Likely the first FA2/4 hybrid incoming

[NoHaveMSG]

Originally Posted by new2subaru

Thank for the reply. Isn't there going to be issues with tuning with FA24 short block with FA20 heads? Will the stock ECU be compatible?

Tuning wise, I don't see an issue. They will need to rechamber the FA20 heads to work with the FA24. Guys do it for the EJ20 heads to go on the EJ25 block.

http://www.larryspower.com/heads/Chambering.html


The guys in thailand claim to have done it with the stock ECU in their 17'. Who knows what they did though, probably just stuck the 17' sensors in the FA24 block is all. They are using the FA20 heads but not sure which timing cover. I know one reason we can't run the FA20DIT timing cover and get that sweet, sweet larger oil pump, is that the cam sensor port isn't in the right spot. Not sure on timing cover compatibility FA24 vs. FA20 though.

[new2subaru]

Originally Posted by NoHaveMSG

Tuning wise, I don't see an issue. They will need to rechamber the FA20 heads to work with the FA24. Guys do it for the EJ20 heads to go on the EJ25 block.

http://www.larryspower.com/heads/Chambering.html


The guys in thailand claim to have done it with the stock ECU in their 17'. Who knows what they did though, probably just stuck the 17' sensors in the FA24 block is all. They are using the FA20 heads but not sure which timing cover. I know one reason we can't run the FA20DIT timing cover and get that sweet, sweet larger oil pump, is that the cam sensor port isn't in the right spot. Not sure on timing cover compatibility FA24 vs. FA20 though.

Just like everyone else, I'm anxious to see these results, how it's being done and at what cost. I'm going to blow my motor eventually and this would be a fantastic option to have.

[NoHaveMSG]

Originally Posted by new2subaru

Just like everyone else, I'm anxious to see these results, how it's being done and at what cost. I'm going to blow my motor eventually and this would be a fantastic option to have.

I am pretty much in the same position. I have 100K+ miles on my engine, 40ish track days with more to come. It's only a matter of time. When I go to refresh curious what options will be when that time comes.

[new2subaru]

Originally Posted by NoHaveMSG

I am pretty much in the same position. I have 100K+ miles on my engine, 40ish track days with more to come. It's only a matter of time. When I go to refresh curious what options will be when that time comes.

I only have 60km on mine but around 35 track days. It is only a matter of time. I'd prefer to have an engine ready to drop in but haven't had any luck finding low mileage used ones. I so wish they dropped this engine in a half dozen other models

[Tatsu333]

Originally Posted by new2subaru

Just like everyone else, I'm anxious to see these results, how it's being done and at what cost. I'm going to blow my motor eventually and this would be a fantastic option to have.

Originally Posted by NoHaveMSG

I am pretty much in the same position. I have 100K+ miles on my engine, 40ish track days with more to come. It's only a matter of time. When I go to refresh curious what options will be when that time comes.

Originally Posted by new2subaru

I only have 60km on mine but around 35 track days. It is only a matter of time. I'd prefer to have an engine ready to drop in but haven't had any luck finding low mileage used ones. I so wish they dropped this engine in a half dozen other models

I only have 10,000 kms (about 6,250 miles) on my 2020 so far, and would likely only have about 20,000-30,000 kms by the time this becomes do-able for me sometime in 2024 or 2025 (I.E. source short blocks available / affordable, and I have funds available)...LOL.

I just want to have my "perfect" combo of the BRZ generations.

[Teseo]

Originally Posted by NoHaveMSG

I am pretty much in the same position. I have 100K+ miles on my engine, 40ish track days with more to come. It's only a matter of time. When I go to refresh curious what options will be when that time comes.

For the cost and hassles, better go with FA20 forged. Plug everything back like before

[NoHaveMSG]

Originally Posted by Teseo

For the cost and hassles, better go with FA20 forged. Plug everything back like before

If I wanted boost, I would agree with that. Staying NA I don't think the forged bottom end is worth it. It doesn't really gain me anything power wise, and at twice the cost of a stock shortblock, it would need to be twice as reliable to pencil out. I'm willing to deal with a bit of hassle if more power is also an option Bench wrenching is fun though. Hopefully we see more development on this in the future.

[Tatsu333]

Originally Posted by NoHaveMSG

If I wanted boost, I would agree with that. Staying NA I don't think the forged bottom end is worth it. It doesn't really gain me anything power wise, and at twice the cost of a stock shortblock, it would need to be twice as reliable to pencil out. I'm willing to deal with a bit of hassle if more power is also an option Bench wrenching is fun though. Hopefully we see more development on this in the future.

Totally agree on that - built block isn't worth it for NA.

Original crank is forged anyway, and the weak point (if any) is the rods (leaving aside the known oiling issues). Cast pistons are more thermally stable than forged as well and allow for tighter clearances in the bore. Aftermarket pistons tend to be forged to be more detonation-resistant, which is great for FI applications but much less important in an NA application presuming the tune is reasonable.

[Opie]

My guess is this shop is using the FA24 block with WRX FA20DIT Pistons, FA24 upper & lower oil pan assemblies & a FA24 front timing cover with farely standard FA20 heads....

[NoHaveMSG]

Originally Posted by Opie

My guess is this shop is using the FA24 block with WRX FA20DIT Pistons, FA24 upper & lower oil pan assemblies & a FA24 front timing cover with farely standard FA20 heads....

Swapping piston's would be a bummer.

[Irace86.2.0]

Originally Posted by NoHaveMSG

If I wanted boost, I would agree with that. Staying NA I don't think the forged bottom end is worth it. It doesn't really gain me anything power wise, and at twice the cost of a stock shortblock, it would need to be twice as reliable to pencil out. I'm willing to deal with a bit of hassle if more power is also an option Bench wrenching is fun though. Hopefully we see more development on this in the future.

A built shortblock could allow for higher RPMs with lightweight and stronger components. You could put higher compression pistons, assuming you are on E85. If you wanted torque, you could stroke the block. If you wanted displacement, you could sleeve the block. My whole point is forged/built/different internals aren't just for surviving boost.

[NoHaveMSG]

Originally Posted by Irace86.2.0

A built shortblock could allow for higher RPMs with lightweight and stronger components. You could put higher compression pistons, assuming you are on E85. If you wanted torque, you could stroke the block. If you wanted displacement, you could sleeve the block. My whole point is forged/built/different internals aren't just for surviving boost.

I'm well aware of the other potential a fully built engine can have, it just doesn't make sense to me. If I had unlimited budget and was competing tightly within a ruleset, then building an NA block would make sense. I track and build stuff for fun though on a normal blue collar wage. I actually have a doner long block with a spun bearing that I think about doing a forged rotating assembly but I keep backing off that idea because the cost goes through the roof pretty quickly. Stroking is not worth it, the rod ratio on the FA is already not good, and stroking it would put it into the bad range, especially combined with more RPM. More RPM's doesn't help without the supporting head mods to take advantage of it not to mention the FA oiling issues. I'd be looking at a $8-10K engine that on E85 might make a little more power then a stock FA24 or K24 on E85, but be no more reliable. If it could initially cost me say 5k, to get into an FA24 swap, but then 2200 for replacement shortblocks. Sounds pretty good to me.

[Irace86.2.0]

Originally Posted by NoHaveMSG

I'm well aware of the other potential a fully built engine can have, it just doesn't make sense to me. If I had unlimited budget and was competing tightly within a ruleset, then building an NA block would make sense. I track and build stuff for fun though on a normal blue collar wage. I actually have a doner long block with a spun bearing that I think about doing a forged rotating assembly but I keep backing off that idea because the cost goes through the roof pretty quickly. Stroking is not worth it, the rod ratio on the FA is already not good, and stroking it would put it into the bad range, especially combined with more RPM. More RPM's doesn't help without the supporting head mods to take advantage of it not to mention the FA oiling issues. I'd be looking at a $8-10K engine that on E85 might make a little more power then a stock FA24 or K24 on E85, but be no more reliable. If it could initially cost me say 5k, to get into an FA24 swap, but then 2200 for replacement shortblocks. Sounds pretty good to me.

Thanks for clarifying your statement, which makes more sense with all those qualifiers.

[NoHaveMSG]

Originally Posted by Irace86.2.0

Thanks for clarifying your statement, which makes more sense with all those qualifiers.

In my head, I thought it went without saying.


Also in my head: