Jump to content
SAU Community

Recommended Posts

Hi all,

I know this is a long shot.... I bought a r34 gtr vspec about 12 months ago. and found it had a smt6 (smart tuner/perfect power) piggybacked on to the ecu.

now the time has come and i want to upgrade to a power fc. so i have purchased the power fc with hand controller.

I need to know what wiring mods have been done to install the smt6 and correct them to install the power fc.

it wont let me just plug and play the power fc until i revert the wiring back. funny thing is the wiring looks all good on the factory side of the ecu plug. as the smt6 is wired into a extension harness.

the smt6 is patched in on a extension harness to the ecu, so i figured just take out the extension harness and plug in the power fc........ but in wouldn't fire. so i thought perhaps the power fc may have been faulty. So i then plugged in the standard ecu without the smt6 and the same thing happened, it would not fire.

I need to get this sorted out before i take it to the tuners. as they are not familiar with the smt6 it may cost me significantly to have them figure it out. they couldn't even quote me on it.

all help appreciated.

Thanks,

Well theoretically if its a piggyback then if you remove the harness extension for the SMT6 you should be able to plug into the factory loom with your Power FC.

Not sure why anyone would but has there been any modifications made to the loom that you can see? Best would be to get the pin out diagram and match it up and check everything is there and nothing has been cut.

Any good tuner should be able to work with any ecu because its the same thing in theory across all ecus except finding some functions may take longer, that is it.

Have another look over the wiring and double check with a diagram. See if you can get the standard ECU to run first before trying the Power FC.

There are 2 wires on the factory side of the ecu plug that I noticed have been cut and reconnected. And it looks like both wires are the same colour. ( they may have been cross connected in order to work with the piggy back ecu ignition set up...... Who knows?)

I will check tomorrow what wires they are by looking at the pinout diagram.

The tuner doesn't need to know anything about the SMT6 because you are going to remove it. You just need to ensure the original wiring is returned to stock. Hmm may not be as simple as it sounds...

Had a quick Google. Did you find the makers instructions? They include this:

". The SMT6 User Kit includes the following items: SMT6 Unit with Injector Driver SMT6 Harness (Wiring Loom) SMT6 Communications Cable SMT6 Shorting Plug (Bridging Plug) This useful product allows you to revert your vehicle to stock standard, should you need to remove the installed SMT6 unit for any reason"

Also you may need to check if there has been any alteration to coil resistance

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

    • What does it look like with highway driving? And yes, I had a similar thought as Duncan. It looks quite similar in my Stagea and I have made myself accept it as normal. Might have to look into it some day  
    • While I was waiting for the new parts to come in for the charge pipe and radiator I decided to do some turbo modification. The drive pressure (exhaust backpressure) was a lot higher that I thought it should be. For 32lbs of boost drive was 55lbs. The turbine housing is a 1.10AR and my turbo builder has suggested to go to a 1.25AR. To test if a larger AR would do anything to reduce drive pressure AND not spend any money I decided to hog out the divider in my current housing. I removed it from the inlet and the whole way through the housing.  After reassembly and testing it doesn't look like this modification did anything for reducing drive pressure or requiring more fuel (making more power). Oh well, it was worth a shot. We'll get some data at the track if it makes it past the 60ft. I also machined a $7 shift knob off Amazon to fit my Stillway shifter since I didn't like the Stillway shift knob. Next on the list was the radiator replacement and fabrication of a new intercooler tube that had no silicon coupler. No pictures of this - I was short on time each night after work to get this done and didn't stop to take pictures.  Next was to get the clutch disks out and replaced. Previously when installing the dogbox I had ordered a set of the same sintered iron disks I had been running because I switched to the 26-spline input shaft. I thought it was odd that they didn't have any markings or brand name on them like all my old disks had but installed them anyway. At the track I could not get the clutch to lock up using my normal strategies. After two track nights I reached out to the clutch manufacturer and ask their thoughts. They said they had to switch the material out because they were having trouble getting the original material and that this new material would not take to being slipped very well.  So out with the first set of 26-spline disks and in with the correct material 26-spline disks. While I had the trans out I added an inspection/service hole. I've wanted one of these for a while. Now I can have a look at things and change the front cover shimming when needed (clutch wear). I hustled and got the clutch change done in a few hours on a Saturday. Hopped in the car and drove home. On the way home I did a 1-3 pull. When shifting from 2nd to 3rd the core plug in the back of the cylinder head popped out and dumped all the coolant. Thankfully I was only 30 seconds from home and coasted it there. Datalog showed nothing unusual and 2.5psi of coolant pressure. That plug has been in there since 1992 but I guess it worked its way out. Pulled the trans AGAIN and replaced the plug, JB welded it in, and made a brace. Also deleted the head drain I had added in during the bearing issue fiasco.  I am currently changing my boost control plumbing to make it cleaner. After that is done I'll make another attempt at getting past the 60.
    • Are you 100% sure this isn't tune related?
    • 140-150 across the board. At this point hoping the grounding harness fixes it. My grounds are all tied to the chassis and none to the battery. For SR and KA that’s never been a problem for me but had a few other guys here and Reddit who told me RB really like a very solid ground setup tied to the battery so going to try that next, I’m stumped if that doesn’t do it. Never had a car have spark and fuel and not fire off before. Only thing I can think is the spark is intermittent/weak because of grounds nothing else really makes sense at this point 
    • I am having close to the same issue. Can you help me with what wire you grounded to get your pump to trigger?
×
×
  • Create New...