PFF - Pennock's Fiero Forum, PDA Edition

3800 sc removing egr or keeping it ??? (Page 2/2)

Dennis LaGrua

NOV 27, 12:48 PM

If you have ever seen the intake manifold of an engine with an EGR valve? It's full of carbon sludge that is one of the hardest substances known. If you are concerned about higher combustion temperatures you can just add an intercooler.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

DimeMachine

NOV 27, 11:27 PM

quote

Originally posted by Dennis LaGrua:

If you have ever seen the intake manifold of an engine with an EGR valve? It's full of carbon sludge that is one of the hardest substances known. If you are concerned about higher combustion temperatures you can just add an intercooler.

I am not concerned about high part throttle combustion temps.

I do like the idea of better fuel efficiency on long road trips. I need to try to find some factual data on what the MPH gain is for a 3800 SC in something light like the Fiero. I am inclined to believe Ryan is correct - very very little...

Speaking of Darth Fiero - I have not seen him on here in a while. Anyone heard from him recently?

Anyone have a number based on some testing or other facts?

[This message has been edited by DimeMachine (edited 11-27-2020).]

DimeMachine

NOV 28, 10:35 AM

This article suggests keeping it and describes why for a reason that makes a ton of sense to me.

Thoughts?

http://www.tuneruniversity....ts-saving-you-money/

pmbrunelle

NOV 28, 12:36 PM

James Watt invented the indicator diagram to help visualize/understand the work performed on a piston over the cycle:
https://en.wikipedia.org/wiki/Indicator_diagram

Old tech.

Cylinder pressure (vertical) is plotted as a function of cylinder volume (volume changes as the piston goes up and down).

To impart useful work on the crankshaft, we desire high cylinder pressure as the volume is increasing (piston going down), and low cylinder pressure as the volume is decreasing (piston going up).

To evaluate the total work, we measure the area enclosed by the indicator diagram. If the indicator diagram is drawn on grid paper, you can count the squares... This is straightforward with a 2-stroke steam cycle (as can be seen in the wikipedia article).

With the 4-stroke Otto cycle, there are two up-down cycles, hence there are two loops:
http://4mechtech.blogspot.c...iagram-actual_9.html

The power loop is counted as positive work, while the pumping loop is counted as negative work.

So what the article is saying, is that during the intake stroke, the cylinder pressure can be higher with EGR, reducing negative work in the pumping loop.

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For my Fiero project, I don't like circulating dirt through my intake, nor the engine bay clutter, not to mention that it's yet another output to have to tune (more complexity) on the computer.

[This message has been edited by pmbrunelle (edited 11-28-2020).]

Dennis LaGrua

NOV 28, 01:01 PM

quote

Originally posted by DimeMachine:

Speaking of Darth Fiero - I have not seen him on here in a while. Anyone heard from him recently?

Anyone have a number based on some testing or other facts?

I haven't seen or heard from him since he ripped me off on a trade deal. I delivered product and he delivered nothing in return. My messages were ignored. If you want the full story PM me. The guy is a thief.