HIGH VOLTAGE FOR SAMARA
Probably, every motorist has his own opinion about what spare parts or accessories to buy for your favorite car. Often this opinion is formed by a complex, expensive and dangerous method of trial and error. The materials of the “Expertise” column, which appeared this year in “Behind the Wheel”, we believe, will help you avoid some mistakes and their consequences. Today we will talk about high-voltage wires.
For the examination, six sets of “nine” high-voltage wires were purchased, covering the entire price range. The cheapest, as expected, were the old, well-known motorists blue wires of domestic production (photo 1) with the "elegant" name PVPPV-40. We purchased them in a store for 30 thousand rubles. The most expensive purchase, and this also did not come as a surprise to us, were high-voltage Bosch (photo 2). For them, we gave 140 thousand. All other wires were located quite close to each other in this price range: the sensational white Caesar made especially for Russia - 65 thousand (Fig. 3), American Web Wire R-200 - 69 thousand (photo 4), Champion - 70 thousand (photo 5) and English Jan More - 80 thousand rubles. (photo 6). With free time, all this could be found cheaper. The characteristics of the wires are given in table. one.
All sets had to pass a set of tests in the laboratory of ignition systems and alarms of the Research Institute of Autoelectronics, where similar experiments were carried out in the days of the USSR, so there was enough experience in this matter.
Before turning to the test results, let us briefly dwell on what the wires should be, based on existing standards. A comparison of the Russian standard TU 16-K81.02-91 and the international ISO 6856–90 reveals some differences. For example, the international standard makes more stringent requirements for the operation of wires at high temperatures: 180 ° C against our 110 ° C, but it is not so picky to work at low temperatures. Judging by domestic standards, we are preparing better for the cold winter: our wires should work properly at minus 40 ° C in a temperate climate and at minus 60 ° C in a cold. There is one more reason to rejoice for us, beloved ones: only our Russian wires should be resistant to the effects of “mold fungi” (this is written in the standard). Nevertheless, it is too early to celebrate the victory, because the standard stipulates only the lower level of requirements, and which of the manufacturers will go further from it is another question.
The requirements of the general standard stipulate far from all the characteristics of the wires, and it is much more important that the high-voltage wires are not only “quality”, but also fit every particular car. To do this, they must be suitable in length, have a well-defined electrical resistance and create the least interference with radio reception.
It is known that imported high-voltage wires, compared to ours, have a greater value of the electrical resistance distributed along the length of the wire. What for? To create less interference with radio reception. But we know: free cheese - only in a mousetrap, and so that it wouldn’t turn out like in the popular parable today - “they wanted the best, but it turned out as always, ” we decided, among other things, to carefully check how the “excess” resistance in the wires will affect output characteristics of the electric discharge.
The discharge characteristics were measured in two different test complexes: the first of them corresponds to GOST 28827–90 and is carried out with only one central wire. The second corresponds to the industry standard OST 37.003.073–85. In this case, the chains “central wire - the longest wire” were checked, interconnected, as expected, through the “distributor cover”. In the first case, it was required to obtain a discharge duration of at least 1.6 ms and a discharge current of at least 75 mA - this is exactly the requirement of VAZ for high-voltage wires. In the second case - the more we get, the better. The test results are given in table. 2.
And now a short comment on the results. All types of wires, except Web Wire R-200, have spark discharge parameters that meet the requirements of TU (technical specifications), agreed with VAZ. The main drawback of the American Web Wire R-200 is an error in the configuration of the set of wires, otherwise it cannot be called. Instead of the usual length of 270-300 mm, the central wire here is 510 mm long. Such a wire is usually used when installing a contactless ignition system on the "Zhiguli" classics, but on "Samara" this "cord" is not needed. Due to the excessive length, the wire has a "record" value of electrical resistance, and this greatly spoils the characteristics of the high-voltage discharge. However, this does not mean that the engine will not be able to work at all. It’s just that in the most severe cases, for example, on a “killed” engine with an “overflow” carburetor, the combustion characteristics will deteriorate, engine start-up will become more difficult, misfires will occur more often.
The main problem with Bosch wires is again the increased resistance (see Table 1). The fact that these wires have very good noise immunity, we had no doubt, but, alas, the duration of the discharge was quite low.
Nevertheless, it is impossible to say that Champion is better than Bosch, or vice versa. We can only state that some of the wires are better suited for Samara than others, and even then with a reservation. If the most important thing for you is the sound quality of the music in the car, then Bosch will probably be preferable, and you will probably not feel any “deterioration” in the engine. If your car has been asking for a major overhaul for a long time, the compression is nowhere worse, the carburetor is not adjusted, and you need to start the engine in severe frost, then it is impossible to think of anything better than domestic wires for these purposes.
Along with measurements of discharge characteristics, climate tests were carried out. The worst performance here was shown by the thermophilic Americans Web Wire R-200 and … our PVPPV-40. Both sets “tan” at minus 40 ° C, although they continue to perform their functions: in the temperature range studied, from minus 40 to plus 85 ° C, the active resistance of all wires changed by no more than 13%, which practically does not affect the discharge processes ignition systems. The noise immunity of the wires was not experimentally determined - such tests are extremely complex. However, generally it would be dishonest to forget about it, because it is in this that our wires are noticeably inferior to imported ones. This explains that in domestic ignition systems install additional resistors to suppress interference. The breakdown voltage was also not measured, but for a different reason: the VAZ 2109 ignition system did not have enough strength for the breakdown.