K20A in 2003 EP3

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06-16-2011, 06:05 PM
DA9_GSR

K20A in 2003 EP3

Hey guys,

I finally got the time to install my 2003 JDM CTR K20A powertrain into my 2003 Civic EP3. Things I thought were important to know is the following:

- swap your throttle body onto the K20A intake and keep you cruise control (only thing is you don't have the green "cruise" icon in the CTR cluster)

- my 2003 got into reverse and all forward gears no problem. I didn't have to notch the shifter base at all.

- my swap included all underdash and underhood harnesses. I only used the JDM CTR K20A engine harness and the reverse lockout works properly.

- In order to get the car to start (because it won't) you have to pull the YEL/GRN and YEL/BLK wires out of main fuel relay 2 and solder them together. This allows the fuel pump to turn on when the key goes to the ignition position II. What this does is bypass the second main fuel relay, which is used for the immobilizer. The OEM ECU would have grounded the coil side of this second relay to allow current to go through the switched side of second relay and power the fuel pump. Because the 02-03 CTR ECU's don't have immobilizer's they don't have the capability to ground that coil in the second relay therefore you have to bypass it completely.

Aside from these little things, the swap went in with absolutely no issues. I also replaced all the fluids (ie: engine oil and filter, trans oil and engine coolant).

Remember, if you remove the powertrain from the bottom you need to get an alignment done because I promise you got the caster angle all messed up due to the subframe being moved from it's original position.

Cheers,
Ryan
06-17-2011, 01:50 PM
02TWSI

Sweet, K20a high compression powa!!!
06-17-2011, 06:03 PM
DA9_GSR

Quote:

Originally Posted by 02TWSI

Sweet, K20a high compression powa!!!

I'm using the JDM CTR ECU and it's a great tune. It runs well on the Sunoco 94 Octane. I'm really pleased with it. The gearing is really short. That might be due to the fact that I've never owned a 6 speed before. Also, the LSD is amazing! Where the car used to understeer in a corner, now I can feel the LSD help me through it. I'm excited to get it onto the track. This way I get to compare lap times, before and after the swap.
06-27-2011, 05:24 AM
NightRaven

how much did you get that engine for? and shipping?
06-27-2011, 08:31 AM
RedSiBaron

Quote:

Originally Posted by DA9_GSR

I'm using the JDM CTR ECU and it's a great tune. It runs well on the 94 Octane. I'm really pleased with it. The gearing is really short. That might be due to the fact that I've never owned a 6 speed before. Also, the LSD is amazing! Where the car used to understeer in a corner, now I can feel the LSD help me through it. I'm excited to get it onto the track. This way I get to compare lap times, before and after the swap.

There are shorter gear ratios in the jdm type r trans...sooo that would explain it

Question though, if I got kpro on my stock a3 ecu, and then did the k20a swap, I wouldn't need to cut the wires on the main relay correct?

Also you don't have to notch the shifter in an 02/03 only 04/05
06-29-2011, 10:46 AM
jdmpendeho

what do u mean about notch?
06-29-2011, 11:00 AM
usedep3

Quote:

Originally Posted by jdmpendeho

what do u mean about notch?

the usdm ep3 stock shifter is for a 5 speed tranny. you need to modify/notch the shifter to get into 6th gear. some earlier usdm ep3 however came with the ep3r shifter assembly so not modding/notching is required
06-29-2011, 01:18 PM
urthworm

Quote:

Also you don't have to notch the shifter in an 02/03 only 04/05

i have an 05 and i didnt have to notch when i did my k20a swap. I think its hit or miss cause ive read both.

Also, if you get kpro.. use the a3 wiring harness and the a3 knock sensor and its all plug and play.
06-29-2011, 03:10 PM
RedSiBaron

Quote:

Originally Posted by urthworm

i have an 05 and i didnt have to notch when i did my k20a swap. I think its hit or miss cause ive read both.

Also, if you get kpro.. use the a3 wiring harness and the a3 knock sensor and its all plug and play.

You mean, use the a3 engine harness and knock sensor?
06-29-2011, 09:46 PM
urthworm

Yup.. the knock sensor plug is different on the a3 so you just use the a3 knock sensor, there is no reverse lock out (dont really need it anyway), and the k20a does not have a vtec oil pressure switch.. so you just leave it unplugged and disable it through kpro.
06-30-2011, 07:44 AM
DA9_GSR

Quote:

Originally Posted by RedSiBaron

You mean, use the a3 engine harness and knock sensor?

I think many people get confused with all the different harnesses. There's an engine harness, charging harness, and front bulkhead harness. The only harnesses I used from the EP3R K20A swap was the engine and charging harnesses. This allowed me to not have to goof around with the knock sensor and reverse lockout. Everything works as it should. If you do the swap, try to find one with uncut harnesses. If you can't you'll have to mess around with the knock sensor and reverse lockout.
06-30-2011, 08:30 AM
RedSiBaron

Gotcha...the wiring is still all the same between the cars essentially then, just a couple different then plugs right? I need this motor bad, then its just a few more items to finish the car.
06-30-2011, 09:19 AM
urthworm

Well the knock sensor only takes about 2min to change out. The reverse lockout would be the only reason i see to keep the k20a harness.. but ive never even gotten close to accidently puting it in reverse when changing gears from 5th to 6th.

Will the k20a harness plug into the a3 ecu? Ive read that the k20a ecu can not have kpro installed on it. Thats the main reason i didnt even bother trying to use the k20a harness. I already had kpro on the a3 ecu.
06-30-2011, 10:33 AM
DA9_GSR

Quote:

Originally Posted by urthworm

Well the knock sensor only takes about 2min to change out. The reverse lockout would be the only reason i see to keep the k20a harness.. but ive never even gotten close to accidently puting it in reverse when changing gears from 5th to 6th.

Will the k20a harness plug into the a3 ecu? Ive read that the k20a ecu can not have kpro installed on it. Thats the main reason i didnt even bother trying to use the k20a harness. I already had kpro on the a3 ecu.

The K20A engine harness will plug into the A3 ECU but the A3 Kpro doesn't have reverse lockout capability. The K20A ECU (PRC/D) cannot have Kpro installed, Hondata will use a PRB (RSX-S) ECU. I'm not using Kpro and running 94 octane on the stock PRD ECU and it runs great, pulls hard and works like OEM (reverse lockout and all).

If I were in your position, I would be doing one of the following:

1 - source out the CTR PRD ECU, installing the JDM EP3 engine harness and running 94 octane
2 - source out the PRB ECU, get it Kpro'd and install the JDM EP3 engine harness
07-08-2011, 09:55 AM
Gilmour

Quote:

Originally Posted by DA9_GSR

The K20A engine harness will plug into the A3 ECU but the A3 Kpro doesn't have reverse lockout capability. The K20A ECU (PRC/D) cannot have Kpro installed, they'll use a PRB (RSX-S) ECU. I'm not using Kpro and running 94 octane on the stock PRD ECU and it runs great, pulls hard and works like OEM (reverse lockout and all).

If I were in your position, I would be doing one of the following:

1 - source out the CTR PRD ECU, installing the JDM EP3 engine harness and running 94 octane
2 - source out the PRB ECU, get it Kpro'd and install the JDM EP3 engine harness

I've been out of the game for a while, but I don't understand why a PRC ECU can't be Kpro'd? In fact I do understand that Hondata can Kpro the PRC ECU as I've owned one in the past. The only down side to a PRC Kpro'd ECU is that it does not support Nitrous settings in Kmanager, at least this was the case a few years ago.

Also no wires need to be cut on the harness, as Hondata will make the adjustment inside the ECU when it is opened up.
07-11-2011, 10:54 AM
DA9_GSR

Quote:

Originally Posted by Gilmour

I've been out of the game for a while, but I don't understand why a PRC ECU can't be Kpro'd? In fact I do understand that Hondata can Kpro the PRC ECU as I've owned one in the past. The only down side to a PRC Kpro'd ECU is that it does not support Nitrous settings in Kmanager, at least this was the case a few years ago.

Also no wires need to be cut on the harness, as Hondata will make the adjustment inside the ECU when it is opened up.

I might be mistaken, however this is what I was told by my local Hondata supplier. They might be mistaken.
07-11-2011, 01:22 PM
PRODIUS

Super informative thread. Thanks for posting GSR and I have PM'd you some extra question.

Thanks
07-12-2011, 08:19 AM
Gilmour

Yep they'd be mistaken, then.

Nice swap BTW.
08-05-2011, 04:35 AM
04SiSpeed

If u kept ur stock ecu u will need Kpro and the crank sensor off the a3 motor. All the other sensors will remain and the engine harness in the car will plug into everything else. U will also pass emissions this way still. If u don't run Kpro u have to use the type r ecu n engine harness, you won't pass emissions n u won't get the extra 20 or 30 HP that Kpro would give you from a tune. I did the Kpro route.

U will also need a jdm ctr front sway bar off a ep or the other routes are get a em1 front sway which is much smaller or a aftermarket header like ssr which runs about a grand. Otherwise the stock jdm exhust manifold doesn't clear our stock sway bar.

You are correct about the shifter also. It's a expensive swap. But I.think its the most problem free n u don't need all kinds of parts to make it work. Just the motor Kpro n a swaybar.
08-05-2011, 04:40 AM
04SiSpeed

Quote:

Originally Posted by urthworm

Well the knock sensor only takes about 2min to change out. The reverse lockout would be the only reason i see to keep the k20a harness.. but ive never even gotten close to accidently puting it in reverse when changing gears from 5th to 6th.

Will the k20a harness plug into the a3 ecu? Ive read that the k20a ecu can not have kpro installed on it. Thats the main reason i didnt even bother trying to use the k20a harness. I already had kpro on the a3 ecu.

Yeah Bro that junk don't plug up. U either use the harness n ecu or neither lol. In our cars at least
08-10-2011, 06:40 AM
DA9_GSR

I need to get this swap dyno'd then. I'm running the JDM CTR K20A engine harness and JDM CTR K20A ECU on 94 Octane. Runs very well. Idles great. Pulls hard. And beat an older Porsche Boxster on the back straight of Mosport.
08-10-2011, 10:46 AM
apexracing

Great useful info thanks.
08-25-2011, 03:07 PM
jdmpendeho

i have the 04 civic si..since they discontinue the buddy short shifter what else can i use to six speeed it??
08-26-2011, 04:55 AM
DA9_GSR

Quote:

Originally Posted by jdmpendeho

i have the 04 civic si..since they discontinue the buddy short shifter what else can i use to six speeed it??

You might not need anything. If you do the K20A swap, find a swap that comes with the shifter base. If not, I still have my EP3R one sitting in the basement.
08-26-2011, 02:23 PM
jdmpendeho

Quote:

Originally Posted by DA9_GSR

You might not need anything. If you do the K20A swap, find a swap that comes with the shifter base. If not, I still have my EP3R one sitting in the basement.

nicee for how muchh to 08882?
09-02-2011, 10:52 AM
jdmpendeho

just order Buddy Club Racing Spec Race Header and exhaust for my k20a swap on my 04 ep3 will it fit np?
11-16-2011, 09:01 AM
04SiSpeed

Quote:

Originally Posted by DA9_GSR

I need to get this swap dyno'd then. I'm running the JDM CTR K20A engine harness and JDM CTR K20A ECU on 94 Octane. Runs very well. Idles great. Pulls hard. And beat an older Porsche Boxster on the back straight of Mosport.

Grab a kpro, rbc manifold, and rdx injectors, and a open exhuast at least 2.5in and you'll grab almost 50 more to the wheels and thats no bull
11-18-2011, 06:41 AM
DA9_GSR

Quote:

Originally Posted by 04SiSpeed

Grab a kpro, rbc manifold, and rdx injectors, and a open exhuast at least 2.5in and you'll grab almost 50 more to the wheels and thats no bull

KPro interests me but I need to find a PRB ECU and send it out. RBC doesn't interest me, because I don't feel like hacking my perfectly good rad support to make it fit. RDX injectors would be nice. I already have a Mugen center pipe (2.5" inside diameter) and the OEM EP3 muffler is very free flowing and quiet. I'm not a fan of the fart can. Right now it has a perfect idle and low rpm resonance that lets all the neighbours know I'm home. And the AEM V2 intake lets everyone in the vicinity know when 6'000rpm VTEC crossover occurs.

I haven't bought any of those things because I'm slowly amassing TODA Racing parts that will require Kpro and a tune anyways. I'd rather have and install those parts and tune it then. Gonna be fun!
11-21-2011, 08:06 AM
04SiSpeed

Yea i hear you on the hacking your rad support up, thats y i hadnt done it yet either. But for real man save your money on the toda stuff. Its about 3/4 hopped up in price over compition that in many cases out perform Toda anyways. Unless you are doing a Vtech killer set up or something.

The SSR header is about 1000 so like 300 less than toda, and been proven to provide more power.
11-19-2018, 01:07 PM
ansbo

Hi. DA9_GSR ,

I don't know if you are still checking this post. But I doing the exact same swap. Have a K20a (JDM) going into a 2004 EP3. I know that you used the k20a engine harness. Given that the harness was for RHD, did you have any length issues? using the harness for your USDM ep3 which is LHD?

Thanks.