In the previous RET Monitor article on the subject of exhaust insulation, we looked at plasma sprayed thermal barrier coatings for exhaust systems. In preceding articles, we have examined the reasons why thermal insulation of exhaust systems is necessary in certain applications, and advantageous in many others. An alternative to coating the exhaust system are the various types of thermally insulating wrappings, which may be in the form of a metallic ‘bag’ or ‘blanket’ or alternatively a refractory cloth, such as asbestos.

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In previous articles, we have looked at why we might choose to insulate the exhaust system of a racing vehicle, the various methods by which we might insulate the exhaust and what the consequences of doing so might be.

In light of this, we discussed exhaust coatings with a British company, one of whose specialities is the application of thermal barrier coatings to exhaust systems. Zircotec, who are based in the middle of an area rich in motorsport expertise, have a number of exhaust coatings which are made available on a Read more…

For those of you following the ‘Focus’ articles in Race Engine Technology magazine, it is clear that recent changes and improvements in manufacturing technology have improved the products being examined, and this is undoubtedly true for most machined parts, and also for parts produced by casting and forging too. Clearly the CNC revolution has not left the world of fabrication untouched with many operations controlled by computer being more accurate than the average man could ever be. We will not include those who make motorsport exhausts as ‘the average man’. Thankfully, we are a long way from being able to replace these craftsmen by robots. Read more…

Last month we looked at the problem of how to contain excessive heat given off by hot exhausts. The problems this heat causes affect not only the engine, but also other systems, particularly electronics. In addition to wrapping or coating the exhausts, we looked at the concept of bagging or blanketing. Heat shields were mentioned and in Formula One at least these are commonplace, being lightweight and effective in shielding the engine from radiative heat transfer. The problem with wrapping or bagging of exhausts is the additional weight which would affect the reliability of the exhaust system Read more…

Some of us have the regular chance to see an engine running hard on the dyno, and in many cases it is visually obvious that there is a lot of heat being radiated from the exhausts. There are many video clips and pictures on the internet showing exhaust systems glowing bright red, especially on very high-speed engines such as found in Formula One. Whilst it is clear that there is a great deal of heat being generated, what to do with this excess of energy is not clear.

The management of this heat under the engine cover Read more…

In previous articles on exhausts, we have talked about how these systems are composed of smaller parts, then welded together to form the whole. We further assumed that these smaller component parts would either be small cast pieces, simple bends or perhaps pressed sections. Pressed sections offer the possibility for different shapes and tight bends where required.

In this article we shall look at a technology which is relatively new to motor-racing, although it has been used successfully for decades in the manufacturing Read more…

In one of the previous articles, the discussion points were on the traditional methods of manufacture, and this month we shall look in more depth at non-circular sections in exhausts.

In the article dated June 14, we mentioned pressed mends as a means of being able to produce very tight radii where space constraints require this. Of course, there are other applications of pressed parts in exhausts, especially where the space envelope is tight. Read more…

There are a wide range of materials from which racing exhausts are made today and the choice depends largely on budget, although some of the very expensive materials available aren’t used because they either aren’t mature enough or engineers haven’t yet figured out how to use them.

Whilst there are a lot of exhaust systems still being made in steel, it isn’t as widely favoured as it once was for a number of reasons. The obvious one is that it corrodes very easily. Welding steel to stainless is a good way

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The modern racing engine, benefiting from many hours of dyno development time and a great deal of simulation, should at least have a well-optimised exhaust system in terms of length. When compared to a Formula One car, sports cars have a lot of room in which to lay the exhaust system out without requiring extremely tight bends.

In Formula One however, there are much tighter constraints on the exhaust, particularly in view

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In the first eight years of the twenty first century (with the single exception of 2003), the honours in the 24 Hours of Le Mans have undoubtedly belonged to the team from Ingolstadt. Since its introduction in 2006, the last three years have been the sole domain of the diesel-powered Audi R10 Tdi, but its predecessor, the petrol-powered R8, took top honours from 2000 to 2005 (with the exception of Bentley’s Audi-powered win in 2003).

It was perhaps inevitable then that the ACO would change the rules in the face of such domination and for the 2009 season the organising body stipulated a 40 cm reduction in the width of the rear wing. Read more…