EGR system with turbo yes or no?

Big P · Post by **Big P** » Mon Feb 07, 2005 3:02 am

Well, I'm trying to think if it would be a good idea to have a working EGR system for when I put the turbo on the T22SED. I mean, the turbo is going to create a lot of heat and combustion pressure. The EGR is supposed to allow some of the exhaust gases to reenter the combustion chamber to be burned. This leads to lower combustion chamber pressures/temperature as well as controlling NOx(Oxides of nitrogen) I'm not sure if a properly working EGR system will provide any type of power increase or system stability on a turbo engine. As far as I can see the only benefit is keeping the formation of NOx to a minimum. Not to mention the loaction of the EGR components. Most, if not all EGR systems have some way of routing the exhaust gas back into the intake tract to be reburned. If, when under boost, there is high pressure in the intake tract that might prohibit the movement of said exhaust gases to flow back into the intake. I am fully aware that the EGR valve pintle is usually unseating and flowing gases at part throttle only. At idle or WOT there is no flow through the EGR valve. Any thoughs/opinions???

MMamdouh · Post by **MMamdouh** » Mon Feb 07, 2005 11:04 pm

as far as i understand the EGR mechanism... it wont work with the boost created by the turbo.

you see, when the EGR is triggered; it uses the vacuum in the intake to move the diaphragm of the EGR valve and thus opening the way for the exhaust to go into the intake... more like the old advacing mechanisms in the conventional distributor ignition system.

with a turbo and under the conditions where the EGR should work, you won't have vacuum in the intake... you will have boost so the EGR valve will not be able to function as it should and it will keep the path of the exhaust closed.

MMamdouh

BosnianLanos · Post by **BosnianLanos** » Mon Feb 07, 2005 11:19 pm

I had my EGR valve completely blocked up buy carbon buildup from the valve cover. That means no exhaust gas was coming in. I found the problem when I was porting my intake manifold. I cleaned the tube and the car ran exactly the same as before, which was fine.

I don't even understand why it is necessary if blocked or unblocked made no difference. I'm going to make a bracket to block off the exhaust gas anyway though.

Basically, while, for all intents and purposes, I know jack about turbos, I do know that EGR on my car anyway, made zero difference.

MMamdouh · Post by **MMamdouh** » Mon Feb 07, 2005 11:48 pm

that happens because the EGR doesn't work that often so people seldomly realize it works... usually people will give feedback as "car stopped accelerating at 4800 rpm" or "the engine seemed to die at 5100 rpm and refuse to go higher"... this is the EGR messing the engine's performance, some people think the car got a speed governer or they have hit the rev limiter when this happens.

MMamdouh

BosnianLanos · Post by **BosnianLanos** » Tue Feb 08, 2005 2:16 am

Never happened to me.

I floor it, the engines RPMs get higher, and the transmission goes into a lower gear for torque. I'm sure I was in 5000-6000 RPM (no tach, but it was loud). I have never felt my car stop accelerating in any way. This is Florida where the ambient air temp reaches 100 F with 100% humidity and my car never cut out. Same in my dad's Civic. 6500 RPM in 88 F weather. Ran smooth and quick.

Post by **PrecisionBoost** » Tue Feb 08, 2005 2:27 am

Do you have emissions testing in Florida??

If no then block it off.

If yes... well your probably screwed anyways.... so block it off

BosnianLanos · Post by **BosnianLanos** » Tue Feb 08, 2005 10:33 pm

LoL.

If there is one good thing that Jeb Bush did is take away emissions tests.

But I doubt EGR is my problem, I have a Daewoo with 185,000 miles on the stock engine and transmission. I'm burning so much oil I'm like a rolling nuclear meltdown.

EGR is the least of my problems, but if blocking it off will make me go 100% illegal, then by golly, I'm doing it!