I'm dropping an 89 motor from an automatic car into an 87 with a manual tranny. I need the counterweights and the flywheel/clutch assembly from an 89-91? Also, because I'll be using the ecu from the 89, do I have to fool the computer into thinking the auto tranny is there? I didn't find the exact answer I was looking for after searching. Could someone confirm this for me.
thanks

 

come on guys. someone has to know

 

You'll need the 89-91 flywheel. The front counterweight is the same. I'm not sure if the auto and manual ECUs are different. I dont *think* they are.

 

Thanks Anthony, I didn't know that would be such a hard question to answer. By the way, those 10thAE wheels look good on your car.

 

Well I got some bad news for you guy. First, youll need the 89 flywheel for use on that engine, hard to find. Cant be off a turbo either, must be of an 89, 90, or 91 nonturbo.

Next, when I converted my last 89-91 automatic to 5sp I found that the car has its own seperate ecu for the transmission, called ec-at. IT has to be unplugged once the transmission is gone, or the car will run like ***.

Since you're using an 87 body, with(i assume) 87 wiring, you wont have to worry about this. The 86-8 automatics did not have an ec-at.

However, if you are keeping the 87 wiring, you cannot run an 89 computer either. # bundles of wires plug into the ecu...2 of which go to teh engine harness, ad one of which goes tot eh dash/car harness. You either have to change them all for 89 spec or none at all. The plugs on the 2 ranges of harnesses are different, and wont plug into another series computer.

 

thanks kevin, I appreciate the help. I was planning on using the engine harness and ecu from the 89. Isn't that the only harness I'll need? This is going to be a full time auto-x and hopefully an ITS car eventually. I was thinking about a lightened flywheel if I can't find one from an S5. Am I on the right track? This doesn't seem to be too tough to do.

 

On the harnesses there is a big job ahead if you plan to convert.

Youre right, the engine harness and ecu is no big deal. The other harness, whcih runs under the dash, to the fusebox, then through teh firewall to the driver side engine compartment and infront of the car, is a REAL BITCH. Frist time i pulled one it took me 6 hours. THe dash has to come out.

You must either change that harness, try to splice in an 89-91 dash harness plug and make it work, or stay all 87 electronics.

The flywheel is the least of your worries.