View Full Version : Help w/ DC5 JRSC on K20A3 EP3

07-13-2012, 10:17 PM
Looking for any suggestions, before I start my JRSC install, Here is a list of my mods and plans for my 2005 Civic Si EP3:

Stock K20A3 and Internals w/ DC5 RSX JRSC and DC5 Manifold <ready to install>
K-Pro <installed>
Sparks Racing DC5 spec RSX Tri-Y Race Header <installed>
DC5 Greddy Spectrum Elite Exhaust mod to fit EP3 <installed>
Injen CAI <installed>
Skeletor Crank Pulley '09 K24 <ready to install>
Plan to mod stock auto tensioner, also have Mercado Brackets from DC5 that I don't think I will need? <ready to install>
RC 750cc Injectors (hoping to have option to run higher boost with aftercooler) <ready to install>
Walbro 255 Fuel Pump <need to buy>
Custom- JRSC Aftercooler, JustinC core, silver front mount, surge tank, bosch pump <ready to install>
Blower pulley size = 3.2 or 3.4 ?? <ready to install>
MAP sensor = assume I need to get 2.5 or 3 Bar?? <need to buy>

Anything I'm forgetting?

I know I need a base tune until I can get to Speedlab here in Vegas, I don't see any base tunes for JRSC K20a3 w/ 750cc's and higher boost pulleys.

From what I've read you can't just upload a kal and change the injector size without changing the fuel tables. Can I just look at the fuel tables for a 750cc tune and somewhat mirror it in a base JRSC tune until I can afford to get a full tune? (I have a lot to learn)

Also from what I've read, the higher speed of the Skeletor CP will allow for a bigger BP to be run which will allow me to keep the Blower RPM's at a safer level. I'm also hoping the aftercooler will assist with engine/ blower longevity.

Been reading on ephatch, k.20, and clubrsx/ep3 for a while and I'm glad to finally being able to get my supercharger install started, any suggestions appreciated.


07-20-2012, 07:37 AM
For the base map you could always talk to ur tunner, maybe he could provide you an temporairy tune/base map

What aftercooler will you be running ?

07-20-2012, 08:57 AM
You can look at 750cc basemaps and get a rough estimate of fuel needed... but you need to compare cam angles as well. Err on the rich side, buy a few sets of plugs, and you can street tune it yourself till you get it to a tuner.

My JRSC experience is with the EP manifold... i never messed with the DC5 mani or any of the aftercooler setups. IMO, you want that much power you should go turbo... or plan on building the engine up a little (higher CR at least, so the blower doesnt have to do so much work to make power).

Ive worked with several EP mani JRSC builds, k20 or 24 and stock compression on up to 11.5cr at 12psi (again w/o an aftercooler). So you have a lot to gain with a little engine work. Youd also benefit greatly from swapping in a k24a1 head casting... if you wanted to stay 2 lobe (your entire k20a3 head internals swap into the k24a1 head... valves and all). More flow and better midrange, combine it with a bored/port matched TB and you are already ahead on the cooler intake air charge game...

There is a lot of power and powerBAND to be found by maximizing what you have... for minimal cost.

07-20-2012, 09:11 AM
For the base map you could always talk to ur tunner, maybe he could provide you an temporairy tune/base map

What aftercooler will you be running ?

Bought the setup from Travisito at http://forums.clubrsx.com/showthread.php?t=828797

He had a clean RSX that's he's parting out, I also got the supercharger setup from the same guy.

My engine runs so good right now I dont have the heart to swap it, so I decided to go with a setup on my K20a3 that would also work great with a K24a2 or a1 later.

I will take alot of pictures and put together a build thread, should receive aftercooler setup in next couple of days.

07-20-2012, 09:21 AM
Ba82Ep3... thanks for info. By the way I was born 'n breed in Mobile Alabama "RollTide" but been working in Vegas since '96. Last time I was back it was sad to see how malls had turned into a war zone. LoL

Yeah I was hoping to get my a3 in the 250-275 range if possible, and save for a minty 06 or newer K24a2 to pop in there later down the road and be little over 300 with mucho torque.

My 05 Ep3 is super clean, hell it looks new since its been in California and Nevada its whole life. I'm one of the older guys on here, graduated from Baker High school in '89 and have been in love with Hondas since the late '80 model Si's. My Ep3 is by far my favorite car I've owned and I plan to keep it forever so I'm going to do it right.

07-20-2012, 11:29 AM
Im not born n bred here... im imported from VA. LOL. I love it all the same though. I guaduated in VA in 91... so youre not too much older than myself. I can relate to the love of Honda... owning many models since the 79 CVCC.

Unfortunately i had to part ways with my EP, but about 75% of it lived on in a 95 Civic EX coupe. I have to say that process was one of the most rewarding endeavours in my life... and can confirm my bond with Honda and K series performances is deeper because of it.

While my goals were guided by OE reliability and parts availability, i spent a lot of time and effort to find ways to make inexpensive OE power with minimal aftermarket support and influence. I love the roots blower through and through... even though it has its limits in our chassis. But thats ok... because my goal was to build the Civic i would have liked to buy off the lot when i was a teenager... if i had the sensibility of an adult.

My EJ has a hand built hybrid k20a3... it has RSX pistons for a bump in compression, the k24a1 head with a k20a2 3 lobe rocker assembly, and k20z3 cams. I have what is called flipped pin VTEC... one valve is locked to the center VTEC lobe, and the other locks at the VTEC switchpoint. So my k20a3 breathes deep in the midrange, with a head to support the flow, and working VTEC for some gas savings. All of this runs thru a hand built ITR trans with a lot of time and effort put into the whole project. My intent is to boost (preferably JRSC again)... but life has its ways of slowing down the best of intentions.

It will happen... and sooner than later. : )

Take your time, buy the right parts, but also maximize what you already have... even if it means going out of your comfort zone with the effort needed. The reward is so worth it...

- Dave