| TUNING ARTICLES FROM THE WEB ON THIS PAGE Mugen MST Current Set Up Engine Break In Nova Rossi Third Needle Associated GT Set Up Shock Oil Conversions CHAD BRADLEY'S MUGEN MST1 SET UP 5/7/03 __________________________________________________________ USING NEW OPTIONAL SPRINGS AND 1.5 PISTONS FRONT Oil .................................... 200 Pistons ............................ 1.5 Springs............................. Grey Shock Position ................. Mid hole on arm; Mid hole on tower Camber Position ............... Outer hole on front bulkhead; 1 mm washer under ball stud. Camber ............................ -1 degree Ride Hight ........................ Front arms level Toe In .............................. 1 degree REAR Oil ................................... 300 Pistons ........................... 1.5 Spring ............................. White Shock Position ................ Inner hole on arm; Outer position on tower Camber Positon .............. Outside hole on hub; Upper outer hole on tower Camber .......................... -1/2 Degree Toe In ............................ 1 Degree hub; 4 Degree arm mount Ride Hight ...................... Arms slightly above level ENGINE BREAK IN - BY RON PARIS Before you even place your nitro car on a starter box or yank its pull-starter, read the instruction manual that came with your engine or car kit. Most nitro kits' manuals have a section that will tell you approximately where the carburetor's needle settings should be for initial start up. We have found that higher-end (more expensive) engines tend to follow the instruction's settings more closely, which means that when the manual says to set the high-end needle at three turns out from closed, this is almost exactly where the engine will run best for break-in. For sport-type engines, the needle position that allows the engine to fire and run may be quite different from what's recommended in the manual. In our experience, if a sport engine won't fire, leaning the high-speed needle in small increments will get it going. Once the engine fires and runs consistently, we will usually richen the needle back to where the instructions recommend. Never run a new engine, or even an older one, too lean. Your new engine's first run We know that you want to go out and do some hot laps the instant your new engine fires to life&emdash;but don't! The first few runs of your new engine are critical. Once your engine starts, place the car on a stand so that its wheels can't touch the ground. Let the engine idle at low rpm for a few minutes (two or three minutes will do), then shut the engine down and let it cool.During this procedure, it's also important that the piston not be at the top of the cylinder while the engine is cooling. Part of what's taking place during break-in is that the engine's mating parts are being heat-cycled; they're expanding when the engine is hot and contracting when it cools. Heat cycling stabilizes the metal and allows mating parts to fit better against each other. Keeping the piston out of the upper portion of the cylinder (which is smaller in diameter than the lower portion in order to create a better seal during combustion) will allow the cylinder to properly contract as it cools; without interference from the piston. To figure out where the piston is in relation to the cylinder, just turn the flywheel; it will become difficult to turn when the piston is at the top of the cylinder, where the fit between the piston and cylinder is its tightest. Just turn the flywheel until the piston is in the middle of its "easy turning" part. Now you're ready to lay down some horsepower, right? Wrong! Repeat the above steps three or four more times. Yes, you can drive it now After you've heat-cycled your engine, you can finally put it on the track. But don't get too excited yet you must run it with a very rich high-speed needle setting. Some engine experts recommend that, during break-in, the engine be set rich enough so that it will actually four-cycle instead of two (our nitro engines are two-cycle, which means that the fuel/air mixture is ignited once for every two strokes of the piston). Four cycling means that the engine is actually only firing one time for every four strokes of the piston. In this condition, all of the unburned fuel passing through the combustion chamber takes heat (and any tiny metal particles created during the breaking-in process) right out to the exhaust pipe! Do you really need to run the engine this rich? Well, the experts know their stuff, but we have broken in dozens of new engines without actually allowing them to four stroke. Whether or not you four-stroke your engine during break-in is entirely up to you; just make absolutely certain that the high-speed needle is set very rich: lots of blue smoke should be coming from the exhaust, and the engine should sound "blubbe. During this procedure, it's vital that you avoid prolonged use of full throttle, which could strain the engine. You should instead "blip" the throttle as you drive the car to avoid spending too much time in one particular rpm range. Run the engine using these settings for three or four tankfuls of fuel, allowing the engine to cool in between runs. Now comes the good part! Once you've put about six to eight tanks of fuel through the engine (as outlined above), it's time to begin leaning the high-speed needle and making some power! Begin by leaning the high-speed needle (by turning it inward, or clockwise) by about one-hour (if you imagine the needle as a clockface, one full turn of the needle would equal 12 hours). Run the car for a minute or so, then bring it back in and lean the needle by another one hour increment. Repeat this process until the engine begins to achieve good rpm, but it shouldn't be allowed to "scream" quite yet. The engine should still be creating lots of blue smoke from its exhaust. Before you achieve that screaming race setting, we recommend that you run your engine for a few more tankfuls in this "almost race" setting. Once you get the needle set to where your engine is making good rpm, richen it (by turning the needle counter-clockwise) by about a quarter of a turn; this is your final setting. The final steps Once you've found a good setting for the high-speed needle that allows the engine to make good power yet still push plenty of blue smoke from the exhaust (especially when the car exits a turn), it's time to set the low-end needle and the idle-stop screw. Most engine manufacturers recommend a specific setting for the idle-stop screw, and they're usually well within the ballpark. For now, set the idle-stop screw so that the engine will idle at a moderate rpm without stalling. Bring the engine up to operating temperature by driving itf or a few minutes. Now stop the car and listen to the engine's idle speed. If the engine idles fast but then slows down in just a few seconds, the low-speed needle is probably set too rich. Lean the low-speed needle (by turning it clockwise in one-hour increments) until, after running a few more laps, the idle stays high for about twenty seconds or so when you stop the car. Once you've done this, use the idle-stop screw to make the final adjustment of the idle speed. For sport engines which lack a low-speed needle, the idle-stop screw is the only method of adjusting the engine's idle speed. For these engines, simply turn the idle-screw clockwise to increase idle speed, and counterclockwise to reduce the idle speed. Setting your engine's idle speed isn't a contest to see how low you can get it without stalling the engine! Your goal when setting the idle should be to allow the engine to run at moderate rpm withoutt he clutch being engaged whatsoever. Your car should be able to sit at a standstill when idling. If you have to hold the brake, the idle is too high. If you have to blip the throttle to prevent stalling the engine, the idle it too low. Nitro powered R/C vehicles can be tons of fun, or they can cause tons of frustration. The difference between success or failure lies with the break-in process. If you follow these steps, have patience, and use your noggin, you're assured of success. Rushingt hrough the break-in procedure or worse, forgettting it altogether, is a recipe for disaster. Tuning your engine is the hardest part of nitro racing. But once you've learned how the carburetor works, and which screw does what, it will all become second nature. So when you're running your car, you'll always know exactly what to adjust to gain the highest level of performance possible Enjoy your new engine By David Andriessen on Tue May 16, 2000:
Nova Rossi Third Needle The screw has several functions. It effects the bottom-end mixture and can be adjusted in finer increments than the screw in the slide. It also can be used to influence the pick up of your engine in a specific way. By adjusting the regular low-end needle and the fine tuning screw both in the same direction you can shift the point where fuel enters the carb venturi. Thus effecting at which throttle position the low-end needle completely clears the spray bar. If you shift it more to the side more fuel will enter the carb at once when you open the throttle, which in turn will give you better throttle response coming from full throttle, to slowing down momentarily, and punching it wide open again. The downside is that it can cause your engine to load up when you're driving in slow sections. As you can see, when set incorrectly it can really screw up your tuning. I don't think many drivers would miss that screw if it wasn't there. The default setting will do fine in almost all circumstances. By Regan LeBlanc on Tue Mar 7/2001
Standard GT Set-up for Richard Saxton
Front: #2 pistons and 35wgt oil, silver springs, outside on arm and tower.
Rear: #1 pistons and 30wgt oil, green springs, outside on tower and arm.
Short wheelbase and 1.5 hubs in the back. Run 0 degree toe in up front and One and a half to two degrees camber front and rear. I highly recomend you get the 1.5 degree rear hub carriers if you do not already run them. Total rear toe-in 4.5 degrees. Short wheelbase out back. . 0 degree toe in/out in the front. Ride height rear bones level. Adjust front so when viewed from the side it's nose is higher than rear. No limiters inside the shocks. Make sure your suspension is not bound up and is very free. Tires are usually Edge fronts in M3 and Bowties in M3. Use small changesin front ride hieght to get more or less steering. Start with chassis level. |