F20C performance out of the FA20

[CSG Mike]

Originally Posted by Captain Snooze

I am all for na and I watch your build with interest. Fi doesn't interest me but I have issue with your above statements.

You have made broad generalisations that may not apply to individual motors.
Sure, a na motor might last to 100k miles but not if it being thrashed exclusively on track at 6-9k rpm. Conversely, a well built turbo engine may last as long if it is being used as a shopping trolley.
Sorry, I am being a pedant but to say one is more reliable than the other doesn't take into account the myriads of ways an engine can be built, used or maintained.

[/rant]

My s2k would like to have a word with you

[airjonny]

Ok assuming both are driven balls out, I'm putting my money on N/A all day being more reliable. There's so much more to take into account going FI.

[themadscientist]

Like air/fuel mixture, timing, cylinder pressure, oil delivery and control, cooling ,,stuff like that. Yeah, only FI engines have to worry about that.

If you want power level X, both motors are going to see stresses. While an FI engine has higher cylinder pressures, the NA engine is going to have to elevate its cylinder pressures as well AND wind up higher to achieve the same power as an FI does at lower RPMs

Nothing is free.

[himbo]

Originally Posted by stevo585

The f20c has variable lift allowing for a very aggressive camshalf and high rpm flow. Our engines do not have variable lift. Also emission strandards are stricter now. Thats all there is to it.

Bingo. Honda wouldn't be able to make an F20C these days. Why do you think Ferrari is moving to FI? I think it's pretty impressive that Subaru/Toyota created a naturally aspirated motor that makes 100hp/l in this day and age. Drink it up kids, we're near the end of the line with these types of motors...

[hmong337]

Originally Posted by Poodles

You're never EVER going to get the VTEC kick out of this engine. The F20C was also a freak, having the highest pistons speeds of it's time for a production car (it's still second to this day).


Two very different engines, but mods can level the playing field a bit...

This car was also not a $40k car when new too. For a sports car built to sell for $25k, the 86 definitely holds its own.

I hope one day some priviteer builds a 12000rpm lightweight internal na fa20 monster. But still, the biggest drawback to this motor is the lack of variable lift.

[CSG Mike]

Originally Posted by himbo

Bingo. Honda wouldn't be able to make an F20C these days. Why do you think Ferrari is moving to FI? I think it's pretty impressive that Subaru/Toyota created a naturally aspirated motor that makes 100hp/l in this day and age. Drink it up kids, we're near the end of the line with these types of motors...

No it isn't. Everyone else already did it.

Toyota did this decades ago.

[Poodles]

Originally Posted by CSG Mike

Know what's scary?

The new Mustang GT350 piston speeds just bumped the S2k down a notch...

Hmmm... wasn't aware of that. Now if only they could fix the derpy look of the headlights on the new Mustang (and maybe cut some weight and bump the quality up a bit)

Originally Posted by airjonny

Ok assuming both are driven balls out, I'm putting my money on N/A all day being more reliable. There's so much more to take into account going FI.

If they were both the same WHP, hell no. Know what's the coolest thing about boost? The fact you can change it on the fly. I've known 1000+HP Supras that started and drove just like it was stock (well, with loudish exhaust as it's hard to shut up 4" exhaust). Drive it all day out of boost and it's essentially boring.


Now try that with an NA engine. You need large displacement, high compression (requiring race gas 100% of the time), and a cam profile that won't like to idle and is gutless until you get into the high RPM's it needs to hit to get those numbers. Speaking of the high RPM's, you'll need to be spinning that high and piston speeds are going to be an issue (as well as valve float, balancing, flywheel, etc)

Originally Posted by hmong337

This car was also not a $40k car when new too. For a sports car built to sell for $25k, the 86 definitely holds its own.

I hope one day some priviteer builds a 12000rpm lightweight internal na fa20 monster. But still, the biggest drawback to this motor is the lack of variable lift.

Yarp, it's why I always find the comparison a bit funny. Yes, I could also go buy a used vette for the price of the twins or a used S2000 and stomp either one... Compare apples to apples and original MSRP's and the twins are a serious bargain.

[OkieSnuffBox]

It's not really "variable lift" in the same sense that modern engines have "variable cam timing."


It's just two separate cam profiles, so it's either the low or the high-rpm cam lobe. Not so much "variable" as "either/or."

[himbo]

Originally Posted by CSG Mike

No it isn't. Everyone else already did it.

Toyota did this decades ago.

It is considering emissions and efficiency regs. Yes it's true that Toyota, Nissan, and Honda all made 100hp/l NA motors a while back, but it's very difficult for manufacturers to accomplish this today where they must meet stringent emissions and efficiency across their entire product line. Turbocharging is the easiest way for manufacturers to reach certain performance goals while meeting regs.

[rlpaul]

I think there's a few 100hp/l NA engines that would meet CAFE regs, but not CARB - California screws it all up for us!

Pretty sure there's a version of the K24 in production that's running right around 240hp. Just not available in USDM. Go figure.

[discretion]

So I'm hearing the F20C is just one of a kind (which I kind of already thought). Is there any decent info/thread out there on swapping the F20C in an FRS/BRZ? I'd like to preserve the handling/balance of the car if possible.

[CSG Mike]

Originally Posted by discretion

So I'm hearing the F20C is just one of a kind (which I kind of already thought). Is there any decent info/thread out there on swapping the F20C in an FRS/BRZ? I'd like to preserve the handling/balance of the car if possible.

http://www.ft86club.com/forums/showt...=39707&page=13

@86Tony seems to think the K20 is superior...

[OkieSnuffBox]

Originally Posted by CSG Mike

http://www.ft86club.com/forums/showt...=39707&page=13

@86Tony seems to think the K20 is superior...

I thought it was K24 + K20 head + cams + E85 = 300whp


At least that's what Andy Hollis has done for his OLOA Miata.

[CSG Mike]

Originally Posted by OkieSnuffBox

I thought it was K24 + K20 head + cams + E85 = 300whp


At least that's what Andy Hollis has done for his OLOA Miata.

That's the basic formula, but there's an inverse relationship between RPM/output and engine life.

At 300WHP, it's not gonna last very long at all.