It seems to me that the EGR (exhaust gas recirculation) system must be killing some power. Allowing exhaust gases into the intake manifold. It's as simple as plugging the vacuum line to disconnect it (my CE light came on and stayed on for quite a while but has since gone off. Who's got some knowledge of what this will do or not do to the engine and power levels?

subywubynwby

Don't plug off the EGR. Recirculate exhaust gas back to combustion chamber will reduce NOx level, therefore, will lower the temperature. Cleaner emission too.

There's only exhaust recirculation under light load conditions.

shiv

EGR?, wot's that then?? http://www.i-club.com/ubb-files/biggrin.gif

Good idea but bad idea if you get what I mean.

JJ

You can vent the more-air vents on the valve covers... in fact, you should. I just have a short piece of 1/2" tubing on each and a little $2 breather from the auto parts store. You can vent the crankcase outlet as well, although as the other posters indicate this is a more sensitive issue. Notice from the plastic Y in the stock setup that the PCV valve has a direct connection to the intake air. If you vent the crankcase I'd advise reconnecting the PCV to the intake rather than capping it.

It's probably not a big enough difference to notice (power).

.....

[This message has been edited by Hashiriya (edited November 02, 2000).]

Its a real bad idea. In Fact I have 100Lbs of scrap motor in my garage because of a non functional EGR. EGR reduces the thermal load on the engine ALOT uder part throttle cruise, and increases gas milage. When under Full throttle it will NOT function giving you full power.

Computer controled EGRs that exist on modern motors are by far the best and have no impart on power at all. My SHO runs the exact same times with the EGR connected, and disconnected. I would tell you about my Subaru wiht the vacume controlled one, but it overheated on the way to the track. See reference to scrap above.

I'm not exactly sure where the EGR is on the EJ25. Venting the more-air vents and the crankcase doesn't seem to have any effect on temperatures on my RS.

thanks for the info. since its just operating at part throttle, i guess its not going to affect acceleration. it hasen't affected my temperature so i'm not too worried about overheating. i realize that by lowering the temperature it might help prevent detonation; however, if i have no detonation why not plug it. it might provide slightly improved part throttle response. i'll have to check the gas mileage aspect. it's location seems odd to me, it sits on the right side of the intake manifold on the runner leading to the no. 4 cylinder. therefore it's only sending exhaust gases into that one cylinder.

subywubynwby

Note that EGR lowers peak temps in the cylinder, and thus reduces the thermal load on the engine. It also make detonation alot less common. It is not a free lunch as it reduces power when "on". This is not a problem because a vacume actuatioor, or comuter controled valve are great ways to make sure that when you want power it is there.

XT6 Wagon,

I've heard that explanation before about lowering temps in the cylinder but if it is important to lower temps in the cylinder, why does the EGR valve on subaru's sit half way down the intake runner going to one cylinder? It seems that the other three cylinders are not getting any exhaust gases.

No idea...

Whats really strange is that the 88 motor I have is the same way. Now to really warp your mind, the 88 CA vehicles did NOT have EGR. So the 49 state models have EGR, and the CA cars don't, which is the exact opposite of industry practice.

Perhaps we could relocate the EGR to the current site of the PCV? That's much higher up in the manifold.

I can tell you that if you disconnect the EGR hose, your throttle response will smarten up. Oops, that's because you're letting unfiltered air into the engine. http://www.i-club.com/ubb-files/frown.gif

My EGR popped off, and I didn't notice it until the day I was installing my K&N drop-in filter. I reconnected the EGR, and noticed a significant lag in throttle response - with my brand new high performance filter in place!.

Sorry, I guess this is getting a little off topic, but my lesson was that the shorter the intake distance, the better the throttle repsonse.

T-WRX,

If you take off the vaccum hose the egr valve stays closed so no exhaust gas gets into the intake tract. When vaccum is applied the valve is pulled open which unblocks the passage between the exhaust side and the intake side thus allowing exhaust gas to enter the intake runner so with your vaccum line disconnected I don't think you were getting any extra air into the engine.