When I was a teacher I was very interested in issues relating to native vegetation. The removal of native Australian scrub has the potential to have extremely adverse affects on soil, especially in the areas susceptible to salinisation and erosion. And of course, these processes have resulting terrible affects on native fauna. So, I was particularly interested in seeing how a privately owned local conservation park was dealing with the issue. Owned by a former university mathematician - a huge, bearded man with a reputation for not suffering fools lightly - the park was located in the Adelaide Hills. As part of a Natural Resources Management course that I then taught, I took my senior class to visit.
We were appalled. This park, widely trumpeted in the media as an example of what could be done by a private person, had stands of exotic (ie non-native) vegetation, still set in plantation rows! The purportedly 'wild' fauna were surreptitiously being hand-fed behind tourists' backs, and the young guide's comments on the characteristics of the animals showed an amazing ignorance of the theory of natural selection.
In short, it was a disappointment. Sure, there were some very good things happening there - the platypus breeding program was exceptional, for example - but there were glaring holes in the project.
A few years later I was at an expo that featured a stand promoting the park. And there, proudly handing out pamphlets, was the owner. I walked up to him and told him of my disappointment with his facility. He stopped what he was doing and glared down at me. "Well," he said, "so what have you done to help the natural environment? Where is your conservation park, where is your platypus breeding program? Hey, tell me that, where?" His scorn was obvious.
Those comments have stayed with me in the years since. Why? Because it is extraordinarily easy to stand back and criticise, especially if you have not actually even attempted to do a similar thing yourself.
I was reminded of this by the flood of email that arrived after we ran the two stories on the new boost control system that I fitted to my Audi. The minute that the first article was released, people started writing to me, telling me how the system didn't work, couldn't work, worked in a way quite different to how I had described, was unstable, wouldn't work on other cars, used the wrong components, or how it could be improved.
And all of these correspondents had one thing in common - not one had tested the boost control system on a car. In fact, none of the correspondents had even built the system...
This was the classic case of 'experts' (all of them claimed qualifications or experience in engineering, or electronics, or some other technical field) passing judgement with absolutely zero hands-on experience of the very system that they were commenting on. And of course, all were writing with the aim of 'helping me' understand where I had gone wrong...
Gee thanks, fellas, but who actually thought up the idea? Who actually sourced the components to make it work? Who fitted the system to a car and then further developed it to give excellent results? Who then tested it every day on his car for eight weeks (in all sorts of weather and driving situations) before the stories came out?
You guys?
No? Oh.....
The correspondence quickly became farcical - how can two people argue the outcome of a boost control system when only one of those people has built and tested it? The following are edited extracts - each correspondent usually wrote at least 500 words every time they emailed me.
Correspondent #1: "Anyway my point is that without some form of linear, or quadratic feedback, it is impossible to regulate boost accurately..."
Me: "...on my car the current system holds boost almost perfectly. Have you read Part 2?"
Correspondent #1: "...I think that if coupled with relatively large turbo (that is capable of flowing much more than what the engine can take) which seems to be common in a lot of aftermarket turbo engine build-ups, that the fact that the wastegate doesn't open further once the set boost is reached would result in the boost continuing to increase..."
Me: The problem will in fact be the opposite of what you say - in some applications boost will fall off as revs rise. You will always be able to limit the peak boost by setting the pressure reg to the desired peak boost level.
Correspondent #1: "Actually this is the point on which I disagree. According to the theory I have previously presented to you which may be incorrect, but I think it is correct, the pressure regulator limits the boost seen by the wastegate to a set level after which it can open no further, as no more pressure can get to the wastegate. In some bigger turbo applications, peak turbo flow will occur at higher rpm than which peak boost can occur, and will rise logarithmic to this point."
Me: "You set the controller so that the actual measured peak boost in the plenum chamber does not exceed the limit you wish it to. In other words, the wastegate opening is set (via the pressure reg) to the opening required so that boost does not exceed a desired level. That makes the above statement nonsensical. How can you have a maximum magically appear that you haven't already taken into account when you have set the control by looking at what the actual [ie on-road] peak boost was?"
Correspondent #1: "I did not mean to imply that if you tuned the control to achieve max boost, that more boost would magically appear. What I meant to say is that I believe that in over-sized turbo applications, if you tuned it for max boost, it would not have good boost at lower rpm even though if a feedback system was used, it could probably maintain max boost at lower rpm, and if you were to adjust it to achieve desired boost at lower rpm, that it would overboost at higher rpm."
Me: How is that [ie poor low rpm boost] possible when you can set the pressure relief valve so that the wastegate won't even sense boost pressure when boost is low? This point typifies the discussion that we have had. You initially didn't understand the system and so said that boost would skyrocket. That is impossible if the press reg is set to control max boost. Now you realise your error in that regard, and so you say that low boost won't be any good. You are making another error at the opposite end of the spectrum - you apparently still don't understand the system.
Correspondent #1: Is there some course that people in media take that teaches them how to twist or take out of context what people say in order to undermine their knowledge in the area. Your attitude initially in print media as well as more recently in AutoSpeed lead me to believe that you were different in this regard, and more willing to expose the truth on important issues that commercial industry may represent otherwise, however a few articles I read on AutoSpeed recently combined with the AutoSpeed sales of products previously judged as not worth the money by AutoSpeed made me question this. In the recent discussion I have had with you regarding boost control you have not understood the theory I have presented, and instead of working at understanding it at best (not feasible as you probably get many other questions from readers and do not have the time), or ignoring it or acknowledging it (would have been neutral at least), instead you pick at my poor presentation of the theory. You have confirmed that my initial opinion of your attitude was incorrect.
I have completed with honours degrees in Electrical Engineering and Science majors in mathematics and Computer Science, in which I have done extensive control courses. I have developed a prototype electronic boost controller for my own use in my own time, as well as having worked in engine management and tackled the problem of boost control in an every day working situation. I have developed mathematical models for turbo engines, and tested control algorithms using such mathematical models. (etc, etc)
I will continue to read the areas of your site which I can get to for free, though with a different hat on from now on.
Me: The bottom line is that you have not tried the boost control system. Do so, then we can discuss the results that you have found. Everything else is simply speculation on your part. I don't doubt your qualifications. I do doubt that you have experienced the system as I have, and have been in a position to compare the actual results with other systems. When you have done this, I am happy to continue the discussion.
Okay, so that didn't achieve much, did it? One annoyed editor, and one pissed-off reader - the latter a person who had absolutely zero experience of the boost control system about which he was writing so authoritatively. Unfortunately, every one of his points did not match the results found on a real car, when fitted with the real system.
The there was Correspondent #2, who had some similar ideas.
Corespondent #2: I am writing in response to your latest boost control. I waited for the second part to see if you reviewed the fundamental error in your system, but it seems you haven't.... The use of a pressure regulator is seriously flawed in this application, and is most likely the reason for the initial poor boost regulation experienced in Part 1. No matter how high the boost rises, the set pressure is constant at the wastegate, therefore there is no closed-loop boost regulation. The wastegate opening is held constant by this constant pressure. On some engines, particularly those with a much larger turbo compared to engine capacity, this would result in rapid overboost...
Me: You set the pressure reg to give the peak boost pressure that you want. Take note of the setting up instructions - you set the pres reg to give you max boost. Maximum is maximum - there cannot then be a greater maximum!
Correspondent #2: After further investigation, I concede that your system will enable the boost pressure to be set on most engines, but not regulated by the wastegate....[Instead] consider this: use your existing system as is, but add an extra pressure relief valve to produce a three stage system. Set this valve at exactly 1.1 bar and plumb it so it delivers full boost pressure to the wastegate when it 'blows'. While the addition of an extra valve may initially seem to complicate the system, it will actually simplify tuning. If desired, this can be set to 1.1 bar accurately before it is installed. It will fully open the wastegate when it 'blows', so you can guarantee your boost will not exceed 1.1 bar, even if your in-car boost gauge is incorrect. (etc)
Me: In my summary table I have stated that boost will not be held [perfectly] constant by the system. Incidentally, I have no wish to change my system - I am extremely happy with how it is working now. Of course, when you build it and fit it to your turbo car, you can make any [design] changes you like...
So another reader who said it wouldn't regulate boost - oh now yes it would - but oh, here's a bonus for you - I'll tell you how to make it better. The fact that the boost control system gives extremely stable performance when assessed in real conditions on a real car seemed to have escaped him. The further point that if he believes that he has devised a better system then there's nothing stopping him fitting it to his car and testing the actual results - and then telling me about them - also seems wide of the mark.
Then there were Correspondents #3 and #4 and #5. One of these even said that I should get other staff to check for my errors - the fact that other AutoSpeed staff were extensively involved in the on-road testing of the systems seems not to have occurred to him... Then another said he thought that the design of the pressure regulator wouldn't work, and yet another said that (really) it was a bleed system in disguise and I should have tested the system, one valve at a time. Of course the set-up instructions suggest that you do exactly that.... But then I won't bore you with the details of all of these emails.
Now let's make something really clear.
If someone builds and fits the system as it has been described in AutoSpeed, and has specific problems with it, I'll be all ears. Or, if someone makes a modification to the system, fits the new system to a car and tests it extensively with better results, I'll be very interested in knowing about it. A person who locates better and/or cheaper components? Tell me! Someone who designs, develops, builds, fits and tests a cheap electronic boost control system? - I'd love to see the details.
Because I am certainly not claiming to be the only person in the universe who can develop boost control systems- that would be simply absurd. So, there is nothing in this column that states - or I hope even implies - that I hold some type of franchise on developing such DIY systems.
But I'd like to make one thing clear. If you're sitting back in your chair, simply theorising on how you think the AutoSpeed system will or won't work - I'm not interested. Build it, fit it, test it - then if there are problems, tell me.
Otherwise, for Godsakes, don't waste my bloody time......
Like the conservation park man said, "Well? What have you done?"
