dbischoff

When some folks ask me "how fast is it?" and I know they aren't the types to relate to HP, torque, or power to weight ratios, I just tell them "I can break every speed limit in the world in second gear." .

So, I was curious, and I searched for top theoretical speeds in each gear, but I didn't find exactly what I wanted. Just for fun, I did some calculating and came up with this:

DaOtherOne

MikeOC

http://fitbodyshop.net/gear/index.php

Zach495

I'm a mile an hour shy on 1st, 2nd and 3rd, can't confirm on 4th, 5th and 6th.

AzDave47

My experience is close to your calcs with:

1-62
2-92
3-122+
4-162
5th- only done 196.5 which was about 6350 rpm

My prior rough calcs were 218 in 5th and 318 in 6th.

Thanks for spending the time to do the calcs.

Bill Dearborn

I have only hit the rev limiter in 1st, 2nd and 3rd and have come very close in 4th. Speed in 1st was 61, 2nd didn't notice, 3rd 123, 4th 158 (so 162 isn't out of line in 4th).

Bill

HOXXOH

Of course, the really big question is: If you were in a vacuum but had a self-contained air source for the engine, a pressurized cabin for the driver, and a rolling resistance value of 7%, how much additional speed could be expected by the thrust from the exhaust at 7000 RPM when using 94 octane fuel vs 91?

08mojo

7, the answer is always 7.

GMuffley

I was only able to reach 322.2 mph in 6th.

MitchyBobby

If you put ceramic muffler bearings in it you can get 325 in sixth gear.

rprice

👍

The only sensible post that I've heard on a good ?

AzDave47

What about Post #5

rprice

Whats 318 in 6th mean?

AzDave47

As the OP indicated, calculated gearing at theoretical 7K RPM in 6th. I calculated 318 roughly vs his calculation. Obviously it would take massive HP to achieve that, plus likely some aero work to keep it on the ground. 1 thru 5 were my observed. The 218 in 5th was also theoretical calculation, all with 325/30/19 tires and no allowance for tire growth due to hi-G growth.

Just as a point of reference, I went to an air show one time where A Kenworth style truck cab body and custom frame with three jet engines on it, did a pass over 300 MPH and it was reported that it had been as fast as 375.

ZO ZICK

Good information

patriotpa

Great graphs and charts. You did your homework.
Now, what is the drag-limited top speed?

HOXXOH

Try this for info about most any car, including top speed.
http://www.automobile-catalog.com/

Dubstep Shep

Take a look at this. It incorporates wind resistance as well. It's not 100% accurate but it's close.

DaOtherOne

That's a very cool graph!

Dubstep Shep

Thanks! Took me awhile to make it haha. Been developing a spreadsheet to work out the effectiveness of gear ratios and other mods for awhile now. That's the current setup I have on a bone stock C6 Z06.