wez_p Posted June 20, 2005 Share Posted June 20, 2005 had the car dyno'd on a mobile rolling road on Sunday mobile rolling road not 100% on the reliability of the thing but they claimed they were usually within 5% of people's comparisons to regular RRs anyway, jsut wondered if anyone could give me some ideas as to why it appears that the power drops off so quickly on the curve could it be leaking boost maybe? Link to comment Share on other sites More sharing options...
adi2009 Posted June 20, 2005 Share Posted June 20, 2005 that s very odd. would suggest that u just get to a good RR and check it out. Link to comment Share on other sites More sharing options...
Nic Posted June 20, 2005 Share Posted June 20, 2005 Wes, what is the scale at the bottom and why is the graph back to front? The power will drop off before the redline on all cars running stock turbos, it's just the efficiency range of the relatively small turbos, ie. they spool up earlier but start to run out of puff earlier too. Fitting cams will reduce the drop off a little but you'll still get a drop off (as you can see on my dyno graph on the link in my sig.) Link to comment Share on other sites More sharing options...
michael Posted June 20, 2005 Share Posted June 20, 2005 Hold it in front of a mirror and it might look a bit better, very odd graph, definately looks the wrong way around. Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 And what's with the lines crossing at 4500K? The units are supposedly lbft and hp. If the printout is inaccurate compared to the scale, how could anybody trust it at all? Did you pay money for this? Link to comment Share on other sites More sharing options...
wez_p Posted June 21, 2005 Author Share Posted June 21, 2005 Wes, what is the scale at the bottom and why is the graph back to front? The power will drop off before the redline on all cars running stock turbos, it's just the efficiency range of the relatively small turbos, ie. they spool up earlier but start to run out of puff earlier too. Fitting cams will reduce the drop off a little but you'll still get a drop off (as you can see on my dyno graph on the link in my sig.) from what i understand, the bottom scale is RPM. I did tell them that it would go up to 7000 but looks like he only went to 6000 - and apparently, the graph is the right way round!! GarethEves had his on the rollers straight after me & there was nothing like that kind of power drop off afterwards for him the operator thought that the massive torque reading was due to him feathering the throttle to avoid the kick down from 3rd to 2nd and then there being more fuel suddenly when he went for it Link to comment Share on other sites More sharing options...
wez_p Posted June 21, 2005 Author Share Posted June 21, 2005 And what's with the lines crossing at 4500K? The units are supposedly lbft and hp. If the printout is inaccurate compared to the scale, how could anybody trust it at all? Did you pay money for this? doh - yes i paid money for this (£30) is it worthless? is my glory of 334BHP possibly just a computer mistake?! tell my secretary to get Thor on the phone... Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 .. is my glory of 334BHP possibly just a computer mistake?! Is it a random collection of bytes, a fluke? That's anyone's guess, but the whole setup certainly looks dodgy... If you like the figure, what difference does it make, it's all in the mind, right? I've seen people add another 20-30% to compensate for 'drivetrain losses' then quote the result as 'at the wheels' because that's what was used to do the test in the first place (as opposed to the steering wheel perhaps ) Be happy Link to comment Share on other sites More sharing options...
Guest Terry S Posted June 21, 2005 Share Posted June 21, 2005 Couldnt agree with John more. As an example I have taken two people out for demos in my car recently, both of whom have also recently been in a similar spec car. Both say my car is definitely faster, but the other car apparently has a dyno showing more power at the wheels than I believe mine has at the flywheel. The figures are irrelevant, and only any use for comparison for upgrades on the same car, and then you need to get similar conditions for them to be meaningful. There are some very high figures flying around on this bbs but they really are only any use as an ego massager. They are not real, and I am sure road performance would prove this. If your car drives well, pulls hard/clean, and has good AFR's, be happy:thumbs: Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 Pffff, amateurs, I like all those 4-digit 'at the wheel' figures of http://www.to4r.com. Especially the 'stock block' and 'pump fuel' claims. (yeah, define 'stock' and 'pump', Bill Clinton's legal team would have a field day lol...) Quite entertaining, methinks... Link to comment Share on other sites More sharing options...
Guest Terry S Posted June 21, 2005 Share Posted June 21, 2005 MMmmmm different can of worms, the Americans tend not to load their dynos so the RWHP figures are always going to be high. I have no doubt that they do however make massive power........BUT.......that is what a 5 second dyno pull, I am not convinced they would stand up to much more than that, but those guys are definitely pushing the envelope. My last car made 690 flywheel bhp on a proper engine dyno. That was at 25 psi, on 106 octane fuel. I drove the car on the road in that configuration. It was unusable anywhere apart from dual carriageways/M ways in high gears. My current set up I would guesstimate is 500-550 FW on optimax. It is a plenty enough quick road car for anyone, and a far better car to drive for its lower output/less lag. As you can tell, I get a little frustrated when people chase numbers whilst wanting a "road " car. Link to comment Share on other sites More sharing options...
Bobbeh Posted June 21, 2005 Share Posted June 21, 2005 MMmmmm different can of worms, the Americans tend not to load their dynos so the RWHP figures are always going to be high. I have no doubt that they do however make massive power........BUT.......that is what a 5 second dyno pull, I am not convinced they would stand up to much more than that, but those guys are definitely pushing the envelope. Indeed they are, John dont be so quick to judge/dismiss their figures and claims just because it sounds outrageous. I've said it before but they've been tuning these cars excessively for a lot longer than we have over here, and on a MUCH larger scale. Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 ...they've been tuning these cars excessively for a lot longer than we have over here, and on a MUCH larger scale. true ...dont be so quick to judge/dismiss their figures and claims just because it sounds outrageous. I cannot judge, I'm not Dredd. Neither can I dismiss something I have no first-hand experience of. But I can be entertained, certainly. Keeps me amused, if you like... Link to comment Share on other sites More sharing options...
Bobbeh Posted June 21, 2005 Share Posted June 21, 2005 I know, more like Judge Judy - hehe Link to comment Share on other sites More sharing options...
CJ Posted June 21, 2005 Share Posted June 21, 2005 I know, more like Judge Judy - hehe Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 Who is Judy, could someone enlighten me please? Link to comment Share on other sites More sharing options...
CJ Posted June 21, 2005 Share Posted June 21, 2005 Who is Judy, could someone enlighten me please? You obviously dont watch enough afternoon crap TV from America She is the "star" of a program showing real life court instances - of the mundane (although entertaining) variety. Link to comment Share on other sites More sharing options...
JohnA Posted June 21, 2005 Share Posted June 21, 2005 ...so am I akin to an Oprah character then? thanks guys, I'm touched. Link to comment Share on other sites More sharing options...
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