Reply With Quotegot a link?
There's a good thread on honda-tech testing RBC, RRC, and skunk2 manifolds on an n/a k24.
got a link?
Last edited by fobman; 03-03-2009 at 11:09 PM.
There was a good article like that in Super Street also.Originally Posted by AttarixEp
http://www.superstreetonline.com/tec...t/viewall.html
What I'm looking for is a breakdown of all OEM k-series manifolds showing which cars they came in from the factory.
for NA and supercharged apps hondata suggests that most power is made at the higher end (toward 50*) of VTC, considering you have high flowing exhaust. But with a turbo setup, the backpressure from the turbine keeps your powerband in the 20* area. im guessing you would only benefit from anything over 30* during low rpm acceleration, if at all.
I would go for a PRC manifold over a PRB, when I had the PRB it felt like the motor just couldn't breathe, it made my k24a2 feel like junk. I ended up with RBC only because i didn't want to deal with the sharp bend in my IC couplers, plus i was going to be boosted, low end was made up for quick boost. I still want to port the RBC and bore the TB. I don't have any experience with the PRC to speak on it. just tot throw that out there. I imagine it would help my partial throttle power out when puttin' around the city, but its not bad at all with the RBC. Prolite wheel probably doesn't help that feeling either. I regret nothing, the car drives beastly.
quick question though, is the flow measured in the heads without valves in on a bench? or is this all theory based on dyno numbers? cause i've read some things and i don't think it has to do with the head castings (port sizes) or locale of ports in the chamber, as i'm pretty sure i read that the dimentions were identical minus a small detail in the bowl. a reliable source told me a secret and i'm trying to back what he told me but i can't seem to get a straight answer from anyone.
After some googling, i've found some more crazy flow figures, but still inconclusive because they were flowed differently. not exactly controlled testing. i know this is somewhat off topic but it has to do with a1 vs k24a2 flow going along with an rbc. rbc and k20a2 head go hand in hand with high rpm flow, where both crv and tsx heads fall off. same with lift, the rsx is more advantagous at higher lifts than both tsx and crv again, but they both outflow at lower lifts, the crv leading tsx, where partial throttle driving would feel much better.
so one would say your choice of intake manifold would depend on cam choice and rev limits, where you would choose a head based on which bottom your mating it to, give or take an a2 oil pump of course. porting negates any of this as cutting enough material brings all heads to the same flow regardless of cams (minus the element head). and depending on how much they flow you would match them up with the most efficient manifold. and seeing that a z3 head (for example) flows 292 CFM @ .500 lift @ 28 inches and the RBC manifold is rated at 320 CFM (i think? cant find a reference...) - well looking for the reference completely threw me off my tangent on whatever it was i was trying to say, but maybe you guys can pick up what im puttin down. im not saying any of the manifolds are better than the other for OP, but the choice should be based on what he plans on doing. things start to add up in the end, esp if your going boosted. 20 cfm doesn't seem like much at 290 or 280, but at 1 bar that turns into 580 and 560 CFM, a ported head seeing 320 CFM and manifold seeing 360 CFM is seeing 640-720 CFM, you get the idea. ok suprise firedrill gotta go. peace.
I dont think so, but if you would feel safer i could always mod your 50* like i did my 50* for my 2.2 build...
RRC= JDM
RBC= USDM
PRC= JDM
PRB= USDM
The RRC is to the RBC as the PRC is to the PRB. The USDM version looks very similar to the JDM version... but the JDM is always better it seems. JDM always carries the higher pricetag too.
Katman on k20a.org was the one that spearheaded that article. There is a corresponding thread along with it... but its got a lot of BS convo in it too. Its informative, just takes time to read it.
Something to keep in mind. A manifold like the RRC/RBC is designed towards the upper half of the rev range. More air, more fuel, more power. While a 2.4 draws in more air than a 2.0, you wont rev it out like you would a 2.0.
For discussion sake, lets say the 2.4 at 7500rpm pulls in the same amount of air as a 2.0 at 8200rpm. If you build (plan for) your 2.4 to rev to 8000k and above, then the RRC would be your choice. If you plan on driving your 2.4 on a daily basis, arent concerned with peak whp#'s and want to have a nice solid powerband so you dont HAVE to rev it out (isnt that why most people want more TQ anyways?), then IMO the PRC is hard to beat. It made 220hp on the original JDM k20a. It makes great midrange AND performs up top. Whats not to love?
And this is what it always boils down to. You have to know what you wanna drive before you can build. Theres enough info out there to cause anyones head to spin into a coma trying to decide just that.
Know what you want... realize its limitations (and your wallet)... build it and love it. I get joked all the time because i have three engines and several head sets. "What is all this shit for...?" Each one will be an engine for its decided path... because one cannot be all three.
Can anyon explain the differences between RBC, RBB, PRC and PRB? I've done some googling but all I can find are that theyre different intake manifolds... What do they mean?!
Prb - ep3, dc5
prc - ep3r
rbc - fd2, fa5
rbb - tsx
rrc - fn2
Last edited by Blah1219; 12-19-2011 at 02:24 PM.
I dynoed my k24a2 with the rbb manifold, the stock tsx mani and made roughly 20hp less than I did when I slapped on the rbc. I also gained tq with the rbc. Final numbers on my 06 k24a2 was 230 198, with the rbb I only made 201hp
The RBB isnt designed to have air run through it as fast as possible to make power (not TQ). If you lost TQ with the RBB... odds are you were using too much cam advance. Its a catch 22... the RBB doesnt like a lot of cam advance (why do you think it only comes with a 25* VTC from Honda?), but you need to use it to make power. Changing the mani is the first step in this case... if better dyno #'s are what youre after.
The real story lies in the dyno curve... not just max whp/wtq numbers.
So true, and so many people fail to realize this or don't care.
A good curve is so much more important than peak numbers.
Yes I completely agree, I want a good smooth curve throughout the rev range.
Also, my intentions are a DD with some pick-up.. 215-230whp would be great, while keeping things as OEM and reliable as possible.. 7,500 rev limit.
Keep in mind that the stock tach is off by about 400rpm at redline, so what it shows will be different. I believe my fuel cutoff is set to 7,600, but the tach shows right at 8 when it cuts.
If you set it to what you want in kpro, you'll be fine.
http://www.youtube.com/watch?v=9mua5-CNjLM
Yea I would always know to shift when it hit the 7 on the tach with the stock ECU because it was off a little. 7 was about perfect with the 6,700 stock rev limit.
That's a good idea though, 7,600-7,700 and just rev it to 8,000 on the tach.
Yeah, it just happened that way by coincidence on my car, but it's really nice for drag racing.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Bookmarks