Wiring harness question TT ATX

[Benjamin]

I'm starting my TT Conversion on my 96 3k SL in about a week or so. Only thing I have a question with now is the wiring harness. I've heard so many different things and I'm so lost on what to do. Because electrical is not my forté.

Okay so, should I get a 2nd gen VR4 ECU, and a 2nd gen VR4 engine wiring harness? If so can you point me in the direction of where to get one. There are none local to me.
Also if I do get the ECU and Harness there should be no splicing involved correct? And no tune is needed?

This may also play a big role in all of this. My car, as an SL, is Cali Spec. So should the ECU I get be also Cali Spec? Or can I buy a fed spec harness and fed ECU?

[IPD]

If the info is lost, it's because much of Shooter83's work has been lost with the loss of the old florida3s site, and from 3sdie becoming a turd factory that really needed to DIAF 6 years ago.

/rant

If you use ANY TT wiring harness, you'll have to manually make it talk to the TCU. If you use an NA harness (at least one off an ATX), that will work fine, but you'll be fairly limited on how much boost you can run with a piggyback ECU off the NA ECU. Now IIRC, if you get a FED harness, you can run FED ECU just fine. There's also JDM spec ECUs--just to make your life a living hell (I know this, because I have one & it only has 1 o2 read, instead of the 2 on FED or the 4 on Cali). Again, you can ask Shooter83 about this--because he did the swap for me. BAADVR4 might be able to chime in as well. My car has turned into an electrical leviathan.

Anyways, I'd figure out if you want to run piggyback, AEM or flashable/chrome. IIRC 96 is OBD2, so you should be able to run flashable ECU on it. Either way, this determination will steer you in the direction you need to go. AEM/Chrome = you can keep your existing harness; just use the right impedence (NA impedence) injectors & don't even worry about resistors/resistor pack. Your alternative (w/ piggyback) is as above, and really depends on how you want to play it. And that depends on your desired power levels, and how much work you want to put into it. If you want fire & forget, sell it and buy a VR4 & live with the asspain of rowing gears. No matter what you choose, expect some rain. Chrome still has quirks & I see troubleshooting threads pop up here all the time; sure, better than it was at first, but certainly not problem free, and DEFINITELY not novice friendly. AEM is even worse. Stock boost will work with stock tt injectors & MBC w/ tt harness & ECU...but you're back to jury-rigging it to the TCU yourself.

Sorry, but there's no "easy way". Just some ways that are slightly less difficult.

[Benjamin]

If the info is lost, it's because much of Shooter83's work has been lost with the loss of the old florida3s site, and from 3sdie becoming a turd factory that really needed to DIAF 6 years ago.

/rant

If you use ANY TT wiring harness, you'll have to manually make it talk to the TCU. If you use an NA harness (at least one off an ATX), that will work fine, but you'll be fairly limited on how much boost you can run with a piggyback ECU off the NA ECU. Now IIRC, if you get a FED harness, you can run FED ECU just fine. There's also JDM spec ECUs--just to make your life a living hell (I know this, because I have one & it only has 1 o2 read, instead of the 2 on FED or the 4 on Cali). Again, you can ask Shooter83 about this--because he did the swap for me. BAADVR4 might be able to chime in as well. My car has turned into an electrical leviathan.

Anyways, I'd figure out if you want to run piggyback, AEM or flashable/chrome. IIRC 96 is OBD2, so you should be able to run flashable ECU on it. Either way, this determination will steer you in the direction you need to go. AEM/Chrome = you can keep your existing harness; just use the right impedence (NA impedence) injectors & don't even worry about resistors/resistor pack. Your alternative (w/ piggyback) is as above, and really depends on how you want to play it. And that depends on your desired power levels, and how much work you want to put into it. If you want fire & forget, sell it and buy a VR4 & live with the asspain of rowing gears. No matter what you choose, expect some rain. Chrome still has quirks & I see troubleshooting threads pop up here all the time; sure, better than it was at first, but certainly not problem free, and DEFINITELY not novice friendly. AEM is even worse. Stock boost will work with stock tt injectors & MBC w/ tt harness & ECU...but you're back to jury-rigging it to the TCU yourself.

Sorry, but there's no "easy way". Just some ways that are slightly less difficult.

Okay, so I have a few options that are appealing to me. I just want to confirm what I choose. I am not looking to run super amounts of boost.
-So your saying I can get tt wiring harness and tt ecu from a 2g vr4 be okay?
-Also, if I decided to go AEM/Chrome and ran NA impedance I would not have to wire in any resistors?
-And I can use a NA harness and ECU with piggyback, and wire in my resistors? But since I already have 4 o2 sensors already I would not have to modify my existing harness to add any extra o2 sensors. Right?

Sorry it's super late and I'm tired. Let me know if I'm not clear enough.

[IPD]

http://www.3sx.com/store/comersus_viewItemBundle.asp?idProduct=24271

These resistors are only so you can use the stock tt injectors in a car with an n/a harness. Point being, screw using the stock tt injectors--and just get injectors that match the N/A specs, and you won't have to worry about the damn resistors. Only problem with this is--you'll have to scout your own injectors, since all of the solutions for TT's are going to be for the wrong impedence.

As far as your solution on which route to go--that's still up to you--it's the TCU connectivity that is the x-factor. If you want the car to function normally as an automatic would--then you still have to make sure it "talks" to the ECU. Otherwise, if you're willing to manually shift the auto, you'll need a controller box & flip switches each time you want to change gears; which is a bit tedious for anything other than racing, imho. But iirc, there's at least one dude who jury-rigged it with makeshift paddles so it mimics more modern cars with sequential shifting. I can't speak to overal transmission durability with those mods though.

The sad truth is, since Mitsubishi never made automatic VR4's (and only sold JDM AWD ATX's), in the USA you're practically trailblazing every time you decide to keep the ATX and go with a TT. Even when 3SX set the ATX 1/4 mile record, it was done via manually shifting. Keeping an ATX in a 3/s is seen as a pariah & the work of lunacy. In years past it was even worse--because there was a lot of bad (and totally baseless) stigma about the ATX being made of glass, etc. Meanwhile, the DSM community has the same transmission (internals) running 8's on the 1/4, and swears by it. So yes, it's really no wonder that the 3/s community has been so badly represented in aftermarket--since we f'd ourselves over with parochialism & idiocy. But I already made a blog post about it on here.

[Benjamin]

http://www.3sx.com/store/comersus_viewItemBundle.asp?idProduct=24271

These resistors are only so you can use the stock tt injectors in a car with an n/a harness. Point being, screw using the stock tt injectors--and just get injectors that match the N/A specs, and you won't have to worry about the damn resistors. Only problem with this is--you'll have to scout your own injectors, since all of the solutions for TT's are going to be for the wrong impedence.

As far as your solution on which route to go--that's still up to you--it's the TCU connectivity that is the x-factor. If you want the car to function normally as an automatic would--then you still have to make sure it "talks" to the ECU. Otherwise, if you're willing to manually shift the auto, you'll need a controller box & flip switches each time you want to change gears; which is a bit tedious for anything other than racing, imho. But iirc, there's at least one dude who jury-rigged it with makeshift paddles so it mimics more modern cars with sequential shifting. I can't speak to overal transmission durability with those mods though.

The sad truth is, since Mitsubishi never made automatic VR4's (and only sold JDM AWD ATX's), in the USA you're practically trailblazing every time you decide to keep the ATX and go with a TT. Even when 3SX set the ATX 1/4 mile record, it was done via manually shifting. Keeping an ATX in a 3/s is seen as a pariah & the work of lunacy. In years past it was even worse--because there was a lot of bad (and totally baseless) stigma about the ATX being made of glass, etc. Meanwhile, the DSM community has the same transmission (internals) running 8's on the 1/4, and swears by it. So yes, it's really no wonder that the 3/s community has been so badly represented in aftermarket--since we f'd ourselves over with parochialism & idiocy. But I already made a blog post about it on here.

Okay I feel really stupid right now. I have noooo idea why I typed TT ATX. I have a 5 speed manual transmission. I'm sorry about all that confusion. That being said I can run a safc and be okay for the time being?

[IPD]

5 speed manual FWD IS glass. Expect it to grenade on you. Stealthee is NA and goes through them like a hot knife through butter. I'd just recommend getting stock vr4 harness & ecu & injectors, and just running that w/o any piggyback. That's the easiest way. You can always upgrade later.

[stealthee]

Not only am I NA, but I am SOHC. I broke 5 transmissions. 4 of them were blown diffs, one was a blown 2nd gear. The blown 2nd was because I had a Quaiffe LSD in it that is almost unbreakable. If you are going to stick with the NA trans I highly recommend the Quaiffe though. It's expensive, but it has a lifetime guarantee, even if you race with it. I just recommend not trying to grab 2nd if you are overpowering 1st.

[Benjamin]

Not only am I NA, but I am SOHC. I broke 5 transmissions. 4 of them were blown diffs, one was a blown 2nd gear. The blown 2nd was because I had a Quaiffe LSD in it that is almost unbreakable. If you are going to stick with the NA trans I highly recommend the Quaiffe though. It's expensive, but it has a lifetime guarantee, even if you race with it. I just recommend not trying to grab 2nd if you are overpowering 1st.

I've heard that from so many people already. That is definitely something I'm going to invest in. DEFINITELY. The transmission that's in it already grinds into second. So I'm going to find another transmission and install the Quaiffe then install it when the current transmission is toast.

[reses]

I think that having a 96 should let you almost plug & play, you just need to add the resistors (if going stock style low impedance) and ignore a few wires (VICS from the NA harness, Turbo meter-ABS signal-AE switch-FP relay 2-FP solenoid-boost control from the TT ecu), there is no cali/fed spec from 96+, number of ecu plugs should match, I have all the info for 91-95 tt/na/cali-fed ecus and wiring (since I had a few of those years) and 91-93 its almost a direct swap, 94-95 needs to be the same spec/year, and if you go from NA fed harness to a TT matching ECU you will be missing a plug (small one with the extra O2's).

[Benjamin]

I think that having a 96 should let you almost plug & play, you just need to add the resistors (if going stock style low impedance) and ignore a few wires (VICS from the NA harness, Turbo meter-ABS signal-AE switch-FP relay 2-FP solenoid-boost control from the TT ecu), there is no cali/fed spec from 96+, number of ecu plugs should match, I have all the info for 91-95 tt/na/cali-fed ecus and wiring (since I had a few of those years) and 91-93 its almost a direct swap, 94-95 needs to be the same spec/year, and if you go from NA fed harness to a TT matching ECU you will be missing a plug (small one with the extra O2's).

Sorry for the late response. So I can find a 96 TT Ecu, and basically cut a few wires a and it will work? I definitely wanna try this. That being said, if I do this is a SAFC still required? So I can run it on NA impedance. I can add the resistors no problem. But if what you're saying is correct then it will make my life so much easier.

[IPD]

You won't need an SAFC if you stick to stock boost. And if you use the tt harness, you'll have a resistor pack, not individual resistors.

[Chris@Rvengeperformance]

I was about ready to do this and backed out due to some concerns, but it doesn't look all that hard. I was going to run a TCU, although now I would probably try to convince the aem to shift the car.

BigTyla had some really good info on this on the other site from 2007:

"
After a ton of testing and countless hours beating my head on a table, I've finally finished experimentation with the TT ECU in my ATX TT conversion. And really, it's quite simple. The hardest part was figuring out what to do with the park/neutral position switch wire. After that the car ran miraculously.

I'm going to tell you exactly how you can put a TT ECU in your ATX car if you choose to do a TT conversion. This will allow you to run your conversion with only ONE oxygen sensor, without any wiring outside of the car (besides what it takes to extend your old sensor to the rear o2 housing)! Note that my conversion was for a 1G ATX car, and I used a 1G TT ECU. I see no reason why this can't work for later generations as long as you use the respective TT ECU for your generation and cut and splice the same wires I'm about to describe. But again, do this at your own risk if you are not a 1G! I'm not sure just how different the ECU pin assignments are between generations. However, I will name each pin so that you can cross-reference for yourself, and I'll also specify which pin designations are only for the TTs.

The following link to stealth316 will help you find out which wire is which: http://www.stealth316.com/2-ecu94.htm. If you are not a 1G and wish to try this modification, your best bet is to research the difference between your current n/a harness and the TT ECU you are going to use in your conversion and make the same modifications I am about to describe.

1) Buy a wiring harness adapter from here: http://www.autosportwiring.com/mitsubishi.htm

2) Find the pins on the TT ECU for the front and rear oxygen sensor, and the one wire on your n/a wiring harness for the rear oxygen sensor (for the 1G, this will be pins 55 for the front bank and 56 for the rear). Cut the wire designated for the front oxygen sensor and splice it in to the wire designated for the rear oxygen sensor. This allows you to simulate an o2 reading from both banks, even though you are really only getting a reading from the rear oxygen sensor!

3) Cut the following wires:
Reduce torque execution (pin 7 for 1G)
Fuel Pump Relay 2 (pin 21 for 1G; this is a TT wire only)
Active exhaust control unit (pin 102 for 1G; this is a TT wire only)
Turbo wastegate solenoid valve (pin 105 for 1G; this is a TT wire only)
Induction valve closed (pin 109 for 1G)
Induction valve opened (pin 110 for 1G)
Induction valve position sensor 1 (pin 111 for 1G)
Reduce torque request 1 (pin 116 for 1G)
Reduce torque request 2 (pin 59 for 1G)
Starter relay signal, A/T only (pin 71 for 1G)

It is imperative that you cut the starter relay signal wire! This wire goes into a pin in the TT ECU designated for a chassis ground, and you will short out that pin if you do not cut this wire! Note that I left the park/neutral position switch wire alone. This wire is now going into an input in the TT ECU designated for the starter relay signal. The car will still start as normal. Without the p/n position wire going into this input, the car will have very erratic timing when you shift into drive. I learned this the hard way, and it took me weeks to figure out the reason behind it.

4) Ground the wire for the chassis ground (pin 71 for 1G) coming out of the ECU side of your adapter. The best way to do this is to crimp male and female connectors on this wire and make an extention long enough to use the mounting point for the relay on the driver's side of your center console as a ground. The relay is the black box in this picture.
http://www.stealth316.com/images/fc-console-ls.jpg
Credit given to www.stealth316.com for the picture.

5) Cap all of the wires you cut to ensure they don't short out on something, and install your wiring harness adapter and TT ECU. Then start it and be happy!

Hopefully this will be a great asset to you guys wanting to TT your ATX.

"

[Chris@Rvengeperformance]

Okay I feel really stupid right now. I have noooo idea why I typed TT ATX. I have a 5 speed manual transmission. I'm sorry about all that confusion. That being said I can run a safc and be okay for the time being?

didn't see you were manual. Oh well, my re-post may help someone.

[reses]

Sorry for the late response. So I can find a 96 TT Ecu, and basically cut a few wires a and it will work? I definitely wanna try this. That being said, if I do this is a SAFC still required? So I can run it on NA impedance. I can add the resistors no problem. But if what you're saying is correct then it will make my life so much easier.

Yes that will be the easy way, you will need to cut the wires for the 6 injectors and put a resistor between the spliced wire, also cut or disconnect your VICS motor and all the ATX Stuff (if still present), TT and NA from OBD2 have the same connector style (4 plug), just make sure to swap/ignore the corresponding wires, I made a few diagrams but thats for 91-95, I have a 96 diagram but I'm still unsure about some pins.

[reses]

http://i.imgur.com/MNKHhyc.png

This is 96-97 TT ECU, I need the EGR Temp pin, can't find anything about that, if you decide to do the harness mod, let me know if you find another wire so I can also add this to the wiki.

[Benjamin]

http://i.imgur.com/MNKHhyc.png

This is 96-97 TT ECU, I need the EGR Temp pin, can't find anything about that, if you decide to do the harness mod, let me know if you find another wire so I can also add this to the wiki.

Okay Yeah I'll definitely try this. If I figure out your matching pins I'll let you know. Can you give me a guestimate on which number wires I will be deactivating?

[reses]

I think that just 4 pins, those are for the VICS system, But I think that if you just leave it disconnected it will work fine (Turbo meter signal its the one that could kill some circuit when grounded)