bcl Toughest BA Turbo Lifetime Members 3,408 Member For: 22y 1m Gender: Male Location: Sydney Posted 10/07/08 03:26 AM Share Posted 10/07/08 03:26 AM Wheelspin is a fact of life.Unless you attempt to measure it roller dynos are a waste of time, and just indicative of power levels as power levels increase. Simon in WA tells me he has an effective way of strapping his car down, using very thick straps; I've yet to see it on this side of the country.Weighing the car down to try to stop wheelspin is a total farce, as there is no attempt to measure power losses introduced from the extra friction generated against the rollers.When you have power to leave a big black line on the road behind you when you stamp your foot at 100kph you don't need a roller dyno to tell you that you have too much power.Brian Link to comment Share on other sites More sharing options...
XF Falcon <put funny sh*t here> Member 3,365 Member For: 18y 2m 16d Gender: Male Location: Perth, NOR Posted 10/07/08 06:50 AM Share Posted 10/07/08 06:50 AM When you have power to leave a big black line on the road behind you when you stamp your foot at 100kph you don't need a roller dyno to tell you that you have too much power.Brian Link to comment Share on other sites More sharing options...
iTec TEAM BA Donating Members 1,755 Member For: 20y 1m 17d Gender: Male Location: North of The Bridge Posted 10/07/08 03:14 PM Share Posted 10/07/08 03:14 PM I have just found myself a new favourite quote! Link to comment Share on other sites More sharing options...
saleen Big Gun Donating Members 4,170 Member For: 22y 3m 14d Gender: Male Location: NSW Posted 10/07/08 04:32 PM Share Posted 10/07/08 04:32 PM I don't unerstand how people can say they have certain amount of rwkw when they use a hub dyno. Woudn't it be rhkw?? And BTW, I can't speak for others, but my cars hub has a smaller diameter than the outside of my tyres. Let's compare apples to oranges. It's makes for good story telling. Link to comment Share on other sites More sharing options...
mic Donating Members 1,725 Member For: 17y 6d Gender: Male Posted 10/07/08 08:15 PM Share Posted 10/07/08 08:15 PM Rear hub kw. that's a good point. Link to comment Share on other sites More sharing options...
bcl Toughest BA Turbo Lifetime Members 3,408 Member For: 22y 1m Gender: Male Location: Sydney Posted 10/07/08 09:10 PM Share Posted 10/07/08 09:10 PM I don't unerstand how people can say they have certain amount of rwkw when they use a hub dyno. Woudn't it be rhkw?? And BTW, I can't speak for others, but my cars hub has a smaller diameter than the outside of my tyres. Let's compare apples to oranges. It's makes for good story telling.Think more about what power (really torque) that I am trying to apply to the road. That is what I want to know.What is actually applied to the road to accelerate depends upon the frcition between the tyre (point of contact) and the road itself.A simpe example is take a car (say my 11.0 F6) and compare a race with slicks vs bald tyres. The car with slicks will win because has far greater frcition with the road, even though the power is the same.The hub dyno gives the consistancy that I want to see, taking tyre slip out of the picture as a factor that impacts the final figure, and so I prefer it as a comparative tuning tool.Remember not all rwkw are same. Once you go over 350rwkw I have noted there is a big difference between shoot 6f dd and (mainline and shoot 6/8/81 and hub dyno values), and the % difference increases as power levels increases.So it is more like apples vs oranges vs pears vs mangos.At the end of the day the BS stops at the track.Brian Link to comment Share on other sites More sharing options...
saleen Big Gun Donating Members 4,170 Member For: 22y 3m 14d Gender: Male Location: NSW Posted 10/07/08 09:52 PM Share Posted 10/07/08 09:52 PM Brian,My main points are:1) Is it really worth the time and effort using a hub dyno(removing wheels, bolting up, etc)??2) Does a car on a hub dyno read the EXACT same power figure every time??3) Are all hub dyno's globally linked and calibratd so every RKW is the same??4) Does axle/tilshaft twist under WOT occur making the hub dyno inncurate??5) I do understand your use of a hub dyno as a tuning tool, but once again, see point 2Rob Link to comment Share on other sites More sharing options...
ms700 Moderating Team 10,170 Member For: 21y 11m 24d Gender: Male Location: Sydney Posted 11/07/08 10:09 AM Share Posted 11/07/08 10:09 AM When my XC reeled off the 567, we just used three ratchet straps, and they were faaarking tight. 285 tyres might have helped too.No fat bastards in the boot, just the one nervously watching...... Link to comment Share on other sites More sharing options...
hanra Into the laaaake Member 1,532 Member For: 17y 7m 10d Gender: Male Location: Nrth Qld Posted 11/07/08 10:16 AM Share Posted 11/07/08 10:16 AM At the end of the day the BS stops at the track.Well said! Link to comment Share on other sites More sharing options...
bloosted Cruise Control 1,383 Member For: 19y 1m 18d Gender: Male Location: Adelaide Posted 11/07/08 10:40 AM Share Posted 11/07/08 10:40 AM Remember not all rwkw are same. Once you go over 350rwkw I have noted there is a big difference between shoot 6f dd and (mainline and shoot 6/8/81 and hub dyno values), and the % difference increases as power levels increases.So it is more like apples vs oranges vs pears vs mangos.At the end of the day the BS stops at the track.BrianYep very true,my car is tuned by Street Tuna and last dyno run on race fuel was 367rwkw on his DD and then it pulled 361 at KPM on their DD and 2 weeks later and Martin has since put in a Mainline and it did 319rwkw.No good for the dyno queens but I must say it is great to have the car logged on the run so he knows exactly what knock sensors ect are doing and the Mainline can also do emisions ect,don't know if it's in my mind or what but I ended leaving feeling like I had a more complete tune,I remember headsex saying logging is the only way to tune and tend to agree with those comments now.ps I will get my car on a DD dyno soon to fullfil the dyno queen in me Link to comment Share on other sites More sharing options...
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