more power

[mighty trooper]

hey im new to this just bought a 2.8 manual mu and starting to tweak it up already lol i only got it yesterday i have disconected vacum lines from what i think is a form of egr and found a vacum operated butterfly between turbo and inlet can i disconect this with out any problems or is this to stop any sharp peaks in the boos affect the engine any hepl would be great as i dont wanna blow it up

[dasnoboarder]

Hey danz20.

I have a on topic question that might add to the thread, could someone add the details of what this group of components are for, and if any can be removed? It has vaccum lines and electrical wires to it.



Andy

[geeves]

Andy That is the EGR. It is common practice to remove it and seal the holes in the inlet manifold and the exhaust line that comes from the other side of the engine. This causes no damage to the engine and may improve performance. Some diesel mechanics even go as far as saying egr is bad for a diesel and should never of been fitted. At the moment it is not illegal to remove them but it might be a good idea to keep the bits just in case the greenies get more power at the next election

[dasnoboarder]

geeves said:

Andy That is the EGR. It is common practice to remove it and seal the holes in the inlet manifold and the exhaust line that comes from the other side of the engine. This causes no damage to the engine and may improve performance. Some diesel mechanics even go as far as saying egr is bad for a diesel and should never of been fitted. At the moment it is not illegal to remove them but it might be a good idea to keep the bits just in case the greenies get more power at the next election

O ok, so when people say they removed the EGR, this line & wire section, you can just rip out? As well as sealing the holes in the manifolds. This won't interfere with the brake booster's vaccum needs?

[geeves]

Brake booster is fed from the vacume pump on the alternator. Diesels dont produce enough vacume in the manifold to run the brakes.

[cooledmu]

what about all the little lines in the same place but on the other side of the engine bay. What do they do? Look like they run into some sort of sensor or something

[MattMU]

If you are going to remove those VSV (vacuum switching valves) you will disable the EGR and also the QWS which is the flap in the exhaust pipe that quick heats the engine in very cold climates.

If you are going to do it the for christ sake do it properly.
There is a vacuum feed off the alternator...large is the brakes and the little one is the feed to the VSVs. The little on MUST be blocked off.

Remove all the small hoses from the engine, remove the EGR and seal manifold and remove the cross-over pipe and cut and weld up a blank to seal the exhaust manifold.
Then run one hose from the back of the intake pipe (boost) to the top of the pufflimiter on the FIP (fuel Injection Pump). If you dont do this you will never get full fuel and the engine will be a slug.

If there is nothing wrong with your system then leave it alone. There is no reason to remove unless the EGRs are blocked or stuck..these will severely reduce power and you will know it instantly. If not...leave them alone and you will reduce the running temp of your vehicle and also reduce the amount of emissions the vehicle produces.

All new Isuzus have these fitted and it IS an emission requirement to have them installed.

Matt.

[nemesis]

Isnt it possible to disable EGR simply by plugging the two hoses to the VSV's?
This will leave all other functions operating and simply prevent exhause recirculation...

[geeves]

I believe that can be done but sometimes these valves leak resulting in big power loss

[nemesis]

Well just finished a test of the alleged economy and power gains and gotta admit this puts the EGR myth in the BUSTED category. I run a consistent mileage each week, ran alternating weeks with EGR connected and disconnected and found:
57 L diesel, 575km, EGR on
65 L diesel, 575km, EGR off
58 L diesel, 575km, EGR on
63 L diesel, 575km, EGR on

ie 10.0km/L EGR on vs 8.82km/L EGR off

Not having access to a dyno quick drags against a friends Mu was the best power comparison we could come up with and from standing to 100kmh there was no appreciable difference, even after swapping drivers, swapping which cars EGR was disconnected etc


Looking through the forum Im not the first to discover this yet the myth persists!
(and OK maybe the VSVs might leak eventually, so might your manifold...going to weld it to the head in case?)

[geeves]

First part is interesting. My wagon had the EGR removed before I bought it so cant compare with and without but on a trip I get about 11.5km/L .
The second part is not surprising as the EGR is disabled at full throttle by design

[cooledmu]

well i have had 2 mu's a 2.8 and 3.1, both of which had noticable power gain after removing the egr system, and like on my 3.1 if you want to run a topmount intercooler its best to remove it anyway

[Jimmu]

Nemesis: Many EGRs are blocked and not functioning properly by the time we have modded them. As such there would not be any difference after they are removed.

Removing them makes more power in theory and many have noticed so in practice

Jimmy

[bluemoo]

my 2.8 had the vacume line blocked when i bought it. but when i removed the valves and piping and blocked it off with 5mm flat bar, i notice that there was less lag ( especially changing from 2nd to 3rd to early) good and easy mod to do. took me an hour to do it, that includes making the plates up.

[geeves]

Is anyone else in a position to try this in as scientific a manner as Nemisis. He has documented his results so well they are hard to argue with. I believe he has a 3.1 so a 2.8 would be the ideal test vehicle. If the results are the same we should discourage the removal of properly functioning EGRs.
If not the discussion can continue.
I cant do this as my EGR was removed before I got the vehicle

on a side note this is copyed from wikopedia
EGR in diesel engines

In modern diesel engines, the EGR gas is cooled through a heat exchanger to allow the introduction of a greater mass of recirculated gas. Unlike SI engines, diesels are not limited by the need for a contiguous flamefront; furthermore, since diesels always operate with excess air, they benefit from EGR rates as high as 50% (at idle, where there is otherwise a very large amount of excess air) in controlling NOx emissions.

Since diesel engines are unthrottled, EGR does not lower throttling losses in the way that it does for SI engines (see above). However, exhaust gas (largely carbon dioxide and water vapor) has a higher specific heat than air, and so it still serves to lower peak combustion temperatures; this aids the diesel engine's efficiency by reduced heat rejection and dissociation. There are trade offs however. Adding EGR to a diesel reduces the specific heat ratio of the combustion gases in the power stroke. This reduces the amount of power that can be extracted by the piston. EGR also tends to reduce the amount of fuel burned in the power stroke. This is evident by the increase in particulate emissions that corresponds to an increase in EGR. Particulate matter (mainly carbon) that is not burned in the power stroke is wasted energy. Stricter regulations on particulate matter(PM) call for further emission controls to be introduced to compensate for the PM emissions introduced by EGR. The most common is particulate filters in the exhaust system that result in reduce fuel efficiency. Since EGR increases the amount of PM that must be dealt with and reduces the exhaust gas temperatures and available oxygen these filters need to function properly to burn off soot, automakers have had to consider injecting fuel and air directly into the exhaust system to keep these filters from plugging up.

interesting because particulate is the current fashonable pollutant of todays anti diesel brigade.

[dasnoboarder]

Hey, sorry to ressurect an old thread, but have a quick question...

In the middle of intercooler install and also want to remove all the vacuum lines/valves from the rear right of my engine (2.8td MU).

Have removed the warm-up dash switch, exhaust valve, intake over-boost valve.

I thought the only line I needed was the boost line to the top of the fuel pump.

But there's two I'm not sure about.
One is a line attatched to the bottom of fuel filter (on the bottom of the water valve?), and the other is the back of the fuel pump (maybe the injection advancing when you push the dash switch?).

[drift]

The main reason Ive blanked off my EGR is when you look at the inlet the amount of carbon that had built up over the years was frightening, so my thinking was this stuff is being recirculated back into the engine, and that cant be good.
It the UK we are not tested for the particular emission the EGR is designed to eliminate
I find the motor a slight more free reving.

[geeves]

The line on the fuel filter should be clear pvc and not connect to anything else. Its just so when you drain the filter it doesnt run all over the hot engine. Just makes a puddle on your feet instead.
Anything conected to the fuel pump I would leave alone