NEED FOAM TIRE EDUCATION
 

are foam tires applicable to parking lot racing? got a hpi rs4 3 18ss, looked at GRP Gandini 1/10 scale touring tires, whats with the shore (hardness ratings) does low to high mean low #, low grip and high #, high grip? I still don't understand what offset means on my car. the fronts came with 26mm tires 0 offset, the rears are 31mm tires 6 offset. I'm only guessing, but does that have anything to do with the rims. I hate not knowing which rim and tire application will fit my car. I'd like to buy outside of hpi when it comes to stuff like this.

You've got the shore part of the equation backward, the higher the shore number, the harder the foam, and softer means more traction, but at the expense of wear. Also, if you were to run your car on a track with high traction, sometimes you can have a foam that is too soft and will make the car traction roll or scrub away too much and cause slower corner speed. Heat also affects tires so picking the right shore tire for the situation comes with experience and knowledge. A softer shore tire will wear out much faster too. It is common for nitro cars to run foam and this rating system is standardized so that you can fine tune your car's set up and easy when switching brands to have fairly comparable tires. Make sure the foams are for nitro sedan too, foams for electric have different families of rubber properties that if you aren't familiar with can be completely wrong for asphalt and nitro. Just stick with nitro foams. Now 0 offset is usually standard and a good starting point for most vehicles unless the manufacturer specs otherwise. Offset has to do with the wheel and how it mounts. If it has a 2mm offset it will move the tread in or out from standard 0 depending on if its marked -2 or +2. Offset is used for different handling characteristics and issues like clearance where offset may be needed to miss hubs, etc. In your case since the rear tires are 31mm instead 26mm like the front, the offset will help so that the tread doesn't rub on your rear hub carriers or helps to make your set up consistent from front to rear. Hope that helps.

Not sure about parking lots, but with foams on carpet it is standard practice to "dope" the tires with traction compounds. Basically various petroleum compounds that actually break the rubbber down some and make it "sticky" to some degree. Things like Paragon Traction Action are used for carpet, even with rubber tires too. Again not sure about parking lots, but be aware, ask what works on that track, look for what other guys are doing, ask at the Hobby Shop. Generally applied 10 to 20 minutes ahead of time, ya don't want wet tires! On carpet generally youi don't do the entire front tire, or you can get too much steering. Always takes some experimenting.

cheers