BRZ / FR-S Boxer Engine Dyno Powerband revealed

[OrbitalEllipses]

Originally Posted by Nurburgring

Comparison 1:
Honda S2000 (F20C engine) vs Toyota FT86:

Curves look very similar. Those who have driven an S2000 will know how the BRZ feels, minus 2000rpm. Makes me wonder if Ti retainers and valve springs will let this engine spin to 9000rpm and continue making power.

[Nurburgring]

Comparison 2:
Honda Civic SI (K20 engine) vs Toyota FT86

[7thgear]

Originally Posted by OrbitalEllipses

Curves look very similar. Those who have driven an S2000 will know how the BRZ feels, minus 2000rpm. Makes me wonder if Ti retainers and valve springs will let this engine spin to 9000rpm and continue making power.

from another forum

http://www.rs25.com/forums/f5/2146164-post4.html

essentially, it's an oil problem

whether this new engine will be able to spin to 9-10K will be found out soon enough.

[Jordo!]

Originally Posted by no_name

Yeah, looks about right when scaled on same units with estimated whp values. Nicely done

[Deslock]

Here's another one converted to English units

[old greg]

Originally Posted by Jordo!

Yeah, looks about right when scaled on same units with estimated whp values. Nicely done

Except for being mathematically impossible, sure.

[blur]

Wow nice and flat

[ahausheer]

Originally Posted by Dimman

My theory on the dip is acoustics. We haven't heard of any variable intake configuration so I think this is a pipe (exhaust and/or intake length) induced 'flat-spot' like on bikes.

Reason being is for the sizing to flatten out the curve as much as it does on either side of a more natural inertial torque peak of ~4800 rpm, there will be neg(intake) or positive (exhaust) waves that had to be accepted as a compromise.

A header and AVCS tuning can probably 'fix' this, likely by moving the torque/power curve up the rev range, but naturally sacrificing the low.

This is an interesting idea. However, I just don't think its possible to get such good torque across the range on an NA motor with a fixed intake size/length, there must be some sort of valve altering intake properties. Either way I agree that if you were willing to sacrafice low end power you probably could get rid of the dip

[Homemade WRX]

Originally Posted by 7thgear

from another forum

http://www.rs25.com/forums/f5/2146164-post4.html

essentially, it's an oil problem

whether this new engine will be able to spin to 9-10K will be found out soon enough.

eh, oil isn't really the problem

This was Dom's budget destroker with stock oiling system. Lived happily until it's guinea pig phase was over and it was torn down and inspected.

[serialk11r]

Originally Posted by old greg

Except for being mathematically impossible, sure.

lol, I wonder how many people actually noticed :P

[OrbitalEllipses]

Originally Posted by Homemade WRX

eh, oil isn't really the problem

This was Dom's budget destroker with stock oiling system. Lived happily until it's guinea pig phase was over and it was torn down and inspected.

Yeah I thought your long-rod motors spun to 9K without problems. How's the thread on NASIOC where EQ's trying to trash the motor?

[jonnois]

a bigger free flowing exhauast and bigger intake system just might fix that dip in the torque curve

[2fast4you]

Originally Posted by jonnois

a bigger free flowing exhauast and bigger intake system just might fix that dip in the torque curve

Doubtful. Larger exhaust diameter combined with most "cold air" intakes negatively affect low-end torque, so if anything, it'll smooth out the bump between 2500-3500 rpm.

[Buggy51]

Ah thanks for the reply, I understand a little more now!