In conclusion - I think!!!!!!

[Ascari32]

Re: Compounding the Ascaris and Complex Impedance issue.
« Reply #3 on: Today at 07:39:26 PM »
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Further to my original post, more information has come to light.

Having concluded there is an inextricable link between the MAF element and the complex nature of the Ascaris, due to the transparency the Colombo Bariani camshafts have created, it seemed I must look else where for a solution - if indeed one could be found.

Returning for a second to the nature of "Tuned Circuits/Devices", although they can be tuned for linearity across a certain spectrum (Bandwidth), they can; and do, go nonlinear when overdriven. In doing so, they go into "Saturation". This is where the L, C and R elements are no longer able to cope with the signal level: in classic terms the output signal no longer represents that of the input x the "Q" - magnification factor).

However, during the period where saturation occurs, the excess energy manifests itself as distortion - harmonic distortion. Turn the input level down and the device resumes linearity and the distortion disappears.

It is this distortion, due to excess input level which is one of the causes of the Ascari "Break - up". Thus, the Ascaris are not wholly to blame for my problems.

I accept, there is a need to have the fuel maps adjusted but for the time being that must wait. Any issue with the ECU maps must be reduced to being in specific and defined areas. In not doing so would result in a real dogs breakfast as softies chase ghosts and consume hours and £££££....... in development costs.

Further research into the 3.2 JTS engine confirms the ECU does not, in a conventional sense enrich the AFR on startup, when the engine is cold. However, advanced exhaust timing and delayed inlet timing effectively starves the engine of air whilst maintaining the quantity of fuel injected.

A combination of factors govern this and one in particular is the NTC Sensor, located within the head, close to the exhaust port of cylinder two. It is this element, when quickly warming up after start up, which the ECU "Reads"', and begins to "RETARD" the exhaust camshafts.

In retarding the exhaust camshafts, the piston travels further down the bore, the combustion process is more complete, the exhaust gas temperature is reduced and so to is its pressure.

It is therefore obvious the response time and the accuracy of the NTC Sensors resistive Characteristic is imperative for ECU to set exhaust valve timing for - in particular startup and low speed operation.

My NTC Sensor was found to be faulty. The additional consequences of this was the unburnt fuel being discharged into the exhaust system resulted in excessive "Burning" within the exhaust system proper, forcing the Ascaris into "Nonlinearity", ie, they were exceeding their power handling characteristics and therefore producing both excess noise and extraneous harmonics.

This I have discovered to be true of the Alfa Boxes. However, being absorption types, their characteristic is "Attenuative", and thus muffle this effect in a much more linear manner - until of course the power level becomes so excessive they too go non linear.

Running with the Alfa Boxes, the exhaust sounds incredibly sweet and pure, provoking me to drive more often with the windows down, just to listen to it. It is in every sense of the word, an "Alfa" sound beguiling, even at 74 years of age.

I am still not totally convinced the Ascaris will now work. However, I have had stainless steel plates, puddle welded along the top and bottom, from input to output, to strengthen them; the central cavity in particular, and will be refitting them in the next week or two.

Aside from the effect the plates should have; and I do hope they don't end up with a drone, replacing the NTC Sensor has made a vast difference to the engine and she is now happily running with a 3.8/4.0L Porsche 911 Turbo MAF element. It however has a 270 ohm resistor in series with its output to the ECU. This just tempers the startup noise a little further. However, it does also take a little off the acceleration at the bottom end - only a little because she is still quick.

Take the resistor out however, and she becomes "R"eally "S"avage!!!!!

Ultimately however, although I miss the sound of the Ascaris over 3,000 rpm: I hope the plates haven't changed that, I believe the only solution to be Supersprint or Ragazzon back boxes.

[Ascari32]

Will there ever really be a conclusion to this project?

Today I will be picking up my modified/strengthened Ascari back boxes. However, as I reported earlier the car has just had four wheel alignment along with an oil and filter change.

The car has been performing well since then. However, there is a suspicion that it is even more lively than hither two.

Early in the modification/research phase, I was intending to do more modifications to the Oil Cooler/Filter module. This came as a suspicion grew about, a) the size of the oil filter and b) the various types of oil filter elements available - some paper, some "open-mesh" types.

Indeed I modified the front camshaft bearing caps with the intention of supplying an oil feed direct, as the inlet camshaft front bearing is lubricated from the same oil feed as that which drives the inlet camshaft VVT's. This came about when I realised constant oil pressure is essential for good VVT response.

This idea was shelved simply because I wanted to progress things and it was difficult to get garage/engineering shops to agree to timescales.

However, in all things lubrication pressure and flow depends upon a good flow across the oil filter element. With this in mind, I also bought a BMW oil filter housing - second hand - with the intention of replacing the standard filter with it. The BMW filter is "Massive" by comparison to Alfa's.

Well puzzling over the seeming difference, post oil/filter change, I now intend to replace the Alfa filter. The oil cooler element will be removed and a mono block of aluminium will be machined to replace it. The water feed will be looped back, effectively maintaining flow, while eliminating the cooler.

However, the feed from the engine oil pump will come via the new block which will be designed to feed a flexible hose to the remotely mounted BMW oil filter. From the BMW filter it will then return, via another flexi to feed back into the block, to feed the Alfa oil filter module.

The BMW module has a oil pressure sensor housing to which I can connect a gauge - the central radio/cd player will be removed - with instruments fitted in its place.

All this has come about as the suspicion I had about the size of the engine oil filter seems to have manifested itself into reality, given this is the second oil change in less than 10,000 miles. If, as I suspect, increasing restriction - no matter how small - is causing a slight drop in oil pressure and in turn slowing the VVT response a little, there is sufficient justification for making the change.

The Alfa Filter Housing will be left empty - no filter element - and the large BMW one will replace it. At the same time it will give me the opportunity to fit an External Oil Cooler. However, the main point of the exercise is to reduce to a minimum any pressure drop across the oil filter element.

It will also give me a further opportunity to feed the Inlet Camshaft VVT's directly and thus further improve the accuracy of inlet camshaft timing.

[Ascari32]

Just trying to figure out how to attach pictures. If these "load" ok, then they are of my Ascari Back boxes - after strengthening plates have been fitted.

[Ascari32]

Hooray! And here is the BMW V12 Oil Filter housing which will replace the Alfa Filter.

You can see the Alfa Heat Exchanger/Intercooler Element has been removed. In it's place will be a machined Alloy Plate which will loop back the water feed from the engine. The Oil Feed from the Engine's Oil Pump will feed from the plate to the BMW Housing, via flexi and return to the plate, which will then take it via the normal path through the Alfa Filter Canister. The canister will however be empty - ie. no filter element inside.

Looping back the water feed and dispensing of the intercooler means there is no oil cooler/preheater. But it enables me to fit an air cooled, oil cooler. The one from the 2.8 Vauxhall Insignia VXR looks a good candidate.

It also simplifies the modification to take oil direct to the front bearing caps to drive the inlet camshaft VVT's - which will ensure both have exactly the same oil pressure/flow capacity.

Second picture shows Colombo Bariani camshaft removed whilst the timing Chain and Sprocket are supported by the tools I designed.

[Ascari32]

Now I have discovered how to attach pictures - thanks to my son, heres a few more

The Closed Loop Lubrication System was also supplied to "Richard" in Aus. He undertook to do a Dynamometer run before it was installed and one after, of which he supplied me with the results. I admire the man for the faith he demonstrated - top man!

[Ascari32]

Some more.

[Ascari32]

Autodelta have "Upped - Stakes" and gone to Greece. Another company abandoning the good ship "Brexit".

But even that's not easy. The Beurocracy involved has led to delays in opening up. Hopefully prices may be a bit cheaper when Jano gets up and running.

Last time I spoke to him, he was doing a 3.2 JTS rebuild for a French customer. When he gets that out the way he wants to test my C.L.L.S. on one of his cars. Also, it is becoming obvious I will not be rebuilding the 159 engine, so all the bits - I have everything - new, bar pistons and head bolts - so we'll negotiate a deal, maybe a few goodies in exchange.

Yes, the C.B.'s went on a treat. But they have caused a headache with the MAF.  Not the cams fault. Just the static timing of the 3.2 JTS results in the inlet opening at 11.5 deg. ATDC with the Alfa cams. So the ECU has only 168.5 deg. to BDC to read the MAF output signal: representative of air flow.

Plus, as the exhaust has closed 2.5 deg. before the inlet has opened, air flow is stymied. So the MAF has to have a fast response curve (steep dv/df) to compensate. However with the increased induction of the C.B.'s and their duration, it is too fast. Plus, it has a low max flow rate - too low for the revised valve timing. So a Porsche 911T (3.8/4.0L) is more appropriate.

Still not quite right. But I want to leave the Softies as little to do as possible. Can't afford to have them going off at a tangent - very few have a real understanding about what their ones and noughts do. And I'm certainly not going to pay for them to learn. I've been there before and I don't suppose they are any better.

There is a world of difference between software engineering and simply filling spreadsheets. The vast majority load files! But that's not the same as constructing the protocols!!!!!

[Ascari32]

Not having seen close relations now for almost two years, we arranged to meet sis - in - law and hubby about equi - distance at Upper Hambleton, on Rutland Water. Up for mid - day Monday, great meal at "The Finch's Arms" - great bottle of Padthway Shiraz to go with the food. The weather held and we started and finished on the patio, overlooking Rutland Water.

They left and we moved on to to our hotel for the night - very nice too.

However, the weather broke and we drove home in driving rain the day after. Dreadful really!

However, 230 miles round trip @ ~ 70 mph, and the first "Distance run" since the engine was rebuilt. 30.9 MPG and tail pipes slate/Smokey grey. Very pleased. Silky smooth and seamless throttle response.

Oil consumption a bit of a concern but I am suspicious that it is coming from the crank case - PCV valve issues??? I think I need to fit a catch - can system. I don't know really - hard to explain really.

That aside, the Ascaris go back on soon. Don't believe the modifications to them will suffice, but I have to give them one more try. I think the car will be quicker, but can't see it being quieter - certainly not below 3000 rpm.

[Ascari32]

27/9/21 - 0845hrs - Ascaris back on. We have chronic petrol supplies inUK at the moment, but that didn't stop "Barney" taking my Q4 for a post - fitting test drive.

No need to have worried about stiffening plates causing droning. One heat shield on rear was loose - rear right - fixed and boxes on in 20 minutes.

Finally got away and she sounds lovely. The difference between them and the Alfa boxes is obvious - on tick over, there is less "Muffling" and a fair bit more noise. But it is clean, not ragged.

No resonances, yet louder, sounding like a Sports exhaust system for the first time! Seems the stiffening plates have worked and once again I can hear that sound above 3000 rpm brilliant.

The car is quicker too - acceleration sharpening up more, due to less restriction with the Ascaris than the Alfa's.

A real head turning sound - lovely!!!!!!!

Very happy!

[Ascari32]

Thanks for that A.T.

However:-

Tuesday 28th September - Finally gave up!

For my wife, it was bad enough with the Alfa rear boxes. But with the Ascaris, several steps too far!

As well as the strengthening plate worked, their internals are being stressed so much by the exhaust gas pressure, it causes vibrations along the exhaust system, albeit much reduced from before, which makes a drive of more than half an hour on main road intolerable. Coupling through the bodywork seems to still be an issue with them too!

On country roads where the engine is working on gentle load, it's fine. Above 3000 rpm, great! But one cannot get away from the fact that it is aggravating, continuously trying not to offend the ears during "normal journeys".

If perhaps, I still had a "Standard 3.2 JTS", they would probably work well, given there is so much restriction in the system of a normal car - Manifold Cats, Twin Cat, Post Cat Resonator, plus the chronic valve timing created by Alfa's Camshafts.

But with so much transparency in my system due to the C.B.'s, Autodelta's, Supersprint Sports Cat and Stainless Centre Section, every element affects the overall performance. It does indicate however, just how restrictive the Alfa Boxes are; given when they are fitted, the car is a lot louder but considerably more civilized, such is the degree of absorbtion the Alfa System produces.

By 1500 hrs on Tuesday, I had Bitten the Bullet and bought a pair of Supersprint rear silencers. I have been pestering Dan at DC Performance about delivery times - 6 weeks plus seemed to be as good as he could forcast. However on Tuseday, they were in stock and delivery is about two weeks. The factory had already answered my questions some time ago, assuring me they were straight through, absorbtion, with low restriction.

I have almost spent the price of the Ascaris, just trying to make them work, what with the strengthening plates and having them fitted, then remove, then fitted again - etc - etc! I just hope this is the final step and I can get on and enjoy the car for a while, before the next project looms large.

As for the Ascaris - I don't care, enough is enough. They are available for a nominal price to another individual that may think; like me, they can get them to work. But they won't linger long, before they go into the skip!

P.S. Am I really that deaf? I can understand the coupling with the bodywork due to the system being rigid and wholly made of Stainless steel, but it is free of resonance. However, the car does sound very different in the drivers seat, compared to standing on the pavement. It really sounds nice to me - albeit loud. So what must it be like for those with normal hearing.

Anyhow, I think my wife's view can't be ignored any longer - "How many times have you told me they will be better after this is done?" I think patience has just exhausted.