I'm building a engine for my 95. In my state we don't have emission testing. What are the performance advantages and disadvantages of using the E.G.R.

Thanks

 

IMO, one advantage of an EGR is the engine was designed to use it. The disadvantage is, anything that dilutes the intake charge can't be good for performance.

I'm sure there will be plenty of feedback for you, both for and against the EGR. You're just lucky you have no smog testing in your state. Here in CA it's the ONLY thing they test.

BIG JIM

 

EGR is not engaged at idle or WOT. You might get detonation at cruising speed (part throttle) unless you reprogram the computer. So at the strip your not losing anything having it hooked up.

 

I ditched it on mine along with the rest of the AIR system. I installed long tube headers so that removed all the AIR plumbing, but I left that actual EGR valve in place, but it didn't actually do anything when it opened.

I had not driveability issues or codes. I later removed the EGR valve itself because it makes getting to the last intake bolt so much easier.

In short if you don't have emissions testing and aren't concerned, you can really clean up your engine compartment by ditching all that crap.

 

Pro: Reduced NOx emissions, caused by the exhaust gas diluting the intake charge and giving less peak temperature and power. Operates only at part throttle, not at idle or WOT. Feel good about helping to save the atmosphere.

Con: Hot, dirty exhaust leaves deposits in the intake and heats the intake charge. 1) The hot intake then reduces power at WOT by heating the incoming air. 2) Because combustion power is reduced at part throttle, more throttle opening is required for any given power setting. As a result, BSFC (Brake specific fuel consumption) rises and fuel economy suffers.

Caveat: The engine compression, cam, fuel injection curve, spark advance curve, and EGR are designed to work as a system. Fiddling with one aspect, such as D/Cing the EGR, will upset the balance and the PCM may or may not be able to fully compensate. To do it right, the PCM need to be reprogrammed (fuel and advance). The end result should be better fuel economy, better part throttle response, and better WOT power.

Note that the LT-4 has no EGR, due to the LT-4 camshaft having enough overlap to produce intrinsic EGR. This overlap also allows a higher static compression ratio. A very valid buildup for an LT-1 would be to use the LT-4 cam (or the Hot LT-4 cam) and tune the PCM to LT-4 fuel and advance curves.

 

I would get rid of it, since we have no emissions in SC. I just am going to wait until i get a 383 or at least until i put a SR on.

Its not engaged at WOT, so it doesnt affect performance, it just inducts alot of crud into the engine to reduce emissions.

 

corvette4life-I don't have Cats, air pumps, or EGR on my '95LT1. OBD-1 is more forgiving than OBD-2, which GM started using in '96. I have never had any hard failure (service engine soon) light come on. When I hook my diagnostic computer on, I have seen an EGR fail warning, but very rarely.
Dan

 

Dump it. You don't need it. It's activated at higher rpm's or speed. I promise you the sound is flabbergasting once you have removed it or turned it of! :smash: :smash: :cool: The sound of power!!!! :chevy

 

Thanks for your very informative post.
Kerry

 

As stated above, your car's engine was designed for use with this component. And yes, the darn things sometimes do cause problems. Removal, well, there are some issues. A note in the Corvette Chiltons, "To little or no EGR flow allows combustion temperatures to rise, which could result in spark knock (detonation), engine overheating, and/or emission test failure." Then again, what do they know.

A functioning ESC system would correct for any detonation, although in normal driving, you would not know when the system was active. When retarding the timing, we are reducing performance. Any additional heat demands placed on a C4 cooling system is generally a bad idea.

I would like to see some dyno results, engine temp results with and without EGR installation etc. Until I saw some factual data, I would make sure it was clean, held vacuum, and re-install.

 

Well like I said I only ditched mine because it went the way of the rest of my emissions system. When I get my computer reprogrammed for the heads I'll have the EGR disabled, but I haven't had any trouble so far.

 

You're most likely right. However I'm not a daily driver. And the temps seem to be in order. My Corvette dealer said it was of no importance.

Again the pokking sound with a downshift is awesome :yesnod:

Do you have an indication on your temps? My temps on the highway is about 95C when i'm waiting for a trafic kight it is about 105C to 110C, after that the fan kicks in an colls it back to 95C