can you put the megasquirt in valet mode?
 

car came with megasquirt already installed.

i have to send it into the panel shop to fix some issues, but not keen on letting it out of my sight without making sure it can only be driven like a grandma.

maybe limit rpm and timing so it drives shit and wont come on boost.

do i need to load a whole new program, or can i hook up a pc and just switch to a limp mode.

On any MS you could just make a new "limp mode" map (save the current one first though!) with retarded timing, lower rev limit and whatever else you might fancy (reduced boost if EBC).

On at least some versions/generations you can also have dual spark tables and a switch to change between them, and just make sure that switch isn't too conspicuous (i.e. not on the dash labeled "GO FAST" and "GO SLOW").

Alternatively, leave your car to someone you can trust. Or replace the steering wheel with a wooden stick that noone would drive at above "parking speed".

Boost cut at 105 kpa, rev limiter at 3500. Write the tune when you drop it off, and write the old one back when you pick it up.

That's what I did last time I got an alignment.

You can just be a total asshole and install a switch to lift ground for a plug and injector. Tell the shop it has cams.

:likecat:

lower the rev limiter and boost cut before you drop it off.

or wire open the wastegate so they can enjoy 100rwhp in all its fury.

Depending on your version of megasquirt the new firmware has a "Pit Lane Limiter" Where you can set speed limit. I have mine set to 25mph. Flip a switch, and fuel cut happens at 25mph. You can also use this feature as rolling anti-lag if you want to :) hold down a button, spark cut to build boost, and then take off.

if you're looking for a "switch" solution that's easy
if you're just doing this 1 time that's even easier

rev limit and boost cut like deezums said

The Enhanced series ECUs from us have a valet mode that limits RPM, TPS and VSS. At the same time they illuminate the CEL to indicate a "problem". :)