a friend of mine and i were talking and he believes that EGR really holds back the performance of LG4s... i said it might take away 1-3 hp but he seems to think that because of the excess heat it brings back, the loss is a bit more substantial. who if either of us, is right?

 

Personally i believe your both wrong simply because the EGR dosnt function at all (or i should say shouldnt if things are working right) at WOT where you would measure peek HP. While it is operating it kills power if for no other reason than exhaust gasses are inert and just do not burn therefore they just take up space in the cylinder which effectively decreases the displacement of your motor. However the amount of EGR gasses passed back into the intake are fairly small in comparison to the motors displacement and again the EGR valve does not function at all at WOT. I cant say how much the temps effect hp but i suspect its very small as not only is there only a small amount of exhaust gasses bypassed into the intake but the gasses themselves are snaked around through the intake allowing them to dissipate heat. Some claim the EGR helps by allowing more advanced timing by reducing detonation but i havent seen any real evidence that this is true nor do i believe that the performance gains of this factor outweigh the losses caused by the EGR valve.

 

sounds logical, any more opinions?

 

EGR doesn't cost HP.

If you remove/defeat EGR and don't retune the timing curve, you will reduce fuel efficiency by backing off the base timing you will have to do to eliminate the pinging you will get w/o EGR, because the timing is advanced during the conditions when the EGR valve is opened to compensate for the exhaust gases in the fuel/air mix.

Unless you have the ZZ4 install kit from the factory (no longer available), EGR is the only street legal carb system you can run in the U.S. (along with the CC carb, of course).