HPI Racing - RS4 Rally Building Tips

Sometimes, due to customer questions, we will find a need to note things that could not be included in the kit manuals due to time or space limitations. This page is meant to show extra tips that we have found out while running the car, and also for listing good tips that we have received from our customers.

In step 12 of the assembly instructions the front uprights need to be cut so that the suspension can reach its' full length. The best way to cut them is to use sharp plastic snips and a fingernail emery board. The portion of the arms that needs to be cut should be smooth and even with the rest of the uprights.

When assembling the self-bleeding shocks, fill the shock with oil, then put the bladder concave side down into the shock (dome-side down). Put the upper pivot into the aluminum shock cap, and gently screw on the cap. Have a towel handy, because oil will come out of the small bleed hole in the shock cap. When you have the cap screwed all the way on, the shock is complete and bled correctly.

If you want to fit the optional Sway Bar Set (#A209), you will need to bend the wires down slightly to fit on the front end. This is in addition to the modification to the arm brace that must be done.

Use a small drill bit to put two small air holes in each wheel, opposite each other. This lets air inside the tires in case the tire is glued all the way around the tire making it almost airtight. If a tire that is almost airtight is compressed, the tire may not fill back up with air and expand, giving you a temporary flat spot on the tire. A couple of 1/16" holes will prevent that problem.

Use rubbing alcohol to clean the rims and tires where you will be gluing the tire to them. Doing this will ensure a good bond so that your tires do not come off in a race.

Use weatherstripping glue (not Shoe Goo or something similar) to glue the ends of the foam strips together on the wheels to form a foam donut. If you use stiff glue it will cause a hard spot in the tire, and if you don't use any glue you will get a flat spot. Either will throw off your tire's balance and make handling somewhat erratic. We like Permatex Super Weatherstrip Adhesive.

HPI racers have found that Pacer Zap CA (CyanoAcrylate, or Contact Adhesive) works best to bond the rubber of the tire and the nylon of the wheel. It is super thin, and it runs very well between the tire and rim. It may run too well, so don't use too much, and have some debonder (super glue solvent) available in case it gets on your fingers.

For Your Information: The shock clips that are included in all HPI shock sets are 1mm, 2mm, 4mm and 7mm thick. This will allow you to know what the measurement is, instead of thinking, "the third thickest spacer".