craigyb Posted November 5, 2011 Share Posted November 5, 2011 I'm having some verniers fitted this coming thursday, with rolling road before and after. The car is used for touring, track days and will be doing some sprinting next year. Question is, should I go for more mid range torque or more top end power? 😶🌫️ Link to comment Share on other sites More sharing options...
Dignity Posted November 5, 2011 Share Posted November 5, 2011 When I had my verniers fitted to my "K" by DVA. I was informed that it would not really affect the top end power. Getting the timing spot on increases the torque which generally means an improvement in the pick up and driveability. A worthwhile upgrade Edit to add. Look forward to hearing the before and after. Edited by - Dignity on 5 Nov 2011 12:00:58 Link to comment Share on other sites More sharing options...
Area Representative Nick Chan Posted November 5, 2011 Area Representative Share Posted November 5, 2011 I'd go for mid end torque and better driveability. Having top end power is all well and good if you are flat out everywhere but in reality you have to slow for corners and having better torque as you come off the bend/corner is going to be better I reckon. Nick Link to comment Share on other sites More sharing options...
oilyhands Posted November 5, 2011 Share Posted November 5, 2011 If the cams are *correctly* timed they will give the best in the mid range withoiut affecting top end power. Badly timed cams give a push at the top and very little mid range, this is the characreristic 'kick' at the top end you sometimes get with Supersports when the cams are madly, wildly, ridiculously timed. The kick may disappear when the cams are properly timed, this is not becuase you are losing anything at the top, but simply because the transition from mid range to high is better as there is a lot more torque lower down. Oily Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 5, 2011 Share Posted November 5, 2011 Mid range torque every time Link to comment Share on other sites More sharing options...
Jason Plato Posted November 6, 2011 Share Posted November 6, 2011 your not going to have any choice between mid range torque and top end power, the cams will either be timed to get the optimal performance from the cams or they are not. unless you have a change of cam, induction length change and reprogrammable ecu you can't change the engines characteristics. time the cams to those settings on oilys pages and don't bother with the rolling road as it won't provide anything except a big bill. Link to comment Share on other sites More sharing options...
Silver Machine Posted November 6, 2011 Share Posted November 6, 2011 Oilyhands fitted mine and changed the charachteristic from ridiculously timed with a 'kick' to the smoother transition. The car has driven a lot better. Mine is a supersport and at the top end the power still fells the same but the retune made the journey through the revs a lot smoother. Link to comment Share on other sites More sharing options...
Steve, Carol and little Cl Posted November 6, 2011 Share Posted November 6, 2011 At a presentation form Cosworth at Uni many years ago the guy started off with something I´ve never forgotten: Power sells cars and torque wins races. Edited by - Steve, Carol and little Claire on 6 Nov 2011 10:02:58 Link to comment Share on other sites More sharing options...
craigyb Posted November 6, 2011 Author Share Posted November 6, 2011 Thanks for the advice all. A pretty clear message that's helped me to get my head around the whole thing :) Link to comment Share on other sites More sharing options...
richard bradbury Posted November 6, 2011 Share Posted November 6, 2011 I changed the cams on my Vx to a version which was quoted as improving power from around 170bhp to 190. With the addition of a more efficient exhaust my power readings went from 169 bhp at 5900 to 192 at 6100. Torque also increased but was higher in the rev range. However, on the road I can say I do not really notice the increase in top end power, but I DO notice a reduction in power below around 3000rpm, so it is not always a winning situation getting more power where you seldom use it. Type of use has a big bearing on the matter and as mine is only used on the road, I would probably have been better off leaving the standard cams in. Big power outputs sound impressive but low and mid-range torque and good driveability account for more on the road. Having said that my Vx is still a pretty impressive engine and mid-range torque is good by most standards, and I would not call it a peaky engine as the cams chosen still use the hydraulic lifters, and required no alterations to the pistons. All in all I am happy with the setup. Link to comment Share on other sites More sharing options...
irrotational Posted November 7, 2011 Share Posted November 7, 2011 Isn't Torque a better measure of power, as people think of it, than power? From the way I've read it described, Torque is about the amount of shove/grunt the engine has, and power is about how quickly it can apply that shove? So for high top speed you need more power, but for better acceleration you need more torque... Is that right? Link to comment Share on other sites More sharing options...
TobyCoulson Posted November 7, 2011 Share Posted November 7, 2011 Quoting irrotational: Isn't Torque a better measure of power, as people think of it, than power? From the way I've read it described, Torque is about the amount of shove/grunt the engine has, and power is about how quickly it can apply that shove? So for high top speed you need more power, but for better acceleration you need more torque... Is that right?Makes sense to me. I'd always opt for more torque over power any day for driving on the road. Link to comment Share on other sites More sharing options...
oilyhands Posted November 7, 2011 Share Posted November 7, 2011 Power is the number of times per unit time that the shove is applied. The area under the torque curve is pretty much the main factor to consider. Oily Link to comment Share on other sites More sharing options...
grumpy the 7th Posted November 7, 2011 Share Posted November 7, 2011 (We're actually Steve, Carol, little Claire and even littler Katie, but I don't know how to change my user name) Neither do I Link to comment Share on other sites More sharing options...
craigyb Posted November 10, 2011 Author Share Posted November 10, 2011 Car's been on the rolling road this morning. 1.6ss, powerspeed 4-2-1 and the throttle body wedge removed and holes filled. 110 lb/ft @6300 rpm and 153 bhp indicated on rolling road (110 at the wheels). Chap in garage reckons it reads 6 BHP high. Verniers now being fitted and will go back later and see what difference that makes on the rolling road. Quite impressed at original readings, so not expecting too much Link to comment Share on other sites More sharing options...
Myles Posted November 10, 2011 Share Posted November 10, 2011 Quite impressed at original readings, so not expecting too much I've been meaning to write in to Evo mag and moan about their astonishment every time they put one of their cars on the rollers and find that the measured BHP exceeds the manufacturers claims. Might well be true, but I understood them to be notoriously-hard to objectively calibrate for absolute readings - relative readings (i.e. before/after or Car A/Car B figures) being about all they were really good for. Link to comment Share on other sites More sharing options...
Myles Posted November 10, 2011 Share Posted November 10, 2011 Oh - and having one seven with max power at max revs - and another (bike engined 7) which doesn't, I'd go for the mid-range torque in the future. The only nice thing about the max-power-at-max-revs thing is that I can impose a rev-limit (and therefore a power limit) should the gf ever want to start driving the car... Link to comment Share on other sites More sharing options...
craigyb Posted November 10, 2011 Author Share Posted November 10, 2011 I'm under no illusions about the absolute accuracy of dynos, test will be to see what changes after fitting verniers, and ultimately the drive. Just want the engine to be as good as it can be Link to comment Share on other sites More sharing options...
craigyb Posted November 10, 2011 Author Share Posted November 10, 2011 Job done :) a couple of BHP more, but that's not noticable, but, from 3000 to 6000 rpm, approx 5 lb/ft more than before. 10 mile drive and the car is noticable more perky. Mission accomplished 😶🌫️ Link to comment Share on other sites More sharing options...
David Brown Posted November 10, 2011 Share Posted November 10, 2011 Myles, often wondered whether the figure at the back wheel wasn't reasonably consistent but that is then upped, in some cases, by over enthusiastic adjustment for losses to achieve a good top line figure. Link to comment Share on other sites More sharing options...
Mr Locust Posted November 10, 2011 Share Posted November 10, 2011 I've been meaning to write in to Evo mag and moan about their astonishment every time they put one of their cars on the rollers and find that the measured BHP exceeds the manufacturers claims. If you were a manufacturer serious about fettling a car to be reviewed in a high profile test, would it be in your interests for the car to be below what you quote? Link to comment Share on other sites More sharing options...
OliverSedlacek Posted November 11, 2011 Share Posted November 11, 2011 Area under the torque curve is what you want. Interestingly, this is measured in horsepower. Link to comment Share on other sites More sharing options...
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