kernow zed Posted July 7, 2015 Share Posted July 7, 2015 Took my 2005 for a dyno run last friday and the whp was 246 and the fhp 269. Now I've done extensive research on this and people state about 15% for transmission losses but for me 23hp is only a 9%. Would love to know if anybody else has got as low a figure as this or whether i need to test it somewhere else Quote Link to comment Share on other sites More sharing options...
Ekona Posted July 7, 2015 Share Posted July 7, 2015 Meh, it's all guesswork. I honestly wouldn't lose any sleep over it. Quote Link to comment Share on other sites More sharing options...
kernow zed Posted July 7, 2015 Author Share Posted July 7, 2015 Pehaps it is but if i had to believe a figure it would be the whp as this is directly measured by power transfer from the wheels to the dyno. Doesn't really matter as the car is more than capable of making me need underwear changes on occasion Quote Link to comment Share on other sites More sharing options...
Ekona Posted July 8, 2015 Share Posted July 8, 2015 That's a guess as well If you want accurate figures, you either need a hub dyno to remove any queries about the tyres or the ultimate and ONLY true way is an engine dyno, which really isn't an option. Best thing to do with dyno figures is treat them as a baseline. You've done one now, so when you do anything else to the car you can then see if you're gaining or losing power in relation to the baseline. Tbh, on a DE they're pretty good numbers. Where did you get the dyno done, what machine was it, and how many pulls did they do? 1 Quote Link to comment Share on other sites More sharing options...
brillomaster Posted July 8, 2015 Share Posted July 8, 2015 the wheel horsepower is as good as its going to get really, and the correction for flywheel horsepower will vary between testing stations. as said, treat it as a baseline, and if you do get any work done then take it back to the same dyno place ideally under the same conditions. Quote Link to comment Share on other sites More sharing options...
StevoD Posted July 8, 2015 Share Posted July 8, 2015 (edited) at the end of the Day its power at the tyres that matters, its all well and good saying to your mates down the pub (adenoides voice) My engine mkes 300bhp, if only 250 makes it to the road i think around a 30hp lose from engine to wheels on a 350z is about right tho from what abbey motrosport told me when i went for dyno run i know my friends evo fq300 lost about 70-80 Hp through the drivetrain Edited July 8, 2015 by StevoD Quote Link to comment Share on other sites More sharing options...
coldel Posted July 8, 2015 Share Posted July 8, 2015 Is the evo 4wd hence the power loss at 70-80? Reason I ask is why does the OP assume its a % loss? Why would you lose more power in bhp terms if you had a more powerful engine? I am no expert by any means but my limited understanding would be that you lose x amount of BHP but that would be a single figure? Quote Link to comment Share on other sites More sharing options...
StevoD Posted July 8, 2015 Share Posted July 8, 2015 (edited) Is the evo 4wd hence the power loss at 70-80? Reason I ask is why does the OP assume its a % loss? Why would you lose more power in bhp terms if you had a more powerful engine? I am no expert by any means but my limited understanding would be that you lose x amount of BHP but that would be a single figure? well im with you on this from an mechanical point of view if a drive line takes 10Hp to turn is irrelevant if the motor turning it produces 100hp or 1000hp it still takes 10hp to turn it like you said i cant see a stock nissan loosing 23hp in the drive line then a 700hp Z loosing nearly 90hp in the drive train its still the same drive train Edited July 8, 2015 by StevoD Quote Link to comment Share on other sites More sharing options...
Ekona Posted July 8, 2015 Share Posted July 8, 2015 More energy = more wastage via heat, twist in the components etc. Quote Link to comment Share on other sites More sharing options...
Rock_Steady Posted July 8, 2015 Share Posted July 8, 2015 (edited) the higher the power goes, the more you loose,that goes for any type of drive-chain. But yes, 4 wheel-drive you lose a hell of a lot more compared to RWD. Edited July 8, 2015 by Rock_Steady Quote Link to comment Share on other sites More sharing options...
coldel Posted July 8, 2015 Share Posted July 8, 2015 More energy = more wastage via heat, twist in the components etc. Ah ok, but I would assume that its not linear as heat increases are not linear as power increases? So therefore a single % figure cannot work? So assume 10% loss 200bhp would mean 20bph loss vs 400bhp meaning 40bhp loss, but that assumes that its twice as hot, which I wouldnt have thought is true? 1 Quote Link to comment Share on other sites More sharing options...
Ekona Posted July 8, 2015 Share Posted July 8, 2015 Yeah, it all gets really complex with some mental physics that I can't even begin to understand. In your example, the heat might not be twice as much but the extra twist could make things bend thrice as much, so you might get more losses or other equally weird stuff 1 Quote Link to comment Share on other sites More sharing options...
nissanman312 Posted July 8, 2015 Share Posted July 8, 2015 I think my loss on Litchfields dyno was 50/60 bhp Quote Link to comment Share on other sites More sharing options...
kernow zed Posted July 8, 2015 Author Share Posted July 8, 2015 That's a guess as well If you want accurate figures, you either need a hub dyno to remove any queries about the tyres or the ultimate and ONLY true way is an engine dyno, which really isn't an option. Best thing to do with dyno figures is treat them as a baseline. You've done one now, so when you do anything else to the car you can then see if you're gaining or losing power in relation to the baseline. Tbh, on a DE they're pretty good numbers. Where did you get the dyno done, what machine was it, and how many pulls did they do? Was at richards brothers in redruth on a TAT Systems dyno whatever that is and they did three runs and all were consistent. the max torque was 254 ftlbs but the car has been remapped so i guess these figures arent unrealistic Quote Link to comment Share on other sites More sharing options...
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