possible to use FWDAUTO trans in manual car

[1Gina2G]

I understand the flywheel / clutch assembley is different, as well as adding another computer, but does the wiring make this impossible?

that is, to put ay kind of 2G automatic transmission onto a 6 bolt motor, inside a 2G car, in combination with a manual EPROM turbo ECU

I searched, all that turned up was using a manual ECU in an automatic, and multiple people claim this alone works, not sure about an automatic TCU working with the manual ECU though

 

[undefined0000]

Only difference in 1gs is the injector size. Think its the same size for 2gs.

Only difference really is how the ECU deals with the extra load the a/t puts on the engine when engaging gear, nothing huge though.

TCU works basically alone.

 

[1Gina2G]

so it sounds like it's possible to use my manual ECU and wiring harness fora 2g automatic transmission?

 

[undefined0000]

I mean, I am personally running a M/T ecu and m/t injectors with an automatic tranny with no issues (pertaining to that) . But I'm a 1g.

 

[1Gina2G]

I guess I'm just trying to understand how the TCU gets it's power from, as well as compatablility. How does yours get power? Surely there's some plugs / wires?

Plus - How does one go about changing the shifter assembley inside the car?

 

[undefined0000]

There are plugs/wires going to it, but I'm fairly certain that all of the communications come from the tranny, you might just have to splice power to power the TCU. Surprised no one else has chimed in. I just wanted you to know its more than likely very possible.

 

[mchustle]

Im pretty sure in a 2g manual car all the clips are there for the tcu, just unused. Mitsu is cheap so pretty much everything 2g is the same and they just plug unused holes etc.

 

[jrohner]

The ECU does not control the automatic transmission, that is what the TCU is for. You can leave your ECU alone. You will need to get the TCU wired in unless you're going to shift with toggle switches or a shift box.

 

[1Gina2G]

You will need to get the TCU wired in unless you're going to shift with toggle switches or a shift box.

where would I look to figure out how to do that?

 

[jrohner]

You just need to run +12V to the 2 shift solenoids with 2 toggle switches. You use 2 toggle switches to shift the 4 gears. It's nothing specific to these transmissions, it works the same for other electronically-controlled autos too. I first did it on a Ford AODE in a Mustang when the aftermarket programmable TCU was not working correctly.

 

[1Gina2G]

thanks again, I was actually wondering about getting it wired in without the aftermarket stuff.


Or are you saying i'd have to run 2 switches if I DIDNT happen to have the plug for the TCU?

 

[jrohner]

Yeah, it eliminates the TCU completely.

 

[1Gina2G]

so how wouldn't you need 1 switch for each gear if you were eliminating the TCU?

how would you know when to shift? sounds kinda messed up honestly.

I'd like to find out if I had the plug or not..

 

[Cox Abele]

http://www.dsmtuners.com/forums/newbie-forum/447185-5-speed-auto-wiring.html

Good luck finding the information. I've searched for hours and have posted here before asking the same question only to be left with a slew of miss-information and "discussion" posts that are irrelevant yet still receive the backing of the mod's here because they don't like loosing the warm fuzzy feeling they get by defending the illiterate.

Anyhow, to clarify, the ECU between the two cars in practically identical. The largest difference is in the tune they carry. Obviously, an ECM programed for a 1g's 390cc injectors isn't going to work well when installed into a car with 450s. Provided it can be tuned, this issue is nominal at best considering the injectors would be dialed in with the tune. An auto's ECU can be interchanged with a 5-speeds freely provided the scaling on the injectors is the same (both programmed to use the same injectors.) While there may be slight differences in load calculation, one would hope that a tune would be in short order anyhow, but in the most boiled down answer... The computers are the same.

By reading between the lines, you may have come to the conclusion that the ECM does not control any of the transmission function. As stated already, this is correct. The ECM does not have any control over the shifting of the transmission. This is left to the TCU, a second computer dedicated specifically for the load and speed calculations that translate into the gear changes. While one may forgo the TCU in lue of a shift box, understand that you will be banging each gear at full line pressure by supplying a hard 12v to the shift solenoids. While this eliminates transmission slip, it can be unbearable to some to drive this way on the streets, especially in situations where you downshift. Imagine, each shift, up or down, the firmness of the shift will be identical to what you would find desirable at the track. Again, for a primarily street driven car, this can get old very quickly.

So, it is best to leave the shifting to the TCU with the option to integrate a shift box for track use. This way you have the smoothness of TCU controlled shifts on the street and full line pressure manual shifts for the track. Furthermore, the shift box doesn't prevent you from accidentally downshifting at high rpm, over revving and possibly [likely] causing damage to the transmission.

But what does this mean to you? Well, for starters, you need to look into getting a TCU and the wiring associated with it, otherwise be prepared for those always-firm street shifts previously mentioned. The engine harnesses between the 5-speed and the Autos is not the same as mchustle suggested, otherwise you would clearly have additional pig-tails under the hood not hooked to anything. You can either find yourself an automatics engine harness and swap it in, or find the necessary pinout diagrams for both the automatic and 5-speed and attempt to splice it in, baring in mind that these harnesses may very well be different from year to year.

The best information I have found regarding the splicing has been with a 1g setup. According to this site, roughly 6 wires will need spliced into the ECM harness. Foreign Muscle (under Tech). I found the information by searching google and coming across this thread on DSMTalk (Need help with Manual to Auto swap).

Aside from the wiring, you'll need to swap out the shifter assembly and research the wiring for the neutral safety switch. You'll need to disable the clutch switch, find a way to incorporate or bypass the shift interlock mechanism and swap your pedals unless you want to keep your dead clutch pedal for some reason. A number of engine mounts will also need changed. In an AWD application, the axles are also different along with the intermediary shaft mount bracket. Also the AWD transfer case and rear differential will need to be properly matched to the transmission so as to keep the appropriate gear ratios.

 

[1Gina2G]

I really appreciate you sharing what you know about this subject, as you've said, there's not a whole lot of useful threads on manual to auto for 2gs, you have to sift through all the repetive posts on auto to manual.

I really didn't think it'd be this much of a hastle if it was actually possible. I mean, I'm an electrician, so finding a power supply is always easy but searching for a few multicolor wires in an old harness....is just going to be a nightmare without any clear guide

not even talking about how I'm clueless when you say 'bypass the shift interlocking mechanism' what is that exactly? Would you happen to have any idea on how the shifter assemblies would be changed since they're different? I think the automatic uses just 1 cable, instead of the 2 I have for the manual.

again, I could do the wiring, saying there's a clear method. bringing powers easy. I just dont see how or why I guess that the tcu could work off anything from a manual car's harness for anything but power...which can always be seperate, unless it needs to be on a relay specifically. Just use the same gauge wire and have it fused is what I always say.

 

[Cox Abele]

The shifter assemblies are bolt on affairs from what I understand and should be pretty straight forward. The trouble you may run into is...

A.) The shift interlock system; We all to commonly forget what it takes to take a car out of park. It's not just grab the shifter and yank. There is a key step involved which disables the shifter lock as we put our foot on the brake. Somehow this lock system needs to be bypassed.

B.) The O/D button will also need to be wired in. However, if you've made it to this step, it should be relatively clear what needs to be done to allow the button to engage and disengage overdrive by sending a signal to the TCU. Getting the dash lamp to work, well that could be tricky.

I have not done this swap myself. I am just giving you the information I have collected thus far. I'll be yanking the engine and transmission, engine harness, shifter assembly and pedals out of my parts car on Thursday in preparation of converting my AWD spyder to an automatic setup.

 

[1Gina2G]

you're right I totally overlooked the parking system. So to bypass is not to eliminate, for what we're talking about right?

that's awesome you just so happen to be doing this. Is yours a 6 bolt or 7 bolt engine? J/W because I just read about the kiggly plate you need for the autos if its a 6 bolt swap.

so you're going to use your manual ECU with the new automatic harness? sounds like the best way if it's possible. Are you getting a matching year harness for your vehicle?

 

[Cox Abele]

I'll be doing this with a 98 7-bolt engine, using a 98 5-speed ECU (flashed) with a transmission and engine harness from a 95 auto (iirc, but it could be a 96).

If I'm lucky, everything should be plug'n'play aside from my CAS wiring. Given I'm putting this in a Spyder, I have some concern about top function, so I'm really hoping I don't run into issues, otherwise I'll have to dissect the TCU control from the auto harness and splice it into my 5-speed's. If I swap the auto harness and everything works properly except the convertible top, I'll have to do a little digging and figure out what in the harness causes the issue, or find a way to re-wire the switch. Something tells me I once read that the gear selector signal (Neutral safety switch) somehow interrupts the top's function if not in park, but I could very well have that wrong.

If you are doing this in a hard top, it's less to worry about and should basically be that harness swap.

 

[richard33]

To put a 2g tranny on a 6 bolt, you will need this - Kiggly Racing - kigglyracing.com

To shift the tranny without a TCU you will need this. ForcedFour.com

You will also need a converter and the motor mount bracket for the rear and front mount.

 

[Cox Abele]

I believe there may also be a bushing in the crank tail that may be required. I realize a manual may require a pilot bushing, however I thought I read something about some kind of bushing being involved with the autos. I will let you know tomorrow what I find when I pull my motor/trans out and apart.

 

[boost97gst]

I have a manual that was at one point auto. I can tell you there are quite a few connectors that will need to be wired in. If you could get an auto loom for the same yr it would make it a lil easier. I wish the previous owner left it auto, i love a stick but damn auto turbos are so fast.

 

[Cox Abele]

I'm now dead in the middle of my swap. I can verify that there is a bushing in the end of the crank that will need sourced and installed. It helps align the flexplate and centers the torque converter.

The shifter assembly has 3 cables. Clearly, the first is what allows you to shift the transmission in and out of gear. The next two involve the interlock system. I have not made it to the point of swapping these two cables over quite yet. It appears that one attaches to the steering column and is likely tied into the key cylinder. The second extends up the firewall to the brake pedal. While I will be installing these, it maybe possible to forgo the latter two cables. I believe the adverse effects would be that you could start the car while in gear and you wouldn't need the key in the ignition in order to shift gears.

Under hood, the harness is standard to a 5-speed except for the additional plugs on the transmission. Inside the cabin, there are 12 connectors and 1 double eyelet that serves as a ground. These 13 connectors are as follows:

1-4 ECU
5-6 TCU
7 Rear O2
8 Shifter illumination and OD switch
9-10 Relays behind the radio
11 white connector behind radio
12-13 blue connectors behind radio
Ground eyelets

I assume #11-13 are for chassis integration for such things as the gauge cluster.

It is worth mentioning that this is for the coupe. At a very quick glance, it appears that I'll have some splicing to get this harness to work with my convertible. On the same branch as the shifter connector and rear o2, there is an additional connector that dives into a harness that travels lengthwise along the door sill. I am assuming this 5-wire (heavy gauge) is for the convertible top motors since there is an assumed integration to prevent the top from opening if not in park, with the brake pedal depressed, or something like that. I haven't pulled the convertible harness yet, but I'll be tracing those wires also in due time.

Since you asked about the shifter assembly in one of the posts, it bolts to the drive shaft tunnel with 4 bolts. There are 2 cotter pins and 1 lynch pin holding the cables on. You'll need an automatic's center counsel since the 5-speed's is shaped a bit differently around the shifter assemblies, the 5 speed clearly having a boot around it's shifter.

 

[Cox Abele]

I is worth mentioning that I overlooked one connector on the interior that I discovered in my 98 spyder.

Connector 14
is located on the rear o2 branch and is only on 98-99s. It is for the evap system on the fuel tank. It had me scratching my head until finding the information and doing a little testing.

I now have my shifter installed, for the most part. The automatic has 3 cables.

1.) Shifts the transmission
2.) Shifter interlock/lockout
3.) Key lock out.

Number one is self explanatory. Number 2 and 3 are not absolutely necessary unless you want some safety features. Number 2, the shifter interlock/lockout cable attaches to the brake pedal assembly and prevents you from pulling the car into gear without your foot on the brake. It is pretty painless to install since you should want to do a pedal swap anyhow. Without it hooked up, you could easily put the car into park without pressing the brake. Obviously, this would be bad. With the simplicity of installing the second cable and the risk or accidental gear selection, I see no reason why this cable should not be swapped unless your car is an absolute hack.

The third cable is for the key lock out. If the car is in any gear besides park, it will not allow you to roll the tumbler to "off" and remove the key. This cable is also not necessary to hook up. Without it, you can just take the key out with the car in any gear much like you would a manual car. It is also the most difficult to swap because the bolts holding the entire cable and tumbler assembly to the column are "anti-theft" so they do not have any heads. You must dig them out or drill them to swap the assemblies. Pray you don't screw up the threads. I have my parts car's column dropped and am still on the fence as to using this cable, leaning more towards not.

 

[1Gina2G]

congrats on getting this far in your swap, and keeping us updated. Honestly after reading half of what is involved for this swap, I felt it was not worth the work, alot of unknown areas I have not been in before. No clear guide on how to do this, with the acception of the 'IPT shifter install' which isn't the easiest task in the world either, nor is it as reliable as a factory TCU control.

for what everything would cost me, plus time, I honestly decided to begin the search on a new chasis, with an automatic trans. Hopefully one will pop up for sale soon. Also why I got another thread, to see if I can use the 4G64 N/T trans on the 4g63, apparently its possible, but naturally you can't go wrong with a turbo trans.

sounds like you're basically done with the swap though, that's awesome man, hopefully you'll get it to where the top works for you too like you were saying.