Kagnus

On a L98 89' is it possible to remove all the BS EGR crap and run it like a modern vehicle with dual cats etc... and still pass emissions?

If a stock L98 motor won't pass what changes need to be made in order for this to work? I mean I could drop in an LS motor and run dual cats and not have to worry about anything. I'm curious as to why an L98 is dirtier than an LS generation motor.

jv9999

A well tuned TPI will usually pass without EGR or even cats. That said, the EGR only helps you. Removing it only makes it more prone to detonation.

gerardvg

Hi i have my EGR disconnected, i have removed the check EGR from the chip so i do not get EGR codes.
The 85 can ping quite a bit even with the EGR operational, i have had my 85 for 16 years and the EGR was connected for half the time.

The compression ratio is too low to have problems with pinging
/detonation in a standard engine. The ecm will retard the ignition if knocks are detected, when some poor quality fuel is used and the ecm will adapt.

With my supercharged intercooled setup i do not run the EGR the PCV is blocked also. I DO NOT have detonation problems running 8 psi boost so you will be fine. When i removed the engine after six years of being supercharged with egr removed for a new 383 engine, the old 350 pistons /rings and ring landings were in great shape.
Note they are TRW Forged pistons standard in the 85 corvettes.

Forget about the doomsayers it may have changed the emissions a bit but the engine will not harm the 350 engine.

65Z01

EGR only comes into play after some steady speed driving with coolant temp >175 deg F.
I think the dual hi-flow cats is great as it allows true duals like used with the LT1 engine.

hooked073

The egr helps does not take aything away from engine as far as power. I would let it be.

corvetteronw

I bought the removal kit from Corvettemods1 and installed it last year. I left the egr valve in place along with the line to my new high flow cat in case the next owner wants to use it in the future. I removed the air pump and the diverter valve along with their brackets. I also removed and blocked of the exhaust pipe from the header to the intake manifold.
Wow - really cleans up the engine compartment and gives you a lot of extra room.
No smog inspection in my state.

WW7

When I installed my 383 motor 3 years ago, I removed all emissions equiptment from the engine..To make sure I didn't get ping/knocking I installed a Dewitt's radiator, high speed fan, 180 degree stat, and had the on/off on my fan changed to 196 degrees on/ 180 degrees off in the chip. Having a running temperture of around 180 degrees took care of any problems I could of had from the motor running at a higher temperture....The higher running tempertures of our stock cars was what caused the excessive ping/knock counts when the egr was removed..When you lower the engine temperture back to what it was in the old days when they had a carburetor, the problem goes away...WW
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MrWillys

Turning off the switch is really not enough. I reset the manifold air temp from -17.5C to 150C in the constants so it's not called for, and expects to see a result. I also zero out EGR duty cycle tables as an added precaution. At this point it is then removed and does not factor in its values.