1MAX2NV

iTrader: (5)

First, it's bad for the environment so it's not a good idea. The EGR system recirculate unburned nasty gas back into the intake manifold. Now, we got that outta the way. Let's get down to why it will make my car faster =) I know 3000GT VR-4TT and Supra TT people do this to prevent hot gases recirculate back into the intake. This also prevents those gunk from building up in the intake manifold. Do to this you need to build a plate to cover the hole where the EGR valve attachs to. The plate usually made out of sheet metal with thickness of a gasket. This will go in place of the EGR valve gasket. They also use a resistor to trick the ECU thinking the EGR system is working properly. Now, is this worthy the trouble? How much hot air does the exhaust really recirculate back to the intake manifold?

MardiGrasMax

iTrader: (14)

Test pipe, EGR Mod... have you hugged a tree latley? LMFAO

I was thinking about this also Tony. Anyone out their got a clue?

sx7r

iTrader: (15)

well, since you have to reset the ecu every now and then because of the test pipe, then i wouldn't even worry about tricking the ecu. just take it off, plug the hole, and reset ecu every now and then.

1MAX2NV

iTrader: (5)

One thing about my 1999 is that there's no O2 sensor after the cat or at the cat. The ECU has no clue I have a test pipe =)

sx7r

iTrader: (15)

no fair, i have a 99 and i've got an O2 sensor after my hollow cat.

Maximamike

For the trouble and costs it not worth it. You're forgetting a catch can to catch all that "nasty intake manifold stuff".

got rice?

iTrader: (2)

you'll need to richen the mixture from 1000 rpm to about 3000 rpm, which is the rpm range that the EGR is functional.

everyone thinks that recirculating burnt exhaust gas back into the combustion chamber is such a terrible thing - it's not. The burnt exhaust gas is inert, so by taking up space within the combustion chamber, it prevents a full usage of the space within. This space <I>could've</I> been filled with fresh intake charge. Since the gas is inert and fills up the space within, it keeps the combustion chamber's temperature lower. Lower temperatures result in two things: 1) lower oxides of nitrogen 2) less chances of detonation.

Detonation occurs when the cylinder pressures and temperatures are high. Since the EGR recirculates the burnt exhaust gas through and keeps the temps down, it lowers the detonation threshold. So why is it important to richen the a/f mixture? When the EGR is removed, the cylinder temps increase, increasing the detonation possibilities for two reasons: 1) detonation is most likely to occur where large amounts of torque is made in XXX rpm range 2) detonation occurs when the temps are high (as stated above). The Maxima engine makes a lot of torque in the 2000-3000 rpm range, so by removing the EGR system you're shooting yourself in the foot.

in summary, it's not worth it. the EGR is not active at wide open throttle or above 3000ish rpm. You will not find a performance gain by doing so.

MardiGrasMax

iTrader: (14)

You da man!

Thanks Phuong!

1MAX2NV

iTrader: (5)

You just cap off the hose.

1MAX2NV

iTrader: (5)

The EGR valve is close during these conditions.

Engine Stopped
Engine Starting
Engine Idling
Low Engine Coolant tempature
Excessively high engine coolant temp.
Wide open throttle
Low battery voltage

I guess it not worth messing with it.

Stillnmax

thats weird .. i dont think i have O2 sensors after my cat either... weird... when i went under to check the exhaust i saw nothing... is there anything built into the cat??

1MAX2NV

iTrader: (5)

You have a cali-spec 1999 then. The fed. spec 1999 has a O2 sensor on the extension pipe right after the cat.

[Edited by 1MAX2NV on 01-16-2001 at 09:05 PM]

Maxima97GLE

1MAX2NV... did you see that EGR section in the latest Turbo magazine? http://www.gr8ride.com

I30CeFiRo

I saw that article but it wasn't too clear on what to do

Maxima97GLE

It talked agout disconnecting the EGR for extra HP... but only like 1 or 2. Im going to do the spark plug change it had in the article... it said that changing the spark plug after 40k miles will free up like 8.8HP... I haven't changed the plugs since I got the car last May so I think I will feel a difference.

Eric L.

Um, it is highly unlikely you will notice any difference by changing your spark plugs after just half a year. The stock NGK Platinums are good for 60k miles. In fact, after 45k I replaced my stock plugs with new NGK platinums, and the original NGK's still looked like they will last another 45k (they were very clean). So, changing your plugs may free up like 0.8hp, but even that is highly unlikely. But 8.8hp? Nearly impossible! I guess if you have worn down plugs which have been in there for 100k miles, then maybe changing them will yield a noticeable performance increase.



[Edited by Eric L. on 01-17-2001 at 12:28 PM]

Enduro

Phuong you said that the exhaust gas being recirculated back is inert...is this because the place where it gets circulated to is after the point where fuel and air get mixed up?

got rice?

iTrader: (2)

no, the exhaust gas is circulated into the manifold then the combustion chamber as the incoming air mixes with the recirculated gas, then goes into the combustion chamber (which is where the new air/fuel get mixed and the spark causes the explosion, then the explosion moves the piston, then the piston moves the crank, etc)

Maxima97GLE

my plugs were never changed... i put 20k miles on my max in 6th months and i have been running it hard so i think i'll feel a difference

JimW

NOt worth the trouble. The recirculated exhaust gases help keep combustion temps under control as well, and can help preven knocking.

got rice?

iTrader: (2)

hehe. all that sounds just like my posts