JamieP Posted June 19, 2012 Share Posted June 19, 2012 (edited) Ibrar did 685bhp at the flywheel on SRR's dyno dynamics rolling road a couple of weeks back. Today he went on Dan's dynapack hub dyno and made 675 at the hubs with no change to the map or boost. And I still stand by what I've said in other threads, hub Bhp is about the same as flywheel, don't go adding anything to it. Edit with more info. Jurgens GTR below. 844 Bhp 1.5 bar at the flywheel at SRR 730 Bhp 1.5 bar at the hubs on dynapack. Mark newman. 736 bhp 1.7 bar at flywheel SRR 744 bhp at the hubs on dynapack. Edited July 6, 2012 by JamieP (see edit history) Quote Link to comment Share on other sites More sharing options...
DARETT Posted June 19, 2012 Share Posted June 19, 2012 I have been saying dans dyno reads higher than others though.... Something is definitely up somewhere when hub HP is calculated as fwhp, physically it's never going to be the same measurement. Quote Link to comment Share on other sites More sharing options...
JamieP Posted June 19, 2012 Author Share Posted June 19, 2012 (edited) I have been saying dans dyno reads higher than others though.... Something is definitely up somewhere when hub HP is calculated as fwhp, physically it's never going to be the same measurement. Dans reads no different than TDI's hub dyno as seen on Rickys car. Say what you like but there is no changing the facts, and the facts are in the first post. Edited June 19, 2012 by JamieP (see edit history) Quote Link to comment Share on other sites More sharing options...
Thorin Posted June 19, 2012 Share Posted June 19, 2012 Fly>Hub>Wheel Quote Link to comment Share on other sites More sharing options...
Parry_10 Posted June 19, 2012 Share Posted June 19, 2012 Thats gonna knock quite a few bhp off the single turbos on here for all those that have added on losses lol my bpu made 427 at srr at the fly so if it was to make around the same on a hub dyno maybe I should just add 15% onto it and have the fastest bpu supra in the world:D Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted June 19, 2012 Share Posted June 19, 2012 Mine makes me do a little sex wee. Quote Link to comment Share on other sites More sharing options...
DARETT Posted June 19, 2012 Share Posted June 19, 2012 Dans reads no different than TDI's hub dyno as seen on Rickys car. Say what you like but there is no changing the facts, and the facts are in the first post. It's all in the old thread, there's enough examples to prove either argument. I had my brothers GTR run a hub dyno then a dd a week later and there was 17% difference. Theres examples for whichever argument you want to push. It won't affect my sleep at night whatever anyone believes. From an objective point of view though it would be good if someone could actually explain how a hub measurement is equal to a calculated flywheel measurement. Quote Link to comment Share on other sites More sharing options...
Abz Posted June 19, 2012 Share Posted June 19, 2012 It's all in the old thread, there's enough examples to prove either argument. I had my brothers GTR run a hub dyno then a dd a week later and there was 17% difference. Theres examples for whichever argument you want to push. It won't affect my sleep at night whatever anyone believes. From an objective point of view though it would be good if someone could actually explain how a hub measurement is equal to a calculated flywheel measurement. Would be good if an actual dyno operator was to log on and post the answer to this. Didn't Charlie have a login at one point (From SRR). Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted June 19, 2012 Share Posted June 19, 2012 hub Bhp is about the same as flywheel, don't go adding anything to it. yup Quote Link to comment Share on other sites More sharing options...
JamieP Posted June 19, 2012 Author Share Posted June 19, 2012 It won't affect my sleep at night whatever anyone believes. I notice you took all the bhp numbers out of your sig Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted June 19, 2012 Share Posted June 19, 2012 mumbers. numbers. numbers. Quote Link to comment Share on other sites More sharing options...
johnny g Posted June 19, 2012 Share Posted June 19, 2012 The only real way to determine numbers is on a true engine dyno. Chassis/Hub dynos all have a certain fudge factor. Personally, I don't care about numbers - I just want mine to make me smile when I boot it. Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted June 19, 2012 Share Posted June 19, 2012 I just want mine to make me smile when I boot it. +1 Quote Link to comment Share on other sites More sharing options...
DARETT Posted June 19, 2012 Share Posted June 19, 2012 I notice you took all the bhp numbers out of your sig LOL Too many issues around dyno figures nowadays, and my hub figures at AME seem high for the boost. If someone asks me how much power the car has, I normally say around 500hp. It makes life easier that way! One definite advantage is that the hub dyno's are awesome to tune on, and don't ruin your tyres!! Quote Link to comment Share on other sites More sharing options...
JamieP Posted June 19, 2012 Author Share Posted June 19, 2012 (edited) mumbers. numbers. numbers. The only real way to determine numbers is on a true engine dyno. Chassis/Hub dynos all have a certain fudge factor. Personally, I don't care about numbers - I just want mine to make me smile when I boot it. +1 Yet i see you both quoting dyno numbers plenty of times, fact is a dyno is the only way we can tell what difference the modifications we have done to our cars have made, the point of this thread is to make people aware that adding a big % to hub figures to get an estimated flywheel figure is wrong. Some people can handle the truth, others cant Edited June 19, 2012 by JamieP (see edit history) Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted June 19, 2012 Share Posted June 19, 2012 Quote Link to comment Share on other sites More sharing options...
mark newman Posted June 19, 2012 Share Posted June 19, 2012 What about when you add % when it is an auto is that still the case, Jamie . Quote Link to comment Share on other sites More sharing options...
listy Posted June 19, 2012 Share Posted June 19, 2012 Personally, I don't care about numbers - I just want mine to make me smile when I boot it. +1 Completely agreed with this. Never dyno'd mine and dont plan to. I know at BPU its "around" 380-400bhp, and thats good enough for me if anyone asks. Quote Link to comment Share on other sites More sharing options...
JamieP Posted June 19, 2012 Author Share Posted June 19, 2012 What about when you add % when it is an auto is that still the case, Jamie . I would not add any % to any dyno numbers no matter what the dyno, just quote the figure the operator has given you and state if it was HUB, FLYWHEEL or WHEEL bhp, that way there is no confusion. Quote Link to comment Share on other sites More sharing options...
tooquicktostop Posted June 19, 2012 Share Posted June 19, 2012 I have always thought it would be much "cleaner" to quote the figure at the rollers not an adjusted figure, that way there is consistency Everyone naturally wants the bigger fly adjusted number though, it's natural I guess Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted June 19, 2012 Share Posted June 19, 2012 interesting topic jamie. i have read that dynapack themselves say to add 25hp to there figures for hub to flywheel. rototest have done there own testing to see what drivetrain losses are in there white papers, and there losses are all very small below 9% some as low as 1%. but i agree adding 15% to hub is unrealistic, it needs a same day, same car, same correction sae or din or even no correction at all, on a dd and then tdi or dynapack for a controlled accurate comparison. i have used my gtech aswell which is repeatable if set up properly and i have dd skyline runs for comparison, and that suggests i would make about 685 whp on a dd roller, but its made from 757 upto 788 on tdis hub dyno. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted June 19, 2012 Share Posted June 19, 2012 The topic was on here a few times and as i said back then i can't see how you can add up % on your figures... why would a stock Car loose less power than a bpu car if the only change was boost? Same goes for single Turbos. Why would a car whose only change was from a GT35 to a gt40 loose more power with the same drivetrain? The loss is in the Drivetrain with given components and weight it will loose a given number of torque and HP. If it stays the same over the improvement of power it will still have the same loss as the weight etc stays the same(of course if something like wheels etc is changed also the loss changes) Just my 2 pence Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted June 19, 2012 Share Posted June 19, 2012 I would not add any % to any dyno numbers no matter what the dyno, just quote the figure the operator has given you and state if it was HUB, FLYWHEEL or WHEEL bhp, that way there is no confusion. the problem with that jamie is that the dyno operator can add what he likes. i have seen a rwd cossie graph on a dynapack and it stated flywheel power with an 18% loss calculated lol i think aswell that a proper engine dyno will actually show more flywheel hp than a dyno dynamics does tbh. Quote Link to comment Share on other sites More sharing options...
johnny g Posted June 19, 2012 Share Posted June 19, 2012 Yet i see you both quoting dyno numbers plenty of times, fact is a dyno is the only way we can tell what difference the modifications we have done to our cars have made, the point of this thread is to make people aware that adding a big % to hub figures to get an estimated flywheel figure is wrong. Some people can handle the truth, others cant I admit, I added 15% to mine, as that's what I remember Lee saying he uses as his factor from fly to bhp. Ultimately, I've got a couple of quick cars and a very fast one on the way Quote Link to comment Share on other sites More sharing options...
suprafan72 Posted June 21, 2012 Share Posted June 21, 2012 Interesting read this one Surely the real Dyno is on the strip In terms of measuring terminal speed's and quarter mile times ? Quote Link to comment Share on other sites More sharing options...
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