Begins to float over 90mph.

Handling, suspension, and brake tuning discussions
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viper
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Joined: Mon Mar 27, 2006 11:12 am

Begins to float over 90mph.

Post by viper »

My Vibe seems to want to float at higher speeds. By that I mean like it lifts up, it's difficult keeping going straight. My brother says get skinny tires because they are way to wide. I thinks it's the body's poor aerio dynamics and weeny suspension or do I need to make some mods like the front spring towers cross tie, etc.
joholste
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Re: Begins to float over 90mph. (viper)

Post by joholste »

All cars will get this feeling at some point....I would say 2 things:1: where are we driving that we would need to be able to steer at over 90 MPH.2: If you want to make it so that it won't have this effect as much then go for lowering your car... and possibly trying to find a true downforce spoiler.
2003 Chevy Silverado Ext. Cab, Z71Formerly2003 Base Vibe (Frosty)
kevera
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Re: Begins to float over 90mph. (viper)

Post by kevera »

Quote, originally posted by viper » weeny .ahahaha
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WaveAction
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Post by WaveAction »

i dont think it has to do anything with the car..if it were like that i dont think they would deem it safe and sell as much as they have
coldmm803
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Re: Begins to float over 90mph. (viper)

Post by coldmm803 »

Quote, originally posted by viper »My brother says get skinny tires because they are way to wide.the engineering student in me thinks thats backwards, on a standard 7" wide tire at around 70mph theres only about 2" contacting the road so if you put on tires that are less wide this would decrease and if you put on wider tires it will increase the area contacting the road
northvibe
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Post by northvibe »

ive gone up to the vibe (1zz base limit) of 115 with no...lift feeling, car drives great up there. My vibe is on lowering springs so that could help a lot.... skinnier tires wont do anything for the "lifting"
Raven
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Re: (northvibe)

Post by Raven »

Our Vibe seems to get strangely quiet and stable above 85 mph but I've only gone about 100 mph max. It seems to squat down onto the road. This is with Tein S-Techs, strut bar, sway bar and 225/45/17s.
TraySeeLea
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Post by TraySeeLea »

who doesn't want their very own hover craft?
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djb383
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Re: Begins to float over 90mph. (viper)

Post by djb383 »

We have some legal 80 mph sections of interstate in West Texas and I have done some stints at +/- 95 mph and our Vibe seems rock solid even with 225/50/16 tires which are 2 sizes wider than stock. Narrower tires for higher speeds?.................somebody needs to alert NASCAR, IRL, CART, FORMULA I, etc., etc. as they are missing out on a speed secret. Narrower tires might do a little better in snow but that's about it.Your Vibe might need some good tires and an alignment.
'05 Lava Tutone base, Pwr Grp, Moon & Tunes, 16" alloys, Auto.....Yep, it's gotta HEMI
northvibe
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Post by northvibe »

yeah id recommend a alignment, tire check, if you want better handling, look at coil overs or new springs, anti sway bars and strut tower bar.
chevelle_lover
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Post by chevelle_lover »

If the car starts to feel light at 90 then it is the whole car's weight coming off the suspension. The air moving over the top of the car is moving higher than that of the air under the car. The high pressure under the car wants to move to the low under the car causing lift. The only way to counter act this is to have parts of the car to create downforce. This could be a wing for the rear and a damn in the front. This would allow for the weight of the car to stay on the suspension and the tires. If you want to really see it try driving a pre 1980 vehicle on the highway at high speeds the steering becomes rediculously light and the whole car seems like it is floating though the air.
If God didn’t want us to eat meat, why did he make the cow so slow? (Ever eaten a cheetah-burger? Nope. And you never will.)
viper
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Post by viper »

Thanks guys, your sugestions are very worthwhile looking into. I will start with the rear sway bar. Can I install it myself?
Raven
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Re: (viper)

Post by Raven »

Quote, originally posted by viper »Thanks guys, your sugestions are very worthwhile looking into. I will start with the rear sway bar. Can I install it myself?It's a piece of cake, a 15 minute job.
Raivis
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Post by Raivis »

in my gt i have hit 126mph and it huged the road. alot better then that 77 camaro i was following. wow was that a site to see!
You got owned by a wagon..... Life is a sexually transmitted disease!!! check me out at http://www.myspace.com/raiviskysdad
northvibe
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Re: (viper)

Post by northvibe »

Quote, originally posted by viper »Thanks guys, your sugestions are very worthwhile looking into. I will start with the rear sway bar. Can I install it myself?Like sunny said its super easy..ill be doing this soon too, little less than 100 bucks for a RSB one from neverenoughauto.
waveresponder
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Re: Begins to float over 90mph. (viper)

Post by waveresponder »

ive only tried going above 100mph twice now...only got to about 113...then i had to stop only cuz i felt the roads unsafe where i tried it to go any further..."curves"...and im not about to wreck it or kill myself or hurt anyone else in the process event though both times were at 1am..with no other cars on the road and a straightaway.so yah i really dont have that much experiance yet at higher speeds...so far i havnt really experienced any lifting..but thats just my opinion so far..lol
djb383
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Re: (viper)

Post by djb383 »

You need to start at the front of your car, not the rear, with a front end/four corner alignment and check your tires for balance/out of round and correct pressure. A bone stock Vibe will run rock solid at 90 mph plus if every thing is set to factory spec............without any after market items (spoilers, sway bars, whatever).
'05 Lava Tutone base, Pwr Grp, Moon & Tunes, 16" alloys, Auto.....Yep, it's gotta HEMI
prathman
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Re: (djb383)

Post by prathman »

I agree with djb that no suspension modifications should be needed to make the car feel secure when driving at high speeds. The description in the original post of having difficulty steering a straight line when at speed is certainly not common to Vibes in general and therefore I suspect that there is something specific on that car that needs to be fixed rather than throwing suspension modifications at the problem. In addition to checking the tires and alignment, make sure that all suspension components and wheel bearings are tight and in good working order. I had a VW Rabbit that developed a similar problem after the dealer replaced the struts but left out a washer upon reassembly.A RSB and other modifications like a front strut bar can improve handling when you're pushing the car's limits in turns, but shouldn't have much effect when you're just going in a pretty straight line down the highway.
duck3
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Re: (prathman)

Post by duck3 »

I agree with prathman....make sure you check out the alignment and everything else out first. The front-end of the Vibe is adjustable, the rear-end you may have to get shims to have it properly lined up. Check your tire pressure too. I have run mine up to 135mph and pretty much hit 100mph daily and I dont' have the float problem. However on some roads when I was flyin around 120-130, yeah you'll float....thats just your suspension going up and down with the roads. If you want to help that, I would suggest a tighter suspension AFTER checking alignment and tires. Definitely WIDER tires, not thinner. And as far as sway bars go, those aren't gonna help you out unless you're turning. Sway bars are meant for handling and keeping your hugging turns better, they won't really help anything out going in a straight line.

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viper
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Post by viper »

First thing I will do is if the problem duplicates, on the same road during a windless day. Usually there is some crosswind. The Vibe is a total new experience after having driven in Peugeots for some 30 years. I traded my super nice 12 year old very stable Aurora because of my wife's dog... You know what I mean, he took to me like a bee to honey practically lives and sleeps in the Vibe's carpeted rear, except on the occasional fast business trips. Thanks, I learned a lot from your guy's experiences. The alignment is good by dealer standards the tires are newiest, 20K on Fuzions. Maybe too much air at 36 lb.
vinny.mca
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Post by vinny.mca »

Perhaps the OP should realize that the vibe is a much much smaller car in comparison to his old aurora. And the stability of a smaller and lighter car during high speeds will be reduced significantly when both of those factors are diminished. Another factor that can cause your instability could just be the the smoothness of the road. Very often high ways aren't flat and smooth, so during high speed cruising, you may feel a litte unstable or bouncy. I highly doubt a alignment or tire pressure check will fix your problem, but obviously having them in the right specs wouldnt hurt. Adding rear spoilers, or rear sways will not help your high speed stability, you best bet is to invest in a good set of tires with the RIGHT BALANCE, and perhaps increase the width of the tire, assuming it doesnt snow where you live. Because a widen tire will have negative affects in snow.
Sublimewind
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Re: (viper)

Post by Sublimewind »

Quote, originally posted by viper »Thanks guys, your sugestions are very worthwhile looking into. I will start with the rear sway bar. Can I install it myself?If i were you, i would START with having the alignment checked... It could be that simple and it sounds like you might need one anyway.. it's also cheaper...
drunkenmaxx
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Post by drunkenmaxx »

let's start with the fact that it's a compact 4cyl car made for economy and utility, not nascar.
chew aura pizza cheat main"the world in my hands, there's noone left to hear you scream, noone's there for you"
Sublimewind
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Re: (drunkenmaxx)

Post by Sublimewind »

Quote, originally posted by drunkenmaxx »let's start with the fact that it's a compact 4cyl car made for economy and utility, not nascar.Well, it does turn left really well you know..... I travel 90mi a day at ~85mph the whole time... my car doesn't float at 90... The tires could be crap also, soft sidewalls can do this...
drunkenmaxx
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Re: (Sublimewind)

Post by drunkenmaxx »

my vibe was pretty stable, all the way to the limiter. on a windy day, however, it would float like a turd in the bathtub.
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djb383
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Post by djb383 »

Doesn't just about any vehicle react differently on a windy day? All of my vehicles have.
'05 Lava Tutone base, Pwr Grp, Moon & Tunes, 16" alloys, Auto.....Yep, it's gotta HEMI
drunkenmaxx
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Re: (djb383)

Post by drunkenmaxx »

yes, but some far worse than others.
chew aura pizza cheat main"the world in my hands, there's noone left to hear you scream, noone's there for you"
viper
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Post by viper »

Agree, some are worse than others...Ok, I took my first peek at the rear suspension ever. The U shaped rear wheel carraige frame has a 3/4' tube or rod I couldn't make out what bolted to the inside Ufacing the rear. I was really looking for a Panhard rod. I should lift the car for a better look. The rear spring seat are rusting (already) will spay-on Extend and coat with brush-on rubberized undercoating. The Panhard rod prevents swaying and improves tracking.
Sublimewind
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Re: (viper)

Post by Sublimewind »

Quote, originally posted by viper »Agree, some are worse than others...Ok, I took my first peek at the rear suspension ever. The U shaped rear wheel carraige frame has a 3/4' tube or rod I couldn't make out what bolted to the inside Ufacing the rear. I was really looking for a Panhard rod. I should lift the car for a better look. The rear spring seat are rusting (already) will spay-on Extend and coat with brush-on rubberized undercoating. The Panhard rod prevents swaying and improves tracking.Panhards are for cars that are RWD and have an axle, usually used in "non" leaf spring set-ups... these cars rears are placed by the forwared pivot bushings on the "U" and somewhat the struts, but not so much...
hank the tank
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Post by hank the tank »

The only time I desided to "test" a speed of a car was in my 944. I hit 150mph and due to the down force of the car it was glued on the road. I have yet to go over 90 in my vibe but when i did that there was no sign of floating.
VictoryInspiredbyEngineering2003 Pontiac Vibe GT
sagekai
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Post by sagekai »

i had a similar experience last night- got a little carried away driving next to my buddy on the freeway and got up to like 110 and it started feeling floatythere was a bit of wind though so that definitely couldve been a contributing factor
2003 Vibe Base- Silver Two-Tone, Injen CAI, Sony X-Plod Head Unit, 16" Voxx MG Rims, Tein S-Tech Lowering Springs, Painted Rear Brakes, OEM Exhaust Tip, Custom Rear Seat Back Covers MiVibe-ToolGuy's Fog Lamp Protectors, 111K Miles!
viper
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Post by viper »

See I am not the only one. Although accepted the fact the Vibe is very stable as is, we should keep em under 85mph for our own and others safety. Today I had a change to lift the car and examened the rear wheel axle and tracking components I was duly impressed. Thus concluded that variable under car turbulance and windage can be the factor causing the slight side to side motion at higher speeds.
Sublimewind
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Re: (viper)

Post by Sublimewind »

Quote, originally posted by viper »See I am not the only one. Although accepted the fact the Vibe is very stable as is, we should keep em under 85mph for our own and others safety. Today I had a change to lift the car and examened the rear wheel axle and tracking components I was duly impressed. Thus concluded that variable under car turbulance and windage can be the factor causing the slight side to side motion at higher speeds.Sure, I can agree to that... but a lowering job and some decent performance tire "should" fix most of that... I still have some Tien S-Techs that i'm trying to decide weather or not to put on the car.. 1.5-2" of drop should help a bit...
manicdan
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Post by manicdan »

just have a freind with a video camera follow next to you at 5mph up to 100 and cut the tape into a few frames and compare the ground clearance at the 2 speeds and see if its noticable how much higher or lower it gets.
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