Speed vs. RPM Calculator


Aug 21, 2005
Lafayette, LA
In reference to the post in this section titled MK3 Gear Ratio/RPM Tables I am posting a link to a tool I made a while back that lets you chart this sort of stuff out. It's pre-programmed with a lot of MKIII and MKIV settings, but you can define any of them.

I'm warning you ahead of time, it is not idiot proof. If you put letters in number fields or if you define a transmission that has a gear order of like short-tall-short-tall, it IS going to give you stupid results and it is NOT going to tell you you're an idiot.

Also, please don't PM me and tell me it's 1 or 2 MPH off because your stock speedo or a GPS says you're doing XX MPH when this tool says you're doing XX+2 MPH. This utility does not account for things like the overall diameter of a tire changing because there's not enough air in it, or that it's changed because you did a 45 minute burnout and it's hot as hell.

Please, DO PM me if you find something fantaastically wrong with it, or you have a suggestion of a transmission or rear end to add with a description. Please, if you request having something added, PLEASE PROVIDE THE GEAR RATIOS AND APPLICATION.

Well, here it is:

Vector90T's Supra Biased (but universal) speed @ RPM calculator

Enjoy it. Feel free to save and use the generated PNGs on the forums, your web sites, whatever. My server does NOT save the PNGs, so please don't ask me for one you generated. If you want it, save it when you do it, or come back and do it again later.

I stopped coding it a long time ago, so it isn't pretty, but it "works." If there's demand and use for it, I might clean it up a bit.

Nick M

Black Rifles Matter
Sep 9, 2005
That is some nice work you did.

What are you using for an A341E in your ratios? I am going to have to look it up. That trans was used in the US behind the original LS400, and has a tall 2.5:1 ratio first gear. I dont' think the Supra ever used that.