EJ22G with SOHC 2.5 heads - ECU questions

cjfike · 02-02-2006, 09:33 PM

Later this month, I am getting a EJ20G block and plan on using the stock internals.

One of the ideas was getting WRX heads and then just using a US WRX ECU.

Then the highly esteemed gentleman I am buying the block from had mentioned if he was going to keep it, he was thinking of using 2.5 heads.

This opens doors to other possibilities. High Boost Turbo, or super charging; but then the choice of ECU then potential need for major re-wiring loomed into view. Although I would like to say I have time to do re-wiring, I don't.

The car needs to remain streetable, and if at all possible I would like to use the ECU in the car now. Knowing that I would have to use add on/piggyback controls for boost, and fuel management.

Admittedly, I am crazy. However I would like your constructive input.

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cjfike · 02-03-2006, 08:38 AM

With the number of piggyback units out there, Who is best, UTEC, Greddy, Haltech?

WOuld it be better to replace the stock ECU with one of the ECU's that connects directly to the existing wiring? The replacement ECU in this case would provide all controls. Pay the money in one major purchase, or piggyback in multiple purchases?

Wouldn't it be more desirable to have 1 ECU rather than a bunch of ancillary controls massaging the information going to the ECU?

swapstar · 02-03-2006, 04:44 PM

um. lota stuff you are posting.

there is no aftermarket ecu that is direct plug into your 99 rs harness that i have heard of.

if doing, it might be deemed prudent to get it done all at once. if going standalone, bite teh bullet and get somthing good. stay away from teh piggybacks.

1 ecu is ideal. if you have to pass emissions it would be ideal to run the full usa WRX setup. you can outsource the wiring harness conversion, lotsa good shops that do that. then any reflash is an easy job.

cjfike · 02-03-2006, 05:45 PM

the engine harness would be fairly straight forward, I would be able to do that no problem. Integrating the engine harness and body harness to the ECU would be the one I would like to stay away from.

Unless you are saying they would give me one from the engine to ECU. I still need to look at WRX to RS wiring.

cjfike · 02-04-2006, 12:27 PM

moderator please move this to the tuning forum.

02-02-2006, 09:33 PM	#1
cjfike Scooby Newbie Member#: 60116 Join Date: Apr 2004 Location: (ab)Normal IL Vehicle: 1999 RS Coupe Silver Thorn	EJ20G with SOHC 2.5 heads - ECU questions Later this month, I am getting a EJ20G block and plan on using the stock internals. One of the ideas was getting WRX heads and then just using a US WRX ECU. Then the highly esteemed gentleman I am buying the block from had mentioned if he was going to keep it, he was thinking of using 2.5 heads. This opens doors to other possibilities. High Boost Turbo, or super charging; but then the choice of ECU then potential need for major re-wiring loomed into view. Although I would like to say I have time to do re-wiring, I don't. The car needs to remain streetable, and if at all possible I would like to use the ECU in the car now. Knowing that I would have to use add on/piggyback controls for boost, and fuel management. Admittedly, I am crazy. However I would like your constructive input. * Registered users of the site do not see these ads. Last edited by cjfike; 02-03-2006 at 08:23 AM. Reason: error correction

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02-03-2006, 08:38 AM	#2
cjfike Scooby Newbie Member#: 60116 Join Date: Apr 2004 Location: (ab)Normal IL Vehicle: 1999 RS Coupe Silver Thorn	With the number of piggyback units out there, Who is best, UTEC, Greddy, Haltech? WOuld it be better to replace the stock ECU with one of the ECU's that connects directly to the existing wiring? The replacement ECU in this case would provide all controls. Pay the money in one major purchase, or piggyback in multiple purchases? Wouldn't it be more desirable to have 1 ECU rather than a bunch of ancillary controls massaging the information going to the ECU?

02-03-2006, 04:44 PM	#3
swapstar * Banned * Member#: 102779 Join Date: Dec 2005 Location: JDM land filling a container Vehicle: 1998 PM if u need JDM bits.....	um. lota stuff you are posting. there is no aftermarket ecu that is direct plug into your 99 rs harness that i have heard of. if doing, it might be deemed prudent to get it done all at once. if going standalone, bite teh bullet and get somthing good. stay away from teh piggybacks. 1 ecu is ideal. if you have to pass emissions it would be ideal to run the full usa WRX setup. you can outsource the wiring harness conversion, lotsa good shops that do that. then any reflash is an easy job.

02-03-2006, 05:45 PM	#4
cjfike Scooby Newbie Member#: 60116 Join Date: Apr 2004 Location: (ab)Normal IL Vehicle: 1999 RS Coupe Silver Thorn	the engine harness would be fairly straight forward, I would be able to do that no problem. Integrating the engine harness and body harness to the ECU would be the one I would like to stay away from. Unless you are saying they would give me one from the engine to ECU. I still need to look at WRX to RS wiring.

02-04-2006, 12:27 PM	#5
cjfike Scooby Newbie Member#: 60116 Join Date: Apr 2004 Location: (ab)Normal IL Vehicle: 1999 RS Coupe Silver Thorn	moderator please move this to the tuning forum.