Still works within reason if you send ecu different ect value's on newer cars.

They dont work at all.....I have put cars on rolling roads with these chips on them they all almost with out exception showed no power gain usually they alter the power curve sometimes small gains in the mid range but almost always overall power losses. Often no differences at all. The more modern the ecu thd more likely it seems that no changes happen.
I have car magazine's from the 1950's and 60's where similar claims were being made for carb and exhaust modifiers.......they never worked either funnily enough they made the same claims as superchips and they were as popular then as well.
nothing is for free when you want more power. The gullible will always look to pay as little as possible for it though. And expect massive gains.

|Given the technology of engines in the 50's and 60's taking the air filter off would probably double the horse power.

yeah removing the air filter would produce that sort power...;-)
no i was referring to the little windmills that were fitted to the carb venturi and the same thing fitted to the tail pipes of exhausts.........
its not an issue for me but the OP asked how good it was likely to be, they are as i said mostly a con.

This is not a resistor mod but a tuned mapping table chip.

As I mentioned earlier it proably won't improve power, but will possibly make for better drivability

Tuning chips can take advantages of things not in place or known when the car was manufactured. In the case of the 2.9 Cologne, 4 Start was still the fuel of choice, it no longer exists.

TT

that is an early Piggy Back tuning chip for the ford EECV or whatever ford called the early EFI ECU's
the principle is that ford left a port or bit on the edge of the ecu PCB behind a bit of plastic that could just take a new program/map should it ever be needed the only issue is when the power is cut the tune reverts back to the one in the main chip hence why you had to leave them in.
i think the turobotechnics fords where done this way?

superchips and other co's used this unused ford option exploited it and made their on piggy back units to take aftermarket tune up chips

there is a similar thing with extra chip holes in 80-90s jap cars