TT Chip question from the new guy

I have a stock 85 GN, I am trying to figure out some performance upgrades for it, and want a chip. I am looking at the TT 5.7. My question is, should I just keep my ECM, and add the chip or get a 86-87 ECM then add the chip. If I change ECM's is there anything else I will need, or is it just plug and play? Thanks.


Staff member
Ok guys, if these are 86-87 intercooled cars, and you are seeing sustained knock retard of 3.0 or more that contines to rise under wide open throttle, with boost levels under 15psi, you have something seriously wrong. Either your fuel pump is dying, fuel filter is clogged beyond all recognition or another bad issue. Get a Scanmaster, unless you already have one, get a fuel pressure gauge that you can stick under the windshield wiper so you can verify 1:1 boost vs fuel pressure under WOT. Meaning, if you set your fp at idle with vacuum hose off at 43psi, and you are running 15 psi, the fp gauge under WOT must hold 58 psi steady, or a 1:1 ratio. Just don't forget to reconnect the vacuum hose after you set it. Battery voltage needs to be 13.5 - 14.3v under WOT as well. Read this page as well as Eric's info. But if you are seeing real knock that doesn't go away in the scenario above, get out of it until you can get the bugs worked out. This applies to intercooled cars, as hot air cars will run lower boost levels and require more finesse with tuning. Remember, the first screen that comes on, after the Scanmaster initializes, tells you O2 mv and Degrees of knock retard under WOT. This is your most important screen to monitor when going WOT. IF YOU SEE MORE THAN 3° (3.0, not 0.3) Sustained knock that keeps rising under WOT, IMMEDIATELY LIFT.
Hope some of this helps.