FRS FA20 turbo vs FRS lsx/2jz

[hmong337]

Been reading around and it's becoming a trend for some people ditching the fa20 for either a v8 or a 2jz.

Now, I would die for my engine bay to lay grace with this engine:




I'm a big fan of this motor too!:





I bought my frs because of how it handles amazingly well. The kicker for all of us is that this car was meant for more power many times more than what it left the showroom floor with. We all know it needs more power. The platform for great handling was the seller for me. Now, add power!

Which takes us to two of these options:

1. Fully build the car using our original FA20 to 500hp

2. Fully build the car tossing in an lsx for 500hp

The unknown here would be how an lsx/2jz would change the dynamics of the car, though. I saw a picture somewhere of a weighed-in LSX BRZ and it scaled at ~2950 lbs. Also, with an upright V8 sitting in the engine room, how will that effect the physics of the car.

So, what would be your guesses on how a built FA20 turbo prepared FRS would go against a zombie swap lsx/2jz prepared FRS?

Just curious as to what the opinion is here as I've never seen a topic like this asked before ahaha.

[Atropine]

The 500 HP FA20 tend to have reliability issues, but seem to be amazing when they work.

2JZ is like any 2JZ swap...a lot depends on donor.

LS swap is same as 2JZ, but seem to be easier to locate...and you can actually buy a crate motor from Chevy rather easily (if you have the money of course).

All 3 of these options are out of my skill range though.

[Timmy_Jones]

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[Timmy_Jones]

Originally Posted by hmong337

So, what would be your guesses on how a built FA20 turbo prepared FRS would go against a zombie swap lsx/2jz prepared FRS?

Just curious as to what the opinion is here as I've never seen a topic like this asked before ahaha.

A zombie swap? Keep in mind an LS1 engine can be mild and make 310-330RWHP or with bolt ons a bit more...with a cam, you are near the 400 mark, with cam and heads and an optimized exhaust you can reach up to 440-450 RWHP.

The LS1 isn't much heavier than our engine, said and done, and is personally the route I would go.

Heck you can go pull a 5.3 block out of a truck or an SUV for stupid cheap and build it for a little turbo. There really is no limit with the right budget....800RWHP can be done with an LS and forced induction...also don't forget how well they respond to nitrous.

[WolfpackS2k]

The big thing to keep in mind is that the 2JZ has an iron block, LS is aluminum.


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[hmong337]

Originally Posted by WolfpackS2k

The big thing to keep in mind is that the 2JZ has an iron block, LS is aluminum.


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As much as a Toyota fan boy I may be, I'd go for the LSx engine in this chassis before the 2j. Like you mentioned, it is significantly lighter and it is way more compact.

[BRZZZZZZZZZZ]

LSX swap is one of my dreams. Maybe in 5 years...

[Poodles]

As with all non-direct bolt in swaps, the cost of the swap is going to be more than the cost of building the existing motor.

[cmdboy_347]

I would rathe build this vehicle ground up...It's more fun that way...

[Reaper]

You are missing one huge point. Torque. A built fa20 at 500 whp will have around 400 ish wtq at 5,000+rpm. A 500 whp ls v8 will weigh about the same but will make that torque around 2000 rpm and can be made to surpass 550 wtq at that whp level if built right.
Weight will be close but the broad torque band is what is the game changer.
I love the 2jz but the ls is the logical superior engine of those two.

[hmong337]

Originally Posted by Poodles

As with all non-direct bolt in swaps, the cost of the swap is going to be more than the cost of building the existing motor.

Not exactly true there.

I've calculated doing a fully built Fa20 with all the turbo stuff going for 500hp and it's up there in costs compared to doing an lsx swap with a used motor. Just with the lsx swap, you'd be in with a used motor and going the fa20 route you'd have a freshly built engine.

Obviously if you went for a crate lsx, it will be quite a bit more expensive than going fully built fa20 turbo.

Most important here would be reliability of the v8 as it would be barely pushed while the 4banger is living at high stress.

The only thing going for the fa20 would be keeping the original car handling dynamics. Going v8 or 2jz is still unknown as far as how the car will change in driving.

[AZFA20]

Mine should be up and running by early next month. Would be this month but I have too many other projects going simultaneously that need to get finished first. Anyway I'll be able to give a pretty good impression review since my personal FR-S was supercharged, then Turbocharged, and now a modded LS2 swap is in process. Previous setup was 430whp on e85. Next will be 525whp NA goodness on 91oct with a whole lot less stress on the engine.

The cost argument is really negligible especially when you consider how much more reliable the LSx is in long run.

[Drift&Drag]

Originally Posted by hmong337

Been reading around and it's becoming a trend for some people ditching the fa20 for either a v8 or a 2jz. We all know it needs more power. The platform for great handling was the seller for me. Now, add power!

Which takes us to two of these options:

1. Fully build the car using our original FA20 to 500hp

2. Fully build the car tossing in an lsx for 500hp

Come on hmong, option...

3. Fully build the car tossing in 2JZ for 500hp

JK But out of your choices, it is a no brainer to go with the LSX over the boosted FA20. Go with your gut instinct bro!

Originally Posted by WolfpackS2k

The big thing to keep in mind is that the 2JZ has an iron block, LS is aluminum.

True. Also comparing the stock internals of the 2JZ vs. the LSX...

"While it may be pushing the limits, the stock internals (2JZ) have been proven to hold over 800 WHP and 7500+ RPM repeatedly. Even this car's previous setup dyno'd 760 WHP at 29 PSI and drove for years at the 650 WHP level." - http://www.motoiq.com/MagazineArticl...-Weight.aspxaQ

Where as a LS1/LS2's stock internals gets "iffy after 550-600 WHP." - http://ls1tech.com/forums/generation...nd-max-hp.html

Again, it depends on your long term goals. With any of the choices mentioned above, 500 WHP in this chassis will be wickedly fast!!!

Originally Posted by Reaper

I love the 2JZ but the LS is the logical superior engine of those two.

I am a fan of the LS engine as well but .. logical superior engine of the two?

Originally Posted by AZFA20

Mine should be up and running by early next month. Would be this month but I have too many other projects going simultaneously that need to get finished first. Anyway I'll be able to give a pretty good impression review since my personal FR-S was supercharged, then Turbocharged, and now a modded LS2 swap is in process. Previous setup was 430whp on e85. Next will be 525whp NA goodness on 91oct with a whole lot less stress on the engine.

525 WHP of NA power sounds like fun! Cannot wait to see some videos and timeslips of that beast!


Honestly if I could have another project car, it would be a full built LSX 86. I already have my hands full with my project so that will have to wait. Still eyeballing the new C7 though.


.

[Poodles]

Originally Posted by hmong337

Not exactly true there.

I've calculated doing a fully built Fa20 with all the turbo stuff going for 500hp and it's up there in costs compared to doing an lsx swap with a used motor. Just with the lsx swap, you'd be in with a used motor and going the fa20 route you'd have a freshly built engine.

Obviously if you went for a crate lsx, it will be quite a bit more expensive than going fully built fa20 turbo.

Most important here would be reliability of the v8 as it would be barely pushed while the 4banger is living at high stress.

The only thing going for the fa20 would be keeping the original car handling dynamics. Going v8 or 2jz is still unknown as far as how the car will change in driving.

Keep in mind even LS motors have weaknesses (piston slap for starters). HP/liter isn't a definitive measure of "stress" on an engine either. Engine layout plays in a hell of a lot.


Perfect example is 2JZ vs LSx. 7 mains vs 5, piston oil squirters, inherently perfect balance, etc


Also, don't get me started on the full variable valve timing and dual injection system of the FA20 being lightyears ahead of most LS motors.


Still say if your goal is only 500HP, the LS is a waste of money (hell, Full Blown did over that on a stock FA20 and a build FA20 should take that all day)