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K20A:
-2157 CC (F22 CRANK/87MM CP XF/CUSTOM RODS)
-TODA A3
-12.9/13 compr.
-76MM EXHAUST
-CUSTOM HEADER
-90MM CAI CUSTOM
-70mm t/b
-K-PRO

With ported rbc
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With skunk2 pro a
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PORTED RBC VS SKUNK 2 PRO.

Image



And one more test with s90 74mm t/b and the engine lost 20ps from 5000 to 9300rpm
For this setup 70mm it's the best choice
 
yes the air flow(speed) decreased.
I think the answer is more complex than this. If you add a larger throttle body and don't port match the manifold, then you will have turbulent flow. I'm guessing you didn't port match the manifold to 74 mm since you swapped back to the 70 mm tb.
 
Discussion starter · #53 · (Edited)
Looks like the ported RBC pooped on the Skunk2 Pro
possibly but youre comparing a modified ported manifold that was possibly port matched(hopefully) to a untouched skunk2 manifold.





And i highly doubt the car made less power with a 74mm throttle body unless like stated above it wasn't port matched and tuned.... Hondas love to move air LOTS of it.
 
I think the answer is more complex than this. If you add a larger throttle body and don't port match the manifold, then you will have turbulent flow. I'm guessing you didn't port match the manifold to 74 mm since you swapped back to the 70 mm tb.
skunk2 manifold tested opened to 74mm.before tested with ported rbc opened to 70mm
 
I have a skunk2 72mm throttle body and i can tell you now i didn't lose any horsepower over a 65mm throttle body with it on my setup. Port matched it to my RBC and smoothed the transition on the left inside edge because it was right in the way of the air coming in with it opened that large.
 
I have a skunk2 72mm throttle body and i can tell you now i didn't lose any horsepower over a 65mm throttle body with it on my setup. Port matched it to my RBC and smoothed the transition on the left inside edge because it was right in the way of the air coming in with it opened that large.
OK.my friend but you fit 72mm not 74mm.your setup/cc?
 
That's not really a very large camshaft heh. That's a much larger displacement slightly higher compression motor though.

And my setup is:

Skunk2 Megapower header
Full Race 3" exhaust
Hybrid Racing 3.5" CAI
Kelford 179-B camshafts
Port matched RBC to Skunk2 72mm TB
Tuned on flashpro


It's somewhere in the 240 horsepower 155+ torque range. I don't know exactly because i haven't put this setup on a "real" dyno, but edynos are accurate enough and they continuously put it between 243 and 250 horsepower every time i do a pull. That's completely different weather between those pulls (250 when it was about 60F and 60% humidity, 243 when it was 52F and 80% humidity)
 
That's not really a very large camshaft heh. That's a much larger displacement slightly higher compression motor though.

And my setup is:

Skunk2 Megapower header
Full Race 3" exhaust
Hybrid Racing 3.5" CAI
Kelford 179-B camshafts
Port matched RBC to Skunk2 72mm TB
Tuned on flashpro


It's somewhere in the 240 horsepower 155+ torque range. I don't know exactly because i haven't put this setup on a "real" dyno, but edynos are accurate enough and they continuously put it between 243 and 250 horsepower every time i do a pull. That's completely different weather between those pulls (250 when it was about 60F and 60% humidity, 243 when it was 52F and 80% humidity)

w00t692, this not related with topic but how much vtc you used max? I tuned a k20a jdm cl7 euro r with kelford 179b, it makes 6whp more after 8000rpm but because of its a virgin engine and its not clayed I used 30vtc and lost around 7-8 ft lbs torque on mid range 5500-7500 rpm. I'm pretty sure that if I used more vtc I can gain the lost torque.

With the topic related, I tuned my car and my friends car same day, same dyno, same size exhaust, both use cai etc. (both are stock jdm k20a engines with bolt ons). Mods are mostly same except I used s2 intake manifold with hybrid 70mm throttle and his car has rbc with stock throttle. Same peak torque, same whp and almost same dyno graph only differenece is I have peak whp at 8400rpm and it keeps till 8800rpm, my friends car with rbc and stock throttle have peak whp at 8200rpm holds it until 8400rpm and starts to drop. And i tuned my car later with toda a3 cams it makes 241whp, I think s2 intake manifold is better at high revs. Engine makes 241 at 8500rpm ad holds it until 9000rpm, I don't think rbc is enough for that high rpms except its ported.
 
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