Stock size tire RPM through the traps
 

I was wondering what the typical rpm is through the traps with a 5A and stock sized tires (26.8") and what gear are you in. Thanks

Anyone have that info?

Your going to be in topping out third. Look to be just under 100 mph.

Hi Pronto. According to Maxima.org, a 6th Gen’s (5spd auto) 3rd gear ratio is 1.982 to one and the final drive ratio is 2.440 to one. If your tire is 26.8 inches tall, it is therefore 2.233 feet tall. This establishes your diameter. We know that circumference equals diameter times pie, therefore the tire’s circumference is 2.233 feet time 3.1415, which equals 6.98 feet.

With this information we can calculate the rpms at 60 mph. To do this, divide 5280 feet by 6.98 feet, which equals 756.44. Now multiply 756.44 by 1.982 (3rd gear ratio) and by 2.440 (final gear ratio). This equals 3,658. This tells us the 5sp auto Maxima should crank 3,658 rpms at 60 mph.

If a stock auto 6th Gen travels 94 mph at the end of the quarter mile in 3rd gear, it will translate to 5,730 rpms (94 times 3,658 divided by 60 equals 5,730). 5,730 is your mathematical answer. That may not be the actual rpm, but it should be very close. (This is math. There is usually a fudge factor with real life numbers. Tire circumferences expand at higher speed and may throw off the actual number.) I own a 6-speed and cannot confirm anything. Perhaps an auto owner can confirm the math.

Pronto, if you want to test reality, put your car in 3rd, travel exactly 60 mph and check your rpm. Take that rpm and multiply it by 1.567 (94 mph divided by 60 mph). That will tell you the car’s rpm at 94 mph in third. If you think you’ll cross the traps at 95 mph, multiply your 3rd gear rpm by 1.583 (95 mph divided by 60). Good luck.

Pi > pie :wall:

All those calculations are theoretical, since they are on unloaded tires.

^Your silly

Thanks guys, I must be hungry.

Excellent. I've been looking at the BFG gForce 245/40/18s and they are 25.6 diameter so with those calculations the trap rpms should be about 6034. which is right over the stock peak hp at 5800. I wanted to figure out if I could stay in 3rd with that size tire and still be near 5800 or just past it.

You will still end up in 4th.

I recall hitting 4th gear just at the end of the 1/4 mile :scratch:

Look who's back from the dead :wavey:

Well if that's the case then the shorter tire might get me alittle deeper into the gear to recover from the rpm drop. Got to get some times with the stock tires first. Coming soon as the track opens and the weather cooperates.

:wiggle: not quite dead... but yeah i'm trying to stop around more :)