What emissions equipment is on my 76 electra 455? I would like to get rid of as much as I can because right now the car is really slow and I don't need emissions testing. How much power do they rob?
Emissions equipment can vary. From what I've seen, the motors will have either EGR, or an A.I.R. pump, but not both. I have a '76 Buick 455 from a '76 Electra in my '85 C20 pickup. My engine has the EGR system. When working properly, neither of these systems will rob much power. Your biggest restriction will be the pellet-type catalytic converter. If you need cats where you live, I would recommend pulling the stock one and putting a high-flow, monolithic style converter in its place. If you don't need a cat, then you can remove it altogether. If your engine is equipped with EGR, and it is working properly, I would not recommend removing it. It has no effect on wide-open throttle operation, as EGR only works at part-throttle. If you do decide to remove it, be sure to unhook your vacuum advance as well. EGR acts as a detonation suppresor, as well as reducing NOx emissions, so vehicles equipped with EGR have much more agressive vacuum advance curves. If you disable EGR and keep your vacuum advance connected, you could easily experience engine-damaging detonation. Your best bet, if you decide to remove EGR, is to re-curve your distributor at the same time. If your engine is equipped with AIR, a benefit will only be noticed if there was something wrong with the pump to begin with, causing lots of extra drag on the motor. When operating properly, the pump uses very little power to turn, and it simply pumps fresh air into the exhaust stream to help decrease HC emissions. A system that can cause a major performance drop if not working properly is EFE (early fuel evaporation). There is a flapper valve in the passenger side exhaust manifold, which closes when the motor is cold, to force the exhaust from that side of the motor to travel through the crossover passage beneath the intake manifold. This aids cold starting and drivability, but if the valve stays closed once the motor is warm, it creates a major restriction, which can really hurt power. This system can malfunction from the flapper valve becoming seized, the vacuum servo motor failing, or from a bad TVS (thermal vacuum switch) on the intake manifold, causing vacuum to be applied to the vacuum motor even when the motor is warmed up. For performance gains on this engine where emissions are not a concern, I would recommend dual exhaust, headers (if you can find ones that fit this application), a better flowing intake, and recurving the distributor. If you have more $ to spend, going to a set of earlier heads ('70-'74) and a performance oriented camshaft will be even more improvement. Good luck!
