'90 F4A22 vs. '91 F4A33

Bandit · 10-24-2007, 02:03 PM

here's the dilema. I ended up with a wrecked '91 Laser Turbo fwd Auto. I then ended up picking up a '90 non turbo Auto from a friend. I've already pulled the engine/trans, wiring harness, ECU, TCU and other odds and ends out of the '91. If you havent figured it out yet, i am going to be swapping everything from the turbo '91 over to the non turbo '90.

the connectors and wiring between the two are completely different (tranny wise. i know all that i need to do for the 90 to 91 conversion and the n/t to turbo conversion). my question is, will the '91 F4A33 work with the '90 F4A22 TCU in any way, or am i just going to have to do the complete rewire?

HighPSI TSi Guy · 11-04-2007, 07:29 PM

You will want to use the TCU which matches the trans. OTherwise the shift tables will be all wrong, since they are based on shaft speed, using a TCU with a differently geared trans will make it shift at the wrong RPMs. I'm not sure how much different it is between FWD turbo and FWD NT but I know the difference between FWD NT and AWD was way different when I tried it.

Bandit · 11-06-2007, 06:52 PM

yeah, after a little research i figured the tcu would need to be swapped...but after finding water inside the engine, im going to hold off on the conversion for a little while. now just have to figure out how well the n/t tranny holds up to power and abuse. waiting for ipt to approve my account for thier forums.