As far as I know you need them all and I can't see how you would get any performance gains by removing them.

You could remove the lines from your AAR and junk it but then you would lose out on easy cold start starting.

 

you can plug the EGR line with a BB and get some power. The EGR dumps excess gas, so plugging it would maintain some back pressure if you were to be drag racing. Anyway ive talked to mechanics about it who say they used to do that to their cars and it doesnt work. Also might cause some probs down the road with running rich etc.

 

These cars are extremely dependent on three things: good vacuum, good electrical connections and a good supply of clean fuel. In my book, 90% of problems with stock engines can be attibuted to simple problems in one of these three systems. (Yet people will spend hundreds of dollars on replacing expensive components rather than take a half-hour to clean connectors and check their vacuum). So, long story short, keep all your vaccum lines, and keep them tight. Even your heater depends on them.

Unless you do the real old-school hot rod trick of swapping the L-6 for a SBC.

If you're a newbie, here's a quickie trick for testing your vacuum system: with the engine warm and idling, unscrew the oil filler cap. If the engine stumbles and dies (large vacuum leak), your vacuum system is tight. If only a small difference or none at all, major vaccuum leak.

 

"you can plug the EGR line with a BB and get some power. The EGR dumps excess gas, so plugging it would maintain some back pressure if you were to be drag racing"

... EGR stands for Exhaust Gas Recirculation. From what I know the EGR valve recirculates exhaust gases back into the intake manifold if there is an excess of uncombusted fuel in the exhaust... this would be detected by an O2 sensor. It's mainly for fuel economy and emssions. Eliminating the EGR valve would waste fuel if your mixture is too rich. It also helps cool the combustion chamber/cylinders. I don't think it has much of an effect on power either way.

I'm a 3rd year apprentice and without looking it up, thats what I know. I wouldn't eliminate and EGR valve from my car without some documentation of the benifits.

 

EGR is ONLY to control NOX emmisions, hurts MPG and part throttle power. It's not connected to the O2 sensor or the computer and isn't for controlling the mixture. At WOT it's doing absolutely nothing so unplugging it does the same, absolutely nothing at WOT.

 

I'm pretty sure the EGR is controlled solely by intake manifold vacuum (at least on cars as old as ours). The valve is set up to open only at mid-throttle settings and it lets exhaust flow into the intake manifold. Its job is to dilute the air/fuel mix going into the cylinders (exhaust is inert - it doesn't have much free oxygen or unburned fuel) and serves to lower combustion temps a bit and so reduce formation of evil oxides-of-nitrogen (NOx).

Since it displaces air/fuel mix, your engine burns less gas per power-cycle, and makes proportionally less power - but that isn't necessarily bad - its a little like reducing the displacement of your engine during cruise conditions which can improve gas mileage a bit. At full throttle intake manifold vacuum drops and closes the EGR and you should get full power (although the EGR does heat the intake manifold which does hurt cylinder filling and robs a bit of power).

Interestingly enough, cooling the combustion at part throttle serves to reduce detonation, so you should be able to run a higer CR and more ignition advance with an EGR. Makes me wonder how high you could push the CR for a pumpgas engine using an EGR - anyone ever try it?

Don Schmitz

 

EGR: dumping crap back into your finely tuned mixture.

 

"From what I know ... this would be detected by an O2 sensor."


a- the 79280zx does NO HAVE an 02 sensor.
b- do not remove the "vacuum lines" since it will gain no power and probably run like crap.
c- read up on the car and the efi system and learn that you need all those lines to help it drive well.

 

...if you dont know how it works leave it alone (that's "old school").
the egr will help your car run better when its cold and does nothing (shouldnt) when @ operating temp....i think its controlled by the vcm....????? i dont know much about the N/As (or anything else i guess).
but i dont think eliminating any hoses or components (or reconfiguring them) will help your power much.... it'll just make it hard to work on when you read the fsm and try to fix something.....
..i'd say people screwing w/the vac lines have disabled or sent as many zcars to the crusher as rust....well maybe not rust....you do find a lot of folks write in for help who are freezing their a$$e$ off 'cause they (or someone) messed w/the hoses .2¢ .....s



Post Edited (Mar 18, 4:43pm)