Automotive Performance Chips

[Darrell]

Are they all that and a bag o'chips? Overhyped? A web search shows a chip for my Toyota, $69.00. They make extraordinary claims of horsepower and mileage increases, plust decreased emissions. If they do all that, why isn't the manufacturer using them? Any good by themselves, or do they require headers/other performance parts to do any good? Are they harmful to the car?

[rightisright]

They run the gamut from garbage to extraordinary.

You will see the most gains in a boosted (turbo or supercharged) engine because it is fairly easy to bump the boost via computer.

If a chip (or ECU / ECU flash) boasts adding 80 horsepower to a normally aspirated 200 HP engine, it's a bunch o' crap.

[Jeffro]

They run the gamut from garbage to extraordinary.

You will see the most gains in a boosted (turbo or supercharged) engine because it is fairly easy to bump the boost via computer.

If a chip (or ECU / ECU flash) boasts adding 80 horsepower to a normally aspirated 200 HP engine, it's a bunch o' crap.

Pretty much. I had my Z71 chipped just after I bought it, and about all it did was change the shift points under WOT, change the rpm cutoff (I had it bumped to redline), and some other little tweaks I've since forgotten. I also changed the thermostat to a cooler version, put in a cat-back dual exhaust, and also installed a K&N intake and air filter assembly. All of those things together helped open it up, but it sure wasn't the chip alone.

And to call it a "chip" is kinda misleading - it hooks up to the OBD port, and exchanges settings in the CPU for settings on the unit. So, all my stock settings are stored on the "chip."

[esa5444]

If they do all that, why isn't the manufacturer using them? Are they harmful to the car?

Asked and answered your own question. Car engines are engineered conservatively. When you go changing the settings for more performance, you reduce the safety factor. Every place says "gains in HP, gains in mileage, gains in torque, faster, etc", but there is yet a place that says " gives you an extra 15 horsepower and we've tested it to determine that it lasts just as long!" or "An extra 50 horsepower, but the engine is only good for 50000 miles between overhauls". Most of these places are a bunch of guys, usually yahoos, so to me its always been a question of do you trust the engineers who built the car or some guys who may or may not sell snake oil?