05RollaXRS

They are installed between the hub and the wheel essentially making the wheel/tire sit flush with the fender too removed that tucked-in look and making the car appear more muscular and filling the wheel wells nicely.

x360box

Why would the Continental Extreme Contact Sport XL be upgrade? are they any better than the Michelins? My RC F has them and I looked up the mileage warranty to be 50,000 miles.

x360box

sounds nice, do you happen to have a Pic after installation?

I am presuming the installation is easy, right?

Thanks

LoSt180

They are comparable to the Michelins. I actually just picked up a set of PS4S so can compare them directly. I doubt you'll get 50k out of them, mine have several track days, so not a good measure.

I'm guessing this is a question about wheel spacers (this isn't Facebook where your replies are threaded). Below is a pic of 15mm all around on my car. I used the style with extended studs, I think they were really easy to install. Could be hard if you've never done something like that before.

cvt

Conti Extreme Sports warranty is 15,000 miles on a staggered set up. I don’t know of a summer performance tire that has a 50k mile warranty.

I can vouch the Conti Sports grip the same in the dry as the MPSS and a little better in the wet.

05RollaXRS

Mine is stock suspension/height and it looks like this with 20 mm Eibach spacers. Drives perfectly. Have had them on sine 2018 and never any issues.

konichiwa3

I have 15mm on the rear which was necessary when I installed my RR penske coilovers to prevent the wheels rubbing against them.

I debated installing spacers on the front but I didn't want to negatively impact the scrub radius, which will consecutively impact the car's handling dynamic at the front.

Aesthetically by going with spacers only at the rear actually makes the car look even more aggressive as the hunches look more accentuated, standing still it literally looks like it's poised to leap any moment. However, I believe this dynamic is achieved along with the spacers if the car is dropped appropriately. Stock, the car has an unacceptable gap in the front which always irked me.

05RollaXRS

I honestly have never seen any negative effects as I have had them on since 2018. I can still pull 1.2 - 1.3G instantaneous on the G-meter and still sustain around 120 - 130 km/h on long sweeping turns. It gives a very planted feel with the wider track with less lean over the sidewalls.

x360box

Wow, it's awesome to hear that they have a practical function too. So in your case the car is wider by 4cm, right?

x360box

Definitely lowering the car with spacers makes it look sportier than stock.

Is 82 a random number you choose?

LoSt180

I've seen people toss out "scrub radius" as a concern against spacers, but then they have no problem lowering their car and/or replacing the wheels. Comes off as a red herring.

The car already has a positive scrub radius, so spacers, lower offset wheels, suspension height changes, etc basically make it more positive. With positive scrub radius, friction from the road basically pushes back on the wheels (toe-out), which is why the alignment specs call for slight toe-in. So on one hand, yes, in theory more positive scrub radius acts as a "larger lever" which can cause a moderate increase in tire wear and darty brakes. But on the other hand, steering will be more responsive to inputs and the car will be more stable at high speeds. Any potential dynamic toe changes can also be mitigated by upgrading the lower control arm bushing. Both Figs and RR sell upgraded bushings and even solid race versions.

In summary, pay attention to the combined effects of suspension/tire/wheel changes. Also, obscure alignment specs that are never documented on printouts are neat to read about but probably not a huge deal in the scheme of things. Thanks for coming to my Ted talk.

konichiwa3

In reality they don't, it's purely aesthetics.

I get it, widening the track may translate to more lateral grip but you have other variables that start to work against you with this setup.

1. Like I said earlier the scrub radius becomes exasperated that means going into a bend your entry and exit points get negatively impacted as the car keeps wanting to track forward.
2. By putting on spacers the effective spring rates of your coils diminishes they will not be able to handle as much lateral and longitudinal load as they were originally designed for. You are increasing the leverage acting upon the springs, an inescapable fact. This affects everything from acceleration, braking to cornering as the spring amplitude tends to move a tad bit more.

These conditions become exasperated as you push your car closer and closer to the limit. For someone driving leisurely it is no big deal but for a more aggressive push the performance envelope of the car is effectively diminished.

Spacers change the geometry of the suspension. If you are trying to squeeze performance out of your car and you keep everything the same in your suspension, spacers inevitably taketh away. The "What one feels" subjectively cannot trump objective truth, we cannot bend the laws of physics.

I know of people who will actually take off their spacers before they hit the track, put them back on when they are done and hit the streets. Crazy as it sounds.

I have 15mm in the rear because it's necessary for my wheels to clear my RR Racing/Penske coilovers. The much higher spring rate of the Penskes combined with the brilliant RR Racing top mount design that articulates keeping the spring in line with the angle of the shock helps negate what would have been impacted performance-wise by the spacers.

05RollaXRS

That is just a generalized theory not specific to how RCF is setup. It is effectively doing the same thing as wheels with wide offsets would on stock suspension. Like I said above, I have pulled 1.2 - 1.3G instantaneous many times and can easily go through at 120 - 130 km/h sweeping turns. Those are actual numbers. Not just theoretical generalizations. I drove the car for about a year on stock suspension and then got the spacers on it. If they had any real world implications, I would removed them immediately as this car is all about driving experience for me.

As a matter of fact, they make the stock suspension feel better and more planted as the outer sidewalls are used a lot less and off-center as I was unhappy with the stock MPSS tires due to their soft sidewalls tendency to roll over the sidewalls even under lighter lateral loads at slow speeds. I put spacers on to make it reduce rolling over the sidewalls (the tires still had 60% tread on them). It actually ended up minimizing roll over sidewalls and made the car feel much stiffer as it would take a lot of lateral load for it to start rolling over the sidewalls so I never experienced any reduction in spring rates probably because already we have outboard springs very close to the hub.

Once the MPSS wore out and I got the PS4S with extra load sidewalls exactly the way I would have liked it when I first bought it, I still kept the spacers because it still worked very well with the tires.

konichiwa3

Lol. I dig it.

Just because a car has positive scrub radius doesn't imply adding more is better. There is a sweet spot of scrub radius that is engineered in the geometry of the suspension, specifically the angle to the kingpin axis.

Add more positive scrub radius and the entire front end gets impacted for reasons I have previously mentioned, and on the contrary to what you stated if you fail to make other adjustments steering feel becomes more susceptible to undulations of the road and hard braking.

The only way to effectively induce the positive effects created by a wider track width is by increasing the suspension arm length so that the entire wheel and hub assembly moves outboard. This will effectively increase the track width of the car while the angle to the kingpin axis remains static. Of course it will call for a custom fabrication, a task Figs engineering is quite adept at performing with their custom "Figs Proangle Kit". Obviously we are now going into an extreme case of performance the average RCF owner doesn't encounter in their daily but it's important to point out just slapping a set of spacers will not make your car better. If you have to put spacers ,15mm spacer at most (preferably at the rear only) beyond that the dynamics begin to change to your disadvantage.



It's very simple, put a stop-watch to it brother. Otherwise we talking in terms of hyperbole and hoopla. Laws of physics don't really care about our subjective feelings.

05RollaXRS

Being able to put such high G-load and carrying so much speed through turns is not subjective. You seemed to have opened the can of worms here. This is not what this thread is about. I created this thread so that people could benefit from other people's experiences with mods. Not long arguments about why something is bad. Please stick to the topic. You can start a separate thread if you want to debate that