Series 2 Engine Performance Curves.

Following a recent remark by Jorgy9, I append the performance curves for the three engines that were introduced with the S2 car. They are not very good quality but were printed from the S2 manual, then scanned to convert them to jpg format and finally copied to photobucket. Afraid I have no comparable info on the older engines (2.0 petrol, 2.1 turbo diesel, 2.0 petrol turbo, 12 valve V6 and 24 valve PRV V6) as presumably they appeared in the S1 manual.





The French torque units are m.daN - meter.decaNewtons, easily transcrbed to SI units by multiplying by ten, so 21.5m.daN = 215Nm.

With the info provided by Jorgy9 we can make a reasonable fist of producing the figures for the older 12V engine. Sorry George, I can't associate torque with mass units so have converted to SI:
Torque at tickover (1000rpm?) = 196Nm, power at tickover = 27.5hp;
max torque (4600rpm) = 235Nm, power at 4600rpm = 152hp;
torque at max power (5600rpm) = 216Nm, power at 5600rpm = 170hp.

Compare these figures with the torque of the ES9J4 engine:
At or above 230Nm all the way from 1000 to 6000rpm; at or above 250Nm from 2500 to5500rpm.

Of course, to convert torque into road performance we need to compare overall gear and final drive ratios.

Derek

Hi Derek

I'm sure I have the relevant graphs for both the PRVs somewhere in my office pc, I'll look for them next week and post them here.

G

Thank you George, that would be good. I would very much like to see the curves for the 2.0 turbo.

Derek

Ok here we go, that's all I found:


1/ PRV 24v (90deg)




2/ PRV 12v (90deg)




3/ ES9J4 24v (60deg) from unknown origine dyno test 1




4/ ES9J 24v (60deg) unknown origine dyno test 2




5/ Volvo 2.5td (4 in line)





Unfortunatelly I don't have the 2lt turbo graphs. I saw its graph in a roadtest I found in my archives in Christmas back home and, from memory, it gives a steady 22-23kg of torque from 2000rpm to 4000 or 4400 -a straight line totally parallel to the X axis-; 4000 (or 4400) is also its max bhp power, which is then kept steady at 150bhp till 5600, where it declines. That is, they've calculated the pace of torque drop after 4000 (or 4400) in such a way that horsepower stays absolutely constant from 4000 (or 4400) to 5600. In other words there's no reason why taking this engine above 4000 (or 4400) -it gives nothing else-. I wonder what are the tuning possibilities of that engine as all those "strange" lines are achieved because of the dump-valve electronic control -and it has no intercooler-.

cheers
G

Thank you very much for that wealth of information, George. I'm going to print it off and study it at my leisure. One odd thing, your graph for the PRV 24V equates to 197 HP rather than the 200 often quoted.

Thanks again.

Derek

Hi George,

One other interesting feature of the Polish road test curve of the ES9J4 engine is that a speed of 206.2 km/hr at 6131 rpm equates to gearing of 20.9 mph/1000rpm. Top gear ratio is 26.5 mph/1000rpm so the test must have been conducted in 3rd (if auto) or possibly 4th if manual, probably so they could guarantee reaching peak rpm.

Derek

Hi Derek

I think you are reading the "147" for Kw ? Next to it there's "200" written.

G

Hi George,

I admit I hadn't spotted the 200.

But I always understood that there are 746 Watts in 1 horsepower, and 147,000W divided by 746 =197 HP, n'est pas? Or am I wrong?
Derek

This post has been edited by DerekW on February 01, 2008 01:20 am

Hi Derek,

Don't really know as my mathematical knowledge of this area is close to 0. Perhaps you are right and the French have used a different measure to homologate the car when converting from KW to horsepower. If you notice the graph the measure used for hp is "ch" = "chevaux", horses, but would you know which "horse" the French are commonly using? With the HP equal to 746W none of the values fit, eg the 12v would be 164hp instead of 170. I know on German adverts they use the "ps" measure and those aggree with the french-given specs.

cheers
G

Hi George,

Yes, wierd isn't it? The ES9J4 figure doesn't make sense either, comes out at 188hp or something. I wonder if they are referring to gross or net horsepower (stripped or with ancilliaries fitted) or even at-the-wheels horsepower although that's unlikely as manufacturers like to quote as high figures as they can.

I'm going to settle down this evening and calculate power from torque (2 x pi x RPM x torque divided by 60), to try to establish what figures they are using. I'll post the results later.

Derek

Hi Derek

Try http://www.citroen.co.uk/conversion/c_conv...converter_rates

For the 24v 60deg engine - yours and mine the torque looks about right, max 191lbft but the bhp looks too low.

Flat torque curve thought )

Cheers

Tony

Thank you Tony, that's a very useful table.

So the horsepower they quote isn't our horsepower as calculated by James Watt, but some anaemic Froggie version!

Derek

I wonder if this is the same with other brands and cars...?
G