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Discussion Starter · #1 · (Edited)
RESULTS:WE GAINED 7WHP UP TOP AT 8000RPM AND AT 6300RPM, AND EVEN GAINED A SMALL AMOUNT AROUND 4000RPM.
CLIFFNOTES=BOLD
I helped a friend install an RBC Intake Manifold on his 2006 RSX Type-S. The stock Intake Manifold is a PRB, and the RBC is what is used on the '06+ Civic Si, and Euro Accord Type-R (K20A running an RBC). The most significant thing about his car is that he has minimal mods. He has a DCRH and a Fujita CAI, that's it, nothing more. What's even more significant is that with just those mods he has pulled off a 14.3 at the track. I thought wow, this kid can drive. Mind you he's young, and has been to a track like 2-3 times, if that.

Car: 2006 RSX Type-S
Mods prior to RBC install: DCRH + Fujita CAI


Before we set out to install the RBC we decided it would really be nice to see if the car actually made an improvement or not on a non-K-Pro'ed Motor. Therefore, we called a local Dyno shop and asked for their assistance. We did a baseline Dyno on Saturday, April 21st. I was also worried about weather conditions, and how that would effect it, so I was sure to check weather.com to cross reference what the dyno put out.

Well, we did the dyno, and the climate conditions on the dyno graph matched weather.com so I was confindent there would be no problems in that area.

The following Friday, April 27th, we did the install.

Well, the week before we started, I knew that in order to do an RBC install it was important that the CAI had a rubber elbow at the top so that it could telescope left a bit and face the new position of the throttle body. Well, in my haste, I forgot to check to see how the Fujita was setup, and instead I assumed it had a rubber elbow instead of actually checking.

On the day of the install, Friday, I looked under the hood and lo and behold, no rubber elbow. DOH!!! I was so disappointed, we had EVERYTHING, except for this! Well, quick thinking, I came up with a solution. My RSX is in the shop, and it's down the street. I have a loaner for another week, while it's getting body work done, it's going to be down and it won't matter if I take the Injen Elbow off of it. Being that I think ahead, I also already had the stock airbox mounted in my car with the stock snorkle turned to the side. So, we ran to the shop, asked if we could swap the intake snorkle and proceeded. NO PROBLEM! PROBLEM SOLVED!

Now, for the scary part. How are we going to get the elbow to work on the Fujita??? We would have to cut the top bend and put the elbow in place. What if it doesn't work??? We'd be out a CAI if it doesn't work! Oh no, that would bad!!! Not to mention we'd have to uninstall the entire CAI just to find out for sure if it would work.

Well, with some good cutting skills and a hacksaw... we lopped the top right off, put the Injen Elbow on, and PERFECT!!! It was unbelievable, it worked!!!
Edit: Here's the instructions on how to modify the Fujita CAI to work with the RBC: http://forums.clubrsx.com/showthread.php?t=483318

After that, we followed the supplied Karcepts adapter instructions, had a few steps missing, but it all came together. The next day, Saturday, April 28th we did the after dyno. Again I checked weather.com to verify the weather/climate conditions output by the dyno. They checked out. I have print outs from weather.com for both days if anyone's interested. Weather from one Saturday to the next was very similar so that was a relief: Cloudy, a bit humid, and around 75degrees. The dyno graph below has the exact climate conditions right on it.

Here's the final result, they speak for themselves, yes it's very nice:





Things to note on the install and Karcepts instructions.

1. The Karcepts instructions mentioned nothing about how to lop off the top of the CAI, to adapt it with a rubber elbow like the Injen uses. What we did is we put a piece of electrical tape (or any tape will do) to mark off the circle of where we wanted to cut, and then we cut. Simple, we just made sure it was just above the vacuum line connection, but right at the bottom of the bend. Easier said than done, sure. The tape was the perfect width since it gave us spacing for where the elbow would strap to the CAI. Thread on how to do it is here: http://forums.clubrsx.com/showthread.php?t=483318

2. The instructions tell you to take a bunch of items off and then tells you to put a bunch of items back on, and fails to mention the most important step of putting the RBC manifold in. This is the most critical step and you must take your time.

3. The instructions also don't mention the A/C line till the very end, where it's too late. You want to make adjustments to where the A/C line routes before the manifold goes in. Karcepts supplies you with a picture, but mentions it at the very end, which is just too late. If you do it at the end, you'll have to take the entire manifold and everything back out. Very bad, and big waste of time. I also found a few nice tricks to adjusting it. First of all, to make it easier to adjust, take off the clip and rubber strapping around the A/C line by the firewall. THAT MAKES IT SO MUCH EASIER. When I did it the first time (on mine), it was a nightmare trying to adjust the A/C line just right. That helped so much, by discovering that. Next thing, the little brackets that hold the AC line against the front support needs to be configured so that the AC line is to the right of the brackets instead of to the left, as in the picture below. Another good idea is to get those little brackets to come to a 45 degree instead of a 90 degree. Here's how: 1. Take the brackets off and using a hacksaw and pliers (second pic below), cut a notch into both of them as I have pictured (third pic); 2. Finally, bend both brackets so that each of them make a 45 degree (see third and final pic). Now, return the brackets to their new orientation, reattach the AC line at both ends, and adjust as needed.

4. Don't forget to buy a Hondata Intake Manifold Gasket if you don't already have one. If you decide you want one later, you'll have to do the install/uninstall all over again. We planned ahead, and had one ready.

5. You can order an Injen Rubber Elbow from InjenOnline.com It's just a click away. So plan ahead if you need one. Also, don't be discouraged if you don't have an Injen CAI, it worked beautifully with what we did (lopping off the top bend and replacing with a Rubber Elbow).

6. Put a zip tie around the radiator hose, and tie it to where the stock intake tube bolts to the front support (use the little mount). This will keep the radiator hose/fluid from heating your CAI rubber elbow. Like this:






I also found a really neat trick to not having to use the hood dampners and being able to use the stock hood prop holder. I loosened the front motor mount straight-through bolt. Then, I put a block of wood and a jack under the motor, and jacked it up so that all the play came out of the front motor mount. Next, tightened it up. Finally, hey what do you know there's enough room now for the hood prop holder!!! Complete the task, by Shaving off the extra material that will end up touching the manifold (I used a hacksaw to cut the two little extra pieces of material, then file it a little), and then placed it just like it was. Ofcourse, you want to do this before the RBC goes in, and be sure to have the ESMMs in, otherwise your motor will just smash that little piece. It may not be the best in the world, but it saved me from having to buy the hood damners immediately.

Recap:
RBC is out
Take the slack out of the ESMM inserted front motor mount
Shave the hood prop holder
Presto, you're done, don't need Hood dampners.

Edit: Things to note on the Dyno: The dyno reads on the low side. Another car with a similar setup (DCRH, K-Pro, CAI) was dyno'ed there in 100degree weather and it only came up with 189whp. It's suppose to be using SAE correction, so what gives? Who knows, but regardless, the before and after tests we did had almost identical climate conditions on the two days so any problems with weather correction were negated. I mean it's the difference in power that matters, not so much the final numbers. Maybe a better dyno might have read 205whp (instead of 201whp), and the improvement would have been 8whp, but that's OK, practically the same difference. Oh, we ran the car that hit 189whp on another Dyno this past January and it hit 211whp, :dontknow:

I think that's it. Besides the very important fact that:
WE GAINED 7WHP UP TOP AT 8000RPM AND AT 6300RPM, AND EVEN GAINED A SMALL AMOUNT AROUND 4000RPM.

Edit: So where did we get the RBC and everything we needed, well we kind of got a local hook up, off this guy:
http://motors.search.ebay.com/130115216013

Here's another look, in color, using ctrl-printscreen off my computer:
 

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If you look at the area under the curve, it looks like just as much was lost in the midrange as was gained on the top end (in terms of total area under the curve, not peak gain/loss). I wonder what the difference in 1/4 times would be on that car between the prb and rbc - maybe the times would be identical.

The rbc definitely shows that it has plenty of headroom, so I imagine once you are revving higher the high-end gains would definitely outweigh the midrange loss. Definitely setting up well for future mods :thumbsup:

edit: after re-reading your post, it seems you are suggesting that the lower numbers from 6000 - 7200rpms are from the PRB, not the RBC - can you clarify which line is which?
 
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Will a car with more bolt ons (cams especially) and kpro lose that much power in the mid range?For instance I have a k24 and all I have is midrange...I don't wanna lose that power
 
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Discussion Starter · #10 · (Edited)
If you look at the area under the curve, it looks like just as much was lost in the midrange as was gained on the top end (in terms of total area under the curve, not peak gain/loss). I wonder what the difference in 1/4 times would be on that car between the prb and rbc - maybe the times would be identical.

The rbc definitely shows that it has plenty of headroom, so I imagine once you are revving higher the high-end gains would definitely outweigh the midrange loss. Definitely setting up well for future mods :thumbsup:

edit: after re-reading your post, it seems you are suggesting that the lower numbers from 6000 - 7200rpms are from the PRB, not the RBC - can you clarify which line is which?
I think there is twice as much area gained than area lost. I mean look at the graph, there is a gain before VTEC (~5200), a large area gain after VTEC (6300RPM), and then the final triangle up top (8000RPM). It's twice as much in my eyes. Totally worth it.

Also, I feel the reason for there not being such a BIG gain is because the RBC manifold opens up the intake REALLY NICELY, and the fact that the stock ECU runs a very conservative VTC not allowing enough air to enter the motor. The RBC allows much more air all at once, whereas the PRB was a bottle neck yet it provided a way to increase the velocity of the air going in, which equals a bit more low end power. As 2k2_nbp_egg asked me what I was expecting before the results were in, and as I was telling him, I expect there to be a gain where-ever the stock ECU opens VTC well enough. Looking at an 02-04 stock K-Manager Kalibration (a stock 05-06 isn't supplied w/K-Pro), it shows that VTC is higher at cruising and somewhere around VTEC. So, that's what I was expecting, maybe better fuel economy and more power around VTEC. What I wasn't expecting was the top end gain that we got. So, without that top end, yeah it would have almost not been worth it.

Here's the change I made to clarify where the gains are:
austinite said:
I think that's it. Besides the very important fact that WE GAINED 7WHP up top at 8000RPM and at 6300RPM, and lost a minimal amount around 4000RPM.
Also, with just K-Pro on a car with DCRH+CAI+RBC, it makes a WORLD of difference, there's no need to wait for cams to see the greatest benefits of RBC. Heck there's no need to wait for K-Pro, just look at the graph. Anyway, on my car before RBC, I had DCRH+CAI+K-PRO. So, I went the other route K-Pro before RBC, not RBC before K-Pro, mostly because my '02 has K-Pro available for almost $500 less than what it costs 05-06's. When I put in the RBC, I immediately felt a gain. It was like I had no passenger in the car, when yet I did. When my car went on the dyno, we compared my car with a car that had the same mods but no RBC, and I had a gain of 6whp all the way through. Mind you, there was absolutely no tune on it, not even a road tune for a 13.2 A/F ratio. We then did a 13.2 A/F ratio adjustment all the way across the RPM, and we got another 4whp, 10whp total gain with an equivalent to JUST A ROAD TUNE!!! We then spent an hour on the dyno, really played with the A/F ratio, did a full A/F tune (nothing else), and gained 5whp more. So, over a weekend, I gained a total of 15whp, 10whp from RBC, and 5whp from a A/F dyno tune. NICE!

After doing this RBC test, here's what I recommend for best bang for you buck:
For an 02-04:
1. CAI
2. Race Header (if you find a good deal, otherwise K-Pro first, then Race Header, then RBC)
3. RBC
4. K-Pro
5. Exhaust
6. Cams/boost

For an 05-06:
1. CAI;
2. Race Header;
3. RBC;
4. K-Pro
5. Exhaust
6. Cams/boost

K-Pro is like $500 more on an 05-06 so it's definitely at #4, whereas on an 02-04, it's kind of a wash between RBC/K-Pro/Race header (RBC works well with Race Header; without :dontknow:).
 

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Here's the change I made to clarify where the gains are:
Ok, that certainly makes all the difference then. At first glance, it looked to me like that was power lost and not gained around the 6300rpm mark. Very hard to tell those two curves apart right there. This is a no-brainer if that is the case :)
 

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Discussion Starter · #12 ·
Will a car with more bolt ons (cams especially) and kpro lose that much power in the mid range?For instance I have a k24 and all I have is midrange...I don't wanna lose that power
You'll lose a negligeable amount for the amount you gain. Totally worth it to go RBC. Just do it. If you were stock without K-Pro, then I wouldn't do it. If you have K-Pro, then do it. K-Pro will take in that extra air and eat it up for more power! Do a search. It's been proven from what I've read. Check out K20a.org there a whole lot more K24block/K20A2head cars running around over there.
 

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nice test - you will be surprised what additional gains you will get from k-pro (when used with RBC)

I got 40+whp & 50+ lb/ft of tq @5000 rpm thru tuning & tuning alone :ugh: (14whp up top) I think the graph is here in one of my old threads/posts. the before was stock ITR map'd k20a. lowering vtec was key

:thumbsup: good stuff

EDIT - I WOULD EMAIL BRIAN FROM KARCEPTS ABOUT HOW INSTRUCTIONS CAN/SHOULD BE CHANGED!!!! or atleast noted for dc5/ep3 owners
 

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nice test - you will be surprised what additional gains you will get from k-pro (when used with RBC)

I got 40+whp & 50+ lb/ft of tq @5000 rpm thru tuning & tuning alone :ugh: (14whp up top) I think the graph is here in one of my old threads/posts. the before was stock ITR map'd k20a. lowering vtec was key

:thumbsup: good stuff
Id like to see that graph.
 

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Discussion Starter · #19 ·
wow! nice i wanna see how u cut the fujita intake pipe and put the injen rubber elbow thing. gj tho man!!
I'll get that picture of the cut off piece for you. I also may be helping another friend out with a Fujita for the same reason. If I do soon, I'll get detailed pics, before and after.
 

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Discussion Starter · #20 ·
I've gotten too much feedback that the dynograph isn't readable. Therefore, I have studied how to graph the files that the dyno shop gave me. Here's the graph in color:
 
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