My Hawk started life as the Nitro Buggy which was fine for awhile, but quickly gets borring offroad. So I decided to convert it to the stadium truck version. There was not a lot of parts needed to convert it, although tuning the suspension proved to be tricky. When I first set the car up with all the gear changes and rims/tires the car would tend to roll easily on sharp corners. I solved this by adding harder springs and lowering the car by raising the shock position one hole.

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To fit the larger 66T 32P spur gear to increase the acceleration and to compensate for the 2.2" Truck rims, I had to raise the transmission up on "castors" using 4mm thick plastic washers and elongate the engine mount screw holes.

Setup:

-K&N Airfilter and prefilter

-TRX .15 pullstart ,mildly ported (see tips+tricks section on this subject)

-Traxxas Stock shocks, 45W oil and monster pirate springs!

-66T 32P spur on stock pro ball diff buggy transmission

-Rear Dirt Hawgs and Front Edge Tires

-Proline Chevy Silverado (fairly used shell, has been on MP as well)

The exhaust system is the Traxxas Rubber muffler, which is pretty rubbish I must say, and as there are no other alternatives for this older car (apart from MIPs and Traxxas own one, which didn't apeal to me), I decided to make my own. Copying the original idea of having the pipe running horizontal to the back shock tower.

I went to the local builders merchant and found what I needed. Fairly common plumbers pipe was just the job.

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Parts Required:

-22mm Dia. "J" joint copper pipe

-22mm Dia. copper pipe end cap

-22mm Dia. copper tube, 50mm Length.

-6mm alu tubing (model shop)

-Silicon 1/8th exhaust coupling (model shop)

-The original divergence cone from inside the rubber exhaust.

Its a fairly easy construction, and it works. The copper pipe is pre-soldered so all that is required is to heat the tube up all at the same time with a blow torch. So to start with the J joint and the 50mm length of pipe are soldered together. Drill a 6mm hole in the end cap close to the end of it and tap the hole with a 5/16. Then cut off about 25mm or as long as you want the exhaust tip to be of the 6mm alu tubing and thread 2mm down on one end. Screw the tip in to the end cap and add some gasket sealant to the threads. The divergence cone or baffle cone sits inside the end copper cap. A short length of silicon coupling tube is pushed over the baffle cone, end cap and the joined J pipe (with difficulty i might add, I used to hot water to make the silicon stretch a bit more easily). Then secured with zip ties. Join the pipe to the existing engine manifold with some of the silicon coupling tube ad zip tie in place where you want the pipe to sit. You can make a mounting bracket to secure the pipe to the back of the shock tower using some thin metal strapping.

Check there are no air leaks in the pipe by opening the throttle and adding some fuel to the fuel tank, put your finger over the exhaust tip whilst turning the engine over. Check that the fuel is rising up the fuel pipe steadily. (the same way you prime the engine without using the primer button)

Believe it or not this is acting like a tuned pipe, it has increased the low end power even more! This is due to increasing the length between the manifold and the divergence cone (see tips+trick section for more on this subject).

It has better low end acceleration than the stock Rustler. The down side to the increased power is that it now manages to keep stripping the idler gear inside the transmission casing.