If I purchase a Pettit or M2 ECU from someone that has intake, dp, mp, ic, exhaust upgrades. And I only have intake, dp, exhaust. will the setup not run my car correctly because the fuel delivery is set different?

 

it shouldn't make a difference

 

really? So the fuel, timing curves will adjust for my mods?
Can someone touch on this more?

 

The mixture will be different than it would be on a car with an IC, but it will still work okay. You'll just be running a little richer, probably. There is no air flow meter, so the ECU will not adjust for any differences in flow. It will adjust for differences in intake temps. The ECU just looks at the manifold pressure, temps, and RPM and chooses a value from the map.

If you open up the flow path a lot (intake, IC with low pressure drop, ports, free-flowing exhaust system), the car will be flowing more air without changing the input values that the ECU uses to choose value from the fuel map. In that case, you would need a new map that had more fuel for a given set of input values. Maps are tuned for the flow characeristics of the whole engine system (intake, ic, turbos, exhaust, etc. -- anything the intake or exhaust air flow through), so changing those will change the mixture you get for a given map, or require a new map that is a better match for what you've got.

That said, you should be fine with that ECU on your car. You'll probably just run a bit rich, but it will be close enough to "work". If you want to run high boost and really push the power envelope, the only way to get good maps is to use an adjsutable system and tune it for your car on a dyno. There are too many differences that come into play for a "mail order" map to work optimally and safely under those circumstances. But just for moderate power, a chipped ECU should be fine (safe), even if it was tuned for a car with more mods than you are running.

-Max

 

Thanks alot for the insight Max.
I might even consider a MP if I do get this ECU. *but loud exhausts drive me crazy.