Taller rear tires?

[Canadian818]

So I'm looking for more tire choices since the federals I wanted have been on back order for 4 months. I got to thinking, what's keeping us from going taller in the rear? Say 26" diameter instead of 25"? Probably have to run a little rake with the chassis, but that would only make the splitter and diffuser more effective. I'm planning body mods for wider tires anyway, so what's the downsides I'm not thinking of?

[Frank818]

One downside I can think of is it will reduce your whp/whtq. The taller the less power at the wheels, everything else being equal.

[dirty kurty]

One downside I can think of is it will reduce your whp/whtq. The taller the less power at the wheels, everything else being equal.

That isn't exactly true. It will not reduce your torque (N.m or lb.ft), but it will reduce the force applied by the wheels (N or lb) on the ground. But in the end a similar effect as going to a bigger final drive gear (which would reduce torque at the wheel.. It may or may not reduce your whp, but it will probably move your peak whp down depending on the torque curve.

[Canadian818]

It would also raise the top speed in each gear, which is a good thing IMO. Only slight difference though, at the same rpm 90mph (145kph) with a 25" equals 94mph (152kph) with a 26". Could also open up the option of (flame suit on) a staggered 18"/19" setup.

[RM1SepEx]

I went with taller tires to make the power more manageable and speed in each gear slightly higher. I expect to have issues putting the power down even with the Quaife...

[dirty kurty]

Can the speedo be recalibrated through the ecu or would some sort of aftermarket solution be required? This thing will be a cop magnet so accurate speed reading will probably be useful.