jackalanche,,,
I have no issues about where you are coming from... It is indeed a performance section, and the question is justified... Top speed it is!! ... I think most people are probably trained or have undergone high speed driving of some sort, but I don't want people walking away from this thread, getting a power programmer, and bumping up the speed limiter... Then for some frank reason, justifying it in their head that this thread told 'em it was ok... Just like you mention, some people are not as skilled as others, and not aware of issues as you and I might be, anyways, here's some considerations:
This is not directed at one person, but all who may step here in the future k?
Tires are the main safety issue in a new Avalanche... The tires that come on the av are Speed Rated to 112 MPH ... This means, in a LABORATORY, A BRAND NEW GOODYEAR AT/S OR HP HAS BEEN TESTED UNDER VARYING LOAD CONDITIONS TO SAFELY WITHSTAND THESE SPEEDS FOR A BRIEF AMOUNT OF TIME... THIS DOES NOT COVER IF THE TIRE HAS BEEN UNDERINFLATED PREVIOUSLY, SLICED IN A MINOR WAY, SUFFERED A MANUFACTURING DEFECT, OVERLOADED AT ONE TIME, OR OVERHEATED... I HIGHLY DOUBT ANY OF US HAVE THE CAPABILITY TO VERIFY OUR USED TIRES ARE SAFE UP TO 112 MPH ... Is it worth the risk? ... It is industry accepted, that if a tire has a speed rating, then a used tire should have roughly an 80% margin of safety... Meaning that 112 MPH S rated tire is probably good for 89.6 MPH with an acceptable amount of safety at the cold recommended max tire pressure ... Fact is, the more mileage a tire sees, heat cycling weakens it... A tire with 30,000 miles might have 70% or it's tread left, and look fine, but it IS WEAKER than it was new nonetheless...
Now you might be thinking, going in a straight line at 112 MPH is safe ... A lot of times when a large truck tire blows, it doesn't always shred and disintegrate, it usually grabs body parts during it's destruction, because the truck tire is really strong in the belting area... The sidewall is the weakest point as this is where heat is generated due to the searing flex it has to tolerate... And two plies of polyester cord inside 1/4 inch of rubber is it, on a P rated tire like the av has... So anyways, you are ?sizzling over 100 MPH along on your 8 mile stretch of highway in your straight line, and a severe tire vibration comes from the rear, and for about 2 seconds you realize that the tire is about to give... The tire tread seperates from the casing, and as it comes around it grabs the rear body panel of the av, and hopefully tears it completely off... All you can hope for now, is the failing tire continues to roll, and not put your 3 ton truck into a rear drift ... And I don't want to mention what happens if ya lost a front ... Trust me, the truck is not going to experience a controlled coast that you will be able to ride out... ?
It takes the average person 1.5 seconds to react to a threat on the road, and in that 1.5 seconds, your avalanche has traveled 176 feet at 120 MPH... Good chance you will collide with whatever it is before your foot even gets to the brake pedal...
If you have no need to apply brakes in your desolate stretch of highway where you plan on running it up, then your main concern is tires... If you don't have tires that are rated for 20% beyond the speed you travel, your taking a great risk... And please realize, tires that are available to the public are not hand sorted, but mass produced... Pushing a tire to it's limit in a 3 or 4 ton truck with a tire that "could" have a defect is not good ... If you want to go flat out, do it in something a little lighter, and with a lower center of gravity... I'm not trying to pee in anyone's corn flakes this morning, but this is something I KNOW about, and I wouldn't chance it...
I don't want to give someone the impression that because this is a Performance Forum, that we condone going 128MPH ... Most people here realize what's important mechanically ... But it's a public forum, and the people that don't need to be considered... I don't post this to antagonize anyone, or come across that I know it all, but to clear my concience of someone who might try something beyond their scope of understanding, or ability...
11H