Compression ratio 12.5:1. Bye-bye Super charger & Turbo build?

[RZNT4R]

what you might be looking at is a flat or even reverse domed piston depending on what they have in there stock.

A straight up vanilla piston won't cut it, DI piston are typically domed, with a deep asymmetric dish near the fuel injector.



(pictured: 2JZFSE)

[madfast]

Originally Posted by RZNT4R

A straight up vanilla piston won't cut it, DI piston are typically domed, with a deep asymmetric dish near the fuel injector.



(pictured: 2JZFSE)

only if they use stratified charge. assuming you can reprogram the ecu to not run stratified charge, a simple piston swap may be enough to lower compression, among other ways...

[serialk11r]

I think you can't mess with the piston shape with D4-S, they don't use stratified charge but the piston is shaped so the direct injector + port injector create a very even distribution of fuel in the cylinder. If you remove the piston shape, don't expect the performance to stay the same; uneven AFR will promote detonation and poor combustion.

[madfast]

Originally Posted by serialk11r

I think you can't mess with the piston shape with D4-S, they don't use stratified charge but the piston is shaped so the direct injector + port injector create a very even distribution of fuel in the cylinder. If you remove the piston shape, don't expect the performance to stay the same; uneven AFR will promote detonation and poor combustion.

D-4S on the 2GR absolutely uses a version of stratified charge for cold start. PI is used on the intake stroke, and DI is used on the compression stroke. toyota calls this "weak stratified charge".

the dish in the piston has little to do with D-4S, because other cars without D-4S have the dish as well.

[Allch Chcar]

Originally Posted by madfast

D-4S on the 2GR absolutely uses a version of stratified charge for cold start. PI is used on the intake stroke, and DI is used on the compression stroke. toyota calls this "weak stratified charge".

the dish in the piston has little to do with D-4S, because other cars without D-4S have the dish as well.

Dish is better for combustion. I have seen it on the Honda L series and they used other techniques to raise the compression ratio.

[Kostamojen]

1) Buy a WRX EJ20 turbo motor, wiring harness and ECU for $2000 used
2) Sell your FT86 motor for $2000
3) Profit!

[ryridesmotox]

Originally Posted by Kostamojen

1) Buy a WRX EJ20 turbo motor, wiring harness and ECU for $2000 used
2) Sell your FT86 motor for $2000
3) Profit!

That will most likely be the best thing to do with the car... except I'll keep my stock motor, that way you can put the stock one back in if you ever sell the car and keep your built subie engine

[serialk11r]

Originally Posted by Kostamojen

1) Buy a WRX EJ20 turbo motor, wiring harness and ECU for $2000 used
2) Sell your FT86 motor for $2000
3) Profit!

Until the fuel costs catch up

EDIT: So for people who only want a tiny bump in power, continuing the discussion from the main thread in main forum, 200hp at 7000 is actually pretty pathetic considering what went into this motor. A better exhaust might be able to give a little more and if you don't mind the slight decrease in fuel economy, bigger cams would do some too. 215hp might be realistic considering how the torque is a relatively impressive compared to torque peak 148ft-lb at 7000.

And I am still betting a few years down the road there will be an engine update. I'm not getting a car anytime soon, still in college, but if I'm right I probably will go for said updated FT, well if nothing better comes out.

[GotBoost?]

You forgot labor for installing your new(used) EJ20 turbo motor.

[GotBoost?]

215.... I hope your talking WHP at that number, and even then your forgetting all the other stuff you can do to an NA motor.

EDIT: I was thinking more in the range of 260-280 still staying NA.

[Kostamojen]

Originally Posted by GotBoost?

EDIT: I was thinking more in the range of 260-280 still staying NA.

Won't happen.

[GotBoost?]

Granted it depends on the block and internals, but it is entirely possible. Throw a really aggressive heads/cam set up on it, plus your headers,intake manifold, throttle body, and other basic bolt on's. I fail to see why you think that its not possible to milk another 60-80 hp out of it.

I'm pretty confident that its a very conservatively tuned motor like most factory production cars.

I've also seen far more aggressive power gains from NA motors, for instance a 99 Formula with a heads/cam/intake/headers pushing 440 whp (305 is stock at crank).

Why do you find it unreasonable to put 280 out of a FR-S / BRZ

[serialk11r]

Not going to happen without changing displacement. And no, I was talking brake hp. There is no way some simple stuff like that will net 40hp in gains. I don't think I'm forgetting, I am just listing the things that would be relatively cheap.

[Shevon]

My old DC5 CR was 11.0:1, i stayed NA but planned on boosting, however car got totaled. But point in case that motor was high strong, many people i know boosted and did fine on stock parts. A friend of mine was pushing 320whp of 9 psi i think with a bolt on greddy kit. Point is though 12.5:1 is pretty high, higher than most wanted it to be, there will be a few kits out there not to mention the few that will custom buld their set up. I prolly boost mine anyway its all about how its tuned, personally im not power hungry so if i can boost and get 250whp running 7psi on stock safely ill be happy.