Need advice choosing B20 VTEC cams for this build
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Need advice choosing B20 VTEC cams for this build
Hey guys,
Doing B20 vtec and not sure which way to go for cams. This will probably be my daily, so I want it to be manageable but of course as much power as I can get would be nice. Let me know if there's anything else I should change too
This is my build plan so far:
B16A2 head
B20Z block stock sleeves
competition clutch lightweight flywheel
Exedy organic heavy duty clutch
B18 water pump and timing belt
Skunk2 pro series intake
Apparently a toda header 4-2-1
2.25" full exhaust with a striaght through muffler (might change to a twin loop in the future) (yes I know 2.5" is probably better but don't have the budget for new system right now)
Skunk2 alpha 66mm throttle body
HA motorsports chipped P28 ECU
Supertech dual springs and titanium retainers
Ferrea 5000 valves
Grams 550cc injectors
Grams performance fuel pressure regulator
Walbro 255 fuel pump
Speedfactory catch can kit
Skunk2 Alpha forged rods
Manley forged pistons (with rings) for B20 12:5:1
ARP Head studs
ARP Main studs
ARP rod bolts
ACL main and rod bearings
Cometic B20Vtec gasket
Will also be getting both head and block shaved and everything balanced
Was originally looking at buddy club spec 3+ camshafts and buddy club racing cam gears but think this might not be aggressive enough to match the rest of my setup
Any advice much appreciated thanks
Doing B20 vtec and not sure which way to go for cams. This will probably be my daily, so I want it to be manageable but of course as much power as I can get would be nice. Let me know if there's anything else I should change too
This is my build plan so far:
B16A2 head
B20Z block stock sleeves
competition clutch lightweight flywheel
Exedy organic heavy duty clutch
B18 water pump and timing belt
Skunk2 pro series intake
Apparently a toda header 4-2-1
2.25" full exhaust with a striaght through muffler (might change to a twin loop in the future) (yes I know 2.5" is probably better but don't have the budget for new system right now)
Skunk2 alpha 66mm throttle body
HA motorsports chipped P28 ECU
Supertech dual springs and titanium retainers
Ferrea 5000 valves
Grams 550cc injectors
Grams performance fuel pressure regulator
Walbro 255 fuel pump
Speedfactory catch can kit
Skunk2 Alpha forged rods
Manley forged pistons (with rings) for B20 12:5:1
ARP Head studs
ARP Main studs
ARP rod bolts
ACL main and rod bearings
Cometic B20Vtec gasket
Will also be getting both head and block shaved and everything balanced
Was originally looking at buddy club spec 3+ camshafts and buddy club racing cam gears but think this might not be aggressive enough to match the rest of my setup
Any advice much appreciated thanks
re: Need advice choosing B20 VTEC cams for this build
I made 236 to the wheels with BC 3+ cams and a DC header, I think they'd be fine for that build, I've always been a big fan of those cams.
Blox Cs would probably also work well there, maybe some rocket M24xx. If you could find Endyn Bumpstix or real Jun3s I'd run those too.
The only problem I see with the build is the exhaust, 2.25 is WAY too small. You'll want to go full 3" for maximum power. Otherwise it looks solid.
Blox Cs would probably also work well there, maybe some rocket M24xx. If you could find Endyn Bumpstix or real Jun3s I'd run those too.
The only problem I see with the build is the exhaust, 2.25 is WAY too small. You'll want to go full 3" for maximum power. Otherwise it looks solid.
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re: Need advice choosing B20 VTEC cams for this build
I made 236 to the wheels with BC 3+ cams and a DC header, I think they'd be fine for that build, I've always been a big fan of those cams.
Blox Cs would probably also work well there, maybe some rocket M24xx. If you could find Endyn Bumpstix or real Jun3s I'd run those too.
The only problem I see with the build is the exhaust, 2.25 is WAY too small. You'll want to go full 3" for maximum power. Otherwise it looks solid.
Blox Cs would probably also work well there, maybe some rocket M24xx. If you could find Endyn Bumpstix or real Jun3s I'd run those too.
The only problem I see with the build is the exhaust, 2.25 is WAY too small. You'll want to go full 3" for maximum power. Otherwise it looks solid.
Yeah I know 2.25 is too small and the plan is to eventually upgrade, I thought 3 would be too big for NA applications though?
re: Need advice choosing B20 VTEC cams for this build
Re: Need advice choosing B20 VTEC cams for this build
As far as making power, bigger = better.
Noise does become a factor though. If this isn't a daily, I'd definitely recommend 3"
Noise does become a factor though. If this isn't a daily, I'd definitely recommend 3"
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From: The South - Roll Tide !!!
Re: Need advice choosing B20 VTEC cams for this build
So if this is what happened at 260 wheel HP, how is 3" exhaust necessary at 235 wheel HP ???
Last edited by JRCivic1; Aug 6, 2020 at 05:19 PM.
Re: Need advice choosing B20 VTEC cams for this build
Well that's fine, but you're wrong.
Anything past the final collector is just restriction.
This subject has been discussed ad nauseum, literally hundreds of users have shown gains throughout the entire RPM band. There isn't really anything left to discuss.
As stated earlier in the thread, every component of the exhaust after the final merge collector is either for emissions or evacuation, and is a restriction.
Using terms like "backpressure" is funny because it makes you look like a fool. It is a non-quantifiable term given to a resistance to flow. It literally does not exist. It is unitless. It is just a word used by people who do not understand exhaust flow and exhaust dynamics. It does not exist in any index of any engineering or fluid dynamics text.
If you need further understanding, or are not satisfied with my brief explaination, buy this book: <ISBN: 1860582095>
To the OP: Yes, run the 3". The only downside to having such a large diameter pipe would be noise level.
Using terms like "backpressure" is funny because it makes you look like a fool. It is a non-quantifiable term given to a resistance to flow. It literally does not exist. It is unitless. It is just a word used by people who do not understand exhaust flow and exhaust dynamics. It does not exist in any index of any engineering or fluid dynamics text.
If you need further understanding, or are not satisfied with my brief explaination, buy this book: <ISBN: 1860582095>
To the OP: Yes, run the 3". The only downside to having such a large diameter pipe would be noise level.
https://honda-tech.com/forums/all-mo...dynos-2860054/
https://honda-tech.com/forums/all-mo...3inch-3166160/
https://honda-tech.com/forums/all-mo...motor-2936591/
https://honda-tech.com/forums/tech-m...lmotor-317080/
https://honda-tech.com/forums/honda-...sytem-3027588/
https://honda-tech.com/forums/all-mo...-dyno-2341715/
https://honda-tech.com/forums/all-mo...iping-3208711/
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Re: Need advice choosing B20 VTEC cams for this build
I don't see anything except people bickering on any of those links. Can you post a single link with back to back comparisons?
The math says 3" would not be as good as 2.5". There is simply a larger volume of gas inside a 3" exhaust that would cause more resistance.
It comes down to conservation of energy.
The math says 3" would not be as good as 2.5". There is simply a larger volume of gas inside a 3" exhaust that would cause more resistance.
It comes down to conservation of energy.
Last edited by jdblock; Aug 7, 2020 at 04:23 PM.
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From: The South - Roll Tide !!!
Re: Need advice choosing B20 VTEC cams for this build
Well that's fine, but you're wrong. We will agree to disagree on this point...
Anything past the final collector is just restriction. This may be true but if the "restriction" doesn't affect power, then it really isn't a restriction is it ?
This subject has been discussed ad nauseum, literally hundreds of users have shown gains throughout the entire RPM band. There isn't really anything left to discuss. Discussion, theory and bickering proves absolutely nothing. I did a back to back test on the same day to PROVE the difference between the two... and in my case, I have proven that there was no benefit in having 3" over 2 3/8" exhaust.
Anything past the final collector is just restriction. This may be true but if the "restriction" doesn't affect power, then it really isn't a restriction is it ?
This subject has been discussed ad nauseum, literally hundreds of users have shown gains throughout the entire RPM band. There isn't really anything left to discuss. Discussion, theory and bickering proves absolutely nothing. I did a back to back test on the same day to PROVE the difference between the two... and in my case, I have proven that there was no benefit in having 3" over 2 3/8" exhaust.
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