egr or not?

D

D347643

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Jan 28, 2003

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portland, OR

Sep 13, 2004

#1

• Sep 13, 2004

• #1

i have the whole trickf low setup and was going to jump to 70mm tb and i was wondering if i would still need egr or would it make it run too hot?

thanks

Drew

 

A

autoXr1

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Sep 13, 2004

#2

• Sep 13, 2004

• #2

It won't make it run hot, but will effect your timing/fuel curves and may throw up a "check engine" light. If you are running a stock computer, I cannot emphasize enough the importance of having the computer recalibrated for your new mods. Yes, the engine will run, and run stronger than it did before, but what you don't know may hurt the engine. The EGR inputs can be removed from the computer with recalibration. The very first dyno pull I did on mine only had 258 rwhp...which totally sucks considering the mods I put into it. The reason was...my stock computer had that engine running nearly 17:1 A/F ratio below 3000 rpm, and then flipped over at around 4000 rpm and went to 11:1 A/F ratio at 5-6000 rpm. My timing and fuel curves were "wacked". End result after proper tuning and recalibration was an additional 115 rwhp and a much broader powerband with Lidio's "conservative" tune.

 

D

D347643

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Jan 28, 2003

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portland, OR

Sep 13, 2004

#3

• Sep 13, 2004

• #3

well i had planned to buy a fast or dfi tuning system and learn how to tune it myself. whatcha think? you said that you will gain power by removing the egr?

thanks

Drew

 

A

autoXr1

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#4

• Sep 13, 2004

• #4

If your vehicle is not subject to emissions testing and you plan on performing computer recalibration, then you may want to remove the EGR and all the related components. A proper tune and recalibration may make the engine run cleaner than it did with the emissions equipment on it, besides, it will make tuning more simple if the EGR system isn't a variable influencing your timing and fuel curves.

The EGR, in my case, wasn't the primary reason for the low power and altered A/F ratio, but it was a variable that needed to be addressed.

 

D

D347643

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Jan 28, 2003

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portland, OR

Sep 13, 2004

#5

• Sep 13, 2004

• #5

wait, so your car can actually run cleaner without egr with a proper tune? if so then why would you have to worry about emissions if you take it off?

Drew

 

A

autoXr1

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#6

• Sep 13, 2004

• #6

Emissions testing often includes a visual inspection in addition to a tailpipe "sniffer" test. If you roll into an inspection station with all your emissions equipment removed, they may "fail" you without even testing it. In some states, it is against the law to remove emissions equipment.

You can plead your case, but it likely won't matter.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Sep 13, 2004

#7

• Sep 13, 2004

• #7

D347643 said:

wait, so your car can actually run cleaner without egr with a proper tune? if so then why would you have to worry about emissions if you take it off?

Drew

Click to expand...

as has been alluded to, the EGR allows spent gasses into the chambers at cruise, thus cooling the chambers and allowing the puter to dial in a ton of timing (since the diluted mixture is less volatile). remove the EGR w/o burning a chip, Tweecer, etc, and the puter will dial in a ton of timing (w/o the diluted mixture) and detonation can occur.

EGR works only at cruise - does not affect idle or WOT performance. ive never seen the real gain from ditching it.

good luck.

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

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Charlotte, NC

Sep 14, 2004

#8

• Sep 14, 2004

• #8

Hissin's right - unless you desire to clean up the engine bay, there is absolutely no benefit to removing the egr system. It helps emissions and fuel mileage when working properly, and is non-functional at wide open throttle - so it doesn't hurt peak performance. And as autoxr1 alluded to, removing it without altering the computer via chip/tweecer can cause part throttle lean detonation issues. If you're gonna remove it, you can 'turn off' the egr functions in the computer with a chip. That's how mine is set up.

 

D

D347643

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Jan 28, 2003

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Sep 14, 2004

#9

• Sep 14, 2004

• #9

nice, thanks guys!

 

M

mooktank

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Jul 7, 2004

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Nov 11, 2004

#10

• Nov 11, 2004

• #10

can you hook the egr up to anywhere in the exhaust tract? Im wondering this becuase i just put a 351w in my truck and on the 302 the egr went to the lower intake. and i guess on the 351w its supposed to go to the intake manifold. well i used my 302 shorty headers which have no mean to connect it to. I removed the smog pump so i think im goin to run the egr to the tube running to the exhaust right before the cats, sound good?

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

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Nov 11, 2004

#11

• Nov 11, 2004

• #11

mooktank said:

can you hook the egr up to anywhere in the exhaust tract? Im wondering this becuase i just put a 351w in my truck and on the 302 the egr went to the lower intake. and i guess on the 351w its supposed to go to the intake manifold. well i used my 302 shorty headers which have no mean to connect it to. I removed the smog pump so i think im goin to run the egr to the tube running to the exhaust right before the cats, sound good?

Click to expand...

the problem i see: EGR gasses are supposed inert. if you source them before the cats, you might have HC's left over which have not been dealt with via the cats. so now this still semi volatile mixture is sent back into the chambers. the puter assumes the mixture will be diluted by inert gasses, not with a mixture which can burn.

i had not thought about it before, but that is my thinking and two cents. good luck.

 

M

mooktank

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Nov 12, 2004

#12

• Nov 12, 2004

• #12

but if it normally goes to the exhaust manifold, whats the difference of moving it "downstream" 2 feet or so? Won't the gases be the same?

 

Michael Yount

Mustang Master

Apr 10, 2002

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Charlotte, NC

Nov 12, 2004

#13

• Nov 12, 2004

• #13

mook - you're confusing egr and air injection - two completely different systems. Hooking your header egr tube to the cats does absolutely nothing except transfer some exhaust gas from the header to a point in the exhaust system a little further downstream. The port on the cat is for AIR injection - provides the cats with additional oxygen from the smog/air pump so further chemical reactions can occur which turn harmful CO, unburned HC and NOx into harmless H2O,CO2 and N2. EGR injects some exhaust gas into the intake where it displaces incoming air/fuel. This cools down the combustion chamber allowing more timing/leaner mixtures to be used without detonation. The result is lower emissions AND better fuel mileage. And as JT said, it's not functional at w.o.t. so removing the egr offers no performance benefit. EGR is one of the few win/win set ups. The only reason to remove it is to reduce clutter in the engine compartment.

AIR PUMP injects air into the exhaust system. EGR (Exhaust Gas Recirculation) injects exhaust into the intake/combustion chamber. Two different systems. Capice?

 

M

mooktank

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Nov 12, 2004

#14

• Nov 12, 2004

• #14

yes i know this. my question is: I dont have air injection anymore since my smog pump is gone. So can i just take the exhaust gases out of that tube to run into the egr? Im going to try it today i think.