red top ecu work with black top sr?

[S13240]

Curious if a red top ecu would work with a black top sr with any problems? Driveability?

I have a good deal in my hands, a red top ecu fully tuned for bigger injectors, turbo, cams, etc... Anyone tried it yet? Or the other way around like black top ecu on red top sr?

[SpeedRacer1]

You can use either.

[Fenvy]

the ecu is nearly same but the harness for each ecu is different, from my understanding

[SpeedRacer1]

The harness is different if you have a 1997-1998 S13 blacktop. But 62, 63, E5, and E6 ECU's are interchangeable.

[Fenvy]

if that's the case then why power fc have 3 different ecu for s13 sr20det? (non-type x)

I called apexi and someone told me it's harness specific, I have also heard that people ordering the wrong ecu and doesn't start.

if it wasn't harness specific I should have ebayed an used redtop power fc for half the price

[TougeTune180]

then if thats true that they are interchangeable, would that also be the same for like an HKS F-con?

[cardinal]

So which wires do you have to change on the 1998 blacktop harness if you used a redtop wire diagram to swap connectors? A buddy did mine and used the retop schematic...it starts and runs but has a check engine light on. I guess the wiring is the reason why...

[S13240]

Thanks guys but I have the chuki black top. One of the knowledgeable guys on FA says all I have to do is probably rewire the o2 sensor wire on the ecu plug if I do use a red top ecu.

[Fenvy]

probably is probably not good enough, research some more

[SpeedRacer1]

The ECU's are interchangeable, but that doesnt mean that you should interchange them. The difference between 62 and 63 is that one is a manual, ones an auto. Its the same for the E5 and E6. I tried an E5 on my Redtop and found a slight bogging during acceleration at freeway speeds. The only important difference between the redtop and blacktop ECU's is the O2 sensor, the redtop uses a thin one, the blacktop uses a fat one. And an O2 wire is in a different place on the ECU.

If you want to know how to run a J4 or J5 Kouki ECU on an earlier model S13 SR, then search, I showed a guy how to repin his harness about a week ago in the same forum. The Kouki ECU needs repinning of most of the coilpacks, tach, O2 wiring, and a couple other misc wires.

[Beemen550]

is it ok to use the fat blacktop o2 sensor on a redtop?

[SpeedRacer1]

No idea, probably.

[cardinal]

If you want to know how to run a J4 or J5 Kouki ECU on an earlier model S13 SR, then search, I showed a guy how to repin his harness about a week ago in the same forum. The Kouki ECU needs repinning of most of the coilpacks, tach, O2 wiring, and a couple other misc wires.[/QUOTE]

I did some searching and didn't see this post. Anybody have a link to it??

[SpeedRacer1]

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