Chad05TL

So, I have the aspec springs and I still get the floaty feeling when driving on the highway mostly. But whenever I buy like $100 worth of groceries, and I put them in the trunk, the car handles like a dream. Going around curves on the highway, even over 60mph, the backend stays glued and it does not "wander". It even makes a difference in the steering wheel stability.

My question: what would I need to do to emulate a loaded down trunk without it actually being loaded? Do I need shorter springs? or stiffer shocks? Or is there no way to emulate more weight short of adding 100 pounds to my car?

I don't really know why or what is causing it to handle so much better with the added weight. Is it the weight or is it the lower ride height that makes it better? or is it both? I'm confused. Any other car I ever had, added weight just made the rear sag and slowed you down. But this TL, it handles better that way. So, I am weary about getting Koni's if I reuse the same spring. I don't know the cause, so I logically cannot figure out the fix for it. And I hate to do the trial and error method.

justnspace

iTrader: (1)

chad, just wanted to point out that you're weird. lol
you've been on the forums since 2008 and even argued about yours being higher or lower (i forgot which) than a regular TL.
then we determined that your suspension was wearing the tires quickly with weight in the trunk.

and now you wanna add weight? lol


grab a thicker rear sway bar.
it will tighten up the rear, and will not make it "wander"
the Progress RSB is a great buy!
it's a big improvement for everyday driving.

JJH

iTrader: (1)

Here's my theory.

When you load up the rear of the vehicle with more weight, you're inducing more negative camber. Naturally, a car handles better with more negative camber. I would check your camber/toe specs in the rear with no additional weight, then throw in a couple 50lb barbell plates and see how much negative camber that adds in the rear. If my theory is correct and the rear gains more negative camber with the additional weight, well you know what to do.

justnspace

iTrader: (1)

^your theory is correct.
and we've been over it with Chad05TL before.

we've asked him to get an alignment with his "normal" load in the trunk, so that the camber is correct.

EvilVirus

iTrader: (8)

Yeah its not your aspec that is giving you the issue

Plus one on JJH

Chad05TL

Slow down already.. I deserve a rebuttal. Your memory is only 1/2 right Justin. Yes it was too high.. not too low, but I never had a tire wear issue. The back wears perfect. Like perfect and it has never been aligned. And I don't want to add more weight. But even if I did, an rsb would not add sprung weight to the body.

JJH , I think you are right about negative camber because when a tire is more zero, it can bounce up higher and bounce more freely. If you consider that with a light duty shock, then its easy to see why it might feel floaty when buzzing down the highway. Have you ever seen a ford truck suspection, like mainly on the front? They have a lot of camber action when just bouncing from a big pothole or when they are loaded. The ford trucks also change camber a lot more than other vehicles that I have seen when the crank the wheel far left or right. My point is that when the camber is very negative, the vehicle does not bounce up very much. And I think this floaty feeling is coming from accessive movement as it rides along on the top of its height. Or the zero camber range. Plus, weak shocks and low dampening makes the body jossle more freely and less stabile which creates this floaty feeling.

Anyway, the last time Justin and I spoke about this, I had base TL springes. But now I have the aspec springs and shocks, and it is better but still not like the way I think it needs to be. So, anyways, I am going to have to address the ride height 1 more time. I hope I can finally put this to bed. Its been a few years. I still only have 70k miles on this car, and I dont know of another car I like better under 35k or even more, so I'm staying with the TL and I have invested about 2k recently on cosmetic things..

justnspace

iTrader: (1)

i'm sorry.
sometimes my crabby attitude gets away from me.

TLtrigirl

iTrader: (1)

this is interesting. the few times i've had my TL loaded (trunk and/or passengers), my TL's handling always feels squirrelly (at speed) and dragging her butt (accelerating-well duh...no low end torque).

EvilVirus

iTrader: (8)

CBN

d1sturb3d119

iTrader: (1)

I pulled everything out of the trunk including the jack and spare and the car handles like a dream. Better acceleration, braking and turn in. I'm getting some more oversteer. If you really want to balance the front and rear a little more, like JJH said, increase the negative camber on the rear and consider relocating your battery to the rear of the car. Not too far back though. Over the rear wheels would be best so that you don't have additional weight flinging the ass around.

EvilVirus

iTrader: (8)

I doubt relocating your battery to the rear of the car will make any difference at all.

nj2pa2nc

happy to write never had any problems with the way my tsx drove the numerous times the trunk and passenger seats were full. Many roadtrips.

Chad05TL

I thjnk my groceries was somewhere around 75 pounds. Just guessing though. Spent 125 dollars worth, but got a few cantellopes and gallon of milk, big deal of orange juice, and 2 big things of hi-c juice and 6 pounds of apples and other avergae weight stuff. I had like 10 walmart plastic bags and i told her to fill them. Haha

Chad05TL

I drove a tsx once on a rental. It drove much lighter than my TL. It didnt lean as much either. But the tsx was newer and updated, and my TL has the 05 design. The tsx was flatter in a turn, but it seemed more like a beefed up corolla. No offense, but it seemed cheaper. But yes it did handle quicker.

nj2pa2nc

no offense taken since it costs less. Never owned a Toyota. Did test drive the TL but the tsx fit what I was looking for. Has served it's purpose very well on our 3 cross country roadtrips, numerous trips from nc to nj and back plus many other trips long and short.

d1sturb3d119

iTrader: (1)

A standard car battery weighs between 30-40 pounds. I know for a fact mine weighs 40.

That's like having a dumbell virtually sticking out the front of your car weighing it down. Now move that weight over to the back between your wheels and as low as possible and you have more balance reducing how nose heavy the car is.

I can feel a difference when the doughnut and jack is out of the trunk. The car handles a lot better with just that slight adjustment. By better handling I mean it oversteer's but I like that! :P

I suggest dropping weight where you can or altering the balance. Running about half or one degree of negative camber will help. Lightening up the front helps too. The battery is the biggest weight sitting up front. Lightweight battery's are available but are pretty expensive. These are mods that require minimalish investment. A sway bar would be a good way to go though.

nfnsquared

I pulled my engine and wow, does my TL ride smooth!! Whisper quiet too!!!!

I hate cars

Big fat fail. So much terrible information.

Chad05TL

speaking of bar bells, mine are 30 pounds too, so I guess I had more like 100lbs or 110lbs in the trunk. Anyway, I think maybe some Tien SA's are in my future.. that or koni's. My only problem with koni's is that given the fact that I have aspec springs, I will still have protentially all that body movement. And thus if I did only the RSB, then that could be bad. And worse than going with the coilover which has a shorter spring, and less body movement as a result of that. So, then it would be safer to put only the RSB on the car and not the front. But if I use Koni's, I might have to add the front RSB also because of the stock spring. See, the reason I say that is because people have broken their rear RSB mounting brackets or frame. I suspect that is because they put a super strong RSB on the car and OEM FSB, and in combination with OEM springs, which allow the car to lean a lot and 1 hard turn and bam! broken RSB mounts.

So I think keeping the aspec springs may still allow for too much movement unless those Koni's are something truly amazing and keep the car from moving that much.

Anyway, I have some other projects to finish first before I buy springs.

I hate cars

I would literally need an hour to fix everything that's inaccurate in that post. Chad, give it a little thought before posting, others might actually believe that the car is really more stable with the rear loaded down. Or that a RSB increases stability when it reduces rear traction or that additional weight in the rear (which is what the swaybar manipulates) will give better traction when it actually reduces traction. It's important to note that those impressions were based on a feeling but not with the car at its cornering limit to determine if its actually more stable or not.

I'm not going to take the time tonight to go over the whole thing but if the car actually feels more stable loaded down, your rear alignment is off, end of story.

Also, the TL does not need a bunch of negative camber because as the body leans it adds more negative camber. There can be too much of a good thing. Many other cars see positive camber as the body leans so they have to start in the negative when static but not us, not on any street legal tire.

Chad05TL

humble yourself IHC. You're going to get a nosebleed up there. haha
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I hate cars

Try to keep it factual based. You're an engineer so use that way of thinking to your advantage. Adding weight will never help stability unless we're talking high winds or if the car has other problems such as alignment.

Chad05TL

Don't tell me how my car drives.

I hate cars

I forgot, your car defies the laws of physics. Carry on.

Did you test the car at its limits to determine it handles better or was this based on a subjective opinion during regular driving? That's what I thought. You're saying the car is more stable with additional weight in the trunk when all additional weight will do is cause that end of the car to lose traction sooner. Learn to be objective and you might actually identify the problem (alignment) instead of these crazy ideas that have no base in reality.

DuoDSG

I can say from personal experience that when the back of my car has been loaded with any significant amount of weight, my car's steering performance suffers as a result, especially in the winter. You would think the car "grips" the road better with that additional weight (like putting sandbags in a truck), but as others have said, with the way camber works on our TLs, it's unnecessary and really is an alignment problem. That's one of the first things techs have told me when I've asked them about the TL during appointments for tire rotations and alignments when I look at the data sheet and ask them to walk me through it.

There's no shame in understanding that the perceptions aren't necessarily reflective of reality. If people were really out to get you, they'd let you wither on the vine, let your car's operation suffer and not share their thoughts and experience on the matter.

We ALL drive TLs so the basic facts of how our cars operate and handle are going to be the same. And it's pretty unlikely that so many people won't know what they're talking about for a car that's been around for almost a decade.

I hate cars

Agreed. I'm here to help but also to make sure noobs don't get the wrong ideas. Unfortunately I'm too busy to spend time on a lengthy post right now.

I guess as long as the basics are understood the rest can be figured out.

More weight means less traction. You have more weight pushing down on the tires, sure, but you also have that weight pushing laterally on the car during cornering.

A stiffer swaybar REDUCES traction on that end.

As the rear suspension is loaded or unloaded, toe changes which is the cause of the less stable feeling when alignment is off. This is your problem assuming you don't have a severely worn suspension component (which would also cause alignment issues). Camber is not what you should be looking at, it's not the problem.

You want the tire to be flat on the road, the load spread evenly across the tread. Negative camber is there to compensate for deflection of the suspension and tires but too much means you're not using the entire width of the tread and a smaller portion of the tire is in contact with the road just like positive camber.

Camber has nothing to so with how much the car "bounces" as it was mentioned earlier. We have a nice suspension setup, tons of negative camber is not necessary nor is removing all body roll.

Coil overs don't necessarily have shorter springs and the TL comes factory with coil overs. Aftermarket just offers some additional options.

You don't know how the car actually handles until you take it to the limit. I could put a 40mm RSB on it and in normal driving it would feel awesome with a light and lively feeling. However, take it even close to its limit and you're going to discover the limit is substantially lower than stock and it's very tail happy.

If you're so worried about suspension, keep in mind that no amount of suspension mods can make as much difference as a great set of tires.

Mine felt like a go cart when I first pulled my 150lb subwoofer setup out and replaced it with a 40lb setup. Eventually I got used to it and I wanted to pull more weight but I can't bring myself to do it.

d1sturb3d119

iTrader: (1)

He's right about that. Battery relocation is a great concept if you are modding your car to that extent. Also makes for better weight bias. The lower the center of gravity the better. My advice so far is purely based off my driving preference and the fact that I've done so much to the car I'm going to hang on to it for a long long time.

I like having a canyon carver but like IHC said, bad tires=bad traction. No matter what you do to your suspension your tires are going to let you down.

Chad05TL

I think the answer is simpler. Increase dampening, and get it aligned. Camber and ride height is less important considering we are talking about 1 inch or less, because I don't need to go down that much. I think the new buicks and Cadillacs ride higher than my car and I doubt they feel floaty. I think the floaty feel just comes from light weight shocks cause too much movement on the back half, unless the trunk has a modest amount of weight it it to stabilize it. I'm not talking about 400 pounds of bricks in the back. Yes 400 pounds would make it swoosh around. But I'm not talking about that much weight.

100 pounds in this car causes a lot more dipping inthe springs and camber offset than my camaro used to.

If you put100 pounds in this car the back end drops a good 1/2 inch or a little more. That can change camber even on the front as the center of gravity shifts to the rear.. but i doubt the camber shift is really causing the stability to feel better. I think its just enough weight to keep the rear from random free moments at the top of the shock. So need more dampening.. and maybe lower it a tick

d1sturb3d119

iTrader: (1)

I have no idea of what lightweight shocks mean, center of gravity cannot shift to the rear and your shock does not have random free movement. Center of gravity can move up or down. Its against the force of gravity. You can either raise it or lower it. What dampening are you talking about? Rebound or compression? Again those adjustments should only be made if you fully understand how suspension works and if you have fully adjustable suspension.
Weight does nothing to make your car feel better. In fact it causes more damage to your drivetrain since your car needs to lug any extra weight around.

The most you can do to improve balance is aim for better weight distribution. Aside from that good luck with your tuning.

Chad05TL

light weight, meaning Light duty.. or low dampening.. cheap shock.. under perform.

It is the opposite of Heavy duty. you know. right..? haha
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I hate cars

I'm not trying to be an ass and it's even worse on car audio sites but shocks damp movement. They don't dampen. You increase damping, you don't make the shock wet lol.

I agree that alignment is your problem. Camber is not as it's non adjustable and you're hardly lowered. All TLs will have close to the same camber at a given ride height, yours should be fine. Toe is what causes the unstable feeling and toe is what changes the most as the rear suspension goes through it's stroke. It toes in under hard braking I believe, to give it a more stable feeling. I would be willing to bet if it's not a bad/worn component, it's the toe that's off.
If you're talking about CG, that is not your problem or every stock TL would have this problem. Half the trucks on the road have their CG near the TL's roofline lol. They do fine, some can even handle well with a high CG.

One thing that is very wrong in that statement is that additional weight stabilizes anything. Additional weight requires additional damping from the shocks to control the weight. Since your shocks don't automatically compensate you have less damping with more weight in the car and you have more wasted body movement. 400lbs will have the same effect as 10lbs on the handling. The severity will be different but the effect does not change.

Relocating weight, taking 40lbs off of the front and adding it to the rear over the rear axle will help handling. You're taking 40lbs from in front of the front axle line which is very bad and putting it in a much better spot. It would be better if we could remove this 40lbs altogether but that might cause problems.
I'm sure the Camaro had stiffer springs than the TL and it was a live axle design with drastically different damping characteristics for the 100lbs of unsprung weight vs the TL's 25 or so lbs.

Since your Camaro had a live axle, there was ZERO camber or toe change no matter what the ride height or how much weight was in it. If you get a camber change in that car, you might want to get the axle straightened lol.
If there is free movement near the top of the shock stroke, something is either broken, worn out, or installed incorrectly. CG can not shift front to rear. Again, more weight REDUCES effective damping so the damping is not your problem. You should read over Inaccurate's TL diet thread. On stock suspension with the weight loss the car was very firm with no body roll. Losing weight is the same as adding stiffer springs and more damping. If you like the way the car feels with additional weight and the alignment was not the problem you should be looking at softer springs and shocks but the alignment is your problem.

You're used to a car with zero camber change in the rear and positive camber under body roll which is the opposite way you want to go. The TL has a far superior suspension in every way except for pure high power RWD straight line acceleration lol. The engineers have fixed most suspension problems and as the body leans in a corner the camber goes negative which is what you want. What this means is you don't need or want much if any negative camber when the car is static. The TL is not like old cars where you have to run tons of negative camber to compensate for the positive camber in the turns. Camber is not the problem, not even a little. Neither is the CG or the ride height or the weight or the damping.

Mr Marco

Wow, you are clueless.

Placement of the weight in a vehicle can drastically change the handling characteristics of a vehicle. IE: Relocation of a battery, fuel cell, etc.

I hate cars

Adding weight will only hurt handling. Relocating weight can help. I believe he was talking about adding weight, not moving weight around as he seems to like the idea of battery relocation.

Chad05TL

In some cases though, some added weight can stabilize the car. Otherwise, sure, added weight usually makes a car more sloppy and slow to react.

Even race cars need downward force on the car to keep it down. But they use airflow to add downward force rather than a few sacks of groceries. Haha

I hate cars

Weight will never stabilize unless you're in high winds and want the car to blow around less.

Race cars have downforce which is "free weight". It only pushes down, it does not push sideways when cornering or backwards when accelerating or forward when stopping as adding stuff in the trunk does. It's a win-win other than hurting the aerodynamics.

Chad05TL

Never say never. :-)

Chad05TL

reason for weight stabilization.
https://acurazine.com/forums/showthr...4#post14723414

swoosh

iTrader: (5)

wait....

Chad = Chad ?

+1 with what has been said before...Upgraded rear sway bar, rear camber, upgraded end links + upgraded sway bar bushing = more stable rear end...

Chad05TL

probably some of that too... haha I'm not saying toe is the only issue. But it does show that added weight can increase stability. The best thing I can do is continue on with mods.. then get an alignment. That way I'll for sure getter done

I hate cars

A rear swaybar actually makes the rear end less stable. That's why it reduces under steer and in many cases causes tail happy oversteer. It's counterintuitive for sure.

Think of it this way. Adding weight to one end of the car makes that end slide easier or sooner. Adding a swaybar reduces body roll. If you add a larger RSB, as the body begins to lean and weight is transferred, the rear end is now resisting the weight more including the weight of the front end. By making the rear stiffer it's like adding weight since it also resists the front weight from leaning too.