Wiring/ecu - Rb25Det In 32 Gts4

[s213b]

Hi all,

Mid way through my s1 Stagea rb25 - 32 gts4 conversion and need some advice.

My plans for the car will involve an aftermarket ecu (link / haltec) and an e85 tune after the motors worn in, im leaning towards skyline loom + ecu due to the parts availability.

Questions

1) - s2 r33 rb25det loom & manual ecu?

- s1 Stagea loom & *(auto) ecu?

- keep current rb20 ecu & loom, nistune ecu and modify loom, loose vct etc?

2) how well will my car run with tomei poncams & std ecu?

3) am I right in assuming my rb20 clutch + flywheel will fit on my Stagea (auto) rb25?

Ill have a few more questions as I get further.

Any help appreciated, many thanks

Edited January 21, 2013 by s213b

[GTSBoy]

1) Easiest option is to stick with an RB25 ECU. Manual or auto makes little difference, although it will be more driveable with manual ECU to go with manual transmission. Little things like closed throttle overrun ignition timing and stuff like that can be quite different between man and auto, even though the main fuel and timing maps are essentially the same.

RB20 ECU will give you the best operation in the long run simply because you can Nistune it and therefore can retune for any mods you make, like poncams. You don't have to go without VCT. You can always add a window switch into it to make it work close to normally.

The RB20 ECU+loom option will mean you have to rewire a bunch of sensors (CAS, TPS etc) to suit the RB25. A better option overall is to use the RB25 loom all the way back to the RB20 ECU and only make the couple of small changes needed at the ECU plug.

2) Would not try to run standard ECU with poncams. Would be a waste of time. Needs a tune to make it worthwhile. Given that you are moving from RB20 to 25, you won't want cams to start with anyway. Just enjoy the enormous pile of torque (compared to the rubber band that is the RB20) for as long as it takes to get used to it.

3) Yes. Needs suitable spigot bush. If the RB20 clutch is not a stronger aftermarket one, then consider an upgrade.

[s213b]

1) Easiest option is to stick with an RB25 ECU. Manual or auto makes little difference, although it will be more driveable with manual ECU to go with manual transmission. Little things like closed throttle overrun ignition timing and stuff like that can be quite different between man and auto, even though the main fuel and timing maps are essentially the same.

RB20 ECU will give you the best operation in the long run simply because you can Nistune it and therefore can retune for any mods you make, like poncams. You don't have to go without VCT. You can always add a window switch into it to make it work close to normally.

The RB20 ECU+loom option will mean you have to rewire a bunch of sensors (CAS, TPS etc) to suit the RB25. A better option overall is to use the RB25 loom all the way back to the RB20 ECU and only make the couple of small changes needed at the ECU plug.

2) Would not try to run standard ECU with poncams. Would be a waste of time. Needs a tune to make it worthwhile. Given that you are moving from RB20 to 25, you won't want cams to start with anyway. Just enjoy the enormous pile of torque (compared to the rubber band that is the RB20) for as long as it takes to get used to it.

3) Yes. Needs suitable spigot bush. If the RB20 clutch is not a stronger aftermarket one, then consider an upgrade.

Thanks gtsboy, I've already got those 3 ecu's mentioned (rb20/ 33/ & stag) I don't want to spend the money on a nistune though because as soon as the motors run in it will be going in for a g4/ e85/ 3076

The motor already has the cams in it.. So it will run ok with the cams (256 9lift I think) just while I run it in or will it be a pig?

Rb20 had brass button of some description, I'm hoping the clutch + flywheel will just bolt on to my crank once all the auto torque converter shit is off

Many thanks

Josh

Edited January 21, 2013 by s213b