toyota VS honda, stock -> turbo Options

[Hanyo]

how come honda engines seem to have more power and boost more compaired to toyota engines. Well to be more specific, the b18 VS the 7afe.

I've heard earlier, under boost conditions the variable valve timing actually hinders performance.

so why does a supercharge b18 engine at 6psi make 190 whp with no aftermarket fuel management?
where as a 7afe only can make 170 whp with a turbo and all the dooo dads? ( i dont remember how much boost nik was using.)


it just doesn't make sense. 7afe and b18 both have 1.8 liter engines. And the 7afe head is suppose to be a good turbo head?

[Kwanza26]

Here's a simple way to look at it... more horsepower vs. torque = head can flow larger volume. More torque vs. horsepower = head flows less volume, but has higher velocity. Strictly talking horsepower... the 7A barely matches a D16 in making horsepower, so same would be true if both engines were boosted. The main reason however, that a D16 can make more power per psi is its oversquared design. It's a 90mm stroke with a 7000 rpm redline, which has been proven to spin fairly reliably at 7500-8000 rpms. The bottom-end is fairly well built. Comparatively speaking, most toyota tech guys who have built 7A's and such, don't reccomend spinning the 7A block pas 7200-7500 rpms. That said, the D16 has more use of its breathing at higher rpms so it has more room to make horsepower. Make sense? Also mind you, there are many many versions of the D16... VTEC, VTEC-E, non-VTEC, all slightly different, and all will produce different numbers under boost, but the most basic reason that the D16 can make more power... it's initial design made more power, and it's stock head can make more power un-modified. A modded 7AFE head will bump the 7A past the D16...

As for the B16/18 vs. 7AFE... again, strictly horsepower here, same reason as above... even better head design. Typically speaking, not having VTEC will make tuning a whole lot easier and will make the engine more predictable... but I've seen some fairly decent turbo VTEC builds. It's a matter of taste.

I might be wrong on this but the last time I pulled the valve cover on a D16 it had two cams with one riding a slave gear. In case anyone was wondering it was from a 1997 Honda Civic EX. I'm not a big Honda fan since they don't pose a challenge like the Celica does, so I never bothered learning more than I need to know about them.

There's only one cam... but there's also a row of rockers... ;]

This post has been edited by Kwanza26: Apr 19, 2005 - 2:42 AM