I didn't notice any change in gas milage. I've always been getting 21-23mpg overall which is good for a 280Z or ZX. I've heard of people getting worse.
On long trips my highway milage is much higher. 27-29mpg.

Drew, if your car is a non-turbo then I can understand. You'll have no chance at beating a stock WRX. (neither will I) Good job at beating him off the line... that's usually where those AWD cars do well, even with a 4-cyl.

As soon as my ZXT is out of the bodyshop, I'll get that win back for you guys... ;)

Update...
 

I finally got the EGR thing all figured out this past weekend. I blocked the exhaust and intake ports by welding up the metal block thing (if that makes sense). Anyway, I have noticed a pretty significant difference. The car seems to rev a lot smoother, especially in the higher RPMs. It also seems like it revs faster and I can rev it just a little higher then I used too. Which brings up a question...

The max horse power and torque are supposed to be at 6500 rpm, right? Well with my car it seems like after about 5300 rpm the engine loses power and just makes a lot of noise. Is there a reason for this? At what RPM do you guys usually shift when you are really reving it out?

[QUOTE=The max horse power and torque are supposed to be at 6500 rpm, right? Well with my car it seems like after about 5300 rpm the engine loses power and just makes a lot of noise. Is there a reason for this? At what RPM do you guys usually shift when you are really reving it out?[/QUOTE]
on my z it feels like power tops out around 6200 or so.

Woah there!
6500 is redline! Don't go there. The stock cam maxes out horsepower at 5200 rpm, so you're just killing your engine after that. I shift at 5200-5300.

If you have ported intake, cam, or higher compression (or all three, but mainly the cam) then your peak power point will increase upwards towards redline. Never go past 6400. That's just my suggestion.

Apollo, you're probably starting to get some valve float at 6200 rpm. you guys are not going EZ on the Z engine!

valve float? . . . . .educate me

I just got a pacesetter header for my 80' 280zx off ebay, it has one threaded hole that looks like its for the EGR pipe. My question is where (on a header) do you put the exhaust gas sensor? Can i put it in the threaded hole, and just plug the intake pipe of the EGR like you guys have done, or is there another way to hook up the exhaust gas sensor?

thanks,

I never rev it over 5300rpm anymore. I only tried reving it over 6000rpm once and it sounded like it was about to exploded so I stopped.

Valve Float: A condition where the valves in the engine are forced back open before they have had a chance to seat. Brought about (usually) by extremely high rpm. The valve lifters lose contact with the cam lobes because the valve springs are not strong enough to overcome the momentum of the various valvetrain components. The onset of valve float prevents higher-rpm operation. Extended periods of valve float will damage the valvetrain. Also called valve bounce.

Tighter springs and/or light weight valves help prevent valve float. Tighter springs also increase wear on your rocker arms and cam lobes due to more pressure against them by the springs. Cams, rockers, and valves would need to be replaced more often as the valve seats are slammed hard into place at all rpms. The valve seats themselves might also need replacing more often.

The EGR valve (Exhaust Gas Recirculation). is there for more than just cleaner emmisions. It brings raw, unburnt fuel back into the combustion chamber to mix with new fuel and new air. By doing this, several things result.

1. Less initial gas is used in the firing process.
2. Less raw emmisions reach the tail pipe.
3. Lower combustion chamber temp (much lower)
4. allows both more fuel AND air into to the combustion chamber because a cooler chamber means higher density is acheived.

Without the EGR functioning, you are running way too lean. it is very possible over time to burn a hole in the top of your pistons. If you want to run without the EGR, you need more fuel coming in to compensate... I.E... Bigger injectors, bigger fuel pump, Bigger fuel pressure regulator. Just because a part is emmisions related doesn't automatically condemn it to the "useless" pile or makes it a burden on performance. Car's without EGR's from the factory had altogether different set ups from the start, so it's not an issue.

If you plug the EGR tube and drive the car you won't notice any power increase, but you will notice a 10-15 degree difference in operating temperature at constant speeds, you will also notice that the temperature rises big time under heavy loads or hard acceleration.

Always know the upside and the downside before making a modification to your car for the sake of "improved performance".

Rod.

For anyone who has removed that pipe to the EGR off the exhaust... I need that pipe! mine broke! I'll pay for one if it's out there and has both fittings attached.

Rod.