Using spacers can get the job done but be advised there are some benefits and some issues that negatively effect the handling and other aspects, some can balance out with other mods, some are a bit complicated to explain, etc....
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Wider track width can generally reduce the effects of the tall center of gravity these cars have.
Wider tires can improve grip greatly if they are effectively used which is not always the case.
Style, in my book only as a second or third aspect of the mod, never first as handling is always paramount in my builds.
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Reduced spring rate effects caused by the longer leverage, one must calculate that which is more complicated than just using wider control arms.
Geometry changes that can hugely effect front grip, this is a complicated area so leaving it at that.
Added wear on wheel bearings, load on the hubs, knuckles, control arms, pick up points, can they take the load and for how long?
Use of the car, autocross issues like hitting more cones until you get used to the wider track width.
I chose a different route to run 15x9 wheels because of several issues, one being the fun challenge of making them fit under stock fenders(rolled and pulled of course) and only considered flares to run 15x10 with 245 slicks or 15x11 wheels with 275 slicks, both Hoosiers which usually are very wide compared to the numbers stamped on them. That would of left me with 225 tires on 15x9 sitting back under the flares and look goofy on the dual purpose car, street and track, when on the street setup as I would simply not run spacers as the offset is not acceptable to me due to a very long history of studying and effectively using known engineering principals in setting up suspensions.
BUT, for certain needs one can compromise to become more competitive in certain classes of events like autocrossing where the rules give some cars advantages over others and you just have to try different things until you find what does the job, like the car in this thread. It might just be the best it can be for such events they way it is setup according to the rules of the class.
I am always pointing out things like this due to the limited knowledge many have when it comes to mods done for "performance or "style" when many are simply the wrong way to go and safety can become a very serious issue like the really bad idea based on cartoons, the highly "stanced" cars which the car mentioned is not of course.
I would love to see the results of a setup comparison, same car, same course, same temperature, same day is always best, same tires but in something like a 225 on an 8, no spacers versus the 245 on a 9 with spacers. If not that then at least class standing over various courses, days, track conditions, where the car placed before and after the mods, etc...if faster then great!
It would still be a mod I would only consider for temp use and not a full time mod for the majority of owners as there is far more at stake there appears to be.
Have a great day
Rick