why do honda engines make so much more power with less boost
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.
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Joined: Mar 2002
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From: Birmingham, AL
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.
can you make 400 hp with just $1500 on a DSM? probably not, because an evo already come with a good turbo, intercooler, Mivec head ect.
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
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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
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Joined: Nov 2006
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From: Fircrest
This doesn't apply entirely, because it's on stock compression, but I just turboed a 06 Civic Si. Turbo is roughly the size of the stock EVO turbo. It does 250 to the wheels with 6-7 psi of boost. The EVO did that stock with three times that boost. Some of it can be attributed to drivetrain loss, and some to compression ratio differences, but it is nice to be able to make that kind of power with so little boost. And with the light weight of that car, it is pretty quick. I have also always heard the theory about the honda's exceptional head flow, but couldn't be bothered to even think about validating it. 
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
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
Last edited by Rcebowl; Feb 9, 2007 at 12:06 PM.
^ 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.
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.
Last edited by honda-guy; Feb 9, 2007 at 12:18 PM.
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ok there are no such thing a 4g63 non Turbo,( theres some misunderstanding here, please read page six to clear up the Miscommunication!) The motor that came in standard with the Rs' and non turobed Eclispes, Laser's and Talons, all had the engine code for the 420a, Thats the same motor that was in the Dodge Neon, and Chryslers POS motor that always blew the head gaskets. So you need to check your info again.
You are correct. But you clearly didnt read his post....So please re Read and understand that he's asking about built motors. Most Hondas that are built "GSRs" or b18c's are all higher compression than the EVO;s stock compression. Unles its a LS motor and i bleive that has 9.1:1 last i checked. but i know its somewhere in that neighborhood.
If you have ever looked at an EVO graph with a 35R then you see that when its making 500WHP its only making like 369-390 Wtq as well. So thats usually a displacement issue found in all these car smaller 2.0 cars. ever notice that a 2.3L EVO with a 35r always has some serious torque numbers.... Hence when its such a popular upgrade!?
You are correct. But you clearly didnt read his post....So please re Read and understand that he's asking about built motors. Most Hondas that are built "GSRs" or b18c's are all higher compression than the EVO;s stock compression. Unles its a LS motor and i bleive that has 9.1:1 last i checked. but i know its somewhere in that neighborhood.
If you have ever looked at an EVO graph with a 35R then you see that when its making 500WHP its only making like 369-390 Wtq as well. So thats usually a displacement issue found in all these car smaller 2.0 cars. ever notice that a 2.3L EVO with a 35r always has some serious torque numbers.... Hence when its such a popular upgrade!?
^ 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.
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.
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Joined: May 2003
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From: Davidson, NC
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.
Last edited by hotrod2448; Feb 9, 2007 at 01:35 PM.
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.
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.
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.
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.
Last edited by honda-guy; Feb 9, 2007 at 05:50 PM.