Jump to content
SAU Community

Recommended Posts

As stated I've realised that my gear box has no wiring what so ever on it and didn't really phase me as i don't care about reverse lights or speedo "cause race car" but found threads saying that the speed sensor wire needs to be hooked up otherwise the ecu tries to cut injectors or something thinking its in neutral?

Found the wire in the ecu my question is, can i run a wire straight from the gear box to the ecu and bypass the cluster all together as i don't care about this, but also which wire do you run as both are the same colour coming from the speed sensor? and only one ecu wire? I'm assuming one is an earth then?

Any one who does conversions shed some light as this is in a Cefiro and not much info on body looms...

thanks!

Link to comment
https://www.sau.com.au/forums/topic/461994-rb25-speed-sensor-ecu-wiring/
Share on other sites

I think it only drops the idle when the car shows speed of 0. Mine never used to have the input to the ECU from the speedo and i didnt even notice till i was looking at some of the ECU wiring one day and saw it had been cut

ok sure thing that's ok as i have an r33 cluster in the car so it should convert it fine. What i really need to know is which wire is the signal wire coming from the sensor itself as they are the same colour??? and then i found this pic

http://s689.photobucket.com/user/rmcallis/media/Speedo%20Corrector/CopyofSpeedo-2RearShowingSignals.jpg.html

so once i find which is signal i can put it direct to the back of the cluster to that top left pin? and then run a wire from ECU to top right? then just power and earth and it should work?

Apparently FYI this really does effect the car, in the FSM it says that's it restricts your idle and has a fuel cut and stops your vct so its something you definitely want hooked up!!

Edited by Franko07

cant find any more info in the fsm about it though just says you need consult to see if its working but she definitely isnt! lol

i took the sensor out of the box and connected a multi meter to both wires and put a drill on the end to spin it and i got a good voltage reading so i know the sensor definitely works as well still doesnt clear up which wire goes to the cluster

Edited by Franko07

well from what i can work out apparently the voltage put out from the sender is in AC frequency so its basically un-polarized can any one confirm this? It explains why there the same colour cause it doesn't matter which way they go then so i might just twitch them together so i can swap them around in case it doesn't work...

yeh a lot of the posts are from people having problems trying to get around the speed limiter. I'm learning to drift atm so my entry speeds don't need to be as hectic for now. I guess ill hook it up and see if it makes a difference and if not i can always just unplug it again from the gearbox

Slight hi-jack if i may but on topic.

How would one go wiring from the gearbox speed sensor to the ecu without using a cluster? Some sort of converter?

I dont have a cluster at all in the car. Was planning in racepak dash and wouldnt mind speedo to show.

Just tuck a speedo head up somewhere in the back of the dash. You don't need the whole cluster.

Otherwise, yes, you would need to build a signal converter, and would need to probe the output from a real speedo head to see what the square waveform's characteristics were at different speeds. ie, you'd be interested to know if they ran a fixed frequency and varied the pulsewidth or if the pulsewidth remains fixed and they change the frequency (duty cycle) of the pulses.

That device would need to be able to take in the AC signal and output the 0-5v square wave signal. This may or may not be within its capabilities, so best bet would be to ask them. Many such electronic boxes (like the Jaycar kit) will only pass out the same type of signal that was passed in - just sped up or slowed down.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...