davidwort 0 Posted October 27, 2003 Thought a few 16v owners might like to see these power curves from AMD's rolling road, one is for my 16v as a standard 1.8, the transmission loss etc is a bit on the dodgy side as it shouldn't be more than about 15% for a FWD car, but the comparison to the 2.0 plot is interesting (I think :) ) The inlet and exhaust manifolds have been cleaned up and the head gas flowed, together with the 1984cc bottom end give a pretty good BHP hike. The cams are the same 1.8 ones and have the characteristic 1.8 peaky power curve, and you can see from the two lines that they have exactly the same characteristics on the engine after the engine conversion. My overlaying of graphs is not perfect and there's plenty of room for error in all of this data but you can clearly see how the low revs figures are virtually the same and it's only over 4,000rpm that it really gets going. Calculated BHP at the wheels is about 20bhp up which is about what you'd expect from this sort of engine work. I've also got a plot from Stealth with a standard 2.016v plotted against mine (run on RR on the same day last year), standard 2.0 16v has a very flat torque curve and actually more torque below 3500rpm but the power curve is also flatter and makes about the same 110bhp at the wheels as a standard 1.8. The 1.8 cams give a small mid range dip in torque and power as the trade off for the top end but on the road it's a pretty good compromise. David. Quote Share this post Link to post Share on other sites
vr6storm 0 Posted October 27, 2003 nice figures you've got there...........though i think 15% transmission loss is a bit of an underestimate even for FWD i'm sure its nearer 20-25% transmission losses for FWD.......all my RR figures have shown between 150-155bhp at the wheels and approx 190-195bhp at the flywheel Quote Share this post Link to post Share on other sites
davidwort 0 Posted October 27, 2003 take a look at some of the info on this site, particularly the Technical articles and the one on transmission losses, very interesting even if the maths gets over my head quite quickly :) http://www.pumaracing.co.uk/ http://www.pumaracing.co.uk/trans.htm I spoke to Dave Baker at length before starting work on my car and he knows his stuff. David. nice figures you've got there...........though i think 15% transmission loss is a bit of an underestimate even for FWD i'm sure its nearer 20-25% transmission losses for FWD.......all my RR figures have shown between 150-155bhp at the wheels and approx 190-195bhp at the flywheel Quote Share this post Link to post Share on other sites
vr6storm 0 Posted October 27, 2003 blimey!!!........someone had fun putting all that info together :wink: see where you're coming from :wink: ..........the only thing tho is that both you and i have had more than 15% losses on different rolling roads(all mine bar 1 have been done at Star-performance) and as the power at the wheels figure is what is the more "real-life" figures to use as that is in essence what is being measured directly.....does this mean that your flywheel figure is out then???........or am i having a blonde moment :? :wink: Quote Share this post Link to post Share on other sites
davidwort 0 Posted October 27, 2003 as far as I know the only actual 'measured' value on a RR is the torque at the roller, as the roller effectively brakes the car with a 'matched' force to keep the car at a steady speed. everything else is calculated and has various corrections built into the software. The temperature and pressure values can have big effects on calculated wheel and estimated flywheel figures. Problem is, manufacturers quote figures for new engines in very controlled conditions and it's difficult to get a real car to 'fit' these figures without some dubious and pretty un-scientific practice. The way I look at it is my on road performance seems to bear out the wheel BHP figures fairly well, I can easily match a standard 1.8T golf and pretty much keep up with Leon cupra's so I must be in the 150-170 bhp area if these newish cars are running close to spec. I'd say my flywheel figures could be too high, maybe they should be nearer 150-155bhp, but it seems likely that most RR give everyone a slightly optimistic calculated crank bhp, mainly because it keeps everybody happy! I think it's more 'cock-up' than 'conspriacy' though :D cheers, David. blimey!!!........someone had fun putting all that info together :wink: see where you're coming from :wink: ..........the only thing tho is that both you and i have had more than 15% losses on different rolling roads(all mine bar 1 have been done at Star-performance) and as the power at the wheels figure is what is the more "real-life" figures to use as that is in essence what is being measured directly.....does this mean that your flywheel figure is out then???........or am i having a blonde moment :? :wink: Quote Share this post Link to post Share on other sites
dan 0 Posted October 27, 2003 Pretty impressive indeed... bet that rebuild wasn't cheap! btw, that guy from 'pumaracing' does seem to know his stuff. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 27, 2003 Circa 160bhp is about right for a 2.0 with KR cams and so is 20-25% transmission loss. I've dyon'd 4 of my VWs, and they all lost 25% through the box. Kev Quote Share this post Link to post Share on other sites
Jim 2 Posted October 27, 2003 I believe that standard 2.0 16v power curve was mine.. 143.9BHP was what I got at the Stealth Racing RR day last year.. and I remeber you chatting to me about what figures I got David :D Quote Share this post Link to post Share on other sites
Mike Edwards 0 Posted October 27, 2003 Right... need to get some gas-flowing done.... 1.8 16v - 153.8bhp at flywheel, 114.7bhp at the wheels, 128.9lbft (38.1bhp transmission loss...) Quote Share this post Link to post Share on other sites
davidwort 0 Posted October 28, 2003 Yep that was it! That C of yours was pretty healthy, nice smooth power curve and lovely flat torque curve too, I think it always makes more sense to compare cars figures on the same RR on the same day rather than just read too much into the peak values you get. Not still got a Saxo have you?! :wink: http://www.pistonheads.com/rants/defaul ... oryId=3132 cheers, David. I believe that standard 2.0 16v power curve was mine.. 143.9BHP was what I got at the Stealth Racing RR day last year.. and I remeber you chatting to me about what figures I got David :D Quote Share this post Link to post Share on other sites
Bally 0 Posted October 28, 2003 I've driven David's car, and must admit it goes really well.. :D definantly doing the flowing etc on myn when funds allow... :D Quote Share this post Link to post Share on other sites
