Extra Vibration @ 100MPH

[CalPencil]

I just installed a new suspension, and now my car is a lot lower. Because of the higher spring rate, I'm experiencing more vibration than I used to with my stock setup at a higher speed.


I'm assuming this is normal, so I'm curious what other mods will allow to remove that vibration. I looked at what can be installed, there is:

-motor mount upgrades, but I heard that'll increase vibration.

-strut tower bar, but I think that won't affect any movement in terms of vibration.

-engine dampeners, they look like they would be the most effective, but they look extremely expensive.




It might be possible to buy a cheaper mod for my need, so I'm asking if anyone has any experience with vibration at high speed and any recommendations to smooth it out.


I'm looking to reduce vibrations from the 95MPH to 115MPH range. Thanks.

[The__J__Factor]

Dont really get what you mean with the xtra vibrations, at those speeds you stiffer springs should be helping you i would think, only thing i can think of would be you need a wheel alignment again.

Motor Mounts will increase vibration, also i dont your problem has anything to do with your engine moving. Your either experiencing the quicker rebound of the new shocks/springs or the spring/shock combo you got is poorly matched and is bouncing around when u hit rough surfaces.

Otherwise id say get some more down force happening, front lip/spoiler not sure what else you can do

[Sancho]

If they're springs, not a whole lot you can do. Because your car is lower to the ground, it's going to ride much rougher and "vibrate" more. If you had adjustable coilovers, i'd reduce the drop to 1-1.5".

Fact is, the roads are rough. Driving on a smooth road versus an uneven one is a world of difference. Softer tires with larger walls will also soften the ride.

I can't understand why you'd be driving 95-115 mph. Try driving at 70-80, that will reduce your vibrations.

[Entranced]

revert back to stock. Changing your suspension setup to stiffer springs will increase vibrations in any driving speeds. It also changes your allignment angles that your car is not setup to be used at. If you don't like how it changed the way your car rides, the best thing you could do is revert back to stock. Other than that, what you are experiencing is normal.

[CalPencil]

Thanks for letting me know that it's normal. I'm traveling at speeds from 95-115 because when you're traveling long distances in california, road speeds increase quite a bit. In fact, the speed from Long Beach to Las Vegas becomes 90 MPH at one point. Other people are going at least 100MPH.

It's very possible that the road conditions are causing it, but it feels more like engine vibration than anything else. Because when I do slow down to 85-90MPH it smooths out completely. Just wondering if it's a certain RPM in the engine does those things.

I might have to invest in engine damping if I need to travel that fast more frequently. More likely that Brash Boy one. But I might look into softer tires...I still have to look into things more.

[GreenBerett]

But I might look into softer tires...I still have to look into things more.



keep in mind that softer tires doesn't mean the compounds the tire is made of, but a thicker sidewall. if you have 17's or bigger, your going to have to stick to low profile, because your wheel well will be getting rubbed if you go bigger. what i suggest doing (its what i do.) is that when your doing those daily commuting trips, have a set of 15's that you really like, with a thicker sidewall. something like a 205/55/15 (what i have) helps A LOT with road noise/vibrations. and when your going to a car meet / competition, throw back on your "show wheels" and since you arn't driving on them all the time, it saves the tread on them. that way if they are competition wheels, you don't spend so much money on tires, and they last you.

I work in a tire shop so thats just my 2 cents.

[CalPencil]

I have the stock GTS 16 rims on right now....it'll be awhile until I get new tires or rims. I need to pace my spending a bit.

[Entranced]

You claimed the vibrations happen at speeds of 90 mph or more. That right there says that this is not an engine vibration problem. If it was coming from the engine, you would notice it at a specific RPM range, not vehicle speed. This says that the vibrations are coming from the driveline; Wheels, tires, axles, etc. You can have a shop re-balance and even road force your wheels. Done right, this could greatly reduce the vibrations you are experiencing.

[GreenBerett]

what size tire do you have now?

[neological]

Thanks for letting me know that it's normal. I'm traveling at speeds from 95-115 because when you're traveling long distances in california, road speeds increase quite a bit. In fact, the speed from Long Beach to Las Vegas becomes 90 MPH at one point. Other people are going at least 100MPH.

It's very possible that the road conditions are causing it, but it feels more like engine vibration than anything else. Because when I do slow down to 85-90MPH it smooths out completely. Just wondering if it's a certain RPM in the engine does those things.

I might have to invest in engine damping if I need to travel that fast more frequently. More likely that Brash Boy one. But I might look into softer tires...I still have to look into things more

Be serious. The highest posted speed limit in the US is in a small part of West Texas and it's 80mph.

The maximum posted speed in California is 70. The maximum in Nevada is 75. There is no stretch of highway connecting Las Vegas and Long Beach that has the speed limits anywhere close to how fast you claim you're going. As a matter of fact, driving that fast is a major moving violation in every state of the union, to be driving as fast as you claim you'd be about 20-30 mph in excess of one of the highest posted speed limits in the country.

oh, and driving 20 mph above a posted limit (90mph in California) is punished with an additional 60 day jail term.

http://www.dmv.ca.gov/pubs/vctop/d11_5/vc23582.htm

Over 100 is 500 bucks, a 30 day suspension.

http://www.dmv.ca.gov/pubs/vctop/d11/vc22348.htm

Just slow down.

Oh by the way an engine damper will probably make the problem feel worse, they are not intended to reduce vibration, they're supposed to help keep the engine stable to prevent wheel hop. They'll actually add vibration.

[miswhite]

:werd:

[CalPencil]

Be serious. The highest posted speed limit in the US is in a small part of West Texas and it's 80mph.

The maximum posted speed in California is 70. The maximum in Nevada is 75. There is no stretch of highway connecting Las Vegas and Long Beach that has the speed limits anywhere close to how fast you claim you're going. As a matter of fact, driving that fast is a major moving violation in every state of the union, to be driving as fast as you claim you'd be about 20-30 mph in excess of one of the highest posted speed limits in the country.

oh, and driving 20 mph above a posted limit (90mph in California) is punished with an additional 60 day jail term.

http://www.dmv.ca.gov/pubs/vctop/d11_5/vc23582.htm

Over 100 is 500 bucks, a 30 day suspension.

http://www.dmv.ca.gov/pubs/vctop/d11/vc22348.htm

Just slow down.

Oh by the way an engine damper will probably make the problem feel worse, they are not intended to reduce vibration, they're supposed to help keep the engine stable to prevent wheel hop. They'll actually add vibration.


I don't know where you're from, because your location isn't stated... but just look at the flow of traffic next time you're out here. Have you taken a drive from Long Beach to Las Vegas? There is a long stretch of highway, where police are virtually absent. By the way, everyone goes around 100MPH and holds it. Relax man...

[TaeMachine]

That highway is a 2-lane road full of socal drivers. That means they pace the slow car next to them regardless of the train of cars trailing behind.

[neological]

I don't know where you're from, because your location isn't stated... but just look at the flow of traffic next time you're out here. Have you taken a drive from Long Beach to Las Vegas? There is a long stretch of highway, where police are virtually absent. By the way, everyone goes around 100MPH and holds it. Relax man...
Relax, I give a sh!t if you get arrested or die in a huge fireball. You're just living the SoCal dream.

My location's there. I'm Bret Michaels.

[CalPencil]

You're not really Bret Michaels from the Rock of Love. I wouldn't think he would drive a Celica. Maybe you two just share the same name...

Is the SoCal dream to drive and get to Las Vegas in about 3-4 hours? :wiggle:

It is nice after all to be close enough to drive there though. Personally, I don't think I'll die in a fireball from doing it since I've done it couple of times already. About other people pacing to the slow drivers, yeah it's annoying. It's almost like people are asleep when they are driving.

Oh yeah...thanks for giving a sh!t. It's nice when people care. That's why I want to reduce this vibration at the higher speeds, so it can be safer, no matter how ironic that sounds.

[neological]

Oh yeah...thanks for giving a sh!t. It's nice when people care. That's why I want to reduce this vibration at the higher speeds, so it can be safer, no matter how ironic that sounds.

It doesn't sound ironic it sounds idiotic.

[Carbonized_GT]

Isn't there a stretch of highway in Montana that has no speed limits?

[neological]

No. There used to be but now there is a 75mph limit.

http://en.wikipedia.org/wiki/Speed_limits_in_the_United_States#Montana

[MicaCeli]

Get an alignment and slow down.

[CalPencil]

I already got the alignment, maybe I need to go back and get another one?

[Snu11zzfe]

Ur going 100 mph of course there is going to be vibration
when u start adding things that are not factory there will be issues

[CalPencil]

well, the purpose for this thread was to find out if there were any ways to reduce the vibration...not whether or not I will drive that fast or not. Turbo and supercharging are not factory, but people still do it. They also are looking to find ways to make their system more secure with as much performance as possible.

[kimGT]

Wheels out of balance maybe? someone may have mentioned this.

[Entranced]

go "road force" your wheels and see what a change it does. not many shops have this function, however. so you might have to look around.

[b18b1tranny]

Ur going 100 mph of course there is going to be vibration
when u start adding things that are not factory there will be issues

Wrong, if correctly installed.

1. Get alignement from another shop to comfirm and tell them to print the report and make sure you have 0 toe in.
2. For each extra 100km/h, add 3psi on you tires. I'm running 38 psi on T1R toyos, when up to 140mph, nothing was dangerous, done it many, many times. Max reached is 255km/h on 6th gear with 205/50R15 T1R V rated. Real speed would be lower from ratio ajustment.
3. Get some V or Z rated tires. They make the difference, get some great product, Michelin high performance summer tires (Pilot) or other great brand. Rubber is the only thing that keeps you connected to the ground. Better get good ones.
4. If your car milage is high (more then 50 000 miles) change the suspension bushings, tie rods and lower control arms balljoints, sway bar links, etc.
5. Check CV axles
6. Swap those heavy cheap bad balanced mags for lightweight 15" forged peices.

Let me tell you the celica has great high speed handling, one of the best from the sport compact cars, only the rsx has better stock vs stock.

From my point of view (02 celica 21 000 miles, race coils rear, koni rear, race bar rear, H&R sport front, stock shock, hotchkis sport bar front, 205 V T1R 15" cast lightweight rotas, custum engine mounts inserts, removed 200lbs) from 80mph going to the top the handling is superb.

The celica actually has a high drag coefficent, something like 0.32 I think, it's very high for a sport car. Hood scoop, car too high and bumper design explains the drag issue.

Drive safe at high speed and better do it on the local track, if your lucky you have a part of the oval section, do it there. Public roads are extremely dangerous, morons everywhere, patches and holes all around, sand, dirt, dead animals, stress from police chase etc. You don't need much to loose the grip over 120mph. On the race track everything is safe and fun.

[CalPencil]

0 toe in???

I got my service from Sears and I can take it back if I need too. Here is the measurements.


Front Toe including Turning Angle Diff.

Front Front
Left Right
-0.7 -0.5
1.9 1.8
0.02 0.01
14.3 14.4
13.7 13.9

Total Toe Front:
-0.2
0.2
0.04



Toe Rear:

Rear Rear
Left Right
-1.8 -1.8
0.11 0.20

Total Toe Rear:
0.31
-0.05



By looking at that, could any of that explain for the vibration or the slight pull to the left at high speed? I mean, it's not a heavy pull, but I think the car feels like it wants to go that way.

What specs should I try to get? Really, is it possible to apply 0 toe to the car? I haven't done this job before, but I would think it would be difficult to get it perfectly at 0.

[neological]

You can get 0 toe, almost every Celica I know of has 0 toe.

driving at 100mph with that much toe in is probably giving you terrible tread life. Remember, it's easiest to blow tires at high speeds and if you're going that fast and blow a tire then we're back to the whole giant fireball thing.

[CalPencil]

Can anyone else verify this, before I go tell the people at Sear to give me 0 toe alignment. Thanks.

[neological]

Jesus, I used to autocross a celica and know several people who still do - all at 0 toe. In my lifetime I have had several celica alignments done, all 0 toe.

It is possible. sears might say it's "non standard" though or a "race alignment" because some places require their employees only to align within factory specs.

Honestly, your ride will always be sh!tty that fast in the celica because the hood starts generating a lot of lift at that speed and the underside of the car/front bumper isn't designed with any sort of high speed aero.

[b18b1tranny]

0 toe in???

I got my service from Sears and I can take it back if I need too. Here is the measurements.


Front Toe including Turning Angle Diff.

Front Front
Left Right
-0.7 -0.5
1.9 1.8
0.02 0.01
14.3 14.4
13.7 13.9

Total Toe Front:
-0.2
0.2
0.04



Toe Rear:

Rear Rear
Left Right
-1.8 -1.8
0.11 0.20

Total Toe Rear:
0.31
-0.05



By looking at that, could any of that explain for the vibration or the slight pull to the left at high speed? I mean, it's not a heavy pull, but I think the car feels like it wants to go that way.

What specs should I try to get? Really, is it possible to apply 0 toe to the car? I haven't done this job before, but I would think it would be difficult to get it perfectly at 0.

oh my god, you will kill yourseft with this alignement.

1. MOST IMPORTANT, you have too much toe, you will blow a tire with heat from friction. That's bad and dangerous. Toe must be 0 to 0.05 MAX.

2. Camber is wrong, it's a daily driver with DOT tires, you don't need camber, stick around -0.25 front, -0.5 rear. Your rear is -1.8 : totally out, you tread life will be divide by 5. Also it's very dangerous on high speed, you don't have much rubber touching the ground, you're going to lose grip easily.

3. Very easy to adjust on the celica, but not many mecanics are good, get somebody else. You will need some front Toyota bolt to adjust camber (# is :90105-15006) 4 times.

Tell the guy to do it in this order :

fix camber
check toe
fix toe
check camber
fix camber
restart is not perfect 0 toe in.

If you always have extra lugage and lbs in the car all the time, sit in the car while he's doing it.

If he has a hard time with the front camber, help him :

Put a long prybar between wheel hub and lower arm, pry to the wheel to push in high part of the wheel towards exterior and the other guy must impact the toyota bolts on the shock. Also loosen the sub frame bolts. toe in is easy. Rear part is hard for camber, use a long socket (19mm if I remember) then turn it till the smallest part of the adjuster is facing exterior. You then have space for the bolt to move, push it toward wheel, impact is there. If it doesn't want to move, remove the bolt and grease everything.

[neological]

Good info. I totally agree with helping them, I used to help the guy at tires plus do my Celica alignment and it's a lot easier with 2 people.