Why is Phoenix good prep for Indy?

[Farpost]

Have read that several times in the past, but it doesn't seem real clear to me why that would be.

Is that more of a historical artifact, from Phoenix being around for a while and having good climate for racing before May?

Seems to me that Indy lap speeds are substantially higher, downforce is much lower, temp/wind are bigger factors, and reliability is more important

Wouldn't Homestead and Fontana be better indicators than Phoenix this year?

[CamKing]

For some strange reason a fast setup at Phoenix has always made for a fast car at Indy. I don't know why, the tracks are completely different, but this has been the case for years.

[step33T]

I think the answer is that mechanical grip is important to going fast at both places.

[dog-ring]

Originally posted by step33:
<STRONG>I think the answer is that mechanical grip is important to going fast at both places.</STRONG>

Ding Ding Ding, we have a winner!!!

[Truth Detector]

Originally posted by step33:
<STRONG>I think the answer is that mechanical grip is important to going fast at both places.</STRONG>

Pretend I'm too dumb to understand this.

[CamKing]

Well I can see I'm going to have to hire an engineer when my kid starts running 1/4midgets.

With all I know about engines, you'd think I'd have some idea about chassis.

[jl]

Homestead probably could also be considered a good track to prepare for Idy. For the same reasons Mnky stated. Get the mechanical and then tweak the aero.

Homestead hasn't been around long enough for it to get the rep Phoenix has.

[step33T]

Originally posted by Truth Detector:
<STRONG>

Pretend I'm too dumb to understand this.</STRONG>

For TD and CK,

Mechanical grip is the kind of grip you have that does NOT include the aero properties. (Silver Crown cars ONLY have mechanical grip, but WoO sprinters have both mechanical and aero grip). Basically, you need to get fast at both places w/o depending on the wings to plant the car.

When you have maximized mechanical grip, you can reduce the amount of downforce in the car. Reducing the downforce also reduces DRAG. Lower drag = faster car.

[Sleepcheap]

Originally posted by Truth Detector:
<STRONG>

Pretend I'm too dumb to understand this.</STRONG>

That's easy. Mechanical grip is when you are too tired or disinclined to do your own gripping so you rent a device.

[Farpost]

Originally posted by Sleepcheap:
<STRONG>

That's easy. Mechanical grip is when you are too tired or disinclined to do your own gripping so you rent a device.</STRONG>

I'd splurge and get the electrical grip myself.

[CamKing]

step, that much I knew.

I just don't understand why Phoenix's setup is almost the same as Indy and other 1 mile tracks are not. I know that at all tracks you are trying to run fast through the corners with less wing.
Is phoenix a track were the wings don't have as much effect on grip, so you have to rely on mechanical grip?

[step33T]

It probably has something to do with the compromise at each end of PIR. Thus you can't lean on the wings to get you through the corners, or you'll be slow down the straights.

Plus, those corners are fairly long, meaning you slow a little bit throughout the corner. Thus losing downforce.

Heck, I don't know. I can't explain it, but it makes sense to me somehow

[Peter Olivola]

Until the reconfiguration, Trenton was also a good pre-Indy set up test. It was also a very flat track with more straight than Milwaukee. Ratio of turn distance to straights?

[CamKing]

Originally posted by step33:
<STRONG>
Heck, I don't know. I can't explain it, but it makes sense to me somehow
</STRONG>

Thanks, that's the same answer I've been getting for the last 20 years.

I guess I'll have to stick with the easy stuff.

[CamKing]

Originally posted by Peter Olivola:
<STRONG>Ratio of turn distance to straights?</STRONG>

That's one of the things I was thinking about. It's just weird to me that the shock setup that would get you through the turns fast at Phoenix, would be fast at Indy. There has got to be a 50-60mph difference in corner speeds.

I think it's all black magic