ZDan

Anyone else going?

I'll be there

The car did just over 129mph in the 1/4, hoping to do 175mph or better in the mile.

We shall see...

I'd be interested to hear if anyone has any data acq from standing-mile runs, I'm trying to model the car's performance but am unsure of tire slip and tire growth, so I'm mostly guessing there. Very critical factors relating to gearing!

marcrx5

While tire slip and tire growth are critical for gearing, aero should be the dominant factor in the entire equation. Do you have good values for aero drag?

ZDan

I'm conservatively (I think) assuming a Cd of .33, frontal area of 20 square feet. Hopefully with skinnyish tires (225/245), all front radiator/brake openings blocked off, taped gaps between lights/hood/fenders, removed mirrors and windshield wipers, the Cd will be .30 or less. But even a small sidewind will give more drag...

I'm calibrating the model to a known 196mph run for a similar V8 FD with ~20% more power. Based on that, I should be in the ~184mph range. Which agrees perfectly with the model I'd already come up with, excellent!

For gearing, the *worst* would be to have more than expected tire slip, less than expected tire growth, and higher than expected speed, which could require a shift to 6th, which is to be avoided at all costs!

With my worst-case (I think) slip of just over 5% at speed, and zero tire growth, my chosen 25.7" tire size should be good for 188mph in 5th gear at 7000rpm, which should be PLENTY.

At the other extreme, with significant tire growth and reduced slip, 25.7" tires could have me as low as ~6300rpm at 180mph, but that's right at peak power anyway.

Spreadsheet model indicates little/no speed penalty for erring on the tall-geared side.

se7ensti

I would love to run the Texas Mile one day, but I should probably take it down the 1/4 first, seeing how I just finished the swap only a month or two ago.

ZDan

Ran 183.8 mph in the mile today. Off by only 0.2 mph!

DeaconBlue

iTrader: (31)

Very cool! How was the event overall?

ZDan

184.8mph this AM. Yee-haw!

Great event More later, sleep now...

Ruler_Mark

iTrader: (16)

Whats your powerplant?

ZDan

LS2 with shaved L92 heads, LS3 intake and injectors, 222/230 .597" cam. Pretty mild build, really. It's a street car, with p/s, a/c, full interior. I drove it down from Rhode Island

djseven

iTrader: (56)

gnx7

iTrader: (10)

Nice speed for a mild engine swap. ZR1 Corvettes aren't running that fast

That motor I'm guessing probably puts down around 450rwhp depending upon which dyno you use.

ZDan

Yup, stock ZR1s were reportedly running 178 - 183 at the Texas Mile this event.


Might be optimistic!
129.2mph 1/4-mile speed at 2400' density altitude suggests 515 (raw) to 555 (corrected for d.a.) flywheel hp.

Similar trap speed and mile speed vs. ZR1 suggests ~540+ hp flywheel.

In any case, it's a LOT more than I'd have expected for the build

85turbo12a

nice man, i know we got off to a bad start in the other thread but trust me i respect others builds, and thats a nice power curve, those LS engines are un-arguably amazing for their size and weight, AND physical size.
looks like you got a nice combo of parts working well with each other, now lets turbocharge it and make it silly

ZDan

Get thee behind me, Satan! I gots to say, the idea of 200+ in the mile on barely any boost at all (even with stabilizing but drag-adding rear downforce) is tempting...

85turbo12a

dont fight it...just relax and let it happen