dyno info

[lautray]

went down to sureflo for some dyno runs today & found some out some interesting info (dyno dynamics):

there is a difference in peak power when dynoed in different gears.

for example, when the car was dynoed in 3rd, peak power was 232.6rwkw, but when in 4th, peak was 246.9.

from everything i read on the forum previously, all indications were that peak power was thought to be the same in different gears, but tractive effort was to be greater in the lower gears. i guess that theory is wrong, about the peak power part anyway.

either way, still happy with result.

:cool:

[markone2]

A tuning tool only :stick:

[MNR-0]

Agreed. A tuning tool only. Although some dynos can be more a hinderance than others. For example, I now program the Monaro myself and have had mixed dyno results from 3 independant workshops ranging from 228 to 233 to 214rwkw. But I pull 108MPH down the QTR so I know its going good.

[lautray]

Also agreed. Blacktop dyno is a good judge of power. Atm car good for 109.54mph 1/4 on stock 3.46 gears, so :D

[Beej]

Also agreed. Blacktop dyno is a good judge of power. Atm car good for 109.54mph 1/4 on stock 3.46 gears, so :D

Well that's good MPH - my "dyno-arseometer" would happily print you a dyno sheet indicating a peak power figure of around 235rwkw for that MPH - if only I wasn't out of paper!! :D

Cheers,

Beej

[vh-holden]

i don't understand how a drag race can be a good indication of a cars power. there are too many variables, the most obvious being the drivers skill.

[Beej]

i don't understand how a drag race can be a good indication of a cars power. there are too many variables, the most obvious being the drivers skill.

:) Go and try it - you will be very surprised! No matter how bad/good the launch, as long as no gears are missed etc and the same (optimum) shift points are used, on a given day my car's MPH will vary by no more than +-0.5MPH - even with the ET varying by as much as 1 sec (for a wheel-spinning crap launch say).

Of course the MPH=power rule does presume a reasonable competent driver of the car - so a few runs might be needed to dial in the true MPH potetial of a car if you have never run down the strip before.

Cheers,

Beej

[Delco]

went down to sureflo for some dyno runs today & found some out some interesting info (dyno dynamics):

there is a difference in peak power when dynoed in different gears.

for example, when the car was dynoed in 3rd, peak power was 232.6rwkw, but when in 4th, peak was 246.9.

from everything i read on the forum previously, all indications were that peak power was thought to be the same in different gears, but tractive effort was to be greater in the lower gears. i guess that theory is wrong, about the peak power part anyway.

either way, still happy with result.

:cool:


think about it for a minute , 4th is 1-1 so very little loss through a gearset , 3rd makes the power travel though the cluster gear hence there is a power loss .

Thats why a dyno is a good tuning and reference tool.

[vh-holden]

:) Go and try it - you will be very surprised! No matter how bad/good the launch, as long as no gears are missed etc and the same (optimum) shift points are used, on a given day my car's MPH will vary by no more than +-0.5MPH - even with the ET varying by as much as 1 sec (for a wheel-spinning crap launch say).

Of course the MPH=power rule does presume a reasonable competent driver of the car - so a few runs might be needed to dial in the true MPH potetial of a car if you have never run down the strip before.

Cheers,

Beej

good point there

i just know that i suck at driving a manual vehicle to it's full potential. i either over rev it, or shift too early.

but i suppose that is where practice comes into it