Obviously the ECM needs a tune because of the intake and other mods done to it; thats a given.. But what specific issues am I looking at because EGR must be eliminated with the LT1 intake?

Will losing the EGR affect gas mileage severly? Before ragging on me for complaing about gas milage, this car is daily driven, so mileage is a concern.

Also, I've read that material must be added to the intake's EGR port when used with cast iron L98 heads. The LT1 intake I'm buying is used, but was purchased from John Millican for a 89 L98 Iroc, so if it needed to be modifed for the cast iron L98 heads, John most likely did it already.

The other misc. parts for the swap have already been taken care of.

I've already read most of the threads that came up with this search.

Specifically looking into these two threads.
https://www.thirdgen.org/techbb2/sho...ght=EGR+delete
and....
https://www.thirdgen.org/techbb2/sho...ght=EGR+delete

 

Won't affect gas mileage, it'll just raise combustion temps and NOx readings.

In the ECM there's a few flags and a table with EGR vs. Load or something (don't remember what its tied to)

 

There is a switch in the eprom for the EGR but all that REALLY does is stop reporting it as an SES code. One effective way to disable the EGR is to raise the "Minimum MAT Temp to engage EGR" to 255 (which is the ECM's maximum of 151*C).

 

If my engine ever hit 151c then I'd be in big trouble. EGR would be the least of my worries.:lala:

Everything I've read says that I'll loose a bit of mileage. Which stinks because I have to drive it this winter. I'm loosing my winter beater, so the GTA needs to drive. :*(

 

Good call that's actually what I did do. I was in a hurry and didn't look over a BIN/ECU.

As for mileage, you really shouldn't lose anything. All it does is inject inert (non-combustible) air into the cylinders to keep temperature down (thus decreasing NOx a lot).

 

So, with a 180* thermostat and the ECM set to turn on the fans earlier I should be able to compensate for the loss of EGR?

 

LS1 engines don't even have EGR anymore. They adjust for it with the newly designed cams made for LS1's. This is just FYI.

Anyway, removing the EGR on an engine designed for it can actually hurt perfromance and lower milage. This is because it's job of re-burning exhaust gas to lower the combustion temps allow for more spark timing without detonation.

If you want to learn alot about EGR read this excellent article written by a member here.
http://sethirdgen.org/egr.htm

 

Actually, I've already read that. And just about every other article on that site.

But with the LT1 intake there is no way to keep EGR. I'm not opposed to keeping it. I spent $80 to repair the EGR system on my GTA for the TPI.

So, the question is, how do I minimise the losses when I delete EGR for the LT1 intake.

 

I had considered making some sort of an adapter to fit our EGR (or the one that came on my LT1 manifold) with the distributor..not quite sure how though.

 

You would also have to plumb exhaust from the passenger side manifold since there's no heat riser in a LT1 intake.