FS M3 3.32 LSD Diff

[dcramer]

115K miles out of my M3

Great upgrade for a 328, put one in my vert, it provides you with an effective 20HP. Cheapest, most reliable 20HP you can but for a 328.

No issues with it, upgraded my diff.

450 OBO.

[doogee]

Differentials dont add horsepower dude...

And are you sure you don't mean 3.23? 3.32 doesn't exist.

[dcramer]

Yes, it is a 3.32, thanks for noticing.

And I said effective HP.

[doogee]

No such thing as a 3.32. And can you explain effective horsepower? Never heard of such a thing.

[dcramer]

Crap, apparently I can't type worth shit. It is a 3.23 as you pointed out.

effective HP is defined here
http://www.merriam-webster.com/dicti...e%20horsepower

Technically increasing the diff ratio increases torque at the wheels, however

Since HP = (torque * rpm)/5252 if you increase torque then you increase HP

Thanks for catching my typos

Dave

[dave.a.cote]

Buddy, your math is wrong. Sure a higher ratio will put more torque to the wheels but it will also happen at a lower tire rpm so your power remains constant.

[dcramer]

Ok, remember I said effective power. I am not suggesting that a higher ratio diff increases actual engine HP.

What does happen is that the higher ratio increases torque at the wheels for a given engine RPM.

The bottom line is that your 328 will pull better, now you will lose top end, but any top end you lose would be illegal here so all in all it's a great upgrade, and it's relatively cheap.

[Dinanstu]

Either way, its a good diff for a 328.

[Mike e39]

just so we have strait. different gearing same HP. here is example :

[Dinanstu]

Wow a graph!

I know what dcramer meant, give it a rest. Gear ratios actually make a difference in performance...If it didn't, they would all be the same...

[dcramer]

Actually it's all good, this is like free advertising. Saves me from ttt every day

[Blades]

Originally Posted by Mike e39

just so we have strait. different gearing same HP. here is example :

lol .. thats from a motorcycle .. you can't compare that type of ratio to a cars differential .. apples and oranges.

[dcramer]

And why not ? Do motorcycles have different laws of physics ?

[Blades]

Originally Posted by dcramer

And why not ? Do motorcycles have different laws of physics ?

Do they have a pinon gear/shaft? and as for physics does a GSXR have one type of force that needs to be converted/switched to another type of motion?

[dcramer]

Some of them do, yes. BMW's , Honda's to name a few. And what difference does it make if you are changing the rotational vector? It's still torque and ratio's

Can you back this assertion up with some math ?

Dave