Lizard928

Finished up work on an 85 Koenig with 87 engine running MS v3.57 w/ COP ign.
We didn't do a baseline so I cannot tell you that.
But I redid the intake and valve covers, and reworked the crankcase breather using a custom made stainless air oil separator.
I then custom fabbed a rear mount turbo. It is roughly a T62.

Took the car to the dyno and put down 450 RW ft lbs (full boost around 1500rpm) and 370rwhp.
This is running 5 psi of boost on a mustang dyno.

The car sounds pretty amazing if do say so myself. I'm hoping to get a tiny go pro video of the sound tomorrow.

On to the interesting problem though.
One of the local lads has an 84 (us/cdn) 928S.
When the key is in the ON position running or not, if you push the rear defroster for high power the headlights cycle up/down w/o coming on.
If I pull the headlight relay they stop cycling until I plug it back in.
If I pull the defrost relay they stop cycling and down come back on till I push the button again.
Has anyone seen this symptom before???
I am thinking defective defrost relay (already rerun solder), but would be nice to confirm and don't have an early relay to test with.

brutus

The relay does seem to be able to feed back , recent report that a car stayed running with key switched off.

Alan

Why not investigate the grounds above the CE panel - maybe one is loose. When unrelated circuits start interacting - always suspect grounding issues first... may not be the only answer but its the most common...

Alan

Darklands

Maybe a broken ignition switch?My shop told me my 84 S has also strange behaviour after standing 1,5 years without an engine.
After reinstalling the "new engine"the new ignition switch cured all strange failures.

Lizard928

Alan,

The grounds above the CE panel were cleaned and tightened down one at a time, as were the ones below the column. This was the first thing I tried, though I will check them again.

Mrmerlin

are the correct PN relays installed?
if one of them has been replaced then the new relay may be causing the issue.
Dont keep testing this as you may short out another system, also check the connectors along the bottom of the CE panel make sure they all are plugged in and that none of the individual wires has come unseated, and been pushed out of its connector.

Also inspect the rear of the CE panel for melted wires,
the wires will have satin look to them unless they have gotten hot then they will turn shiny

Lizard928

Stan,

Original relays untouched before this. Will check the back of the panel as well.

Alan

Check the grounds @ both ends - make sure they look good (panel too). Check for power as expected at the rear screen heaters when this is supposedly operating.

Alan

Iwanna928

What are your thoughts on the rear mounted turbo. Is it where the muffler would be or more mid mount. Any pics? Sounds fun!

dragonflyjones

Collin! Sweet project! That's awesome that you're building full boost so low. Are you using an inner cooler? Do you plan to go up on boost? Are mustang dynos pretty accurate?