it could go much higher.
What kind of boost level are you seeing. You may be closer to 300 HP if you're in the 40 PSI range. You have about the same setup there as Eggman. Not sure it will be any quicker with the automatic. You have some power loss going thru an automatic. Just the nature of those but shifting can feel quicker.
It's good to take your time and workout possible bugs before they occur.
1 - 5 of 36 Posts
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