I have some questions on transmissions and parasitic loss is with each transmissions.

I was hoping to get some facts from fiction.

The M6 tranny has approx 16% parasitic loss?

Automatics are around 20% parasitic loss?

Racing transmissions have less parasitic loss than, what we have? What makes a racing transmission a racing transmission? Are there parts that can convert over to racing tranny or does it require complete new tranny?

Will a stall converter change the parasitic loss of a automatic tranny?

I have some questions on transmissions and parasitic loss is with each transmissions.

I was hoping to get some facts from fiction.

The M6 tranny has approx 16% parasitic loss?

Automatics are around 20% parasitic loss?

Racing transmissions have less parasitic loss than, what we have? What makes a racing transmission a racing transmission? Are there parts that can convert over to racing tranny or does it require complete new tranny?

Will a stall converter change the parasitic loss of a automatic tranny?


From what I understand the 6 speeds are around 14-15% and the autos are around 17% parasitic loss. Oh I'm sure racing transmissions offer a much less parasitic loss as these trannys are built with 100% performance in mind and not so much concerned on the price. That is why a good performance tranny will run you easy $20,000.

I'm not sure on the converter question.

Many manual race transmisions are also not overdrive varieties. This allows the input shaft to be directly coupled to the output shaft. This eliminates any load transfer through gears which result in less friction loss.

In our transmissions, you will lose less power in 4th than other gears as it is the direct gear.

Many race transmissions also have less helical angle in the gears, which makes them stronger, less prone to frictional loss, but they also make quite a bit of noise.


As far as automatics, the internal design has a lot to do with the losses as well as the rotating weight of all components. This is why many race automatics have upgraded aluminum drums for less rotating weight.

Converters typically lose more hp to the wheels as the stall speed increases, although it will get the car down the track faster by keeping the rpm in a more optimum range as well as allowing it to launch much harder.

Most people that dyno automatics, try to lock the converter if possible to get more accurate readings.

Many manual race transmisions are also not overdrive varieties. This allows the input shaft to be directly coupled to the output shaft. This eliminates any load transfer through gears which result in less friction loss.

In our transmissions, you will lose less power in 4th than other gears as it is the direct gear.

Many race transmissions also have less helical angle in the gears, which makes them stronger, less prone to frictional loss, but they also make quite a bit of noise.


As far as automatics, the internal design has a lot to do with the losses as well as the rotating weight of all components. This is why many race automatics have upgraded aluminum drums for less rotating weight.

Converters typically lose more hp to the wheels as the stall speed increases, although it will get the car down the track faster by keeping the rpm in a more optimum range as well as allowing it to launch much harder.

Most people that dyno automatics, try to lock the converter if possible to get more accurate readings.

:thumbsup3: Good post

:thumbsup3: Good post

:iagree: That was good reading :cheers:

Can tranny's be upgraded with the needed racing parts or those gears to become more efficient?

Typically no, that generally requires a different trans design. Upgraded gears are available, and offer increased strength, but will do little for improving parasitic losses.

Good thread, I have automatic and have been looking around at different information on these transmissions. Would be nice to reduce the parasitic loss now that I have a greater understanding of it :coffeetime:

Typically no, that generally requires a different trans design. Upgraded gears are available, and offer increased strength, but will do little for improving parasitic losses.

Gears will just strengthen the tranny right?

Short of trying a different synthetic fluid, I would concentrate my efforts elsewhere.

:iagree: :iagree: :thumbsup3: