Vibe GT is top speed limited

[Smokin' Rubber]

Got bored last night with my friends and we were just making sure we knew how to install the motor mounts by jacking the tranny/engine and car up and I decided to jack it up completely off the front wheels (think I got baout 2" of clearance off the ground). Then I hand peddled, as to not add weight on the jackstands and have the possibility of the wheels hitting the ground or the car rocking, and shifted into 6th gear. Then I got up enough so I could see the speedometer and yet still push the accelerator.So basically what happened was at about 147 mph (6400ish rpms I think, I wasn't looking closely at the tach) the ECU automatically reduces gas to the engine for you so hitting lift in 16th great is impossible with the currect ECU. Doh!

[Psychobroker]

Quote » Vibe GT is top speed limited Well technically, it's drag limited at ~132, but that's a cool find

[Smokin' Rubber]

Well yeah limited to 132 with about stock HP, if you did something to get it higher without changing the ECU you'd be limited to ~147 which I gotta say its pretty good for a consumer family car, alot of other cars are limited to 120

[esjones]

Quote, originally posted by Smokin' Rubber »So basically what happened was at about 147 mph (6400ish rpms I think, I wasn't looking closely at the tach) the ECU automatically reduces gas to the engine for you so hitting lift in 16th great is impossible with the currect ECU. Doh!Are you saying you spun the front wheels, off the ground, at the indicated speed of 147mph? I have always been led to belive that this would/could lead to tire separation from the wheel, or tire disintegration due to the inertial forces not being damped by the road surface.You got bigger cojones than me, friend....

[Mavrik]

Good find but yes dangerious... I've seen a car go sailing off a hoist before.

[Smokin' Rubber]

Uh it was prolly jacked...... I have 3 jackstands and all 3 were leveled on the front metal crossbeam on the the chassis it wasn't going to fall over. I didn't sit in it to take extra precautions that nothing would go wrong. And if anything had my car would had about 50 yrds to peel out and kill the engine since if the car hit the ground going 140 then had no gas the engine would die pretty fast.So in reality as dangerous as it sounds it wasn't really based on the circumstances and surrounding. And yes I do know how to proper jack a car up =PQuote, originally posted by Mavrik »Good find but yes dangerious... I've seen a car go sailing off a hoist before.Well how did that happen? Lol it took me a total of 20 seconds to figuer out the limited speed then right after I lightly pressed ont he brakes till the wheels stopped moving, then unjacked the car. Meanwhile the parking break was on so even if it fell it wasn't gonna go very far Quote »Are you saying you spun the front wheels, off the ground, at the indicated speed of 147mph? I have always been led to belive that this would/could lead to tire separation from the wheel, or tire disintegration due to the inertial forces not being damped by the road surface.Yep thats what I did. I would think that it would only seperate from the wheels under heavy accelerate with the wheels up just because of the interia of the air and rubber in the tire pulling against the rim as it gains the necessary speend to match the rim. However if you accellerate "relavitly" slowly then I don't think it would be a big problem. But as i said it only took 20-30 seconds

[Mavrik]

The car was thought to have been in park when it was in reverse and it went out off the hoist and outside. only damage done to the car was to the driver's door when it caught on the corner post of the hoist since it was open. The hoist was a drive on and all the way down but still.You can never be to careful... a guy in this town was pinned under his car the other day when he was working on it outside in a parkinglot, Fortunatetly for him there were a few people around to lift the car off of him.

[Smokin' Rubber]

Quote, originally posted by Salsa! »WOW, you realize that if the car had fallen on the ground, and let's say nothing bad would have happened, you would have still probably needed a new transmission....It is known that if you spin wheels, on ice for example, and you keep them accelerating and finally touch a dry surface you can damage your transmission or driving axles.... The stress that is exercised on the wheels when they "stick" to the ground is very intense, if the wheels had been spinning real fast!Anyways, happy to see that nothing went wrong during your little experience!Very true the car would most inevitably be damaged and probably more than the transmission. The suspension would probably be damaged from the straight down fall, engine cradle with the stock motor mounts would more than likely be damaged too, and the tires probably even have a chance of poppingBut glad to hear you're happy it turned out for the better (instead of maybe whishing I got run over or something lol) and we gained new insight into our cars. All in the name of science and automobiles! hehe

[Jahntassa]

Regardless, it's still something good to know, no matter what the methods. So as a warning to people who have never done this before, don't! It's dangerous! If you're okay with the dangers you're putting yourself, and others, into, then that's your deal.We don't have to tell him how dangerous it is... people around here, and especially Smokin', have shown their intelligence, so i'd have all confidence that he took at least a decent level of precautions..

[MadBill]

If the car is properly supported, I don't see any big problem. The tires have a much easier time just spinning at a speed they're rated to or near, compared to running at full load, high temperatures, possibly underinflated, etc. The really dangerous move is to jack up one wheel and then buzz it up to high speed, as this doubles the wheel RPM, so you can easily spin a tire to way over 200 MPH!!

[Smokin' Rubber]

Quote, originally posted by Jahntassa »We don't have to tell him how dangerous it is... people around here, and especially Smokin', have shown their intelligence, so i'd have all confidence that he took at least a decent level of precautions.. Thanks man

[drummerdude]

Quote, originally posted by Smokin' Rubber »Got bored last night with my friends and we were just making sure we knew how to install the motor mounts by jacking the tranny/engine and car up and I decided to jack it up completely off the front wheels (think I got baout 2" of clearance off the ground). Then I hand peddled, as to not add weight on the jackstands and have the possibility of the wheels hitting the ground or the car rocking, and shifted into 6th gear. Then I got up enough so I could see the speedometer and yet still push the accelerator.So basically what happened was at about 147 mph (6400ish rpms I think, I wasn't looking closely at the tach) the ECU automatically reduces gas to the engine for you so hitting lift in 16th great is impossible with the currect ECU. Doh!Ever heard the Jeff Foxworthy bit.... "Here's your sign" "I'M STUPID!!!" Sorry dude, that is definitely one of the most hairbrained ideas I've heard to date. It's something you would see on J ack a ss! It reminds me of Ferris Buellers Day Off when they put the car up on jack stands and put it in reverse to take the mileage down... If you've seen the movie, you know how that ends. The sports car in the ravine behind the house! Bad Idea!! Sorry dude... but it was definitely not the wisest decision of one's life.

[Smokin' Rubber]

Quote, originally posted by drummerdude »Ever heard the Jeff Foxworthy bit.... "Here's your sign" "I'M STUPID!!!" Sorry dude, that is definitely one of the most hairbrained ideas I've heard to date. It's something you would see on J ack a ss! It reminds me of Ferris Buellers Day Off when they put the car up on jack stands and put it in reverse to take the mileage down... If you've seen the movie, you know how that ends. The sports car in the ravine behind the house! Bad Idea!! Sorry dude... but it was definitely not the wisest decision of one's life.Wow the fact that you took a comedic movie and compared it to real life... THEY ARE COMEDIC FOR A REASON BECAUSE THEY ARE SO UNREALISTIC! First of all they were stupid in teh movie and only had it up on the jack. I HAD IT ON 3 JACKSTANDS!!!!! HOW IS THAT NOT SAFE!?!?!? It was balanced and level and there was no one infront of the car to hit the jackstands and knock them over like in the movie! NOT TO MENTION THE 50 YARDS OF ROOM IN FRONT AND BACK OF THE CAR!!!!!!Not only that you're being a hyprocrit.... as if racing on normal road WHERE THE CAR IS ACTUALLY MOVING IS ANYMORE SAFE!!!!!! as silver nicely pointed outQuote, originally posted by drummerdude »Recent Kills: Dakota R/T, Tibouron V6, Ram 3500 cummins turbo, Acura Integra, Ford Focus zxt with "Mach" badging, a Mitsubishi Diamante, numerous f-150's and silverado (all the hicks in tx think that they're trucks with 33"swampers are still fast)

[MadBill]

I'm with you, smokin'! If it isn't possible to safely support a jacked up car without imminent risk of it falling off due to the vibration of the running engine and drivetrain, then it's sure as hell not safe to go under there and start yanking on wrenches!At one extreme of this issue is the jack stand manufacturer who (presumably at the urging of the corporate lawyers) put this label on their products: "Caution! Do not allow any portion of your body to extend under the perimeter of the vehicle while supported on these stands, as death or injury may result." (and I bought these things why?) The other is revealed by a tour of the pits at a major drag race event, where any number of cars, including those of multi-milion dollar Top Fuel teams, can be found on stands, rumbling away in gear at maybe 3,000 RPM, to properly warm up the drivetrain and lubricants before a run. The sanctioning bodies are ultra safety conscious in every way, e.g., cars capable of under 14 sec. require an external battery shut off, even though every current new Corvette can easily better such a speed right off the showroom floor, yet their only concern is the proper number and placement of supports

[drunkenmaxx]

Quote, originally posted by drummerdude »bunch of mean stuffi guess testing top speed on the actual road is much safer?

[drummerdude]

Ok, Seriously... I don't care how you look at it having a car up on 3 jack stands with the engine racing and the wheels spinning at 147mph... this isn't a good idea. I wasn't flaming or anything... i wasn't even meaning for it to come across as though I were trying to make you look stupid. I was trying to make light of the subject by bringing in the Ferris Buellers thing. As for racing, I've never once said it was safe... There are way too many variables to call street racing safe. Do I street race, occaisionally, when I'm challenged. I understand that in the pits at a drag race they have the cars up on stands and have the engines going to properly warm the drivetrain and such... But! they als have the chasis strapped down, just like they do in a Dyno test. Regardless of how you look at it if something went wrond and a jack stand broke or became off balance, you might be having your insurance total your vibe, one for the tranny being completely shot and 2 for whatever the car might have hit. I know you had 50 yards infront of you... but what if the car would have hit you... you were standing on the side/leaning in to the car while the tires were spinning that fast. It would really suck to lose a genviber!

[drunkenmaxx]

dude, you called him stupid. not directly, but, yeah, you did

[Mr. Poopypants]

Quote, originally posted by drunkenvibe »dude, you called him stupid. not directly, but, yeah, you did Not to join in after the fact, but you did call him stupid in so many words.

[drummerdude]

Quote, originally posted by Mr. Poopypants »Not to join in after the fact, but you did call him stupid in so many words. Well if it came across that way, I didn't mean for it to... It was a bit that Jeff Foxworthy did... People would go to buy a car and drive it around the block then get out and touch the exhaust pipe and say "D*** that's hot!" and he would reply with "Here's your sign" I wasn't trying to be rude. *side note* Why the crap am I quoting Jeff Foxworthy... I apologize for even bringing him up... he's an embarrassment to Americans!

[drummerdude]

Ok, well since humble apologys aren't accepted here I guess It's a complete mute point to even try to reconcile a wrong. So I guess i'll cya when I cya! Bye!