I don't think this is as cut and dried as you might think.. A restricter in the inlet tract could act as a Venturi which increases the speed of the air flowing into the cylinders at certain operating conditions upto a certain point, after which it will just strangle the engine.

with the tiny restriction thing it will probably have little to no effect at idle, but will cut out too much air at full bore, of course the other potential problem with this is that the engine needs to be under load, when there is no load and the engine is free running there may still be sufficient airflow for it to run with little ill effect, for the results to be accurate the vehicle or engine would need to be run on a rolling road or a load cell to properly simulate the effects of a blocked intake.

basic physics tells use you need a fuel, a source of heat, and oxygen to have combustion, however the engine ecu may be clever enough to read the reduced airflow at the mass airflow meter and compensate the fueling accordingly..

I'd be very interested to see the results of these tests so I will follow this topic with interest.

Hey dude! Forgot to add to the original post. The test engine is fitted to a dynamometer where we apply how much load we want to, along with altering the engines rpm etc all electronically controlled from the test cell and everything is recorded in there and formatted in a spread sheet so I can analyse that.

 

If the engine is strangled, that's exactly what i'm after, as that is what would happen if the inlet is clogged up that much!

 

Just an example to show an egr that's clogged up that much

 

 

 

If the engine doesn't run i'll machine a larger hole, maybe 10mm so doubled of that of the smallest.

Bear in mind pi × r²

So doubling the diameter increases the volumetric flow by a factor of 4.

Edited 25 January, 201412 yr by MicMac

Bear in mind pi × r²

So doubling the diameter increases the volumetric flow by a factor of 4.

Good point there, was going to say that.

 

Also basically what you're doing is turning it into an old tractor engine, in the way that when you want to stop it it doesn't cut the fuel pump like a car but you pull the stopper out and that stops the air from going in, when it's not pulled all the way it splutters and judders.

I'm conducting the test next week!

 

A bit of feedback, I received my dissertation report back today which is worth 25% of the overall grade and I got 88%! I am so so happy

I was wondering how you got on with this.. Let us know the results of the testing.

Engine problems meant that it was pushed back :( It's actually happening tomorrow now.

 

With regards to the limp mode and it throwing up errors etc, we're going to map out the faults so the engine still runs! 

a little tease before I write the results up haha

 

Engine problems meant that it was pushed back :( It's actually happening tomorrow now.

 

With regards to the limp mode and it throwing up errors etc, we're going to map out the faults so the engine still runs! 

 

Did you manage to simulate any of it on Ansys?

I did mate! Managed to get get the pressure contours on all 3 inserts and it showed it really well when displaying it visually! 

Okay little feedback. It was so fun and I really think i'd love to get into proper engine testing as a job. We ended up killing something on the last run though, with the tiny insert in.

 

 

Using the 36mm and 24mm hole inserts didn't provide anything amazing but the last one did, the engine didn't run properly so we opened the hole to 12mm not 5mm as it was simply choking the engine and it wouldn't rev over idle speed.

 

The engine was ran at standard at first then the 3 inserts, one after the other. first at 25% load, then 75% then 100% whilst increasing the rpm of the engine. The results are below and it's given me excellent feedback, look how much its affected the engine torque on the last run with the 12mm hole! Also the THC's went crazy too on the last one..

 

 

 

Benchmark!

 

 

 

36mm Hole

 

 

 

24mm Hole

 

 

 

12mm Hole

 

 

 

 

But yeah, as per facebook, some guy ran into the lab saying ohhh bloody hell theres a **** load of smoke coming out of the chimney haha, turned out it was the test engine and something has gone maybe a piston ring or burnt valve as its lost all power. Turbo is okay though.

i can't see the pictures? must be my browser settings

Are those two huge jumps not just anomalies as they go down further up the rev range?

Did the engine do what the models suggested?

Edited 14 March, 201412 yr by cheezemonkhai

I think it's when the EGR kicks in and out mate.

 

Yep it's pretty much bang on as to what I wanted to see which is good

 

As the inserts got smaller, the flow of air was reduced at the MAF, o2 levels went really far down, THC's went up by a lot which i've been told is essentially unburnt fuel so lots of black smoke out of the exhaust, engine power also decreased overtime that's why when you have a clogged up egr you get low engine power / torque.

 

Strangely enough the flow of fuel went down and didn't go up but maybe when I calculate the BSFC it will show higher fuel consumption.

Thought i'd update this as I got my Uni results back yesterday.

 

Managed to get a first class honours overall for the course, ridiculously happy with that :D

 

My supervisor also emailed to tell me that I got the highest dissertation mark out of everyone in my year (technologists, mech and auto engineers) which is around 120 pupils!!

 

Got 85% overall for the final year project. 

Edited 25 June, 201411 yr by Dann2707

Congratulations.

I think it's when the EGR kicks in and out mate.

 

Yep it's pretty much bang on as to what I wanted to see which is good

 

As the inserts got smaller, the flow of air was reduced at the MAF, o2 levels went really far down, THC's went up by a lot which i've been told is essentially unburnt fuel so lots of black smoke out of the exhaust, engine power also decreased overtime that's why when you have a clogged up egr you get low engine power / torque.

 

Strangely enough the flow of fuel went down and didn't go up but maybe when I calculate the BSFC it will show higher fuel consumption.

Just seen this, but it does make sense. As you cut airflow, the EMS will cut the fuelling, but there will be a minimum fuel level someplace in the map or the software, so eventually you'll reach a point where you're over-fuelling.