My present car delivers (on paper) 144 ft/lbs of torque from 1905 cc.
The Citroen C3 delivers 151 ft/lbs from only 1400 cc. ( I hope my figures are correct)
Question. Are the ft/lbs the "same". In other words will it feel like more power or will it run out of urge on hills, for example, simply because even though it gives 151 ft/lbs it is giving them from only 1400 cc and not 1905 cc.If you see what I mean.
T I A
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Tony, I assume the C3 engine you are referring to is the 16 valve diesel. It's certainly an incredibly high torque figure but is 'max torque' and *could* be very peaky, i.e. achievable over only a very narrow engine speed range.
Perhaps someone has access to the torque curve and can describe it to us?
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I thought most diesel torque curves were fairly flat?
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Not turbo diesels! Think table mountain. I had a Saab 9-3TiD, torque didn't really start to come in until 2000 revs, then drops off at 3000. OK on the flat, but you try driving it somewhere hilly (e.g. Austria), and you will really notice it.
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To Tony Bee, there are no stupid questions, only stupid answers in my opinion.
To Dizzy:
here is the curve for the PSA HDi 90 bhp, is this what you are looking for? Shows before and after chipping, the torque curves are the top two, I'm sure you knew that. Quite peaky for a diesel I would say.
www.superchips.co.uk/curves/psahdi90.pdf
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FiF,
I have bookmarked the Superchips website, it looks a useful site for power and torque curves. Thanks for that.
I've often wondered why the car makers don't fit so-called 'superchips' from new. For example, why is it necessary to pay an extra £400+ to Rover for them to chip the Rover 75 diesel. Does any backroomer know if there is a downside to chipping?
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Since I last updated IE/OE pdf files don't download so I can't see this.
Wonder what has changed on the PC?
MM
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MiddleMan
Maybe your copy of Acrobat Reader is corrupted.
Try right-clicking on the link and select "Save Target As". Then double-click on the downloaded file. If it downloads but doesn't run, it must be an Acrobat Reader fault.
Ian
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Hmmm thanks Ian,
Your "right click and save as" does at least force it to download to the PC but it opens in Wordpad so reads as garbage...I'll re-load Acrobat from somewhere a bit later
MM
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MM,
Check the file associations. There may be nothing wrong with acrobat at all.
Try it the other way, open acrobat and then use acrobat to open the file. Or, depending on your version of windows, right click and use open with.
More by e-mail if you need it.
M.
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Thanks Mark, spot on with the clue to the problem...not sure why it happened though.
Right clicked and "opened with" to find a screen showing Acrobat latest version loading...like after you'd clicked install following a download.
Had to accept the licence and all that guff then the pdf file opened fine.
I'll come back with Citroen TD torque fighting talk later.
MM
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I think there's something funny about the Superchips curves, FIF. I've seen them before, but not paid much attention.
For the unmodified 90bhp HDi engine they show peak torque at about 2300rpm, whereas PSA publish 1900rpm. That's quite a lot of experimental error.
Their (Superchips) curves are, presumably, net figures - but they can't measure this at the flywheel in a customer's car. I think they use some fancy system whereby they "measure" the inertia of the drive train - or something like it.
However, their peak torque figure at the front wheels (which is what they actually measure) should still occur at about the same engine rpm as the manufacturer.
Unless PSA have it wrong.
;-)
Ian Cook
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I think there's something funny about the Superchips curves, FIF.
Know what you mean Ian. Eg for my Mondeo TDCi in the Ford brochure the curve looks like a cross section of the most mountainous parts of K2.
Yet on the superchips site they look bit like the HDi90 curve being discussed.
I just dismissed it as a function of the X & Y scales being used.
ie IIRC the Ford chart the axes did not intersect @ x=0, y=0
however the superchips curves are properly drawn IMHO.
I always thought they (Superchips) did this on a rolling road.
As for Dizzy's question about why don't manufacturers fit better chips as standard, I'm sure its all about emissions and trying to get a good result during the artificial test situation.
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The PSA HDI 90bhp curve on the Superchips site is the 2 litre model as fitted to 306, 307, 406, Vans, Xsara, Xantia, C5 etc
There isn't yet a curve for the newer 1.4 HDI engine. Nor is there the same car with both the 1.4 HDI 16v and the 2.0 HDI 90 for comparison purposes.
I have been driving a 2.0 HDI 90 Picasso recently and find it a very relaxing drive, and when you spin the turbo a bit, quite quick.
Ben
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Superchips really ought to have thought to specify the exact engines that their curves refer to. The lack of such important information is not very 'professional'.
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I'd've thought you would struggle to notice the differemce in the same car, if the curves are similar. Whether is will run out of urge will depend to a great extent on the weight of the car, and modern cars seem to keep getting heavier ...
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Had a drive in a colleague's new (to him, actually 51 reg old shape) Vectra 2.0DI 16v, found the engine to be incredibly peaky compared to my Octavia.
There's a set of traffic lights near my office, in the Skoda you can turn left at 15-20mph in 3rd gear, 1200rpm, and it will accelerate uphill smoothly to 3000rpm. In the Vectra I tried it in 3rd, no acceleration at all, dropped it to 2nd, now 1900rpm, still negligible increase in speed all the way to the hill top.
Drive the Vectra like a petrol, however, and it would out-drag the Skoda anywhere. A diesel car for petrol drivers...? (Still sounds like a diesel though)
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Had a drive in a colleague's new (to him, actually 51 reg old shape) Vectra 2.0DI 16v, found the engine to be incredibly peaky compared to my Octavia.
Correct me if I'm wrong but isn't this a case of comparing apples with oranges.
IIRC your Octavia is an SDi.
If so then 8v non turbo vs 16v turbo will give the result as described.
Also agree that the curve on the Superchips site is probably not the 1.4 as the bhp would presumably be described as 92 bhp and not 90. Also the torque figure is lower for the 1.4 than that on the curve.
Nevertheless when Diesel Car tested the C3 16v 1.4HDi they described it as peaky and not particularly relaxing, but quite sporty. If a 1.4 diesel could be described as sporty. I'd bet the curve is not too dissimilar in shape to that presented though.
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Stuart you said...
>>when Diesel Car tested the C3 16v 1.4HDi they described it as peaky and not particularly relaxing, but quite sporty. If a 1.4 diesel could be described as sporty.
Well that is where the C3 shows just how far we've come.
Take the performance figures that are associated with real world driving and compare them with that popular sporting icon of some ten years ago..the Peugeot 205 1.9GTI.
Left in 4th gear the C3 gets from 30-50mph in 7.5secs compared with 7.9 seconds for the 205 when making best use of the gears. In top the C3 can make 50-70mph in 8.8secs, just 0.1 sec slower than the 205 also in top. Yet the C3 has the apparent massive disadvantage of a 27.3mph/1000rpm top gear compared to the 205 with a gear of just 20.8mph/1000rpm.
The overall fuel consumption of the 205 on a brisk run would have been about 28mpg, I bet if the C3 was running in convoy on the same route it would do about 65mpg.
That's progress.
MM
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David,
I just love it when these feed lines get a response ;-)
Now I've done the straight man bit, I quite agree actually.
Seeing as you have the data in front of you how do the kerb weights compare?
Bet that shows just how good diesels really are these days. Another thing DC commented on was that the 16v was more peaky than the 8v, which is to be expected I suppose.
But go back even further, seeing as the latest 007 film is being plugged at the moment. How many modern cooking cars could give the DB5 a helluva run for its money. In its day that was one quick motor, and still no slouch but.....
Have you got the comparative figures for that in that pile of old magazines up in the loft. Is my impression correct?
Speaking of lofts I've go to go and clear up after installing a loft ladder. just had a cuppa break.
(off topic sorry, smacks own wrist)
Cheers hope all else is OK, I owe you a mail sorry been rushed off feet work and home. Off again at the w/end, back for Christmas.
FiF
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So you see me in a practical dark blue coat with fur round the hood ehh...instant access to all the data??
Spooky about the DB5, I had the figures for that car to hand but thought it taking the thing a bit far.
If you'd been the proud owner of an Aston Martin DB5 in the mid 1960s you would have never guessed some 35 years on a 1.4 diesel would have lived with your car in the most common overtaking speed ranges.
DB5 30-70mph in gears 7.4sec, the C3 is just 0.2sec slower left in 4th.
DB5 50-70mph in top 9.3sec, C3 0.5sec quicker...and the Aston is lower geared!
DB5 overall fuel consumption 14.7mpg.
AS a matter of interest the 205 1.9GTi has a kerb weight of 909Kg compared with the C3 at 1072Kg.
The C3 is quite heavy really, about the same weight as a lower spec ZX.
MM
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Disappointing that seeing as the C3 is a good car in many ways, that Citroen have wasted an opportunity by the interior trim.
Must make many punters remove the car from their list simply after the initial look in the showroom.
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MM
Another thought to this occurred.
Do you remember a while back, someone came on site and asked a question along the lines of..
I have this xxxx (fairly small Peugeot cooking diesel) and I want to see how it goes and handles. Should I try a track day?
Also do you remember the self proclaimed cognoscenti coming back with replies varying in rudeness from "it wont go much faster just get more noise," to "get yourself a proper car."
Personally wouldn't have blamed the guy for giving the Backroom a virtual two fingers and going elsewhere for advice.
I'd bet if the car had been a 1.4 diesel C3 the replies wouldn't have been any different.
But what would they have been if it had been a DB5???
We might have come a long way in performance, economy and dynamics. But not come very far in attitudes, snobbery and condescending attitudes.
With that wooden spoon extracted after final stir. ;-)
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Ah, but wasn't that a 1.9D? Not fast, but really quite refined for its day (I'm still running one in my BX. I agree many people still equate diesel with slow and noisy. That 1.9D was the first step to changing all that. It's truly remarkable how far diesels have come in just the last decade. I am very excited about the January arrival of the HDI 90 I just bought. Incidentally on the test drive(s) I kept over gearing the HDI on corners. One thing the 1.9 does have is low down torque.
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