Heya..

First we had 9-11 conspiracy theories, then the global warming and now.. Diesel engines!

I have this strange feeling that its not fair in both WTCC and Le Mans cars. The regulations on the WTCC site are dead links but afaik this is the case in WTCC:
- Diesel: 2 liter turbo (what do they get, 300hp?)
- Real fuel: 2 liter normally aspirated .. (close to 300hp?)

- 1980s turbo F1, 1.5 liter turbo (fairly reliable 800+ hp, sometimes 1000+)

I don't know about Le Mans, and worse, I don't really know about engines. If someone here does, I'm quite interested to hear about what WOULD be a fair comparisson. Simple thinking you'd say if a NA car is limited to non turbo and 2 liters, the same should go for a Diesel. If this non turbo diesel turns out to be 100hp short, then petrol has won and diesel should go back to vans and trucks.. Unless the fuel savings make the difference at places like le mans.

Or are there more things to consider to try and come up with a comparable set of rules so you could have a 'real' diesel vs na battle?

It's quite a complex process. If you balance power then diesels have a large torque advantage. If you balance torque then petrol has a large power advantage. If you balance maximum revs, then diesels have an advantage. If you balance fuel mass flow rates then diesel has an advantage.

The best way, in my opinion, is to regulate the calorific value of fuel per second delivered to the engine, so that the diesel fuel flow is slower (more energy per unit mass of fuel), and both engines have the same energy to work with over time.

Fuel economy isn't that big an issue really, as race cars are at full throttle, when the petrol throttle butterfly (or slider) isn't a restriction (much).

As for turbos, it's another whole kettle of fish. A common ratio is that a turbo engine is worth 1.4 (correction needed here) capacity of a NA engine. Thus a 2.0 litre petrol engine is roughly equivalent to a 1.42 litre turbo charged engine, assuming all else remains roughly the same. But in practice it's never quite that simple.

Having said that, it's plain for all to see that the rules in WTCC and LeMans favours diesel. With a set of regulations equal for both engines, then petrol would win by MILES still...

Tristan: the 1.4 ratio was the thinking behind Group B regulations during the 1980s.

Of course in practice, turbo can be increase maximum power (and torque, even more so) by seemingly unlimited amounts. F1 turbo-era cars managed 1000BHP from puny 1.5L engines.

Niels: the WTCC cars are built to Super 2000 regulations with estimated maximum power of 280BHP for petrol engine cars. I dare say that turbo-diesels could match that. But the problem isn't power: it's the superior torque. Turbo-diesels deliver torque sooner and in greater quantity than naturally-aspirated petrol engines.

I like Tristan's idea of balancing on the basis of calorific value of fuel per second. Enforcement of that regulation would be difficult, I imagine. In fact, I can't think of any racing category which regulates parity like that.

Perhaps they could make Turbo-diesels run with 4-speed gearboxes instead of 6-speed.

Quote from Niels Heusinkveld :

(...) Simple thinking you'd say if a NA car is limited to non turbo and 2 liters, the same should go for a Diesel. If this non turbo diesel turns out to be 100hp short, then petrol has won and diesel should go back to vans and trucks. (...)

Just what I thought after watching WTCC yesterday. It would certainly get rid of all the discussion. However, that's probably not feasible, as some manufacturers (Audi, Peugeot, Seat) obviously have a huge interest in racing Diesels to market their production car Diesels. And even though Diesels are certainly not great for the fans, it's still better to have them, than to have nothing. And I thought the battle between the Seats and the BMWs were quite entertaining to watch, actually. Also, it doesn't look as though the diesels in WTCC have that much of an advantage as it is right now. On tracks that are not 1000m above sea level (or almost 2000 as Mexico is, I believe), the BMWs and Chevrolets should be very competitive (if Chevrolet can avoid crashing, that is).

But that was really besides the point of your post, I suppose.

I suppose a mandating body can supply a fuel flow regulator, calibrated for the calorific value of petrol or diesel (to match the fuel suppliers' sample calorific values), and just fit them in-line with the fuel system. Mandate that all fuel TO the engine has to pass though it, and allow any fuel returning to the tank to bypass it (I don't think many injection engines run fuel return lines though, so this isn't an issue).

The F1 turbos of old were unreliable, undriveable (except by driving Gods), thirsty, expensive, and at a stupid state of tune. They wouldn't even be considered for WTCC or LeMans where driveability, reliability, frugility and cost are more important than outright power. There was nothing 'special' in the F1 engines - it was actually quite basic engine technology, just aiming for power without compromise. A modern 1.5 Turbo F1 engine would easily reach 2000hp after a couple of years development in the same way, though of course driveability is considered more important now anyway so we wouldn't see much more than 1200hp in race trim.

Diesels NEED forced induction to get anywhere near the power of petrol engines, diesel engines just don't breath well.

There is a similar argument going on in WSB's ATM, where by the V-twins have a capacity limit of 1200CC to keep them competitive with the IL4's (1000cc), is it right?, who knows, probably not, but for the interests of diversity in racing, I say both rules, the forced induction diesels in WTCC and the 1200cc limit in WSB, are a good thing for the sport (and subsequent sales of production vehicles)

In other words, to provide the marketting departments with suitable material, LeMan and WTCC are no longer level playing fields. Diesels have the advantage at LeMans not because they are better (as I said before, with the same regulations petrol would dominate) but because the rule makers have MADE them better.

Therefore I have no interest in watching LeMans or WTCC.

If the rules were such that energy flow was restricted, but capacity, compression ratios, number of cylinders, number of valves were relatively free, then you get a fair comparison between engines, and the best one wins. Simple. More entertaining. And more honet - people actually buy diesels these days thinking they make decent performance cars!!!! How gullible is that!

Quote from tristancliffe :

In other words, to provide the marketting departments with suitable material, LeMan and WTCC are no longer level playing fields.

Yup, unfortunately that is true, but it's always been like that in racing, ran by the marketing men?, as in the old adage, win on Sunday, sales on Monday.

Quote from tristancliffe :

people actually buy diesels these days thinking they make decent performance cars!!!! How gullible is that!

I think they offer better performance vs ecomony, but petrol will always be the performance engine fuel of choice, I personally prefer diesel engines (and v-twins in bikes) because of the way those engines provide their performance.

I like WTCC, regardless of the rules favouring the TDi's, it does provide some good racing, as does WSB, even though it's the same story regarding the rules favouring some, and not others.

Quote from tristancliffe :

Therefore I have no interest in watching LeMans ....

I like that the ACO still has some (maybe vague.... but at least some...) interest in encouraging something other than single formula racing. There's a balance to made between puritanical fairness, and allowing deviation from the norm, encouraging engineering variety, that means that the sport doesn't simply stew in its own bathwater.

Whether the ACO has that balance I haven't recently been watching close enough to know, but I really don't see the point of anything done in the name of equality, that simply means "tried and tested" wins ... again.

Bring back Formula Libre...

There's encouraging engineering variety, and there's making one solution artificially superior to keep diesel manufacturers happy. I'm all for variety - I don't like one make racing in real life - as long as everyone works to a common set of rules, not better rules for one method.

It's got little to do with "tried and tested wins again", because given a certain amount of freedom to do what they like with common regulations would create new solutions that are directly comparible. As it is, we only know diesels make better racing cars when the rules are biased in favour of diesels - which manufacturer would turn down a relatively easy advantage?

Quote from tristancliffe :

There's encouraging engineering variety, and there's making one solution artificially superior to keep diesel manufacturers happy.

But they aren't, infact, they are fairly well balanced, the BMW's that finished 3rd and 4th in race 1 had a best lap of 1:25:1x and the SEAT's in 1st and 2nd had a best lap of 1:25:4x

The 3rd place BMW finished 0.7x of a second behind the 2nd place SEAT, not overly superior is it?

tristan thats the whole point of those regs though
give one engine concept a sizeable advantage to push manufactures in that direction and once youve got a nicely mixed field nerf it to create a level playing field again thus steering development torwards better more efficient diesel engines

I always thought the regulations (for engines) should balance out the different types to give the same performance, so that there should be no obvious preference for either fuel, on a performance basis. That way, in either case, you have to innovate in order to gain a performance advantage.

Edit: and what shotglass said

Quote from Bob Smith :

I always thought the regulations (for engines) should balance out the different types to give the same performance, so that there should be no obvious preference for either fuel, on a performance basis. That way, in either case, you have to innovate in order to gain a performance advantage.

Edit: and what shotglass said

You only have to look at the laptimes and results to see that is exactly what WTCC have got.

But they don't in Le Mans

Ahh, well, TBH, I know very little about Le mans, certainly not enough to know if the rules favour the diesels over the petrols.

Give them x amount of energy in whatever fuel they desire. Give them a race distance. Give them a basic set of regs for body size/shape and see what happens.

WTTC isn't a real racing series anyway, it's just entertainment, FWDs get favoured over RWDs, good drivers get punished with wheight ballast, now all this Diesel crap. Just enjoy the close racing and the crashes, forget about fairness and it's fun to watch

I wish I could do that, I really do. But for me the engineering and technical side of any racing series is important - The dullest F1 race (in 'action spectators' eyes) remains a hugely satisfying event for me. The best A1GP race (spec series) is as dull as ditch water for me.

Regarding WTCC I don't want to make any statement until round 8 when we have seen the cars on a number different tracks. But last weekend things looked pretty balanced. ...You don't see RAC drivers complain about the FZ5's unfair advantage on the straights either.

Apart from that racing is always the workplace of automotive pioneering. That means all regulations should be made to reflect what the automitive industry is trying to achieve. Right now we need more and more efficient diesel-engines. When we process oil we produce diesel as a by-product and at the moment it doesn't find as good use as it could (which we can see in the price). Thus we should promote diesel powered cars until this imbalance is rectified so we can make the most efficient use of the resources we have.
Also, diesel-engines still have a lot of room for improvement. We should really encourage any move towards advancements to diesel-engines. When we want to see cars that go 100km with less than 3 litres of diesel (we already got 4 L/100km) we need to make expensive diesel powered cars worthwhile in the car-shop, which means promoting diesel powered cars to customers through racing to break the "diesel is for trucks"-prejudice.

Vain

Quote from Vain :

Apart from that racing is always the workplace of automotive pioneering. That means all regulations should be made to reflect what the automitive industry is trying to achieve. Right now we need more and more efficient diesel-engines. When we process oil we produce diesel as a by-product and at the moment it doesn't find as good use as it could (which we can see in the price). Thus we should promote diesel powered cars until this imbalance is rectified so we can make the most efficient use of the resources we have.
Also, diesel-engines still have a lot of room for improvement. We should really encourage any move towards advancements to diesel-engines. When we want to see cars that go 100km with less than 3 litres of diesel (we already got 4 L/100km) we need to make expensive diesel powered cars worthwhile in the car-shop, which means promoting diesel powered cars to customers through racing to break the "diesel is for trucks"-prejudice.

So how is giving them an advantage from the start promoting improvements? Why should they make more economical diesel engines if they got a bigger tank anyway?

I forgot about the insanity of WTCC with the weight penalties; the whole series isn't based on 'may the most clever engineers win' but on 'make all the makes happy'..

Kind of useless series really isn't it!

Sorry for kinda ot, but as a fact/correction;

The Renault V6 turbo, from the last year that turbos were allowed in F1 (88/89?), went off the scale on the dynamo at their plant more than on one occasion. It read up to 1400 bhp.

This is around what these cars qualified with (maybe a tad less).

Quote from lococost :

WTTC isn't a real racing series anyway, it's just entertainment,

Er, no.

Quote :

FWDs get favoured over RWDs

How, exactly? There's only one make that uses RWD (BMW) in WTCC, and it's not as if they are uncompetitive.

Quote :

, good drivers get punished with wheight ballast,

Er, FIA GT and many other series use championship ballast. It also balances the cars up, a little.

Quote :

now all this Diesel crap.

How do TDI cars improve the show, specifically? OK, a few rule tweaks are needed with them (I'm thinking of a turbocharger pressure limit and possibly a base weight increase) but last year it was rather even. This year, however it could be different. BMW have made no secret of the fact been developing a 320d (they could introduce it at the third meeting to avoid an engine change penalty), and supposedly 888 have been developing a D2000 Vectra.

Ideas for Group C style fuel/energy limits are silly for touring car racing, all it will lead to is even more homogolation specials, leading to cost inflation - therefore, forcing out privateers, the lifeblood of touring car racing.

Touring car racing should be about racing modified versions of the sort of car people drive to the track in. It's not about technical development, or finding a cure for AIDS. Sportscars or F1 are series that can be used a platform for development. I'd say sportscars for that, given the distance.

Quote from bbman :

So how is giving them an advantage from the start promoting improvements? Why should they make more economical diesel engines if they got a bigger tank anyway?

Because when you switch from petrol to diesel you switch to new fuel which you simply don't know as well as you knew petrol. Basically it is all about making the transition easier and more tempting. Diesel engines in racing are not as advanced as petrol engines are (yet) so the transition phase evens out the differences. After a while the diesel gets better and the rules need to adapt and make diesel slower or petrol faster.

It is a bit like in F1, when they switched from V10s to V8s the first V8s weren't as sophisticated and refined as the latest V10s.

It is all about getting teams to use diesel and develop it better.