nskyline34

After a few days of researching I have finally narrowed down my questions. I'm planning to run my C5Z at the Mojave mile this spring and want to make sure I'm not too disappointed, or worse, push the car into the trailer - so no hero passes!

It makes 480 to the tire on motor and I have a nitrous kit kicking around, and I'm thinking of using to help me along. I only plan to spray a 50-75 shot (dry) from 3rd through 5th (3500+ rpm). I know its well into the safe range and I could run more, but if I go back with a LS6 block looking like swiss cheese, I dont care if I go 300mph, it will be a bad weekend IMO.

Goals:

Satisfied with 150 in the mile, and 165 mangum
Pumped to hit 165 in the mile and 185 magnum
I'd loose my mind if I hit 200
Main priority: come home with the car running just as good as it left only with a few more bugs on it.

The odds of hitting 200 are slim yes, but I would like to have the gearing just in case, I truthfully would be pumped with hitting 185.

Questions:

I'm curious what people are running for tires and gears to eclipse 200 in 1.5 mile with a C5?

The car is stock trans/diff/axles; with this power (no more than 550whp) will there likely be a catastrophic failure? (just running nitto NT01s, NOT going to launch the car hard).

What are the consequences of running a higher gear (3.73, 4.11, etc) and using 6th gear?

Why are people always nervous about standing mile events or top speed runs on drugs? I feel like a 50 shot is nothing and should be fine, am I wrong?

What are the safety requirements for running 180 vs 201 at the MM? (waiting for 2016 rule book to come out).

This is a street car first, so if there are a lot of drastic changes like a full cage or something like that, I will not be doing that. (car does have racing seats, 5pts, and roll bar/harness bar in it)

Thanks everyone. I would be curious to hear about peoples different setups and mph they have run that would be comparable to mine.

RC000E

PeteZ06

Ditto



nskyline.. you need to do a few searches first because a lot of your questions are very basic.

The cheapest way to hit 200 is a taller tire. With a 315/40/18 and a 7000rpm rev limiter, you'll hit something like 202mph.
But 480rwhp is not going to get you there.. You're looking at around 700rwhp to get it done. My car running 560rwhp ran 157mph in the 1/2 mile. I doubt I can squeeze out another 43mph over the next 1/2 mile to hit 200... it comes on quick and the rate you're gaining speed at that point is pretty miniscule.

nskyline34

I did do a fair amount of searching, I opened with that.

Also I know that hitting 200 in a standing mile reqires a lot more, that's why I said I was curious about 1.5 miles. The car makes 480 NA, just north of 550 on drugs. Also running a stock LS6 bottom end at 7k rpm for that long (or north of 6500 at least) seams like a bad idea. I am guessing a rod bolt will let go right?

Considering there is a gentlemen on here whom with a stock 04 Z did 176 in the magnum mile (5th gear stock rearend and just hit rev-limiter). I'm guessing that 200hp (ish) more to the wheels will get there. I'm just waiting for someone to prove me wrong or say 'yes its right.'

the mile and 1.5 mile races are two completely different animals for sure.

Laser Guided

I got 165.2 in the mile with just an intake and reflash (definitely could have squeezed out a few more with better driving). Never did the 1.5

480 NA i bet you will be pretty deep in the 170s for the mile.

Dan Z06

I was there last year and when 176.2 Bone stock with a cage in the car for added weight lol. Ask my anything you want, ill help if I can nskyline34

63Corvette

I have a stock (except for BBK) 04 Z06. I went 163mph or within 1mph of that on 9 runs over two days at the Texas Mile. The limiter or fuel cuttoff (whatever) is at 6600rpm. At that speed in 5th gear my car is running 177mph, but it takes longer than one mile to get there.

momo20

i thought the stock c5z was limited to 171 with the OEM gears and trans?

doneworking

Pretty sure your car will pass tech at a 175 speed limit. Any faster and you will need more safety gear. They have license requirements for the driver also. I see after just a few days then event has already reached half of their limit on entry's so you might look into signing up soon. It is a ton of fun though.

nskyline34

a stock C5Z has already been through the traps at 176.X mpg, this was rev-limiter 5th gear and I'm assuming an OE tire size.

Yes after speaking with the officials I'm limited to 180 tech speed on the car in its current config. Later this spring/summer (not in time for the first race of the MM) I will be adding seats, harnesses, and harness bar/roll bar - NOT a cage though. We will see if that will allow me to tech for 205mph. after that I need to work on getting the power to do it. I feel like 500-550whp should do the trick over the 1.5mi.

Going to either change to a 3.2x (ish) gear or try and get a set of rear wheels and a taller tire. (305/40-18 ?? or similar)

Currently with math (NOT REAL) the car will hit 217, BUT this doesnt account for hp, or more importantly tire slip. based on a lot of comparisons to real numbers vs math it seems like 5-7% is lost to tire slip. this dumps me down to 198...so close, but still a mile away.

Dan Z06

Just hope for the tail wind

nskyline34

Hoping for more than just that!

Moto One

Something to think about is Wheel Speed. I did my 150 at Bonneville (and it took a number of Passes on the 3 mile course and 400lbs of added weight) my wheel speed was in the range of 168 with stock size tire (yes that was on salt) but on the way on pavement we had a GPS reading of 169 with wheel speed of 174. almost a 6% slip factor. I also believe that there is an aero wall with the stock body.

Mark

nskyline34

Mark,

Thanks for chiming in with first hand experience! Much appreciated. And you are correct wheel slip is a HUGE factor (especially at Bonneville or Black Lake). I have taken this into account for my run. With current 'gearing factors' (trans/diff/etc) I have a THEORETICAL top speed of 217mph (5th gear). I did a lot of research and calculations and found that the common wheel slip factor was about 5-7% so I did 6. Makes me feel good that you confirmed this. But this only puts me at 198. (so close, but a mile away still). Mind you 198 is assuming I have the power to pull it, which I'm not completely convinced yet that I do.

There isnt an aerodynamic wall with the stock body. It just takes 8x the power to go from 100 to 200. if it takes 100hp to do 100mph, common knee jerk reaction is that 200hp should get me to 200mph. When in reality 800hp = 200mph.

Moto One

It does look like you have done your homework. By the way the added weight was all down low and is a way of countering aero by not adding wings, and the other safety factor is a much lower CG incase things go sideways.

Good luck in reaching your number. It only took 2400hp to get my red hat.

Mark

nskyline34

Top speed runs like weight, race tracks and corners like aero.

2400hp?! what were you in? A Mach truck!? in all seriousness though, lets see this thing?!

LSR team I was on went to bonneville and did 143mph with 78hp...sooooo you guys were REALLY pushing some air. (granted if you ran 298mph you'd get the hat and require just a couple more ponies than 200mph).

63Corvette

I agree there is no "wall" in the C5Z, but THIS should give you some idea of what it takes to run over 200mph (255) with this body:

nskyline34

Moon discs? Takes a little more than that to get to 200? Or did you run 255? Did that car have 2400hp?

Moto One

It belongs to a friend/sponsor, I only made two passes. That's all it took.

Mark

nskyline34

Dude are you serious? I've watched and drooled over that on youtube! LOOOOVE that sound. Just WTFO for so long!

How fast did you run?

Goal is to run 200mph before I'm 30 and 200mph in the mile before 30, then 300mph sometime before 50.