Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) result of air intake "research" Sigma 4/4

To make it short, (haha after writing added) it was more about a longer perioud of try and error than a genuine research. But during the process the tasks could be narrowed by growing experiences. THB the hole project was more about the fun for it and sometimes I felt like reinventing the steam engine because the professiolas have all the knowledge since generations of men.

On the other hand despite of all the general existing knowledge this project shows how important a fine tuning can be with regards to a specific case.

I think I happily reached a solution which addresses my needs, which are:

- give the sport manifold the condition to achieve more efficacy
- avoid to sacrify low rev torque, but try to enhance it
- achieve an as good as possible seamless and wide revband with focus on road drive rev priority
- keep the performance better if the engine has warmed, due to the relocated maf sensor.
- keep the loudness down, because this car should remain a sporty cruiser - my aim was not to transform her into a race car which is high rev focused and screaming (even if this engine is also a good base for such an aim).
- give a more subtle and quicker response of throttle behave
- as a side effect, the mpg seems to be better (I can really say after 500 km driving with the system)

So all in all the result is not a principal change of character but a more refined interpretation of her given behave.

I notice that now I have two different ways to drive her, which was not so obvious - in terms of two "programs" before. One way is that now I can move and cruise quickly without needing more revs than 3000 at any gear. The best is that it works by using very low throttle way, much less than with the standard intake in combination with my newer sport manifold.
Yes, I felt that the throttle response with the newer sport manifold combined with standard intake was worse than the standard solution on both sides, in and out.

The second way to drive her:
if I want she pulls really strong up to 6.000 rpm, she gets 160 km/h uneffortly quick (beeing compared with standard 4/4 not with any Ferrari) in forth, she can cruise in 5th at 150 to 160 km//h also on uphill highways without the need to gear down. And on a flat piece of highway the reaches 185 km/h satelite measured, and on cold days even more. This is only driven for testing, I usually drive her at 120 km/h on a highway with a lot of caretaking love, and will have the fun on B-road sections.

I learned that the most important objective is - beside to find a good working length and diamter of tube, that you try to avoid any edge.
I must really admit that the standard 4/4 intake system also is very good on this demand, with the exception of the first rubber hose between the filterbox and the steel tube. All this rubber hoses which are built like an accordion are only a working compromise.

My first trials using straight alloy tubes which were linked together with curved silicon hoses were ok but not subtle.
I was dissapointed by the way how only certain smaller regions of the revband were enhanced. This is an unhappy solution because you get used to the "good" rev band spots and this points out the "weak" sections even more.

To let the engine breath a bit more but to keep the speed of airflow (plus to keep the resonance effect) I landed with 60mm diameter tubes, 1,5 mm strong. The total lentgh of the system is comparable to the standard, just a tad shorter. In fact the diameter of 60mm is equal to the airbox output diameter and it is also the same diameter behind the throttle body at the intake manifold (I know that because I removed the TB for some work to do on it you will see in the pics).

The standard intake metal tub is 57mm outer diameter, so I added 3mm of usable diameter which seems not much but is a significant difference. If you take a wider diamter the speed of air could be slowed too much.

To make a seemless and edgeless link to the TB intake side, which is 57mm outer diameter as well as the standard tube, my shop formed a nice pice of tube with a transition from 60mm to 57 mm at the TB intake.




My shop also refined the TB intake section to meet the new tube in a good and free of edge way.
(I choosed the same guy who made my manifold, he normally only makes exhaust systems, but he is such a good craftsman that I asked him to realize my intake system as well).





Basically his work was to make two parts of tube, Between those tubes the relocated MAF sensor is positioned which helps a lot for a better control of the throttle response.
Both parts of tube are made of morer pieces of curves and straights, welded good together on high quality level.

Note the new fixing point at the alternator.



Perhaps I can make some video of engine behave, but the difference is more behind the wheel than visable in a video - with the exception of now reachable speed.

An interesting post Heinz, it would appear you've had fun and a good result through your experiments.

Very interesting Heinz. Do you think it's possible that simply relocating the maf sensor would have the greatest impact?
Nick

I tried the standard 57 mm tube with the added maf sensor plastic tube mounted directly to the throttle body. The result was not so good, but I think, that was because of the additional length of total tube and also because it seems that the maf sensor neither works not at best too far away nor mounted directly to the TB. I don't know why, possibly the sensor itsself adds turbulences just in front of the TB because it is "in the way" or possible as well it seems to be better if the ecu has a little bit of time to make it's calculations when the maf sensor is a little farer away but not too far giving incongruent results to what the TB "sees" in terms of temperature etc.

To sum up, the slightly wider diameter of my new intake tube makes sense in cooperation with the sport manifold which also has wider diameter tubes.
I'm pretty shure that in team with the standard manifold a relocated maf sensor mounted at the standard 57 mm tube at the position more or less where my maf sensor is placed should improve the throttle behave significantly. Remember I know no other car of any brand where the maf sensor is so far away from the TB as on a 4/4 Sigma.

If you like to keep the standard system it could be an improvement to change the accordion rubber hose mounted at the filterbox for a smooth one, but then you have to take one which has 60mm diameter at the box side and 57 mm at the tube side.

Thanks Heinz. I will look at where the sensor is in a typical ford car. I also wonder if it would be possible to put an obstacle in the tube near the filter which would cause the air to "rifle" through the rest of the pipe which might increase flow....or am I going mad now?
Nick

Thank you very much for this posting. It is a nice kind of "synchronicity", because i was just collecting any piece of information about the ways to improve the air intake of my 4/4 sigma engine. I already have a very good sports exhaust, and your post has given to me some interesting ideas.
So, thanks again, and many happy miles!

Another way to improve the air intake is to considerably shorten the ducting system by removing the closed airfilter box (difficulty of changing the filter element) including the long tube and change to an open airfilter system directly fitted to the intake manifold (K&N 57i Induction System Ford Fiesta 2008-2011 1.6L) via an Samco elbow (45/60mm); no relocation of the MAF-sensor.
You can add a cold air ducting system (intake funnel fixed at the bottom side of the radiator) directed to the open air filter.
I did the conversion with good results (better sound and torque without loss of driveability).
Pictures on request ( dherdebart@telenet.be)

I was also thinking about an open system but I did not want more noise. Car makers not always construct items which are not good performing. An air filter housing is not only made to restrict airflow (and noise) as one could think, it may help to improve the airflow.

Watch this video and see what happens performance wise without the filter housing in comparison when the car (in this case) is significantly slower accelerating:

http://youtu.be/lDnptzZBrUM

I have a hose fitted to the bottom of the filter box which leads to the front below the radiator. So all air in the box is cool.
I have not tested a short path system until now, I will do later on, but I'm wondering how it could improve low rev torque.

Nick, the sensor is on different places depending on which model uses the same 1.6 ti vvc engine. I.e. the filterbox of the 4/4 seems to be a Fiesta item, but in a Fiesta the filter box which contains the maf sensor in this case, is much closer to the TB.

BTW I use a genuine Ford Focus 3 1.6 Ti VVC maf sensor plastic tube. This tube is shaped in a so sophisticated way at the inlet side that it makes no sense in my view just to take any flat tube and put the sensor simply in. Out of curiosity I dismounted the additional "clarinet" piece inside the Focus item which is just clamped. Without this flow leading - and slightly air compressing piece- the car drives almost horrible and the engine sounds rough.

Regarding the obstacle, I'm not sure if it would irritate or reduce the flow more than it helps. If I understand you right you think perhaps it could speed up the air? Give it a try.
If you could get a spare standard 4/4 tube from anyone who has changed his intake system you could give your thoughts also a try and replace a piece of the tube where it is straight with a Ford maf sensor tube.

The noise level is only slightly higher and mainly due to induction sound (suction of air) and not particularly exhaust sound.
The main purpose of this conversion is to shorten the intake path to the throttle and thus lower the resistance to the air flow.
Don't forget that the filter box, situated behind the radiator and the long metal intake tube are getting hot, being close to the engine, so the cold air aspirated through the filter box and intake tube is heating up rather quickly.
Besides, the space around the intake manifold seems to be the coldest place in the engine compartment.