48dp vs 64dp

[Mike145]

My latest question is this. What, in drivers opinions are the pros and cons of 48 and 64dp gearing on touring cars? From what I've observed of other cars ive raced with, drivers seem to opt for 64dp while I'm using 48dp as this is what came in my car. Is it personal preference or is there a technical advantage for their use?

[BNT]

Originally Posted by Mike145

My latest question is this. What, in drivers opinions are the pros and cons of 48 and 64dp gearing on touring cars? From what I've observed of other cars ive raced with, drivers seem to opt for 64dp while I'm using 48dp as this is what came in my car. Is it personal preference or is there a technical advantage for their use?

You technically have more contact surface with 64dp. But I think the main reason the pro's use 64dp is they can fine tune the FDR with smaller increments over a 48dp. Other than that there wont be any other pro/con between them.

[danielc3009]

Pros:
64dp gives you more options for gear ratio and is slightly more efficient and quieter.
Cons:
Harder to mesh and more likely to strip as the teeth are smaller

I've always used 48dp on all my cars and do most people at my clubs. I personally don't think it's worth buying a load of new pinions and spurs for a few extra choices on gear ratio

[mattr]

Originally Posted by BNT

You technically have more contact surface with 64dp.

Unlikely, they are pretty basic straight cut gears, so you've got (on average) just over one contact line at any time on either 48 or 64 DP. Depending on size/tolerance and so on.

It's more likely to be gear ratio related.

[beale]

Smaller tooth less contact less friction less noise, you will only really notice the noise and that they strip easier but indoor I like to hear the motor so use 64dp outdoor 48dp is first choice but whatever's in the car sometimes (outdoor I don't have as many big impacts so have never a stripped a 64dp!!!)