I think people just make them up, but its possible that there is a JDM blockoff plate, unless a JDM head has no EGR passage.

 

or, is it being said the ebay piece is a beer can part?

 

I will look at JDM EVO engine rooms next EVO meeting here. (Actually most EVOs are JDM here. ) Since EGR is not only for better emission, but also for better cruising fuel economy (only 1~2% though), I wouldn't be too surprised if I see one at non-USDM EVOs.

How cleaner does intake manifold become if EGR is blocked off? I know older Honda Accords had an EGR related problem, exhaust gas passages on intake manifold were completely blocked by carbon deposits and made weird engine rattling noise.

 

I have a IX and I don't have and EGR system. Or at least haven't seen the EGR valve. Is it possible for one 9 to have it and not another? Or am I missing something?

Edit: nevermind, I'm stupid- it's been a long day.

 

A few parts I saw at Ebay were pretty well-made. There were all 1/8'' thick CNC machined aluminum plates, which should be much more robust than the pop or can.

 

I have the ebay egr block off plate on my car. It is the same thickness as other aftermarket block off plates. It holds just fine. When I boost leak test my car, I pressurize the system to about 45 PSI. No leaks at all. Even on race gas the car pulls 35 psi with no problems or leaks.

 

If you don't like Ebay....Buschur sells them to....but at a much higher cost of course.

 

Mitsubishi makes a block off plate. It's 1/8" thick and steel.

I don't recall the part number or what it came off of but I have ordered one from the dealer before and they ahd no trouble getting it.

I don't remember the price either. The aftermarket ones may be cheaper.

 

you can get both, steel and aluminum, off ebay

The one I have is steel

 

Those valves leak even when hooked up properly. Not through the stopper as it would when open, but through the exhaust side of the chamber and out the referense port under the diaghram. Thats why the lower hose becomes brittle over time.

Even if the valve was leaking as you describe it really wouldn't make a huge differense. What might be noticed is transitional knock (from small charge temp spikes) and a greater WOT spark lead requirement because of slower burn with more knock tolerance (CO2). It might also show slightly leaner because whatever bit of remaining recyled O2 isn't metered by airflow sensor the second time around, but the reverse (richer) will actually happen if metered air is leaking out the hose thats off the valve in the first place.

Blocking off the valve altogether will increase throttle response because of an increase in volume accross the TB with no exhaust induction. But MPG will be less.

 

You know, I have read articles on this and either don't understand or don't agree with eliminating EGR getting less MPG.

With EGR, you are displacing some of the air with an inert, already combusted gas. This supposedly helps to reduce combustion temperatures and also slow the burn. This is why we have an EGR timing advance table.

But, when I think about, without EGR, you will be getting more mass airflow, more power, and increased thermal efficiency, requiring less throttle to maintain the same HP. Not only that but we have the ability to tune our timing to our liking. So, in theory, those should cancel out. I don't see how we couldn't get the same MPG without EGR than with.

I think it's because of one major assumption, that may or may not be true: that you can't reach MBT during light loads without EGR. I've read in some papers that mentioned that EGR lowers the combustion temperatures, which in turn lowers the possibly of detonation, which in turn allows increased timing and better gas mileage. Btu you need that increased timing due to the slower burn. The only way mpg would increase would be if you could now add more timing to reach MBT whereas without EGR you couldn't. Under light loads are we really unable to reach MBT without detonation? Maybe that's it, but I don't think so.

Has anyone actually tested MPG with and without EGR, tuning for both?


Eric

 

EGR diaphragm top port is referenced to PORTED VACUUM. Ported vacuum is ONLY present at low throttle angles. If the EGR solenoid is disconnected or off it WILL NOT open, period. There is no seat diameter to speak of like a BOV or WG, its a needle valve.

There is NO reason to remove it or block it off.

Our shop beater has a fully functional EGR system that is solenoid DC% controlled by a 3D table of TPS%, RPM, and a thermocouple on the port exit so I know EXACTLY when it is flowing, and how much.

There is NO reason to remove it or block it off. 0% DC = NO EGR FLOW, EVER.

EGR at cruise reduces pump losses. You slow the pistons down on intake stroke trying to pull 35 kpa vs trying to pull 65 kpa, think negative HP.

 

That makes sense and something I hadn't considered.

Thanks,
Eric

 

w3rd... just bought mine. Thanks.

 

There has to be some seat diameter, otherwise there is no flow through. The fact that its a needle valve doesn't change the fact that exhaust gas pressure will create force on the valve. As ace33joe said, it all depends on whether the load produced by exhaust gases can overcome the spring load. At any rate, the best answer is that you've documented that you've never seen it open, presumably under very high boost conditions.

Definitely true about EGR reducing pumping losses, but I don't think it does much on the Evo. I definitely don't see a change of 35 kpa between having it enabled and disabled when cruising.

One other interesting tidbit is that Mitsubishi does not have an EGR system on the Evo 10.