EGR delete yes/no/????

[DeWynter]

While I do the swap from my Old TPI setup to the Accel Super ram, new heads and cam. I was thinking of droping my EGR valve. Will I be sacrificing anything? I also plan on swaping to the Accel DFI gen 7 engine managment system which will not control this anyways. Emisions testing is not a problem for this car. I have already deleted the AIR system. What benifits will I gain from keeping the EGR if there is any.

[Injuneer]

EGR is used to reduce combustion chamber temperatures under conditions that promote the formation of oxides of nitrogen (NOx). Typical condition would be lugging the engine at low RPM in to high a gear (and I know we wouldn't drive our cars that way ). In that situation, the EGR will help reduce the potential for detonation (knock). In some ways it can also be considered a "displacement on demand" feature, since by filling a part of each cylinder with a small amount of "inert" exhaust gasses, it reduces the usable volume of the cylinder. I guess in theory this would give you some sort of tiny gas milage improvement, but I doubt you could measure it. Finally, it does reduce emissions.

I run an aftermarket ECU, and kept my stock PCM to control the things the ECU can not control - VSS, IAC (MoTeC can only operate PWM control, not "stepper"), EEC, and AIR. It was a bit of a pain, since the stock PCM needs things like coolant temp, and the pure resistance sensors like the thermistor need to be duplicated to provide the required data (unlike MAP or TPS which use a 5V reference voltage and a variable resistance).

[DeWynter]

Since I have already yanked my AIR system, the only thing left running on the old ecm would be EGR. As the new DFI gen 7 runs fans, Injection, Timing and ignition, A/C, O2, Knock and posibly IAC and TPS with optional harnesses. I guess everything hinges on if I can get it to run my TPS and IAC. If it can I was hoping to just drop the entire original system.

[Injuneer]

Any system you buy will require TPS input, so that's not a problem. I'm not sure if Gen 7 will run stepper type IAC or not. I do have a fairly detailed comparison of the capabilities of various aftermarket systems in a Kinsler Fuel Injection catalog... I'll check and see what it says.

MoTeC I know has a problem since it can only handle a pulse width modulated IAC valve, at least in the version that I have (M48Pro). I think they may have updated it to the GM "stepper" design in the latest version (M800).