Built FA20

[Nigruto]

Hi,

I have no background in cars or much technical knowledge at all but I’ve been learning heaps over the course of my turbo build and now I’d like to start planning for next year or so for a built FA20 engine.

I have a clear goal of roughly 400hp or (300kw) for the end build of this car. I mainly want to build this engine for reliability purposes as I know these cars tend to have issues with rod knock later on and I also want to own this car for a very long time. I’d like to know what parts I should consider for a built engine to safely handle this power and what process I need to go through to get it (am I meant to retain my current engine and replace it with the forged short block?). Also what other supporting mods will I need to consider? Such as stronger rear axles or any gear box upgrades?


I am located in Melbourne, Australia and hoping someone might have gone through this process here so I can hopefully be guided.

Relevant Current Specs:

I have a manual 2013 (late model) GTS Toyota 86 with 67,000km boosted at 60,000km. I’m sitting at (236kw) 316whp on E85 and my mods include:
SME turbo kit
Injectors 1050cc
Exedy HD clutch
340LPH fuel pump
Oil cooler
catch can

That’s most off the top of my head.

Thank you.


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[ybotspawn]

There’s a lot more intelligent people than I who could comment in the motor, but I do know at around 400whp the transmissions start becoming a weak point. That’s why you see people do things like ls swaps


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[Limitless_BRZ]

IAG stage 1 or 2 block.. get a Trans swap for the 350z cd009

[Limitless_BRZ]

https://www.mazworx.com/mazworx-favq...t-frs/brz.aspx

[WC-BRZ]

No more need to struggle with "built FA20s" anymore (they blow up either way; built or not)

K swap is the way to go - 141 lbs weight savings and infinitely more reliable.

https://kpower.industries/blogs/news...ft86-swap-faqs

[DarkPira7e]

Here's a list of most important to address vs least in my opinion.

Oil pressure when boosted needs to be addressed. More power means keeping the oil wedge on bearing surfaces is tougher and your bearings won't take it. Resolve this by running a thicker oil (5w-30 or a 10w-30 based on your demographic and usage case) and keeping it cool via an oil cooler (which you already have). Monitor your oil pressure- get used to what it should be so you can tell if something is funny if it's lower or higher than normal. Anything that makes oil pressure change besides temperature is probably not something you want to let continue.

You're going to want to upgrade the valve springs in your heads to keep valves from floating.

Rods are likely to give out from added torque stress and/or poor poor tuning. Getting stronger rods will be something that has to happen eventually.

You will shear 4th gear with some level of increased power and traction, especially if you're rough on it. This is where you either go all in or back off and accept that ~300whp in this platform is cooler than spending your weekends swapping out stock transmission or spending 5-6k for something that will survive. Other gears can also go, but 4th is typically the first for a variety of reasons.

Axles will break, especially if you're lowered quite a bit. If they break from traction and power, you can upgrade to driveshaft shop axles. If they're breaking because you're hellaflush, you need to fix the axle angle, or else you'll be throwing money away.


I would advise staying around 300WHP. It gets terrifically expensive to push the envelope past that and keep it reliable. 400whp sounds cool, but the more you learn, the more you see why there aren't many of these rolling around. Having a setup that can make 4-500whp does not mean that it will be sustainable. Making the power is not the hard part. I am leaving out other basic supporting mods like tuning, fuel, clutch, because know that already.

Questions?

[Nigruto]

Originally Posted by DarkPira7e

Here's a list of most important to address vs least in my opinion.

Oil pressure when boosted needs to be addressed. More power means keeping the oil wedge on bearing surfaces is tougher and your bearings won't take it. Resolve this by running a thicker oil (5w-30 or a 10w-30 based on your demographic and usage case) and keeping it cool via an oil cooler (which you already have). Monitor your oil pressure- get used to what it should be so you can tell if something is funny if it's lower or higher than normal. Anything that makes oil pressure change besides temperature is probably not something you want to let continue.

You're going to want to upgrade the valve springs in your heads to keep valves from floating.

Rods are likely to give out from added torque stress and/or poor poor tuning. Getting stronger rods will be something that has to happen eventually.

You will shear 4th gear with some level of increased power and traction, especially if you're rough on it. This is where you either go all in or back off and accept that ~300whp in this platform is cooler than spending your weekends swapping out stock transmission or spending 5-6k for something that will survive. Other gears can also go, but 4th is typically the first for a variety of reasons.

Axles will break, especially if you're lowered quite a bit. If they break from traction and power, you can upgrade to driveshaft shop axles. If they're breaking because you're hellaflush, you need to fix the axle angle, or else you'll be throwing money away.


I would advise staying around 300WHP. It gets terrifically expensive to push the envelope past that and keep it reliable. 400whp sounds cool, but the more you learn, the more you see why there aren't many of these rolling around. Having a setup that can make 4-500whp does not mean that it will be sustainable. Making the power is not the hard part. I am leaving out other basic supporting mods like tuning, fuel, clutch, because know that already.

Questions?

You have given me the perfect answer. Thanks for going in-depth. As I looked into costs of building an engine i worked out it may be more worth to even do an engine swap haha

I believe I’ve settled with this conclusion:

Everything about my car right now i believe is good and done right.
the tune is done properly (torque is kept low, boost only comes around 4.5k to not stress rods)
I have most/ all supporting mods
My low boost is 8psi and my highest map is 10psi
I’m weary of launching because of said axle issue
I am running 5W-30

As my car is relatively low miles/km I will run this engine and this build until it gives in. if I do decide to do anything to the engine the very least will be springs, forged rods and pistons, but I don’t believe that is justifiable for solely reliability... anyway when the time comes I will most likely just forge the internals or just pickup a second hand FA20 motor.

I would also like to consider the possibility of one day transplanting the the new model 2022 BRZ engine into this car...

Thank you for the insight and I appreciate your reply


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[grumpysnapper]

I know its not a turbo, but I ran a Harrop supercharger on an internally standard FA20 for about 4 years (from brand new), with conservative tune putting out around 166kw/222hp at the wheels.
Upgraded cooling, upgraded oil cooling, exhaust, HD clutch but standard trans.and drive shafts.
Did about 30000km of fairly hard road driving with no real issues at all.

Wanted to release the max (reliable) power available from the Harrop, so I went with the low comp. (10.0:1) IAG stage 2 bottom end, upgraded valve springs, injectors, E85, Motec, etc etc.

Now at about 260kw/346hp at the wheels, but have also had to add uprated drive shafts, bigger injectors/pump etc.

If you are going to go forged internals, I would %100 definitely grab a IAG bottom end, as it is a much much cheaper option than getting the parts/work done here in Oz....and they address the oiling issues as part of their block work.

No troubles (so far) with the gearbox... but I don't run wide/sticky tyres, so that is a little easier on the driveline stresses.

I also end up running mostly on 98ron (and about 228kw/306hp at the wheels), and I actually feel that its a nice sweet spot of power for what I do with this platform. (and E85 is hard too hard find regularly in Brisbane.)

[ybotspawn]

Originally Posted by grumpysnapper

I know its not a turbo, but I ran a Harrop supercharger on an internally standard FA20 for about 4 years (from brand new), with conservative tune putting out around 166kw/222hp at the wheels.
Upgraded cooling, upgraded oil cooling, exhaust, HD clutch but standard trans.and drive shafts.
Did about 30000km of fairly hard road driving with no real issues at all.

Wanted to release the max (reliable) power available from the Harrop, so I went with the low comp. (10.0:1) IAG stage 2 bottom end, upgraded valve springs, injectors, E85, Motec, etc etc.

Now at about 260kw/346hp at the wheels, but have also had to add uprated drive shafts, bigger injectors/pump etc.

If you are going to go forged internals, I would %100 definitely grab a IAG bottom end, as it is a much much cheaper option than getting the parts/work done here in Oz....and they address the oiling issues as part of their block work.

No troubles (so far) with the gearbox... but I don't run wide/sticky tyres, so that is a little easier on the driveline stresses.

I also end up running mostly on 98ron (and about 228kw/306hp at the wheels), and I actually feel that its a nice sweet spot of power for what I do with this platform. (and E85 is hard too hard find regularly in Brisbane.)

Concur with this as well… iag bottom end is rock solid.


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