How to combat the effects of heavy wheels?

[Neofolis]

Some time ago, I had this great idea to put 19" rims on my MS6. I knew that unsprung weight had ahuge effect on perfomance and handling, but I managed to find a set of 19" rims that weighed the same as the 18" stock rims, so I thought, with a little less weight in the rubber, this would be a good option. After waiting for 2 months and finally being told, I wouldn't receive the wheels, I had the problem of already having bought the tyres, so I had to stick with 19" wheels. The only ones I could find that would fit were 19kg, compared to about 12kg stock. The wheels are now fitted and look great and despite having 215/35 tyres and lowered on H&R's ride quality is still fine. Unfortunately handling has been very badly effected, as you would expect with the extra weight, so I was wondering what can be done to combat this.

I am not prepared to replace the wheels again, so there is not much I can do to reduce unsprung weight other than lightweight brake discs, which won't make a huge difference. Will increasing rigidity with sway bars and struts get me back to somewhere near stock handling and would I stil have a bearable ride quality?

Would a lightweight flywheel help to counter the centrifugal effects of heavier wheels on acceleration and turn in?

I intend to do some power tweaks in the future anyway to help with performance, so handling is my main concern at the moment.

 

[GoFast]

Here is where I am confused on this situation....

You say that you are not in the position to get new wheels and tires again but you are in a position to get new sways, flywheels, brakes, etc....?

Why not sell the 19's for a bit less then you payed and take the money you were going to spend on the other things, add that with the money you sold these rims for and get something that works better?

 

[Blendercloud]

The flywheel won't help you in the regard that you're thinking.

In my opinion, here are your options:
1. Sell the wheel & tire combo here or on Craigslist/eBay/etc and mitigate your losses.
2. Try tying the load points together on the suspension with tower braces in front and rear.
3. Try option 2 as well as a hefty rear anti-sway bar.

I think you knew these options already, I just wanted to confirm that you were on the right track. However, no matter how much suspension work you do, you're still going to be left with ~30% increased unsprung weight. The effects of that will not be fully relieved by feasible suspension work.

I suggest selling your 19" wheels and tires as a package and buying tires for your OEM wheels as well as a rear anti-sway bar. The car will feel about 500 pounds lighter through the corners and you'll be much happier with overall acceleration as well.

 

[tunersteve]

Also, in addition to whats been mentioned, regardless of what size wheels you run, get some SPC adj. ball joints and a proper alignment. That will help liven the steering up and combat heavy wheels.

 

[Neofolis]

Here is where I am confused on this situation....

You say that you are not in the position to get new wheels and tires again but you are in a position to get new sways, flywheels, brakes, etc....?

I didn't say I'm not in a position to get new wheels and tyres, I said I'm not prepared to. This is partly because of having been forced to wait over 3 months in total to get these on and partly because I really love they way it looks now and I won't be able to achieve the same look with any 18's. This leaves me with trying to make the car perform and handle as well as possible with the extra unsprung weight. I may decide at some point in the future that no changes will make it acceptable, but I want to see what can be achieved with the current wheels before I give up on them. At the end of the day, if I decide in the future I can't get good enough handling with the heavier wheels any mods I do between now and then will still be worthwhile.

 

[Blendercloud]

I didn't say I'm not in a position to get new wheels and tyres, I said I'm not prepared to. This is partly because of having been forced to wait over 3 months in total to get these on and partly because I really love they way it looks now and I won't be able to achieve the same look with any 18's. This leaves me with trying to make the car perform and handle as well as possible with the extra unsprung weight. I may decide at some point in the future that no changes will make it acceptable, but I want to see what can be achieved with the current wheels before I give up on them. At the end of the day, if I decide in the future I can't get good enough handling with the heavier wheels any mods I do between now and then will still be worthwhile.

With all that said, the mods that we've mentioned will improve the handling characteristics of your car regardless of your wheel size. If you decide that after doing them, it still isn't satisfactory, they will only further improve your car if/when you switch back to 18 inch wheels.

 

[dquarasr]

Unfortunately handling has been very badly effected, as you would expect with the extra weight, so I was wondering what can be done to combat this.

How has the handling been affected? Please provide some details. For instance, are you noticing a problem at turn-in, steady-state cornering, reduced overall grip, or some other nasty behavior?

Are you sure what you are experiencing is caused by the wheels being heavier? Are you sure it's not the new tires you fitted on the wheels? I would expect that a change of tire would have much more dramatic effect on "handling" than would a heavier wheel (although I fully admit that heavy wheels can have a detrimental effect).

Don't forget that changing more than one thing at a time can make it difficult to assess what effect were influenced by which causes.

 

[Neofolis]

Yes, I did think about the tyres contributing, especially as I have had Falken FK-452's fitted and most of the comments I have read say that they don't perform too well for grip until they are worn in a bit.

The best way I can describe it is, when I first got in the car, it felt instantly chuckable, like it was a much lighter car and the handling felt poised and encouraged me to drive faster around corners, even in the wet, basically it inspired confidence. Now, I can feel the extra weight on the corners and so the car feels less nimble and feels like I'm driving at the limit of traction, even though I'm at much lower speed. Add to this that breaking is slower, so I don't have as much confidence to attack a corner, because I know that any adjustments I may need to make will take longer. The handling now inspires caution. It's like driving a much bigger, heavier car.

I appreciate that much of this could be the result of less grippy tyres, but I have changed tyres many times in different cars and it has never felt as different as this does after the change.

Sorry if my descriptions aren't very technical, but that's the best way I can think to describe how it feels.

I will probably take the car for a track day in a couple of weeks, hopefully I will be more confident to push it in that environment, so I should get a better idea of what it can still do.

 

[Blendercloud]

Neofolis, I understand exactly what you're talking about. Essentially, the car is understeering now where it was "just right" before. You just feel like you have less overall control over the car, whether it be accelerating, braking, or cornering. It just feels bad.

 

[Neofolis]

So the obvious next question would be, which are the best rear anti-sway bars and strut tower braces to go for? Obviously I want as lightweight and as rigid as possible.

 

[Blendercloud]

Corksport makes an affordable front and rear tower brace. It's $149 for the front and $99 for the rear. Just an FYI though, the front is on backorder until July 24th. I know, I tried to order it.

I think tunersteve has just installed the rear anti-sway bar on his MS6 (or may be in the middle of it). He would probably be who I personally would ask when I buy one.

 

[tunersteve]

Yes, I'm currently in the middle of installing the Whiteline adjustable RSB. It's a long job, but I would suggest it.