Dyno Auto Vs Manual

[JA2473]

I am just wondering if anyone can tell me if a dyno is, or can be adjusted

to compensate for the difference in gear ratio from auto to manual.

I/e

a manual in 4th has a finial drive of 1.0 to 1.0

a auto in 4th has a final dive of 1.14 to 1.0

if my maths is correct (probably not) that's a 14% advantage to auto if we are

compairing dyno sheets, from one to another.

In other words the gearbox in auto is helping power figures on a dyno as its

not 1 to 1 ratio..???

dont shoot... its just a question..

[F6_Tornado]

You also need to consider the diff ratio which is different on the auto to manual. Most dyno shops dyno the zf in 3rd as 4th is too fast and are running 230kmh+ at full noise

So 4th in manual 6 speed and 3rd in auto 6 speed

My Manual 6 speed used to run over the line in 4th over the ¼ mile and my auto would hold 3rd if I held it over the ¼ . STD power that is not worked.

Making the final ratio and speed very similar in those two gears between 6 speed autos and manual.

hope that helps?

[blueboost]

  JA2473 said:

I am just wondering if anyone can tell me if a dyno is, or can be adjusted

to compensate for the difference in gear ratio from auto to manual.

I/e

a manual in 4th has a finial drive of 1.0 to 1.0

a auto in 4th has a final dive of 1.14 to 1.0

if my maths is correct (probably not) that's a 14% advantage to auto if we are

compairing dyno sheets, from one to another.

In other words the gearbox in auto is helping power figures on a dyno as its

not 1 to 1 ratio..???

dont shoot... its just a question..

the disadvantage there would be to the auto,not the manual.

the auto would be behind about 7-10kws, mostly because of the extra power to run the oil pump and convertor loss. not because of the gearing. the auto would lose 2-3kws I think from the gearing

this is only rough estermint from tuning them both.

David

[7MA61]

Most autos are run in third on the dyno (well 4 speed ones anyway) as that is the ratio which is closest to 1:1 ratio. Its all a moot point anyway because if the figures are inputed into say a dyno dynamics dyno correctly the shootout mode will make compensations for all of this.

I've had back to back run between 3rd & 4th gear in my supra and the difference was about 2-3kw.