New 2022 FA Swap into Old 2014 BRZ Qs?

[NoHaveMSG]

Originally Posted by PulsarBeeerz

Before anyone even gets that far.. The combustion dome will be very undersized and need machined out. FA24 94mm bore vs the FA20 86mm bore. There is literally no room for the pistons with this combo. By comparison the K20/24 is 86mm vs 87mm.

Not that big of an issue to overcome. I kinda figured on that since they both have the same compression ratio but the FA24 is obviously bigger so the chamber has to be bigger.

I am not saying it is going to be easy. But even if it is difficult it has the potential to be far cheaper then a K swap.


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[Goingnowherefast]

The issue here is engine controls. Being that the chassis is literally the same, fitting the engine will likely be extremely easy if even a drop-in, no extra work affair. The problem is going to be controls. Maybe the ECU architecture is extremely similar and we can retain the "old" ECU and run the new engine with a different tune and some wiring. If not, it's going to be realistically easier to just go the K swap route since they have that all figured out.

Originally Posted by zc06_kisstherain

why bother swapping same engine? LS engine maybe

x2 race classing. Not only for size, but lots of race sanctions allow same-manufacture swaps for little/no points.

[Kona61]

Originally Posted by Goingnowherefast

The issue here is engine controls. Being that the chassis is literally the same, fitting the engine will likely be extremely easy if even a drop-in, no extra work affair. The problem is going to be controls. Maybe the ECU architecture is extremely similar and we can retain the "old" ECU and run the new engine with a different tune and some wiring. If not, it's going to be realistically easier to just go the K swap route since they have that all figured out.



x2 race classing. Not only for size, but lots of race sanctions allow same-manufacture swaps for little/no points.

In one of the articles I posted, they stated that the car has one ECU instead of two. So there is no longer a separate one to run only the motor.

[NoHaveMSG]

Originally Posted by Goingnowherefast

The issue here is engine controls. Being that the chassis is literally the same, fitting the engine will likely be extremely easy if even a drop-in, no extra work affair. The problem is going to be controls. Maybe the ECU architecture is extremely similar and we can retain the "old" ECU and run the new engine with a different tune and some wiring. If not, it's going to be realistically easier to just go the K swap route since they have that all figured out.

If you can use the FA20 heads and timing cover I don’t think it is going to be an issue running it off the Gen1 car ECU. If we can use those items that means the cam position sensors are going to correlate properly. This is the reason we can’t use the FA20DIT timing cover to get the larger oil pump, cam sensor is not in the same position on one or both heads. That also means the DI’s are going to work, and you can use the gen1 section of the engine harness for the spark plugs, the DI pump from the FA20 would then work along with it’s sensor. The only other things would be the TB, knock sensors, coolant and oil sensors, port injectors, and crank position. Even if none of those work off the FA20, it wouldn’t be difficult to splice the FA24’s sensors in to work with the FA20’s engine harness, they are either power/ground, or power/ground/ecu trigger. The worst of those would be crank position sensor being in the wrong place, but that isn’t insurmountable considering you could probably reindex the reluctor wheel to have the correct timing. I really am planing on buying a set of FA24 engine cases as soon as I can get them. That would tell me about 90% of what I would need to know.

[OkieSnuffBox]

Originally Posted by NoHaveMSG

Not that big of an issue to overcome. I kinda figured on that since they both have the same compression ratio but the FA24 is obviously bigger so the chamber has to be bigger.

I am not saying it is going to be easy. But even if it is difficult it has the potential to be far cheaper then a K swap.


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Wait, did you say completely milling out the heads and reshaping the combustion chambers, keeping proper squish, etc, is quote, "Not that big of an issue to overcome?"

[NoHaveMSG]

Originally Posted by OkieSnuffBox

Wait, did you say completely milling out the heads and reshaping the combustion chambers, keeping proper squish, etc, is quote, "Not that big of an issue to overcome?"

Yes. Though FA20 has basically no squish band. At that point it would just be milling the CC and reshaping.

Edit: Actually I shouldn't say that. Most of the squish looks to be designed into the piston crown.

I feel the need to reiterate I in no way think in the best case this will be easy.

[OkieSnuffBox]

Originally Posted by NoHaveMSG

Yes. Though FA20 has basically no squish band. At that point it would just be milling the CC and reshaping.

Edit: Actually I shouldn't say that. Most of the squish looks to be designed into the piston crown.

I feel the need to reiterate I in no way think in the best case this will be easy.

"Not that big of an issue" "this will not be easy"

Those two statements are at odds with each other.

[NoHaveMSG]

Originally Posted by OkieSnuffBox

"Not that big of an issue" "this will not be easy"

Those two statements are at odds with each other.

So you want to take two statements out of two different posts, combine them out of context, and say they are at odds? Let me paint by numbers explain it to you then.

Even drop in is not easy for a lot of people. When I said not easy, I am referring to the whole project, not just modifying the combustion chamber.

If all that needs to happen is the combustion chamber milled bigger and reprofiled that is not that big of an issue in the grand scheme of things. It is not insurmountable. That is if it can be done.

There may not be room to cut the combustion chamber that deep without getting into a valve seat, there may not be material to go large enough without getting into a water passage. The head bolts may not line up. The water jackets may not line up. Those are insurmountable problems. I am well aware of the potential issues and the likely hood that it is not going to work. I actually have two junk heads I am going to start mocking up to see if I can scale up the combustion chamber size without getting into anything I shouldn't.

[OkieSnuffBox]

Originally Posted by NoHaveMSG

Not that big of an issue to overcome. I kinda figured on that since they both have the same compression ratio but the FA24 is obviously bigger so the chamber has to be bigger.

I am not saying it is going to be easy. But even if it is difficult it has the potential to be far cheaper then a K swap.


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Originally Posted by NoHaveMSG

So you want to take two statements out of two different posts, combine them out of context, and say they are at odds? Let me paint by numbers explain it to you then.

Actually the same post chief. Give it a rest.

[Dzmitry]

Originally Posted by OkieSnuffBox

Actually the same post chief. Give it a rest.

You're also totally misquoting him... chief.

"this will not be easy" is not the same thing as saying "I am not saying it is going to be easy"