Reduce Body Roll with 16" wheels

[jrfeimst2]

Hey guys I am planning on going with 16x7 wheels so I can either get indy 500 tires or the new contact extreme tire. The size would be 205 45. I am doing this to keep the Diameter pretty much the same and also drop some weight from the car as well. I am planning on buying the Eibach Anti-Roll bar set and I have the 2 point rear Torsion bar already installed. Do you think that would be enough to get rid of most of the roll and somewhat back to how it feels with stock size wheels? Would appreciate any thoughts and suggestions to add more parts that might be needed. Thank You

 

[BRGT350]

Vehicle body roll isn't a bad thing, it helps your body feel the amount of load transfer and provides predictable handling. It also allows for more compliance in situations where tire grip is reduced, such as in the rain. Increasing sidewall tends to allow for additional compression, which would actually increase the amount of body roll. The torsion bar won't do anything for body roll as what you are talking about is suspension bump travel. How to reduce the amount of bump travel can be done by increasing the wheel rate. Stiffer springs, higher damper rates, increasing sway bar rate, and increasing tire pressure. Roll bars should be used as a final tweak to the suspension for cornering stability. Spring and dampers are the first place to start. Remember that sway bars only work in corners and do nothing to help with pitching motion. Also remember the trade off for stiff suspension setup is reduced traction over bumpy surfaces, less traction in damp conditions, less warning of loss of control, and a more abusive ride over rough surfaces. Proper suspension tuning is the best compromise of performance, comfort, and conditions.

 

[VirtualRonin]

Reduce Body Roll with 16" wheels

Hey guys I am planning on going with 16x7 wheels so I can either get indy 500 tires or the new contact extreme tire. The size would be 205 45. I am doing this to keep the Diameter pretty much the same and also drop some weight from the car as well. I am planning on buying the Eibach Anti-Roll bar set and I have the 2 point rear Torsion bar already installed. Do you think that would be enough to get rid of most of the roll and somewhat back to how it feels with stock size wheels? Would appreciate any thoughts and suggestions to add more parts that might be needed. Thank You

I have Team Dynamics 1.2s in 16x7, 42mm offset with 205/45/16 BFG Sport Comp 2s. I'm running stock dampers with Mountune springs and Eibach sway bars. I had a Pierce rear torsion bar but removed it in favor of just the Eibach sway bar in the rear. I also have a Mountune upper strut bar, Mountune lower brace, and a Pierce 2 point lower tie bar.

I autocross with this setup and it's been working well. Could it be better? Probably but this is the most suspension work I've put into a car and I've only been autocrossing for about 1 year so it's been a constant learning experience. I've had the sway bars in for 4 months. It dramatically reduces body roll through the slalom and corners, allowing me to run faster and more predictably but my daily drive is a bit harsher over gaps in the road surface and high speed bumps. I'm personally ok with it. Keep in mind this is at speeds of 60mph or less (autocross), I can't speak for how it handles at high speed (track).

If I were to do it over again I would buy coil overs with camber adjustment instead of springs and sway bars. Then I would have the ability to adjust and tailor my setup according to what kind of handling I want. The front sway bar is kind of a big job (IMO) and I had to sacrifice ride quality. I would wait on those until I get a set of coil overs dialed in. As far as my current setup, it does feel like a go cart which I enjoy for the most part! My setup works pretty well as is for my driving style but I do plan to go full coil overs in the future.


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[jrfeimst2]

Thank you so much. That is exactly the response I was hoping to get and really appreciate the input

 

[Waterfan]

Hey guys I am planning on going with 16x7 wheels so I can either get indy 500 tires or the new contact extreme tire. The size would be 205 45. I am doing this to keep the Diameter pretty much the same and also drop some weight from the car as well. I am planning on buying the Eibach Anti-Roll bar set and I have the 2 point rear Torsion bar already installed. Do you think that would be enough to get rid of most of the roll and somewhat back to how it feels with stock size wheels? Would appreciate any thoughts and suggestions to add more parts that might be needed. Thank You

I upgraded to 16x7 with 205/45-16 BFG SC2 (Indy500 did not exist at the time). According to my butt dyno, there is zero difference in bodyroll from OEM 205/40-17 RE050A. The only difference from OEM is a slight loss of turn-in responsiveness which you will adjust to and forget it was even different after about a dozen turns or so. The BFG SC2 is a FAT tire on 7" wheel for its official sizing. A different tire with a tiny bit of stretch vs a tiny bit of bulge OR additional sidewall stiffness could have exactly the same turn-in response as OEM 17.

Also +1 on coilovers or springs and shocks AFTER wheel/tire upgrade and BEFORE any other suspension mods (a.k.a. stiffer anti-roll bars last - unless you are trying to maintain SCCA Street Class.)

 

[jrfeimst2]

Did you by chance notice any gripping issues from starting out on a line? I have heard going with a lighter tire/wheel setup may decrease grip from flooring from a stop light. But the tires I am looking at see to be very sticky at the same time and I think it will be only a 6 pound loss on each wheel/tire as well.

 

[Waterfan]

Did you by chance notice any gripping issues from starting out on a line? I have heard going with a lighter tire/wheel setup may decrease grip from flooring from a stop light. But the tires I am looking at see to be very sticky at the same time and I think it will be only a 6 pound loss on each wheel/tire as well.

Me?

Yes, the brand new 205/45-16 and ~4lbs lighter tire package were much better off the line than the just-past-end-of-life OEM 205/40-17 (replaced at 21k miles)

Grip has far more to do with tire compound, weight transfer off the line, and psi than any possible minor contribution of wheel/tire package weight.

Learn to feather the throttle off the line, enjoy the multitude of other benefits from lighter package and don't sweat the small stuff

 

[LILIKE16ST]

Me?

Yes, the brand new 205/45-16 and ~4lbs lighter tire package were much better off the line than the just-past-end-of-life OEM 205/40-17 (replaced at 21k miles)

Grip has far more to do with tire compound, weight transfer off the line, and psi than any possible minor contribution of wheel/tire package weight.

Learn to feather the throttle off the line, enjoy the multitude of other benefits from lighter package and don't sweat the small stuff

When I went with a 15x8 pro race 1.2s and 195/55/15 sport comp 2 (7.7 tread width so there's a slight stretch they're big for a 195) I didn't notice any additional body roll or loss of turn in response. I am still on stock suspension but do plan on swift spec r springs as my next mod. I don't race the car it's a daily and back road carver so springs may be the only suspension mod I do. I might go with some dampers like the orange konis when it comes time to replace the stockers. The only thing I noticed going to the new wheel and tire setup was the car felt much more nimble and light on its feet in all situations and I dropped 6 lbs or so off each corner (these bfg are actually 1 lbs heavier than my oem Michelin all seasons). My next tires may very well be 205/50/15 star spec 2. They are 19 lbs each so I'd lose a couple lbs per corner over the bfg in the most important part plus have more grip and about the same amount of before hand mentioned stretch I currently have (they have a 7.5 inch tread width). Should be a nice setup for my needs and perform great while being 8 lbs per corner dropped from my oem setup. This in combination with the swift spec r springs should be nasty on the backroads here in SWVA

 

[jrfeimst2]

Thanks for all the response guys. I just got my 16x7 wheels paired with the new Continental Extreme Contact Sport. I am very impressed with these tires. I have a little over 100 miles on them from enjoying them on my first weekend I have never owned the pilot super sport, but they are supposed to be compared to that. I can say they grip and just do not let go and I don't notice any body roll. They have great response too. Very happy! Slightly improved comfort. I wasn't concerned about that though since I want to take corners fast! lol Nice benefit I suppose