Compression Ratio = Gear Ratio??

Is the Compression ratio also called the Gear ratio?

I have a 2004 350Z and the compression ratio is listed as 10.3:1 and I wanted to see if that's the same as gear ratio.

I'm having a custom supercharger built and I need to know. The 350Z forum isn't very active so I thought I would ask here. Any help would be greatly appreciated.

no, compression and gear ratios are two completely seperate -not even connected in the slightetest ways- things

Ok, I found the gear ratio for a manual. I can't find anything on yahoo or google for an automatic. Any ideas? Call a dealership maybe?

compression ratio is the volume in the cylender at bottom dead center divided by the volume of the cylender at top dead center. so a 10:1 compression ratio means that there is 10 times more volume when the cylender is at the bottom then when it's at the top.

gear ratio is just the ratio of the input speed vs the output speed, or input torque vs output torque. it's usually speed. so a differential that sais it's 3.50:1 means that the input shaft will spin 3.50 times when the output shaft spins once. i dont know if this is clear, im not very good at explaining some things. someone clear it up.

Ask.com got me this

04 350Z Roadster
Final Drive Gear Ratio = 3.357

That look right?

Or am I going to look for ratios from 1st gear all the way to 5th gear?

well i dont know why you'd want the final drive ratio for a supercharger. you'd want the compression ratio because it will determine how much boost you can run. do a search in this forum and the forced induction forum for octane, or boost, and look for something that tells you about it, there are countless threads about it.

Ok. Thanks for your help. I hope this turns out the right way. I've spent a lot of money for it not to turn out the right way, and that would suck.

might be a strange question but wouldn't the guy making the thing for you be able to tell you?

You would think. It's all worked out now. Thanks for your help. Prolly would have been screwed up if you all didn't help. Many thanks!