Guest ntc Posted July 23, 2008 Report Share Posted July 23, 2008 Neil the truck can do it because of its gearing and the heavy duty clutch. A 320 hp pulling 44 ton wouldnt do too well either as that size is considered way too under powered for that weight nowadays, 420 up to 610 is more the norm!I suspect the Audi could probably do the same if the clutch would take it but its power curve is totally different, the trucks maximum is delivered around 16/1800 Rpm! Stuart.. Wow trucks have got more powerfull my point was Stuart that the maths in calulating torque to bhp don't work here.I observed the guy's running the rolling road at Malvern and frankly was not impressed these young lad's were only trying to make a living like us all but there was a few errors in there methods. I wonder if anybody noticed that there car was tied down as opposed to being restrained on three of the car's this was to such an extent the rear tyre's was almost flat try getting good economy and power like this i think not Regard's Neil Quote Link to post Share on other sites
Jony Posted July 24, 2008 Report Share Posted July 24, 2008 does anyone have the details of the guy there? iv totaly forgot his name as im poo with names! which is really annoyin me! can anyone help? Quote Link to post Share on other sites
rpurchon Posted July 24, 2008 Author Report Share Posted July 24, 2008 100@125, whatever that is.Gear 3 But my gear 3 is not your gear 3, how/if he compensates for that..... ? I suppose I should have asked him what all the other figures mean, I'd somewhat lost interest. I got a separate print of the torque. Peak was 88 ftlb at 2850rpm, then fell off to 75 at 3200 then wobbled around 75 until 3,900 then tails off to nothing by 5,700rpm. Can torque be grossed back in the same way as HP? If so that would be 113 ftlb at the flywheel. HP peaked at 95 @ 5,250 but was above 90hp from 4,400 to 5,600. Ivor i have been searching the net re dyno dynamics machines. it appears they do test them in 3rd gear. i even read on one site they would get higher figures in fourth straight through the gbox. in the right hand little panel on the test sheet. all the figures seem correct re air pressure temperature humidity etc. lower down it says shoot 6 on my test.this apparantly means the operator cant fiddle the results to give higher readings.but this definatley isnt the case here with all the unhappy customers that i saw. it was just the same 2 years ago at the rolling road. a dutch bloke with a gt6 got 150 bhp.he definatley wasnt happy a chap with a tr5 got 138 and he wasnt happy. richard Quote Link to post Share on other sites
88V8 Posted July 24, 2008 Report Share Posted July 24, 2008 (edited) .....all the unhappy customers that i saw.it was just the same 2 years ago at the rolling road. a dutch bloke with a gt6 got 150 bhp.he definatley wasnt happy a chap with a tr5 got 138 and he wasnt happy. Jony - he was called TCS Performance. No address on the printout, but this might be him. http://www.tcsperformance.co.uk/5.html As regards the unhappy customers, like so many feedback exercises you're mainly going to get reponses from the unhappy. Unfair really for me to be carping on about this guy when he's not here to justify/explain, he has bills to pay and a living to make. After all, if my figures had been as I hoped, I would have been happy, wouldn't I ? Unimpeachable impeccable Really quite ineffable The very modern model of a motor measurer. Ivor Edited July 24, 2008 by 88V8 Quote Link to post Share on other sites
dblenk Posted July 24, 2008 Report Share Posted July 24, 2008 (edited) Hi Lads as i said earlier i got 82BHP at the wheels which i was disappointed due to all the info in the books saying this and saying that but when out in the car it pulls nicely and if the sun is shining and roof down i tend not to think about a piece of paper printout i have in the garage i will now use the print out as a starting point to gauge how my improvements work on the car, eg if doing the head gives another 15BHP then thats an 18% improvement on 82 therefore 18% more happy when driving and so on i think it makes sense what i am saying regards david PS i didnt use the guys at Malvern Edited July 24, 2008 by dblenk Quote Link to post Share on other sites
Kiwifrog Posted July 24, 2008 Report Share Posted July 24, 2008 I have never understood the rolling road/Hp thing for a road car myself. Fair enough if you are into competition etc. All I know is when I sneek my TR out into the road for a spin is that I come back grinning from ear to ear and the stress of my day just dissolves. I dont give a brass monkeys how HP'S it has, it goes and is bloody fun Cheers Alan Quote Link to post Share on other sites
Andy Moltu Posted July 24, 2008 Report Share Posted July 24, 2008 Rolling roads for road cars are useful to make sure things are set up right - particularly fueling - but the exact figures are essentially for comparison after modifications/adjustments. Quote Link to post Share on other sites
Guest ntc Posted July 24, 2008 Report Share Posted July 24, 2008 How much power http://www.diagnosticpower.com.au/multimedia/hp_promo.htm Quote Link to post Share on other sites
88V8 Posted July 24, 2008 Report Share Posted July 24, 2008 The major problems with these systems occur when changes are made to any of the rotating masses in the system. This includes items such as the clutch, flywheel, or aftermarket wheels. These items do not change the power of the engine (obviously). However they will change the rate of acceleration of the vehicle. Therefore these changes will change the power output measured on an inertia dyno. So a car like mine with big wheels will record lower power. And when I fit the 4.11 diff that's lurking in the garage, that will record higher power. Huh. Seems to me this type of dyno is a pretty useless thing for measuring absolute power. What it is useful for, I guess, is checking on a given day the effect of changes you make during the day: Power shot when you arrive. Fiddle with car. Another power shot Etc. Well we live & learn. Ivor Quote Link to post Share on other sites
Alec Pringle Posted July 24, 2008 Report Share Posted July 24, 2008 Hi Ivor, Yep, correct conclusion. Rolling roads are intended primarily as an aid to setting-up a car, an aid to making the best of its engine's potential. The rollers are not the answer to everything, they are a useful additional resource prior to fine-tuning the car and engine on the road or track. There are lots of rolling roads around, only a small proportion of these I would wish to utilise if I was looking for even a reasonable approximation of absolute power and torque curves. However, the fact that many rollers might be inaccurate in absolute terms is neither here nor there . . . their usefulness lies in their ability to rapidly record the effect of small changes. The idea that meaningful absolute figures might be achieved from a portable rolling road is, frankly, laughable - the exercise might be an excuse for a good-humoured wind-up, and that's about it. There's a lot of truth in the old saying, incidentally, that a rolling road is only as good as its calibration and its operator. Cheers, Alec Quote Link to post Share on other sites
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