Also in all seriousness, the scion tc's seem to be holding boost extremly well. i think it is another good example of a head that flows good, and on the dyno, it reads high because the drivetrain loss is minimal. They use that vvt-i cam that works very similar to v-tec.

Okay, I apologize for taking your comment out of context. But it really shouldn't be about the evo vs the b-series. It should be about the b-series vs the 4G63, no matter what car you find it in - or put it in.

I've never tried, but I think 325-350hp is within reach. That's still much higher then what $1500 will do for a '99 Si.

Wow, there is some damn good information in this thead. I must say I am very surprised to see the offtopic posts kept to a minimum.

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Food for thought. B18b on (Xpsi) will make Y hp. Remove nonvtec head on B18b and replace with any Bseries vtec head. Retune for new head at the same (Xpsi) and your Y will be greater. That's pretty much why everyone is Frankensteining these B and K series engines. Its the head design. Manufacture a "high flow varable valve timing and lift control with advanced intelligence " 4g63 head and slap it on the current Evos and all of a sudden the playing field is levelized. Basicly I just said what was already said by many in this thread but more examles don't hurt.
Cheers

something sounds wrong with that kit. with I/RH/E/Kpro/IPS cams a K20 can crank out 240whp all day. on 6-7psi that motor should be near 300whp. the K20 was built off F20 in the s2k, a stock s2000 on 6psi(turbo kit) will make 315-320rwhp every time. and since the K20 has only slightly lower compression then the f20, the k20's always come close to 300whp on 6-7psi.

can somebody summerize this thread?

a couple things to think about

i think a key thing for why Honda motors make more power at lower boost is the they have less drivetrain loss... i mean no one really brought that out ... well one guy did but no one responded about it. I think that should be a pretty big thing... think of how much we could pick up if we were just RWD or FWD ... we'd pick up around 8% or more (the 8% is 100% a number from my head but i believe to be pretty reasonable) not only that u have to look at the V-tec cam its self ... i mean a stock V-tec cam from a b16 has a gross intake duration of 412 and an exhaust duration of 379 those are on the STOCK cams ... modded cams go as high as 468 I/E on cams ... i think with that kind of duration the life must be nuts as well..

but ::shruggss: just something to think about

^ drivetrain power loss is definitely a factor, there's no doubt about that. AWD = more mass to spin and more friction. but i don't think it's as much as 8%, maybe 5%.

i think high duration cams is not necessary a good thing on boost car. if you have large overlap, the boost would leak out the exhaust valves. i think high lift and short duration is more suited for boost cars.

There is a naturally aspirated version of the 4G63 and it's found in a 1990 Galant GS that I own. This motor only produces 135 N/A horsepower. On that part you are the one that's giving the wrong information.

that's a good point about the cams I wonder what effect it does have.... that's just highest duration that crower has for turbo cams on B series motors based on their website

You're right. It's been addressed by several people. Back on topic and moving on.

I'm wondering if the dyno's don't play a part in the numbers as well. 2wd vs 4wd dyno means that most of the numbers probably aren't taken off the same dyno and even if they are how do you know there isn't some type of correction factor going on in the software that is part of how it measures power that may be a skewed. I mean we have all seen how different the numbers can be form one dyno to the other. Maybe there is a difference from 2wd dyno to 4wd dyno as well.

We need more engine dyno info not chassis dyno.

The reason is simple, the cylinder heads have a better design and flow more air. Atleast this is true for some B-series and definitely the K series heads. My RB26 race head flows ~300cfm on the intake and ~290cfm on the exhaust whereas the K series race head flows ~375cfm intake and ~330cfm exhaust. A standard K will outflow the EVO 8 head by ~35cfm in stock configuration. It is not that the EVO heads don't do well, it is the fact that Honda heads do better.

Here is my head on Endyne's website.
My RB26 Head
I sent them a spare head to do whatever they wanted to and try different port configurations as well as drilling to check wall and chamber thicknesses.

BTW, Endyne is finishing up their CNC EVO VIII head. I will post results when it is finished.

Makes me wanna make Honda head for Evo bolt on !

very interesting, nice to have to some hard numbers.
what's the valve size fo the RB26 head vs. K20 head? that's quite a big different on the intake side. if the K20 can flow that much, i wonder what the F20 from the s2k will flow.

nice looking RB26 head btw.

don't do it. if you add VTAKKK, you can kiss your torque goodbye. just kidding!