Xeon

I am not sure abt this, so dont take my word for it.

I heard that a kompressor engine give up to a 50% boost, well..basically it means that our 2.3L engine will have the power of a (let me do some maths here) 3.45L engine. Can anyone verify if this is true....also....out of sheer curiosity....those with pulleys....how do your car do against a 330 or 325 or 328?

vadim

I don't think 325 will be a problem at all, not sure about 330. Haven't had a chance yet.

trench

The way the math is works is that the amount of boost pressure is multiplied by the displacement. Therefore a 2.3L motor running at 0.5 bar (7 psi of boost) would be rough equivalent to a 3.45L normally aspirated motor; if you were running 1.0 bar of boost (14 psi) then the rough dispacement equivalent would be that of a 4.6L motor. Therefore, a M111 (2002 C230K) motor running at about 5 psi (0.36 bar) should theoretically be the equivalent of a 3.1 L motor. However, in practice the M111 had about the same output of the old 2.8L W202 C280 V6 motor, so you can see the maximum theroretical gains usually aren't acheived due to other engine differences.

Cheers, BT

lars

Informative reply, Trench. Thanks.

Mike T.

There is no way to generalise and say that a supercharged or turbocharged engine is any fixed percentage more powerful than a naturally aspirated one. There is too much variability to generalise about this.

The FIA used to handicap Turbo cars in the old days (in WRC and F1 competition) by applying a multiplier factor of 1.4 to forced-induction cars.

In the case of the 2.3 L C 230 K, the naturally aspirated version of this engine was rated at 148 HP in Europe and the version in the C 230 K Coupé was rated at 197 HP, so that's 1.3333 times as powerful.

So using the technique in the old FIA formula, we arrive at a capacity equivalency of 3060 cc...

trench

The "1.4 rule" was the old FIA correction factor, primarily used in Group B rally racing from 1983 to 1986. The actual FIA rule was for turbos in Group B was "capacity x 1.4 shall not exceed 4000 cc." It wasn't intended as an exact correction factor; as an aside, I don't know why they didn't simply have a rule that said, "3.0 L maximum displacement for forced induction." These cars were quite awsome, in 1986 Henri Toivonen drove a Lancia Delta S4 Group B rally car around Estoril, the Portuguese Grand Prix circuit, so quickly that he would have qualified sixth for the 1986 Portuguese Grand Prix. By the way, talk about overkill, the S4 was supercharged and turbocharged to the tune of 500 hp out of a 1.8 L motor. For current rally racing (including GroupA/WRC) cars the FIA has mandated a 1.7 engine displacement multiplication factor for super/turbo charged cars combined with restrictors to keep motor output roughly equivalent, instead of using just a simple displacement multiplication factor, which can't take into account different levels of boost delivered. The amount of boost being delivered has to be taken into account to accurately determine displacement differences.

In F1/Grand Prix racing they never really could figure out how to properly handicap forced induction motors. In the 30s forced induction engines were the norm (mostly supercharged, turbos didn't become wide spread until the 60s and 70s), the rules were changed making the engine displacement differential between normally aspirated engines and forced-induction engines 3 to 1. This handicap was simply too much for forced-induction engines to overcome, so everyone began running NA motors. However, by 1977 the rule was reduced to a 2 to 1 ratio - so Renault developed a 1.5 L turbo motor (since the NA engines were then limited to 3.0L of displacement).

Within a few years, everyone was running turbo charged motors (early 80s), then the turbos were finally banned in 1987 (with the ban to take effect in 1989). This makes 1988 the last year that turbos ran against normally aspirated motors (NA motors were allowed this year for manufacturers who wanted to get a jump on NA engine development - such as Ford). In 1988 the NA engines were allowed a displacement of 3.5 L with unlimited fuel, while the turbo motor formula was 1.5 L displacement with 2.5 bar maximum boost and limited to 150 L of fuel for the race as well as a 40 kg heavier minimum weight.

Therefore, 2.5 x 1.5 = 3.75 L, however since this is a theoretical maximum not normally reached (primarily because boost levels change as RPM varies), it was thought they would be roughly equivalent to the power output of the 3.5 L NA motors, with the additional handicaps of more weight and less fuel the FIA thought that running a turbo would be a disadvantage. However, Honda and Ferrari, the primary turbo runners in 1988, found many ways to maintain the turbo's superiority that year. Primarily by locating the FIA-supplied pop-off valves in low pressure areas of the intake (delivered boost was more like 4.5 bar instead of the 2.5 that it was supposed to be), also the NA V10s and V12s required way more fuel than the 1.5 L turbo - and in the days of no pit-stops, this simply made the NA cars too heavy at the start.

Oooo... sorry, that post was a little longer than I originally intended.



BT

Xeon

wow..i am impressed...but for me...as long as i can beat the opponent's car, i dont care if his is a 8000cc monster or 80cc scooter...

wont the world be a lot nicer if all the watever factors of engines are standardized?

Mike T.

Yes, of course, it was 2:1 in F1 for quite a while - I was thinking of Group B when I wrote that and I can't think of why I wrote that the 1.4 rule applied to F1 too...sorry for my mistake.

Although the Lancia Delta S4 was a very impressive car, the Peugeot 205 Turbo 16 was arguably better, winning the championship in 1985 (pre-S4) and 1986 (first year of S4). Of course, Lancia might have made further gains in 1987 if Toivonen/Cresta had not died on the Tour de Corse in 86 and the FIA over-reacted by banning Group B. On the other hand, Peugeot was about to introduce the 405 Turbo 16 for 1987, which they ended up having to use only at Pike's Peak (where they crushed everyone and got the record with Robbie Unser at the wheel) and on the Paris Dakar and other Raid-type events after the FIA legislated Groups B and S out of existence.

lars

I remember watching the group B cars in 1985. I was a spectator at the Olympus Rally (WA northwest) which was being observed by the FIA the year before its inclusion in the WRC. Audi sent two factory Quattros for this event, with Hannu Mikkola the lead driver. The power of those cars was just awesome: they left well-defined grooves in the gravel roads from wheelspin exiting the corners.