Clarifications on a few K20A2 swap questions...

[acemanic]

Hi,

Regarding this 'simple' swap that i plan to do, i have come up with some questions i'd like to get clarification on . Let's start with what i know about the swap:
- 2002 USDM EP3
- EP3 spec exhaust system: DC shorty>stock cat>Megan Bpipe>Spoon N1 axleback. This is the exhaust that will be used with the A2
- plan is to get an A2, with tranny, ecu, harness (charge and engine)
- use the A2 intake manifold, A2 throttle body, ep3 shifter linkages
- swap the idler pulley
- could replace the serpentine belt, or just use the stock a3 one
- may have to modify the shifter arm for 6th gear
- will be getting a K Pro
- would like to retain immobilizer
- would like to have the reverse lockout

My questions:

1) I have read that people can either use the A3's ecu WITH K Pro, OR use the A2 ecu but will have to get it reprogrammed. This is where i get lost and not really sure about. If I use A3 ecu without k pro, I won't get the reverse lockout (obviously), and if I use the A2 w/o k pro, I will get the reverse lockout but I will need to get the ecu reprogrammed for my keys to get the immobilizer to work. So, does using K Pro solve both of these problems?? Will using K Pro with the A3 ecu let me use the reverse lockout? Or should I use the A2 ecu with K Pro, and will that allow me to keep the immobilizer without a trip to Honda/Acura?

2) K Pro: if I buy used, do I have to buy the ecu that was attached to it, or may i use another ecu?

3) In regards to the harnesses, do I use both A2 harnesses (charge and engine)?

4) are engine mounts and rad hoses the same for the A3 and A2 (or all K20's for that matter?)

5) I have an aftermarket alarm system that came with the car. Does it affect the swap at all?

Thanks for the help!

[mitchlikesbikes]

Hi,

Regarding this 'simple' swap that i plan to do, i have come up with some questions i'd like to get clarification on . Let's start with what i know about the swap:
- 2002 USDM EP3
- EP3 spec exhaust system: DC shorty>stock cat>Megan Bpipe>Spoon N1 axleback. This is the exhaust that will be used with the A2
- plan is to get an A2, with tranny, ecu, harness (charge and engine)
- use the A2 intake manifold, A2 throttle body, ep3 shifter linkages
- swap the idler pulley
- could replace the serpentine belt, or just use the stock a3 one
- may have to modify the shifter arm for 6th gear
- will be getting a K Pro
- would like to retain immobilizer
- would like to have the reverse lockout

My questions:

1) I have read that people can either use the A3's ecu WITH K Pro, OR use the A2 ecu but will have to get it reprogrammed. This is where i get lost and not really sure about. If I use A3 ecu without k pro, I won't get the reverse lockout (obviously), and if I use the A2 w/o k pro, I will get the reverse lockout but I will need to get the ecu reprogrammed for my keys to get the immobilizer to work. So, does using K Pro solve both of these problems?? Will using K Pro with the A3 ecu let me use the reverse lockout? Or should I use the A2 ecu with K Pro, and will that allow me to keep the immobilizer without a trip to Honda/Acura?

2) K Pro: if I buy used, do I have to buy the ecu that was attached to it, or may i use another ecu?

3) In regards to the harnesses, do I use both A2 harnesses (charge and engine)?

4) are engine mounts and rad hoses the same for the A3 and A2 (or all K20's for that matter?)

5) I have an aftermarket alarm system that came with the car. Does it affect the swap at all?

Thanks for the help!

1. you can turn the immobilizer off with any k pro ECU but if you want to keep the immobilizer AND have reverse lockout you'll need to get the k pro done on the A2 ECU, turn off the immobilizer, then take it to the dealership, turn the immobilizer back on and have them program it. you can't have reverse lockout with the A3 ECU even on K pro.

2. K pro is actually a modified ECU. it doesn't transfer from ECU to ECU. you have to send it into hondata so they can put it in, or if you buy it used it will just be whatever ECU it comes already put in. if you're buying it used and want reverse lockout you'll need a "PRB" K pro ECU from the 02-04 RSX type s.

3. not sure on this one

4. all engine mounts and hoses are the same as far as i know.

5. not sure on this one but i don't imagine it would if you retain the immobilizer. you might have to contact an alarm specialist about that one because they're all different.

[bchaney]

Mitch covered most everything but I will add,

1) You're going to need to get any non-stock ECU reprogrammed if you want the immobilizer. The easiest would be to just get KPro on your stock ECU if you can tolerate the downtime. I personally think it is very unlikely that you'd misshift into reverse (especially on a 6spd) but if you're willing to spend the $ it's a decent feature for peace of mind.

3) Use your stock a3 harnesses unless your swap comes with them.

5) I don't think the alarm should affect your swap unless the system is tapped into your a3 harness and you're swapping in a different harness. I've never installed a car alarm but it's an upcoming project...

[acemanic]

awesome this is very useful thanks guys!

in regards to the harnesses, will the a3 harnesses suffice if i used an a2 ecu to get reverse lockout?

[talonXracer]

The A2 and A3 use the same exact intake mani and TB


you can not use the A3 ECU unless it has Kpro

It is easiest by far to just use the A2's ECU, though you will need to have the ECU/Keys and immob synched at any Honda stealership(regardless of an aftermarket alarm)

If you are worried about the reverse lockout dont, if you ever hit R when downshifting from 6th to 5th, you need to throw the keys away and retire to the front porch in a rocking chair for the rest of your life, LOL

There is NO CORRECTLY sized serp belts to fit an A2 with the EP3's idler. The EP3's belt will be rather loose, a few washers placed between the alternator and block(2 or 3 washers per bolt(3 bolts)) easily takes up this slack and allows a stock EP3 belt to be used.

[15000rpms]

Talon, I think you meant to say "upshift" from 5th to 6th. Nobody can shift from 6th to 5th and get into R.

Regarding the reverse lock out. I heard that you "NEED" the "A2 ECU" and the "A2 Harness." Or you have to wire the reverse lockout.

[talonXracer]

Talon, I think you meant to say "upshift" from 5th to 6th. Nobody can shift from 6th to 5th and get into R.

Regarding the reverse lock out. I heard that you "NEED" the "A2 ECU" and the "A2 Harness." Or you have to wire the reverse lockout.

Nope, I DID NOT MEAN UPSHIFT !!! the reverse lock out is intended for RHD vehicles, the reason for that is human ergonomics, the arm naturally pulls inwards when you pull back, this is to PREVENT going into R when going from 6th to 5th DOWNSHIFT. For a LHD vehicle it is entirely not needed. Even in a LHD car without a reverse lockout a sloppy unskilled driver could most assuredly hit reverse on the downshift.

You need the A2 harness and a PRB ECU and the 6 speed to have a reverse lockout.

[02TWSI]

There is NO CORRECTLY sized serp belts to fit an A2 with the EP3's idler. The EP3's belt will be rather loose, a few washers placed between the alternator and block(2 or 3 washers per bolt(3 bolts)) easily takes up this slack and allows a stock EP3 belt to be used.

Did not know that, good to know.

[bchaney]

There is NO CORRECTLY sized serp belts to fit an A2 with the EP3's idler. The EP3's belt will be rather loose, a few washers placed between the alternator and block(2 or 3 washers per bolt(3 bolts)) easily takes up this slack and allows a stock EP3 belt to be used.

I have an ep3 serp on my k24 with an a2 crank pulley and although the auto-tensioner marks no longer align, it's pretty tight. Is some of the slack taken up by the taller block or what?

[talonXracer]

I have an ep3 serp on my k24 with an a2 crank pulley and although the auto-tensioner marks no longer align, it's pretty tight. Is some of the slack taken up by the taller block or what?

Not tight enough, open the hood and rev the engine, you will see the belt and tensioner move alot. A loose belt will cause the tensioner to move alot and this will take out the idler eventually. There is no diiference between the K24 and k20 as far as the ancillary components go, the height difference is entirely above where the water passageway is.

[15000rpms]

Nope, I DID NOT MEAN UPSHIFT !!! the reverse lock out is intended for RHD vehicles, the reason for that is human ergonomics, the arm naturally pulls inwards when you pull back, this is to PREVENT going into R when going from 6th to 5th DOWNSHIFT. For a LHD vehicle it is entirely not needed. Even in a LHD car without a reverse lockout a sloppy unskilled driver could most assuredly hit reverse on the downshift.

You need the A2 harness and a PRB ECU and the 6 speed to have a reverse lockout.

I still don't get it. To downshift from 6th to 5th, you have to push the shifter forward. How can you hit R when R is in the down position? I only understand that if you try to shift to 6th from 5th that you might hit R.

[RHCP0801]

you mean 5th to 6th