I believe that M-F was saying that his TT does indeed still allow throttle & brake inputs at the same time.

That I was 🙂 Not that I ever actually DO it (I just had to try out of curiosity this morning)

should have phrased his initial post differently

Indeed.. I meant sports car as opposed to hot hatch ie a car that's not just a souped up family car.

Next question – is my Orange 5 Agressive XC, All Mountain or Freeride Lite? 😉

molgrips, it doesn't matter.

Your Orange 5 won't handle as well as a proper factory built Aggressive XC, All Mountain or Freeride Lite bike. You might as well get a shopper. 😀

That I was Not that I ever actually DO it (I just had to try out of curiosity this morning)

Are you sure? My understanding is that declaration/engine braking when fuel is not being supplied to the engine is very severe with a modern common rail diesel, to the point of it being very strange to drive. So to stop this the pump/fuel supply still runs very slightly until you brake, where it cuts as engine braking is not longer an annoyance. I thought this was the norm with at least all VW?audi diesel engines.

My Audi does it every time, and it is very very annoying as it takes a while to put the power on again. I have experienced the same with a Golf, A3, Transporter T5, Crafter and Mercedes Sprinter.

But for those of us who know about road positioning, braking zones, apexes, straightening corners, left foot braking would almost all prefer a proper petrol engine that will rev freely up to 7 or 8k+ and give us the flexibility to use the much broader power band and minimise gear changes. They are simply more balanced.

I don't really agree, I haven't bothered owning a petrol road car for around 6 years, and there is no way I would go back. Providing you have 150bhp+ in a diesel they are fantastic drivers cars, and in terms of driving quickly I don't believe a petrol has anything over a diesel.

With regards to gear changes, I disagree, the torque of a diesel allows you to use fewer gears, and top end does not drop off after the power band in the same way a petrol does.

One of the only upsides is that you can heal and toe a little easier in a petrol due it reving-up quicker, although it is not an issue, just requires a little more care.

it takes a while to put the power on again.

Are you sure that's not just turbo lag?

FWIW my Ibiza didn't have any strange characteristics, but that may have been a PD engine, it was a 53 reg.

Are you sure? My understanding is that declaration/engine braking when fuel is not being supplied to the engine is very severe with a modern common rail diesel,

Mine is not diesel…

And I was thinking about the whole petrol v diesel performance car argument last night and came to this simple conclusion…

Diesel cars can be very quick and in some circumstances quicker than petrol engines (as I have already stated). But if they were overall quicker, better and more suited to performance cars then, quite simply, why aren't all performance cars diesel?

marketing would be my guess……….generally people want a petrol, rather than a tractor engine in their 'sports' car.
Perhaps that will change over the next few yrs as diesels continue to become more popular/improve.

There's going to be many reasons, including the ingrained thought that oil burners are not for sports cars, but also the image wont sell well, CDs have only fairly recently become a reality capable of decent power etc.

The market is driven by loads of forces, not just pure engineering logic.

So there is mass ignorance from Touring Car drivers (bar a few token diesels), Formula 3000, F2, F1, A1? And the vast majority of cars I see racing are petrol (watch hill climbing all summer) – Ferraris, Lambos, Scoobies, Evos, Westfields, Mini Coopers, Escorts Mexicos….

They would all be better off driving diesels?

Now I am not saying there aren't diesel racing cars, but the simple fact is that the vast majority of racing cars are petrol, right?

State the obvious why don't you? Any claim of greatness has to be relative. I mean there's just no point whatsoever comparing a Ford Ka to a Lotus Elise, is there? No-one on Earth would think a Ka would really compare to a proper sports car, there's not much point in even typing something like that. It again just makes you sound like a car snob

Well you were the one suggesting a Ka handles really well in a thread looking for a diesel *sports car*. As far as I'm concerned a hot hatch isnt a sports car and the original request was for a sports car, not a shopping trolley with above-average-for-class handling. Sorry if I misinterpretted but as far as I can read the original post asks for….

"something with 2 seats and no roof" not a skoda VRS. Theres a massive difference obviously, and leaving the "no roof" aside (screws with chassis rigidity and weight for the sake of wind in your hair, unless very well designed), you're comparing apples and oranges. As soon as you start bringing a Ka into the equation you're downgrading the class of car required (no longera sports car) and THEN say that because its made by the same people as make the focus shopping trolley it must be good handling it doesnt really sit in the original context of requesting a *sports car*.

m_f – there's no ignorance, lots of those manufacturers are experimenting with Ds currently, it IS a viable *alternative*. It just takes a very large shift in technology and knowledge to go from all-petrol to diesel. Some will always stay petrol, others will experiment. Think about your comments regarding the formula series and any organised motorsport – most of these series rules specify the fuel used, no motorsport team would experiment with other fuels in the hopes that the rules may change in the future.

To paraphrase a friend who works for a company subcontracted by Lambo, "lambo are great to work for, they dont consider emissions limits while designing".

Its a huge technological shift in production, sourcing and knowledge – not an easy step to make. Some just wont bother because the differences are fairly small, some will stick with one as its part of their heritage etc. Imagine you have a team of 100 engineers, they all have all of their knowledge based around big honking petrols, know them inside out. Someone suggests making a D engine – where do you get the knowledge? Buy in more engineers? convert some of your others? Take a risk on all that, or just stick to what you know and do well?

Well diesel is not permitted in any of the series you have mentioned for a start.

Formula 3000, is this the 90s already? GP2 replaced it, and has a spec engine.

A1 – see above.

F2 – assume you mean the new palmer series rather than the original, see above

F1 – whilst they can use there own engine they are limited to naturally aspirated 2.4L V8 petrol engines. They also cannot use turbos.

There are actually only a few series which permit non petrol cars, BTCC and ETCC (in which diesel cars have been sucessful race wineers) as you have mentioned, as well as Le Mans (in which they have also been sucessful race winners).

Why are they not more common? I put it down to fashion and the fact that performance diesel is a fairly new thing (really since Golf GT TDI). Also cost, it can be very costly to develop a diesel over a petrol.

Don't forget it wasn't long ago that diesel was something you put ina van or tractor.

I guess our definition of a drivers car differs.

racing cars are petrol, right?

Mostly due to rules, very very few series allow any choice of engine or fuel. If it were permissible to use different fuels then diesel and petrol would not get a look in.

I imagine it will change as time goes on, a diesel single seater series will not be far away imo (think Palmer Audi TDI).

I give up – I have not discounted diesel engines in race cars but the simple fact is that petrol cars are preferred (fair enough, in some classes required). Diesel is allowed in touring cars, it is allowed in hill climbing (anything is allowed there – they have every class going). Fair enough if some of the classes I mentioned no longer run, I was thinking off the top of my head – my knowledge of racing classes is clearly not as good as yours.

I have never doubted diesel is better in some circumstances – I have said so and repeated this too.

How many Le Mans have diesels won compared to petrol?

I have no doubt that diesel technology is vastly improved over what it once was, but still it is not as suitable for a race car as petrol. If it were, quite simply, more performance cars WOULD be diesel. It MAY change in the future and if it does become the better choice, people will buy…

It MAY change in the future and if it does become the better choice, people will buy…

Diesel Golf GT easily outsells the petrol for one example.

How many Le Mans have diesels won compared to petrol?

It was only recently legalised, since it was permitted a petrol has not won again.

hill climbing (anything is allowed there – they have every class going)

Good point, only reasoning behind this is that they rarely develop their own engines or technology, they let other people spend the money they take the redundant machinery for their cars. Most LArge hillclimb single-seaters use old IRL, F1, DTM technology. Perhaps if somethings becomes available to them one day then they will, but nothing is old enough to be passed "down the line" yet and they do not have the budget or know-how to develop their own. For saloons I believe there already are diesels competing.

I have never doubted diesel is better in some circumstances – I have said so and repeated this too

I know, I appreciate you are not damning them to hell, but you said that with your experience of high-performance driving they were not as good as petrol, I merely said in my experience diesel is superior. At the end of the day not one can be right or wrong here as it is our own opinions, and if I didn't respect yours I wouldn't have debated the matter with you.

I'm getting confused, on one hand you're accepting they're good and winning competitions and therefore obviously suitable for sports/race car use, yet on the other hand you say they're not as good or more sports cars would have them. You're aware of the fact that there are large barriers (mostly non-technical) in front of bringing Ds into performance cars and that in time it may change, yet you still claim its not as suitable.

The way I've interpreted what you've said from the start was that Ds are inherently not suitable as sports engines, yet this has already been proven wrong with several motorsports wins.

Look at the top two drivers in WTCC and what cars they drive….

Diesel Golf GT easily outsells the petrol one for one example.

That isn't a sports car 😉

It was only recently legalised, since it was permitted a petrol has not won again.

Interesting fact – I am impressed – but there is conjuncture that minimum weight (and other) regulations were increased at the same time to make the diesel competitive… The rules had to accommodate the need for a high capacity engine with a turbocharger and high boost, whereas both possibilities are no longer allowed for gasoline engines

For saloons I believe there already are diesels competing.

Yes – everything competes – I haven't seen a diesel go particularly quickly though. One of the fastest production cars I have seen is a mk1 Escort – beats the Scoobies and Evos at Harewood Hill Climb

and if I didn't respect yours I wouldn't have debated the matter with you.

Respect 🙂

Yes – everything competes – I haven't seen a diesel go particularly quickly though. One of the fastest production cars I have seen is a mk1 Escort – beats the Scoobies and Evos at Harewood Hill Climb

Again it comes down to the technology and parts available to them. Your Escort man does not make his own exhausts, inlets, ignition etc, he buys performance parts off the shelf from Aldon or whoever. Petrol performance parts for the club racer or tuner have been available/developed for many years, and there are many specialist companies who make and supply them. Diesel performance is relatively new, and they are very few things available at this time, this will change and they will become more competitive.

That isn't a sports car

Maybe not, but it is a "sporty" car, and I mentioned it to illustrate that currently there is a popular sporty model of car that has two choices of engine and that people are choosing diesel.

but there is conjuncture that minimum weight regulations were increased at the same time to make the diesel competitive…

Correct, and the same thing goes for BTCC, however you should consider that diesels have had circa 5 years of motorsport development and petrols have had 100. The weight advantage in BTCC and ETCC is very small. Le Mans was fuel related.

Interesting fact as to (possibly) why diesels are competitive at Le MAns… Diesels racing at Le Mans
Audi's decision to use a diesel engine emphasizes the commercial success of Turbocharged Direct Injection (TDI) turbodiesel engine (and its competitors) on Europe's roads. Diesels have been successfully used in other forms of racing as well, as their broad power band and fuel economy can prove advantageous, while in turn, the higher weight and lower rotational speed of the engine requiring new power transmissions are the disadvantages. The rules had to accommodate the need for a high capacity engine with a turbocharger and high boost, whereas both possibilities are no longer allowed for gasoline engines, as these had developed over 1,000 hp (746 kW; 1,014 PS) in several race series of the past.

So – a more economical car (meaning less fuel stops) running with a higher output than allowed for petrol variants…

Does that indicate to you that diesels only won due to that advantage? The fact that the petrol opponents were not in the same day of the week.

The real question is, does this affect whether or not a diesel is a fantastic performance drivers car? Interestingly it also mentions the power band, which contradicts one of your earlier statements.

I assume your TT is a new shape model?

Again – I don't doubt that diesel technology as come on hugely – it may become the weapon of choice for performance cars but like-for-like they do still seem to have more disadvantages than advantages.

Ahh well, really MUST get on…

Yes – mine is the new model TT

they do still seem to have more disadvantages than advantages.

Sorry (before you go), explain these to me?

Nooooooooooooooooo – read back the last 5 pages!

afternoon boys, is this thing still going!
ive missed out i feel, pesky work getting in the way, at work….

FWIW molgrips (or whoever posted the OP)
my suggestion would be:

Time, space, and money allowing (and being bothered)
why not buy a kit for a westfield, stick in a 1.6HDi, a hoofing great turbo, and remap it into mid feburary.

if i had the time, money, space and inclination, thats what I would do.

what fun, even if it never gets driven, just to build!
if it worked, you could get into enduro racing and hill climbing! 😀

Well the amount you edit your posts after publishing they may have changed by the time I get there!

😉

buy a kit for a westfield, stick in a 1.6HDi, a hoofing great turbo, and remap it into mid feburary.

That would be awesome, or an Elise with a blown engine/head gasket gone (not rare).

As soon as you start bringing a Ka into the equation you're downgrading the class of car required (no longera sports car)

I didn't! That wasn't me, I'm no lover of Fords! I've never driven a Ka. All I meant that was if a company makes a car that beats its class rivals hands down then that could be a great car – it was the definition of 'great' that I was talking about.

How much is a Westfield kit? I (as mentioned before) could really see myself putting the 1.9TD from my Passat in one, since I know exactly what I'd to do it to get 200+bhp 🙂 That's another advantage to diesel btw, it's easy to get bags more power out of it since you can up boost and fuel as much as you want without worrying about pre-ignition and whatnot. All you have to do is make sure the pistons don't melt and the head stays on 🙂

Interestingly on the fuel debate – a lot of sportscars are made by very small companies that don't have the money to invest in what is really new technology with the diesels and all. But I think it is changing – witness the R8 concept and some of those other sportscars pictured in this thread. That would never have happened 10 years ago.

I think the main advantage of diesel has to be the fuel economy. The more you increase the power the bigger the difference between the two fuels becomes I think as with diesel you are pretty much only injecting the fuel you need to move the car at cruising speed. A performance diesel could easily return double the fuel economy of a similar petrol in normal driving, but with the power when you need it. So for those who want hot hatches with practicality, or GT/roadsters etc (not a small market) diesel could be very attractive. It's certainly the reason I would be tempted.

Anyway it'll all be history when ethanol becomes widely available and they start making variable compression ratio engines like Saab are researching… tons more power than either fuel and potentially eco-friendly too.

a lot of sportscars are made by very small companies that don't have the money to invest in what is really new technology with the diesels and all

That is utter nonsense… Bugatti and Lambo are owned by VW / Audi, Ferrari, owned by Fiat, etc, etc

…and are developing diesels Linky

So – a more economical car (meaning less fuel stops) running with a higher output than allowed for petrol variants…

No, I think what it means is in order to reach similar powers they were allowed to use higher capacity and a turbo. Even with that higher capacity and a turbo they are still more efficient, meaning fewer fuel stops.

I know someone who worked on a westie with a commonrail D engine, I'll see if I can chat to him at some point.

They ran a diesel in that enduro event that Top Gear entered. I seem to remember that they had to stop for fuel three times less often than similarly powered petrol teams. That's pretty damn handy in an endurance race!

Btw that was one of the few TGs I actually enjoyed – it was great seeing them be real people rather than just pr*cks for TV.

It was me that mentioned the Ka, not molgrips.

I know, I just ended up merging all of my replies as I was busy, then confusing who I was replying to. Arguing on too many fronts at once, I need to spread myself less thinly 🙂

I always fancied a 406 coupe 2.2HDi but couldn't fit 2 bikes in it so bought an estate instead.

How much is a Westfield kit? I (as mentioned before) could really see myself putting the 1.9TD from my Passat in one, since I know exactly what I'd to do it to get 200+bhp That's another advantage to diesel btw, it's easy to get bags more power out of it since you can up boost and fuel as much as you want without worrying about pre-ignition and whatnot. All you have to do is make sure the pistons don't melt and the head stays on

kits are around the £5-10k mark. but remember theres lot more to a westfield kit that just bolting a few bits together. and sticking in a VW diesel – what gearbox will you use?
as for upgrading – i'd stick to the standard power for a while, tho you may find going for a petrol engine option best in a westie – remember a westie is around half to 1/3rd the weight of your passat – jumping straight into the 400BHP/ton will be a express ticket to the exiting the road backwards very quickly!

a good starter kit would be the MX5 based westfield – with either the 1.6 or 1.8 engine – and the supercharger kits can be fitted under the hood at a later point.

if your after 45+mpg sports car – get a 1400cc K Series Caterham, yes it might only be 100bhp or so – but again in something that only weights 500kg

petrol turbos are just as easy to remap btw – a simple plug in stage 1 reprogramming of the Saab's ECU will take the stock 150bhp to 210+bhp, changing the exhaust will allow better breathing and give a bit more power – then a stage 3 reprogramming will take the oringonal 2.0 low pressure turbo to close to 300bhp.

but remember theres lot more to a westfield kit that just bolting a few bits together. and sticking in a VW diesel – what gearbox will you use?

Well I realise that it's never going to be perfectly easy taking a transverse mounted fwd engine and putting it the other way round and driving the back wheels.. but if I ever were to do something like that there'd have to be a load of research done up front… As for tuning – I turned two screws on my Passat and gained what, 20%? I think I'm at the limits of my injectors and close to the limit of my turbo now.

Anyway, building a kit car is a long way from buying a diesel sporty car isn't it… 🙂