Austin area dyno day

[Chuck]

Anyone in the Austin area have four extra Mustang wheels with tires on them I could borrow for the dyno day? I have no wheels right now.

JJ

I have spare 16" 5 lug wheels, some with RA1s that are good enough to dyno. For the front I have two '98 Cobra wheels with tires good enough to roll around on, will clear PBR or Brembo brakes not sure about other big brakes.

Let me know if you need them. Could meet you Friday PM.

Chuck
CMC#14

[ShadowBolt]

I have spare 16" 5 lug wheels, some with RA1s that are good enough to dyno. For the front I have two '98 Cobra wheels with tires good enough to roll around on, will clear PBR or Brembo brakes not sure about other big brakes.

Let me know if you need them. Could meet you Friday PM.

Chuck
CMC#14

Thanks Chuck!

Call me on my cell when you can. 512-658-7640. I would like to use the wheels if you don't mind.


Jerry

[RichardP]

Just a reminder that wheels with a significantly different rotational inertia than what you actually plan to run will show up in your dyno numbers...


Richard P.

[Adam Ginsberg]

Just a reminder that wheels with a significantly different rotational inertia than what you actually plan to run will show up in your dyno numbers...

Yes, it will.

[ShadowBolt]

Just a reminder that wheels with a significantly different rotational inertia than what you actually plan to run will show up in your dyno numbers...


Richard P.

By how much Richard? If the wheel and tire is lighter than what we are going to run would I show more or less power with the heavier wheel/tire combo? Even maxed out with timing and everything my 4.6 does not make the numbers.

JJ

[Chuck]

Just a reminder that wheels with a significantly different rotational inertia than what you actually plan to run will show up in your dyno numbers...


Richard P.

Thanks for the tech. Richard. Looked up some Toyo RA1 tire data:
275/40R17 is 29# and is 25.7" tall.
255/50R16 is 27# and 26.1" tall.

So the normal 275/40R17 is two pounds heavier, but 0.4" shorter than the 255/50R16. Assuming the wheel weight is about the same, how big of an effect will this have on dyno numbers?

Thanks,
Chuck
CMC#14

[ShadowBolt]

Thanks for the tech. Richard. Looked up some Toyo RA1 tire data:
275/40R17 is 29# and is 25.7" tall.
255/50R16 is 27# and 26.1" tall.

So the normal 275/40R17 is two pounds heavier, but 0.4" shorter than the 255/50R16. Assuming the wheel weight is about the same, how big of an effect will this have on dyno numbers?

Thanks,
Chuck
CMC#14

Yeah.....what he said.


JJ

[marshall_mosty]

It all depends on where the weight of the wheel and tire are concentrated. Weight in the center will rotate a lot easier than weight on the outside, so a larger (read heavier) tire will show lower HP than if you run a smaller tire (less weight on the outside of the circle).

Same principal comes into play during Michael's favorite sport to watch (ice skating). During a spin/twirl/whatever you call it, if their arms are out = slower rotation. Bring the arms in = faster rotation for the same initial input of energy.

[jdlingle]

It all depends on where the weight of the wheel and tire are concentrated. Weight in the center will rotate a lot easier than weight on the outside, so a larger (read heavier) tire will show lower HP than if you run a smaller tire (less weight on the outside of the circle).

Same principal comes into play during Michael's favorite sport to watch (ice skating). During a spin/twirl/whatever you call it, if their arms are out = slower rotation. Bring the arms in = faster rotation for the same initial input of energy.

Nicely done! Good information with a jab at the sibling thrown in. I give it a 8.5!

[ShadowBolt]

It all depends on where the weight of the wheel and tire are concentrated. Weight in the center will rotate a lot easier than weight on the outside, so a larger (read heavier) tire will show lower HP than if you run a smaller tire (less weight on the outside of the circle).

Same principal comes into play during Michael's favorite sport to watch (ice skating). During a spin/twirl/whatever you call it, if their arms are out = slower rotation. Bring the arms in = faster rotation for the same initial input of energy.

SO if I'm good with the 16's I should show less power with the 17's?

JJ