Ping Tom De Moor

All sounds bloody brilliant. Sorry to be a bore, but I thought I'd pick up on this bit, and quickly mention that to save anyone else having to work it out - divide 282.5 by a l/100km figure to get mpg (our gallon, the one that has 4.546 litres in it).

It all sounds very impressive.

And for the benefit of non-German speaking English follocks, I've done a quick babelfish translation of that German bloke:

"Wass have it made?! So fast commodity the 928 not? Is test vehicle fur the new 928? How quickly geth it?"

so when it comes to the question 'any modifications' by the insurance company it becomes a very long phone call?

still my BM could 'av it i bet :)

Yeah yeah: you lot sold the Americans gallons with 3.8 liters in it :-)

You've got the translation more or less right. :-)

"What have you done (to it)? The 928 was never so quick! Is it a testmule for the new 928? How fast does it go?"

As to the fuel comsumption: I must have been focussed too much on the high speed runs and optimalised that area. The car uses more fuel going slow than going fast.

This -in my view - is a genuine reason to get the tuning tool from John Speake, visit the UK again and save planet Earth while have more power and less fuel consumption (*)

Tom De Moor

(*) The 928 has a rather good fuel flow meter so you can immediatly see the fuelmods John Speake's Sharktuner makes. Very well done.

"AstraVanMann" gurgled happily, sounding much like they were saying:

Which means that the 35l/100km when he's flooring it is... Eight mpg.

Actually, I'm surprised it's not worse...

Big tuned V8? You just aren't trying hard enough or have it in too high a gear. A little 1.8L 4 pot on stock 370cc/min injectors can drink it's juice quicker when tuned to stage 2. 250bhp maxes them out so people fit 444cc/min for stage 3 (300-330bhp), 550cc/min and even bigger for higher power. Maxed injectors run about 0.85 duty.

250bhp = 0.85 x 60 x 4 x 370cc/min = 75L/h (tank lasts 48min).

In 1st at 50 Km/h (5900rpm) is 150 L/100Km. In 2nd at 80 Km/h (5450rpm) is 94 L/100Km. In 3rd at 130 Km/h (5900rpm) is 57 L/100Km. In 4th at 175 Km/h (5900rpm )is 47 L/100Km. In 5th at 220 Km/h (6100rpm) is 34 L/100Km.

Put it in 2nd or 3rd, nail the throttle pedal to the floor and then see what your L/100Km is.

The 197 did 28.3mpg combined according to the trip over the 2,600 miles jaunt I've just done :) 10 countries, 5 days, included autobahn work and 4 laps (so, close on 50 miles) of the ring... All done loaded with luggage, 3 non-petit guys and having the aircon maxed 90% of the time.

Ican't grasp that either. When you said that you sent it to the states, I thought WTF? It's sad that there's no interest in Europe in engineering performance Porsches of that era.

Well, that is fairly simple: in first, second or third putting agressively the pedal to the floor results in lots of white smoke from the rear arches followed by the RPM-limiter cutting in. The fuel flow is not quite readeable as it doesn't get the time to stabelise. PSD-light comes on immediately :-)

I went to some programming and the enrichment procedure is just a number and set at 300%, so it is quite normal that under acceleration fuel flow goes through the roof.

What is however less normall, is that cruising at 120 kph is heavier on the fuel than at 180. So I guess that the fuel map on full and part loads can be optimalised a bit further. Anyway: the no-cat X-pipe will reclaim its position, so that will need some calibration too.

Finally: before it was modified, lapping at Spa resulted in an overall

44 l/100 km fuel rate, meaning every 50 minutes a fill up. I shall let know what it has become now :-)

Tom De Moor

[snip envy inducing Porsche story]

Mate, that sounds awesome! Next time I'm strolling through Belgium village, I'll keep my eyes peeled for the beast!

Depressingly, your 6.5 litre engined car has better fuel economy at

180kph than my 1.6 litre engined car does at 110kph! I always knew I needed a Porsche really.

Hmm, I suspect his car either has better mpg or it's doing 180kph, but not both. I did Milan to Frankfurt once, getting into Frankfurt at about

2PM, the drive from Milan to Chiasso was fairly frantic, hitting 240km/h when I could. From Chiasso to Basel was bloody pedestrian for the Swiss are barsteward policemen. And then Basel to Frankfurt was done ignoring speed limits and averaged 230km/h.

In Switzerland the mpg was quite reasonable. In Germany it was pathetic.

My 6.5 litre-car sees only limited action: on one I fear getting "used" to it, on the other side: the Belgian State seems to have augmented its desire for "variable taxing". The rate at which speed tickets fall into my mailbox, makes a private airplane become an affordable way of transport.

But even so: I am shocked of the performance potential that lies hidden, unused and eventually wasted in every car and the experience with the

928 highlighted that.

Performance is defined by power, weight and drag.

I am convinced that "weight" is rather easily adressable. Do not worry: with steel prices increasing 60% for car makers, they will pull out some solutions which were kept stowed away for too long now.

All the best,

Tom De Moor

We'll be back to the Citroen BX soon, some buyers thought it was "tinny" but it used high spec steel for light weight, pioneered the plastic bonnet/hatch for the same reason and offered good economy and performance for the class as a result. The later cars were engineered for "feel" rather than light weight, because buyers insisted on a "quality" feel.

The odd thing is that Jaguar owners were happy to change to a very lightweight alloy monocoque even though that meant that the doors feel much lighter than any previous Jag.

Sorry Steve, I've had my Munchen-run and things confirmed.

"Cruising" at 170-180 kph (GPS checked) at the Autobanh resulted in

8.5-10 l / 100 km as long as I kept it steady (read cruise control)

Unfortunatley (but wanted) I met some friends, well not friends but people/ cars I know, and as little kids we showed off, embarassing the Lambo who can't run away no more, in the proces.

Acceleration fuel rates go through the roof, but "steady state" became rather acceptable.

Stabelised fuel flow at 230 kph arond 14-15l/100 kph. Things tooks off at 260 kph (around 20 liters/100 kph). Above that the flow rate couldn't stabilise because even at night a bunch of maniacs travelling at + 260 can not keep that speed for long because of "tight Autobahn" corners or other trafic dictatating it, not to mention one has to keep a look at the road.

I am guessing but 260-290 results in 30-35 l/100 km fuel flow, which is still lower than the "top" acceleration fuel flow figures. The car is definitely capable of + 300 kph but the raods are not.

All in all: the Brussels-Munchen-run has spiced up but due to trafic my personal best (4Hr48' for 880 km; car Audi V8TDI) is not broken. The 928 did it somewhat 15 minutes slower but had to fill up once more than the AUdi). If I can hold a constant speed of 240-250 kph for the duration and be spared of slow trafic, than chances are tbe "old" 928 will bring the A8 to shame (in time, not in money spent as the Audi drinks the fuel Pete M and Burgerman hate ;-) )

Which is not bad considering the 928 shape / aerodynamics dates back to the 1980's...

Tom De Moor

I think rather that the marketing department insisted on that "quality" feel and more specific the "quality" clonk of the doors closing. Of course safety regulations imposed weight gains too but were cars of the

80-ies really that deadly?

Who is to blame that a mid-sized, normal car now tilts 1600-2000 kg on a scale, is not important: it's about 600 kg too heavy. The engine guys run out of solutions (and tanc capacity) to keep the car away for petrolstations, the owners run out of bancnotes to fill up :-)

I suspect that the actual big, heavy cars are going to depreciate faster that a brick can fall. The situation exist in the US allready: a year old monster SUV (50.000 US$) is yours for 12 tot 15 kUS$

The Jaguar (and Audi) story about "lightweight alloy" is somewhat blurred: the lightweight alloy versions come in close to the same or even more that the steel versions they remplaced. As to the makes of similar cars only Jaguar has a smallish weightadvantage.

XJ6 1580 kg. Merc S350 1700 kg. Audi A8 1800 kg . BMW 7 1880 kg.

Don't get me wrong: aluminium will play its part but untill now it hasn't fulfilled the initial hype around it. Only two cars have massively embrased the gains of aluminium: the Honda NSX and the Lotus Elise. That was because fron concept they were designed around aluminium, each however using a different method.

Light alloy usage in most cars ends up as with the light alloy wheels, who weigh 20 to 30% more than their steel counterparts. Back to the drawing boards and add less weight, please!

Tom De Moor

I qwouldn't call a 300Kg weight advantage over the BMW "small", and it's notable that the Jag is 220Kg lighter than the aluminium A8, and 155 Kg lighter than the S350 ( you dropped 35Kg off the S350). People pay Ferrari and Aston Martin £40K plus to lose as little as 150Kg from their cars.

I'd say the XJ "massively embraced" aluminium and did a better job of it than the Audi sogmobile. FWIW, the Jaguar uses a very similar technique to the Elise, having epoxy bonded aluminium components, and goes further than the Elise in having a true monocoque.

Well, yeah, understandable. What car was it?

Do you not get points on your license there then?

Oh, I've no doubt! But I'm certain it won't be running cars on water, no matter what the spam in this newsgroup tries to say!

It's ridiculous isn't it? Shows what the average Joe knows, though. I'd have thought that a light-weight steel door could have it's sound changed with some shrewdly placed sound-deadening material (adding weight, I know).

I would have thought that Jag could get away with such a switch due to the bias it would set up: Jag use this new stuff, jag are a high quality car, therefore this new stuff must be a cut above the rest of the tat out there.

And so on.

One of the Jags. I think it achieved 2mpg climbing the Gotthard pass, and infinite mpg on the descent, averaging 27mpg for the transit of the pass.