yow

I may have an opportunity to do a controlled, legal top speed run on video, clocked. I've been tuned to 11.8 afr under boost. I am going to do a lot of research first because I want to do it right and see if I can break 200.

Main question is this: Is my motor going to be safe doing this?

What should I be concerned about? What precautions should I take? And yes, I have searched and will search for similar threads.

I want to do it right if I get to do it but I don't want it to cost me the car or wind up in injury.

Thanks for any input!

wolfdogs

Set your tires at 34 psi first.... cold!

And remember.. your tires are speed rated by the manufacture to the O.E. top speed of the car... which is not 200 mph.

Torchsport

Hold on tight!

Turbooo2u

If your driving a Z, I would think it's straight-line stability would be an issue. A Vette with a softer suspension setup with softer springs will probably offer better high-speed stability. I've found this to be true in all the Vettes I've owned. My stiffly sprung 07'Z, with it's quick steering and nervous ride is not real confidence-inspiring over 150. My base 05' with the soft springs but larger sway-bars and shocks, is a much better ride at triple digit speeds. Good luck.

BornSUPERCHARGED

High speeds and high rpms under boost, well you knew the risk of modifying your engine when you went to F/I. "Safe" is relative, your motor is not going to be as safe at high speeds as it would have been stock, but it also wouldn't be as fast. If you've got the money in the bank in case your engine blows, go for it! At least you'll have it on video. Best case scenario, you top 200mph and are able to come to a stop without so much as a bug hitting your windshield

talon90

As noted, verify your tire pressue with a good external gauge. Check everything mechanical you can about your car. If you are aware of any imbalance, vibration or noise, I'd consider running it to ground before you attempt a top speed run. Small problems get much bigger at high speed and you will have very little time to react.

Final note, unless you have done some serious HP mods (meaning north of 600 hp) to your car, I would say don't plan on seeing 200 mph. Look at the math of the models. The C5 has an aero limited top speed of around 175mph if I recall (350 hp). The C6 has an aero limited top speed as published of 190 mph (400 hp), the C6 Z06 is claimed to be 198 at 505hp and the ZR1 with 638 hp hit 207 and averaged 205 mph. It took the ZR1 133 hp to break the 200 mph barrier.

Good luck on your run!

AORoads

I see bad things ....

yow

RPM in CA dyno'd at 570. It's got the widebooty with nitto invos that I think can handle the speed. Updgraded to z06 sway bars and LG GT2 coilovers. Vortech V-2 sc.

200 does seem optimistic, but if I get close, it'll still be admirable.

topper7788

An old saying would be... If you have to ask you probably shouldn't do it...

With that said, stay to say 160 or so and you shouldn't have any issues nor blow your car up.... And it's a no issue for the car, basically a drive on the thruway!!! LOL...

peter pan

Is this a mile run? I ran the Texas Mile in my 771 RWHP boosted C5 and was able to hit 190 MPH, car had lots more in it for a further distance, oh I ran Hooiser A6s for those speeds

brooklync5

Go for it man. You put all that work and money into your car to make it go faster now see how fast it can go. Your motor can break while just going for a cruise. You risk something happening to it every time you drive it. Might as well push it a bit and see what it can do. You should be fine doing a few runs. Obviously don't do it everyday but im sure you will be ok. Good luck have fun and be safe. Be sure to post results.

Wayne O

I'm not a fan of FI (especially on a stock, cast-piston engine). It's OK at more subdued levels but turn up the boost too far and bad things can happen. It may be just fine but it does increase the risk of damage. I don't know what aero improvements you've made to the car, if any, but I suggest you turn the mirrors inward and perhaps even tape-off major portions of the forward opening if you're trying to hit 200. I'd talk with Corvette guys experienced at top speed runs (the Texas Mile comes to mind) to see what all they did to prep for the run.

Obviously, bad things happen fast approaching 200. I'm not trying to dissuade you but you might want to watch this first:

http://www.youtube.com/watch?v=BtPOI4hkCKA

Good luck! Let us know what happens.

Bill Dearborn

I have never had any instability in my Z when traveling over 150. It feels as rock steady as it does at 50 mph. However, if you look at some of the recent Texas mile video you will see a Z06 tumbling out of control at the end of the run. I think that was due to a tire failure so you need to make sure you have really good speed rated tires. You also need to consider the aero affects once you get over 200. A number of years ago C&D did a high speed run with a modified Firebird. Once their speed got to a certain point over 200 the REAR of the car lifted off the ground and the car immediately rolled. Nobody was hurt in either of those cases but both cars had roll cages in them. If you are seriously considering upping the HP so you have enough to make such a run you really need to consider installing a roll cage that will keep you intact if the worst happens. Engine failure could lock the rear wheels or spray oil all over them which could cause the car to spin and tumble.

Bill

Gering

From what I have heard, is that the Vet in that video had used the wrong tire set up. If that is true, then maybe he would have benefited from a thread like this. Good luck OP & be safe.

Mad*Max

good luck!

Xedes

Nobody has mentioned installing some type of roll bar or something. I always say, hope for the best but be prepared for the worse. Good luck!


TAG for the video.

jschindler

Listen to the people who are trying to talk you out of it and listen to them seriously. Then do what you want to do. But as others have said, at those speeds there is no room for error. A blown engine could spew oil all over the rear tires. A slight rise in the road could create havoc... read this.. http://www.autoblog.com/2006/08/03/t...h-speed-crash/

He lived to tell about it and regrets he did not run the road first (as Talon suggested above).

Good luck and have fun. BTW, I've roadraced motorcycles, and pretty regularly see very high speeds on my motorcycles and occasionally the Corvette....you know, in "Mexico" - so I'm not trying to preach - I'm on your side!

MikeyTX

W/o a roll cage it's suicidal. Just my .02

SloChicken

Regarding high speed stability. You can affect this by adjusting toe-in/out on your front and rear wheels.
In addition, a low rate shock (softer) will not be better for high speed as (should be obvious) things happen faster at speed and the suspension needs to react faster as the imperfections come on faster. Ergo higher rate/stiffer shocks/springs are better suited for this task. Kind of how you don't see f1 cars wallowing down the road.
Last, the voice of experience regarding downforce and keeping air from under the vehicle is in order.
After that it is right foot and lots of guts!
Have fun!

redzone

The Invos are W rated,meaning somewhere ~162mph.....they may be fine for a short burst,but do you want to chance it at 200 MPH?