djinuk 2 Posted October 27, 2007 Been to a rolling road today. (stock engine) xs 1360 Few pics here. I got 91 bhp on the fly, 66 at the wheels, question is am i right in thinking thats quite a large loss from fly to wheels the exhaust is blowing and the carb is on its last legs, could these be the factors. opinions and a couple of pics, just to add was a really good last , enjoyed it a lot Share this post Link to post Share on other sites
M_R_205 5 1 Cars Posted October 27, 2007 im no expert but i normaly add on 10-15% for transmition losses, so 100 at the wheels 115is at the fly... but like a lot of people im of the opinion that if it goes fast and you have fun thats all that counts!!! Share this post Link to post Share on other sites
stu_woac 1 Posted October 28, 2007 good figure standard is 85 at the fly so your carb playing up must be a bonus lol or is there a k&n on there lol Share this post Link to post Share on other sites
GLPoomobile 958 Posted October 28, 2007 If it was still putting out 85 bhp and lost 15% through the transmission then it'd be seeing about 72 at the wheels. So, it's either loosing a s*it load through the transmission, or they have been extremely generous with the fly figure of 91 bhp. Wonder which it is! Not wanting to start another of these boring debates about RR figures though. At the end of the day, if it's a standard engine and you know it's not at full health then 66 bhp at the wheels isn't too bad I guess. Share this post Link to post Share on other sites
djinuk 2 Posted October 28, 2007 the head recently had a overhaul, decoked, valves reseated and a skim (head gasket went), the carb just hestitates an awful lot between gears and overfuels wen the cars stationary. A loss through transmission, would that mostly come down to gear box , and clutch, as the gearbox has got a loud whining noise and the gearbox oil level is fine so im not to sure what that is. No KnN standard airbox on it, does however have centre pipe and a backbox on it. Share this post Link to post Share on other sites
stu_woac 1 Posted October 28, 2007 ok just done some sums and if the wheel figure is correct the flywheel figure would be 84.444444* which is right on the money for a standard xs so it may just be optimistic flywheel figure but if it sounded like it was running right on the rollers who cares the carb fault could be the gasket in the middle of the carb breaking down Share this post Link to post Share on other sites
djinuk 2 Posted October 28, 2007 thats all good new then , . nah gasket in the middle of the carb is fine, checked it all over. Share this post Link to post Share on other sites
Casanova 0 Posted October 28, 2007 Surely all a rolling road can tell you is the at-the-wheels figure? Then they extrapolate from that to estimate the at-the-flywheel figure. 66bhp at the wheels sounds fair, but 91bhp at the fly sounds like ego massaging! § Share this post Link to post Share on other sites
Guest smokinslim Posted October 28, 2007 (edited) question is am i right in thinking thats quite a large loss from fly to wheels the exhaust is blowing and the carb is on its last legs, could these be the factors. opinions the exhaust n carb wouldn't affect loss from fly to wheels, only power at the fly... renew/upgrade suspension n mountings to reduce the loss Edited October 28, 2007 by smokinslim Share this post Link to post Share on other sites
GazRallye 0 Posted October 28, 2007 the exhaust n carb wouldn't affect loss from fly to wheels, only power at the fly... renew/upgrade suspension n mountings to reduce the loss Really? I thought that on an older car it would be because of the gearbox internals getting worn and loosening up and wheel bearings causing extra drag, im not talking about this car, just generally. Share this post Link to post Share on other sites
