Not to sidetrack the thread but this is the first time I've heard about their being some minor differences in the 86's. Seeing as how I have one and am new can My5ABaby or sonorous7 take a look at this picture and let me know if I have an early 86 as well? Thanks.

 

Looks like mine and I know the coolant reservoirs were moved later. So yes, you have an 86.

 

i have a 88 n/a convertable and the color are precisely the same! im with you man im grounding the solid black but yeah dude precisely the same!!! coolant over flow on pass ALL original bone stock and the boost sensor harness reads the same :

------▲---------
B | B/W |
-----------------
Br/W | Br/R |

weird huh im about to ground mine too ill get back to you on results!

 

still a hesistation (@ 3800rpm) even after the added ground at the boost sensor as well as added extra ones to the stock ground on top of the rotor housing both near transmission/and under the plenum (top intake) i will now research about adding grounds near the ecu particular to the harness there are a number of pins on the ecu that are grounds ive seen a couple of threads on adding grounds here as well as adding grounds to the ground that acutually holds the ecu down it self pls post links and/or replys reguarding the issue of the "ecu grounds" it would be apprecited for all i think!

88 s4 N/a convertable