amschind
Well-known member
- Thread starter
- #1
I have been laboring under and spreading lies. I thought that the exhaust to coolant heat exchanger in the Powerboost is part of the low-temp battery loop and was designed to make sure that the LiFePO4 battery quickly gets above freezing temperatuure so that it can be charged (i.e. used at all) in cold weather. That interpretation was WHOLLY WRONG. As I have been informed (hat tip to HammaMan), the exhaust to coolant exchanger is actually part of the high temperature loop and as such its only function is to raise the temperature of the engine coolant more quickly.
At first glance, that distinction might seem unimportant, but in terms of removing a failure prone part that has earned its own Thread Of Shame, this means that we can realistically delete the stupid thing and be done with it. Were it part of the battery management system, removing it would require us to replace its role in warming the battery because lithium batteries hate the cold, and most importantly any effort to charge one while it is below 32F will rapidly kill it. If Ford's battery management system didn't have the right failsafes from direct battery temperature monitoring and just assumed battery temp based upon other inputs (not saying that this would be a good design.....but it's Ford), there is a real risk that removing a battery heater could kill your battery. However, if the stupid thing only makes the engine heat up a bit faster, then the worst case is slightly increased engine wear from slower oil warmup in cold weather. We know that a 3.5L Ecoboost doesn't require this part, so the engine can clearly run well with baseline auto start-stop. If wear really is an issue, then preemptive fix for faster wear is to change engine idle behavior in cold weather with a tune or simply using your app to warm the truck up before you drive anywhere (since it will automatically idle to run the heater in cold weather).
Bottom line the consequences for this mod are 1) hypothetical and 2) have solutions which are being actively engineered for and deployed on the most popular engine in the most popular truck in the world. I think that leads us to the question of: how?
The three steps are:
1) shunt the inlet coolant line to the outlet coolant line. Ideally, you have a double SS connector and leave plenty of hose attached to the exchanger so that it's easy to reuse/reinstall.
2) remove the exchanger from the exhaust path. This is simple for an exhaust shop, but they are VERY nervous about touching these things. That may make #3 easier to do first:
3) develop a spud connector with appropriate resistors which can attach to the controller wires to avoid angering the ECM. In some ways, just having the unit sitting on the truck without coolant is simpler, but that risks ruining the exhanger if the system directs exhaust through it while there is no coolant flow. That wouldn't hurt the truck (since the coolant loop is no longer involved), but it would likely kill an expensive part that you might want to restore some day or could at least sell.
My aims with all of this are twofold:
1) get a full custom exhaust
2) preemptively remove a failure point. I was driving through middle of nowhere West Texas last night, and it would've been pretty miserable to find out via an overheat message that this exchanger had distributed my coolant along 100 miles blacktop. It would need to have a pretty important job to justify that risk.....and I have learned that it provide nearly zero benefit in return for the threat of stranding us.
So what say you?
At first glance, that distinction might seem unimportant, but in terms of removing a failure prone part that has earned its own Thread Of Shame, this means that we can realistically delete the stupid thing and be done with it. Were it part of the battery management system, removing it would require us to replace its role in warming the battery because lithium batteries hate the cold, and most importantly any effort to charge one while it is below 32F will rapidly kill it. If Ford's battery management system didn't have the right failsafes from direct battery temperature monitoring and just assumed battery temp based upon other inputs (not saying that this would be a good design.....but it's Ford), there is a real risk that removing a battery heater could kill your battery. However, if the stupid thing only makes the engine heat up a bit faster, then the worst case is slightly increased engine wear from slower oil warmup in cold weather. We know that a 3.5L Ecoboost doesn't require this part, so the engine can clearly run well with baseline auto start-stop. If wear really is an issue, then preemptive fix for faster wear is to change engine idle behavior in cold weather with a tune or simply using your app to warm the truck up before you drive anywhere (since it will automatically idle to run the heater in cold weather).
Bottom line the consequences for this mod are 1) hypothetical and 2) have solutions which are being actively engineered for and deployed on the most popular engine in the most popular truck in the world. I think that leads us to the question of: how?
The three steps are:
1) shunt the inlet coolant line to the outlet coolant line. Ideally, you have a double SS connector and leave plenty of hose attached to the exchanger so that it's easy to reuse/reinstall.
2) remove the exchanger from the exhaust path. This is simple for an exhaust shop, but they are VERY nervous about touching these things. That may make #3 easier to do first:
3) develop a spud connector with appropriate resistors which can attach to the controller wires to avoid angering the ECM. In some ways, just having the unit sitting on the truck without coolant is simpler, but that risks ruining the exhanger if the system directs exhaust through it while there is no coolant flow. That wouldn't hurt the truck (since the coolant loop is no longer involved), but it would likely kill an expensive part that you might want to restore some day or could at least sell.
My aims with all of this are twofold:
1) get a full custom exhaust
2) preemptively remove a failure point. I was driving through middle of nowhere West Texas last night, and it would've been pretty miserable to find out via an overheat message that this exchanger had distributed my coolant along 100 miles blacktop. It would need to have a pretty important job to justify that risk.....and I have learned that it provide nearly zero benefit in return for the threat of stranding us.
So what say you?
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