Now, i've noticed there are more newcomers than ever on this board, and i'd like to answer ALL your questions once and for all so you will never ask the same question again. You might say, dang, this is way too long, im not readin it, but i will gaurentee you will learn alot more if you read this. Admins, if you find this article good enough to be a sticky, please make it one.
So let's start with the basic specs of the 4-tec.
-The nitro 4-tec is a 1/10th scale, gas-powered touring car.
-It takes 200mm size bodies. 190mm size bodies will also fit, but the tires WILL stick out a little bit, and there will be a good chance that the
body's wheel wells will rub against the tires.
-The 4-tec can take any 1/10th scale wheel. All from the standard size rims to super-size rims, any brand also.
-The tire width the 4-tec takes is 24mm-26mm for rubber
tires on 26mm rims. For foams, you can fit from 26mm-32mm.
-The 4-tec can accept any engine ranging from .12-.18 size without modifications.
-The 4-tec can take any electronic setup made for cars. Every
combination ranging from 3-channel fm to 2-channel am. You can use any servo for any reciever, just make sure that you've got the rightconnector for the reciever.
-The 4-tec takes a centrifugal clutch, and all clutches will not fit. If youare looking to put buy a new clutch, make sure it is made for the 4-tec and not any other car. The only other car that might take the same clutch are other traxxas cars such as the nitro rustler or maybethe T-Maxx.
-The nitro 4-tec's fuel tank is 75cc's large. It is possible to put a largerfuel tank, i've seen someone put in a 100cc tank. But it is not worth it, it will probably mess up the car's center of gravity and won't be a big improvement.
-The 4-tec can take any fuel made for CAR engines. As long as the fuel has at least 18% oil content and 10% nitro, the fuel will work fine.Remember, this is only for trx racing engines.
-The intake is a basic part and IMPORTANT part of the 4-tec. Any
intake will fit the trx racing engine, just make sure it's made for yourengine's size.(ie .12, .15)
-The nitro 4-tec has a 2-speed clutch type transmission. Look in yourowner's manual to figure out how to adjust this.
-The drivetrain of the nitro 4-tec rtr is 4WD belt drive. It has 2 gear diffs front and back.
-You can adjust camber,toe-in,shock positions, change swaybar
positions, and differentiate between shock oils and springs.
Now that we have covered the basics of the 4-tec, it's time to learn how to maintain this beast..
-After your done running your car for the day, you must put after run oil in your engine so it does not rust from the leftover fuel, which will
attract moisture and create water, which will rust the innards of the
engine. You should put 3-8 drops of after run oil into the carb.'s
opening or take out the glow plug and drop it oil right into the engine.
After you have put the after run oil, rotate the engine a couple of timesto spread the after run oil all throughout the engine.
-Diffs, if you have a rtr 4-tec, you have gear diffs, which need
absolubtely NO maintenance at all. If you have a nitro 4-tec PRO, youhave pro ball differentials(basically limited slip differentials), you mustclean take these apart and regrease them as soon as they start
becoming gritty when turning. Use the grease that came with your pro kit.
-Cleaning, it's good to clean your car after anyday you run it. It will keep everything shiny () and keep the car rolling smoothly. It will help the car's rotating parts work better and more freely. You can use many different types of cleaners on your car. Just make sure they won't harm the car. Most people use air compressors, denatured alcohol, and specially made r/c car cleaners.
That's pretty much the basic maintenance this car needs.Now, let's talk about how to tune the engine and all the rights and wrong for this car.
-The basics of tuning: There are 3 tuning needles on your carb. Thehigh-speed needle(hsn), the low-speed needle(lsn), and
the idle speed needle(isn).To tune the engine for performance, you only adjust the hsn, and lsn. Once you have adjusted the isn to idleyour car perfectly, you never touch that again. To richen the engine, you turn the needle counter-clockwise, the lean it, turn it clockwise.These is how you tune for both hsn and lsn needles.
-To check temperature, you can use a temperature gun, but if you donot have one, you can do the "spit test." You basically spit on the cooling head, if the spit boils away in less than 3 seconds, than yourrunning too hot.
-Some symptoms of a lean engine are: Engine cutting off at high
speeds, smoke coming from the cooling head, engine makes a
"detonation" sound when de-accelerating, and no smoke coming from the exhaust at highspeeds.
-Some symptoms of a rich engine are: Stalling when accelerating off the line, excess fuel and smoke coming from the exhaust,engine shutting off when shifting into second gear, and engine constantly getting flooded when trying to start.
-When you start to tune your engine, turn in very small amounts.
These needles are sensitive. You should turn in 1/16th turns. Very slowly until the engine is running good.
-There is a way to tell if your engine is running to rich or too lean
besides the way i stated above. You can "read" the glow plug.
Basically, you take out the glow plug, and look at the bottom of it. If itis wet and a dark color, then it's too rich. If it's brown and dry, it's toolean, and if it's tuned good, it will be the natural color of the glow plug. You can only read silver or any other light-colored glow plugs. Some
glow plugs are black and you cannot tell how your engine is running.
Those are the basics of engine tuning. Now, were going to figure out how this beast of a car works, inside to out.
-The car is powered by the engine, so let's figure out how that works. Theengine has many parts. The crankshaft,piston,sleeve,connecting rod,
carburator, backplate, bearings, cooling head, crankcase, and the glowplug. Those are the parts of a two-stroke engine, this is how it works.
-Fuel comes into the carb and the carb adjusts the fuel/air mixture going into the engine. After the fuel has gone into the carb, it heads downinto the crankshaft, directly from the crankshaft, it goes into the
crankcase. Then, the crankcase has fuel in it, so as the piston goes down,
the fuel goes into the top of the crankcase, the explosion chamber,so when the piston goes up, the glow plug will ignite the fuel and pushthe piston back down, causing the crankshaft to turn, this rotation happens many times per second. After the piston goes down after theexplosion, the exhaust will go into the header then the pipe, if any un-burned fuel goes into the pipe, the pipe's backpressure will take thatfuel and put it back into the engine. This is why 2-stroke engines aren't
very fuel efficient. 4-stroke engines have more of a complicated process,4-stroke will be alot more efficient, but im not going to get into 4-stroke.
That's how an engine works, so let's figure out how the drivetrain and transmission works...
-Let's start at what engages the car to move. The clutch. The nitro 4-tecuses a centrifugal type clutch. The clutch is held together by extremelystiff springs, so as the engine rotates, the spring will expand and let the clutch hit the inside clutch bell, causing the car to move. It's a very simple design.(NOTE: Clutch's should be replaced once a year or so)
-So after the clutch engages the clutch bell, it will turn the transmission.
The 2-speed mechanism works just like the clutch. As the spring expands,it'll hit the 2nd gear, then engage the 2nd gear and leave the 1st gear alone. (NOTE: When you adjust the shifting point, you are basicallyadjusting the stiffness of the spring, so anytime you forget which way you turn to make it shift later, remember this, if i turn it clockwise, i am screwing the spring IN, so i am making the spring stiffer, thus makingthe 2-speed shift later)
-We got through the 2-speed, now, the power evenly spreads to the frontand rear of the car thanks to the 4wd belt drive. After the belts spin, it hits the differentials, this is an important part on the handling of the car.
-There are two types of differentials, gear differentials and limited slip differentials. I will explain the gear differentials first.
-When you get power to the gear diffs, it will adjust the power to the leftor right wheel. Say you are making a left turn and pushing the gas, the gear diff will give more power to the wheel that's spinning more, which will be the inside of the wheel. So the inside wheel(the left side when making a left turn) will be spinning more than the outside.
-A pro ball differential(or limited slip differential(lsd)) will make the car handle MUCH better. Let's say were making a left turn again, once again, the inside will tires will be spinning more than the outside, so what the lsd does is give all the power that's being lost by tire spin on the inside tire, to the outside tire. Causing the car to have much greater traction and be more direct.(NOTE: Look in the manual of your nitro 4-tec PRO to see to adjust a lsd)
-After it goes to the diff it hit's the driveshaft, which will directly go to thewheels and make the car move.
Now you get how the nitro 4-tec works MECHANICALLY. Now, we will learn
about what the parts of the 4-tec are made up of.
-There are 3 types of parts available for the 4-tec. Aluminum, plastic, and graphite.
-PLASTIC: This is what the car comes with. Plastic is heavier than graphitebut lighter than aluminum. Plastic has pretty good strength, strength levelis in the middle, aluminum being stronger, graphite weaker. Plus, plasticcan bend to a certain point without breaking, and of course will bend back to it's original shape. Plus plastic is very cheap, there usually won't be a part over 5 bucks that's made out of plastic.
-ALUMINUM: The shiny stuff. Aluminum has it's pro's and con's.
Aluminum is the strongest of the three but also the most weight and money. ALuminum parts usually range around $22. Once aluminum bends, you cannot bend it back, unless the part is flat(ie rear shock tower) and you have a vice. People usually buy aluminum for strength and show.
-Graphite: These are what the racers use for chassis flex and saving weight. Graphite is the most brittle but has very little flex. It is the lightestof the three and the cost range is between plastic and aluminum. Graphite parts usually won't break because they're used for parts that usually do not hit curbs or anything. They are used for flat parts such as the rear shocktower, upper chassis, front tie-bar, brake disc, and rear brace. This will
take almost all chassis flex out, a stock 4-tec barely has chassis flex, graphite nearly eliminates ALL chassis flex. Chassis flex is how the car will bend left and right or up and down but bend back to shape. You want tohave the least possible amount of chassis flex to have a more controlled car.
In my opinion: Graphite and plastic. Aluminum is way too expensive, and once you bend a part, you lose 11 bucks. Plastic is the way to go for me.
It's cheap, strong enough(for me at least) and it's light. I use all the graphite parts since i have a nitro 4-tec PRO. So basically, my advice, stick with plastic parts and get all the graphite parts.
There are titanium parts and some "graphite" parts(losi's graphite editions), but those are not available for the 4-tec.
Weve almost covered the entire car, now for the good stuff, what YOUneed to know for racing.;D(my favorite part :chuckle
-CAMBER: Camber is the angle positioned on the wheels. You want negative camber all around on road, if you run oval, then it's a different story. You want 2 degrees negative in the rear, and 1 degree in the front.The whole point of camber is to get all the tire on the ground during a turn. So when your turning in the sweeper after going 40mph on the straight, when you turn, the tire will shift, so all the outside tires will be on the track getting the maximum traction.
-TOE-IN: Toe-in is the angle on the front of the tires turning in. The rear is not adjustble(by turnbuckle) you can change the stub axle carriers foreither 1.5 degree's toe-in, or 0 toe. You can have toe-in or toe-out. For the front, it matters on your driving style.(I like to have no toe at all in the front, 1.5 in the rear)
-Chassis Height: If your racing, and your track is fairly smooth, you want to be riding around 3-5mm high max. If your track is bumpy, it's ok to ride at 8mm or so. Basically, you want to go as low as you can without hitting the ground. To adjust chassis height, you put spacers in the shocks to lift the car. You can also adjust shocks positions for height.
There are more adjustments, such as length, width,ackerman, and such but those are not adjustable on the 4-tec. RPM sells tools for adjusting allthe things i stated above^^.
-SHOCKS: Shocks are the main part of your car. Without them the car can't stand. Shocks need lot's of maintenance if you want them to run smooth and perform at their max. You should clean your shocks and re-oil them anytime they sound like they have air in them.(if they have air in them, they should make a "squishy" sound when compressing them) When you re-do your shocks, you want to make sure there is no air in them, and they all rebound at the same rate. There are 3 things you can adjust on
your shocks, the shock oil weight, spring stiffness, and shock piston. Most people use around 50wt oil all around, 3-hole in the back, and 2-hole in the front. You can buy spring sets for your shocks. (My setup is 50wt in the rear, 60wt. in front,3-hole in the rear, 2-hole in the front, 25lb springs in the rear, and 30lb springs in the front)
-SWAYBARS: Swaybars aren't too big of a deal. I wouldn't even
recommend using them if you have gear differentials. You can adjust them by putting them in different positions on the a-arm. If you have gear diffs, only put the swaybar in the front,because if you use them in the rear, you will only lose traction because a gear diff can't control the car as well as an lsd. If you have a lsd's, you can use it for front and rear. (I personally don't use them and i find it better without
-Tires: There are 2 types of tires, rubber and foam. For rubber, you can have threaded tires or slick tires. For bashing, i would recommend threaded tires, for racing slick tires. I use slick tires for practice at the track, threaded for bashing, and foams for raceday. Then there are inserts for rubber tires. I would highly recommend you to use hpi pro molded inserts, i wouldn't use the inserts that tires come with, those are just strips of foam. Hpi pro molded inserts are a mixture of foam and rubber and make your tires perform to they're best.
Foams do not require inserts and most are pre-mounted on wheels. Use foams only on CLEAN surfaces, if you use them in dirty or rocky streets, they won't grip or just chunk pieces. Foams last pretty long that is, it matters what softness your foams are. So only use foams if your racing on a track.
Weve talked about the basics you need to know if you want to start racing. So let's talk about the parts that make these things MOVE!!!
-PIPE/HEADER: Pipes can be made for top-end power, low-end power,backpressure, or just plain speed thoughout the power range. Pipes are a crucial part and they consider how your engine acts and how your car sounds. The header is also an important part. You want to a have a header in a large diameter and the port fitting the crankcase port perfectly, so itisn't restricting any fuel or smoke to go throught the header. (i use a paris
turbo ring pipe and traxxas blue header, the pipe is awesome and the header has a BIG diameter)
-Engine, many people say,"man, i want the FASTEST engine." But, once you get more into the hobby, your not going to be as concerned about speed, you'll just think about handling, because pretty much any nitro car with a 2-speed has plenty of power. You can use .12-.18 engines for the 4-tec. I would recommend you to just stick with your current engine, only buy a new engine if your current engine is gone or there is a REALLY good
deal on a good engine. The 2.5 has LOTS of power and that's pretty much the fastest .15 there is. So don't get too concerned with engines.(i run a .12 picco, it is very reliable,holds it's tune, and has plenty of power)
-GEARING: I would recommend you to use the optional gears. They are awesome for tight tracks, and they have a good top end for large tracks.I would not recommend using stock gearing for racing.At ALL, it's just too tall. If your bashing, and you want some FAST acceleration off the line, then getting the optional gearing will improve speed like no other hop-up,
plus it's cheap, a little bit of a pain to put on but all worth it.
Alrighty!!! I hope this article has improved your knowledge. THis article is all about the nitro 4-tec. If you have any questions about this article,feel free to pm me or talk to me on aim( my name is mr 3bub1es )or if you have a question that isn't in the article feel free to ask. I will be making an articles all about different brands, parts, my opinions on them, and i will be making another article that tells you how to install/assemble any hop-up
you buy, all these articles are made to help you, and i spend lot's of time on these so please put them to use. GO TRAXXAS!!!
dood you r right about lots but some things u r way off like sway bar action. i race these cars on a 24 degree high banked oval with super abrasive concrete on factory tires. im smokin the electric boys lap times at comfortable pace. getting a lot of guys interested when they my 4 tecs run. i know how to make these cars fun and uncatchable on a oval and it doesnt cost anything. this is a track where my cars run 6 to 6.5 sec laps
thanks a stack for a great article. It was full of facts and info I really appreciate as one does not always get the relevant information you need on specificic topics. I have place a thread on starting problems and would appreciate it if you can reply on it when convenient. I am really battling with this car and want to invest in a new one but would first like to sort this one out before I buy a new one.
I'm wondering if you can point me in the direction of general engine maintenance, when I pull my glow plug I can see buildup on the top of the piston and I'm not really sure how to approach it
First id say you have to take the engine apart in a clean area and use a soft cloth to clean the buildup. The build up may be coming from glow plug failure or too rich of a fuel/air mixture. Try tuning your HSN/LSN(Watch out because small changes can be drastic).
Here's an article on cleaning an engine if you have time to read it
5-Step engine cleanup
It's amazing how many of us expect our engines to run well no matter how we neglect them or how dirty they may be. Not only is it difficult to see broken and loose parts through dirt, but a filthy engine is also just plain ugly. If you haven't been able to see your crankcase or carburetor in months because of a filth buildup, this article is for you.
1) DE-GUNK IT! Engines and exhaust systems run best when they are clean. A clean engine dissipates heat more effectively (baked-on grime retains power-robbing heat), and it's easier to solve a problem when your engine is clean because you can actually see its components. If your engine runs poorly and is so dirty that it looks as though you dipped it in chocolate and rolled it in sawdust, don't bother to troubleshoot. Get cleaning!
* First, remove your engine from your vehicle, and then use an old toothbrush or a stiff-bristle paintbrush to rub away as much grime as you can. Aerosol nitro cleaners work well as long as the gunk buildup hasn't been left for so long that it's baked onto the engine like armor. Before you use the cleaner, remove the air cleaner and the exhaust header, and stuff little wads of paper towel into the engine openings. Next, slide a thin rag between the flywheel and the front bearing, wrapping it around the flywheel to protect the front bearing (an old Ron Paris tip). Spray the engine liberally with nitro cleaner, and wipe away the excess cleaner with paper towels and your trusty old toothbrush. Using paper towels and a brush, clean your engine, reinstall the air filter and the exhaust, and remove the rag from the flywheel.
* So far, so good. If your engine or exhaust has been dirty so long that the gunk has baked and become varnish, disassemble the engine and use an RC nitro cleaner (Trinity's Nitro Blast, for example) to loosen and remove this varnish. If your engine needs more help than nitro spray can provide, try Gunk, which is an automotive engine cleaner. If you have to resort to something even stronger, wear rubber gloves and eye protection, and be aware that really aggressive cleansing agents may strip off any coatings your engine has (goodbye, anodizing and paint); these products are best reserved for raw aluminum). But if you've allowed your engine to get so dirty that milder products don't work, really strong cleaners may be your only option to restore your engine's performance and looks.
2) CLEAN GLOW-PLUG AREA. You'd never intentionally dump dirt into your engine's combustion chamber, would you? For this reason, before you remove the glow plug from the cooling head, you must thoroughly clean the area around it with motor spray. If you don't, you risk allowing the dirt that has collected around the glow plug to drop into the combustion chamber.
This maintenance "trick" isn't difficult or time-consuming, so be one of the few who take the time to clean this area before you remove the glow plug. If your engine runs poorly and you plan to install a new plug to fix this, clean the glow-plug area first. At the end of a day of running, allow your engine to cool completely, and then clean the area around the glow plug before you drop after-run oil into the glow-plug hole. (You do use after-run oil, don't you?)
3) REBUILD THE CARBURETOR. Many of us rebuild our engines with replacement parts for everything except the carburetor. These engines are usually the ones that are hard to tune and never seem to hold a "good tune" if you do manage to tune them. If your engine still has good compression, your carb's 0-rings may be causing the problem. These small, rubber 0-rings on the needle valves serve a dual purpose: they seal the needles against air and fuel leaks, and they provide the resistance against their housings that's required to keep the needle-valve settings stable while you drive the car.
* First, turn each needle with a screwdriver to check for resistance. Do the needles feel loose and offer hardly any resistance when you turn them, or are they very difficult to turn? If they feel loose, the 0-rings have worn out; replace them. If a needle is hard to budge, its 0-ring has probably torn and is binding up the threads. In either case, your carb may have an air leak or a fuel leak and simply needs a rebuild.
* Some engine manufacturers offer engine-sealing kits. The kits typically include every seal you'll need for the carb, and some have other engine seals, too. If you don't find all the seals you need in one package, check your engine's manual for the individual 0-rings' part numbers, and order them from the manufacturer. 0-rings are cheap, and replacing them is an affordable fix for carb leaks and erratic engine performance. This is the most overlooked area of maintenance, yet it may be the one thing that makes a difference between running a temperamental, difficult-to-tune engine and one that's a breeze.
4) SEAL IT. After you've cleaned your engine thoroughly (or you'll contaminate inner areas) and replaced any worn carb parts, seal certain areas to further protect it. Sealing takes only a few minutes, and it can save you hours of frustration later. Take the engine out of your vehicle, and remove its carb and back-plate. I recommend a high-temperature, oxygen-sensor-safe automotive silicone sealant such as Permatex Ultra Copper (available in auto-supply departments of hardware stores). Use a small flat-head screwdriver or the end of a zip-tie to apply a bead of sealant around the carb neck and the backplate area. Don't apply too much; excess can easily be sucked into the engine. Reinstall the components, allow the sealant to cure overnight, and your engine will be ready to go.
5) REPLACE THE FUEL TUBING REGULARLY. This is yet another relatively cheap, easy-to-replace item that is often overlooked. Over time, fuel tubing is likely to crack or develop tiny puncture holes, and most bashers will run it until it fails. Unfortunately, a leaky fuel tube can mimic defects such as bad needle settings and a dead glow plug, so it's difficult to track down the cause of the problem. Incorporate fuel-tubing replacement into your engine-maintenance routine, and you'll avoid problems. When you route the fuel tubing, keep it away from moving gears and drive shafts, and the fuel-delivery and pressure lines should not be longer than 10 inches. Excessively long fuel tubing can be kinked easily, and this will starve your engine of fuel.
No one can expect an engine to perform well forever, but good maintenance can help you to avoid poor performance caused by negligence. Simple maintenance steps such as the ones outlined here will quickly become a habit if you do them regularly. Don't be that guy with the filthy "mystery engine"; keep your 2-stroke clean for better performance and easier problem-solving.
Credit goes to Stephen Bess from RCCA
Last edited by NeonVortex57; 04-11-2016 at 08:27 PM.
Stickified, at least for a while! I guess this has become an unofficial FAQ thread. So, if you've got any tips pertaining to the N4-Tec, post 'em here...
Last edited by BobR; 11-10-2003 at 11:36 PM.
Six in a row makes it go.
good info..........lots of info.....but one thing.......on the old rtrs with the pro 15 u do have to do some minor mods to get the slide carb in.......mainly cutting the plastic lip around the back of the fuel tank.........so the slide carb can open........for the 2.5 i don't know if u have to do that but other slide carbs u do.........just thought i would add that
a bit more info on tyres:
tyres make one of the biggest handling differences to ANY vehicle.
a bad tyre choice will give u a bad handling car, and you will be forever trying to "dial in" the rest of your suspension to get them to work..
if you made a bad tyre choice theres one simple fix .. take your tyres in your right hand, throw them over your left shoulder, and go buy some decent ones, It will save you a lot of time, and probably a few crashes aswell.
for rough or dirty roads, or for those who want to just bash + expect good tyre life then most ppl recomend HPI X-Pattern **BELTED** tyres with
HPI Moulded GREEN Inserts fitted to any standard 26mm touring car rims, for examplethese cool lookin' black stock car rims.
"shore" is the compound of the tyre, higher "shore" rating is a harder tyre with a longer life, and a little bit less grip, while lower number is a softer tyre which will wear fast, but give good grip.
ALSO -->> front foam tyres ARE NOT the same are rear foam tyres, they have a different mix of foam + rubber.
Usually you would run a lower shore (softer) tyre on the rear, to help prevent the rear sliding out easily.
i would recomend anyone wanting foams, to start off with something like these jaco nitro shoes on the front, with EITHER these jaco 2 degree rear offset foams or these jaco 0 degree offset foams
Last edited by NitroRCracer; 11-20-2003 at 12:29 AM.
Im no expert. i just play one on the TRX forums
offset wheels give your car a wider stance, while no offset will give your car a shorter stance (wheels closer to the chassis)
wider offset wheels (like 2mm offset) give the car a wider stance. this makes the car less likely to traction roll, but will allow the rear end to slide a little more..
narrow offset (or 0mm offset) wheels will give less stance, making the car more likely to traction roll, but the rear end will not slide out as easily..
Also, a higher offset wheel is more likely to stick out past the body.
Im no expert. i just play one on the TRX forums
Are there any posted step by step instructions on the 4-Tec? The owners manual is a little sparce on details like replacing the front drive belt.
download the assembly instructions for the nitro 4tec pro from the traxxas product page.
Im no expert. i just play one on the TRX forums
i recommend the hpi x pattern belted tires. they lasted more then an hour. and still had a lot of tread left, as mentioned by nitrorcracer
I LOVE MY RIGGED MAXX!
how can I grt HPI Xpattrn moulded green tyeres please help
dang, this is way too long
~MM5700 Rustler ~ 2s 5000mah Lipo is 50.5 MPH~
What would be the best rubber tires to get for racing?
Agree with slowenufs sig wheres the new 4 tec?
what in the world is DOOD? Are you tring to use a new slang term for Dude maybe. I am kinda confused. If your setup is faster please post it. Then we ca have a look and we can determine if they will work for what we need them for.
I think we have another aznrevlazn that thinks he is the cheezzOriginally Posted by xlt69er
LIVE TO RUN MY TRX 4-TEC 3.3
no man u got it wrong,no cheeze just know how to put these cars on rails when it comes to the oval.especially after one of the electric gurus said i would never run this car faster than their 7sec class now im smokin their lap times with my car built simple but smart. It's all in knowing what to do with chassis handling being a mechanic since 1988 helps alot in knowing what i want and need out of these cars on this track.
no slang,just easier to spell. not good on the ol computer.anyway, i run my 4tecs on a really high banked concrete oval that is almost too tightly turned for the weight and speed of the gas touring cars like ours. one of the electric gurus at our tracktold me i would never run better laps than their 7 sec. nascar class.bieng a mechanic since 88 iset out to show them up.now they all stop what they are doing when i fire up the nitro and put it on the track.go to lakewyliehobby.com then click onto racing in the middle
well what do you do. you keep saying the same thing over and over again. run smaller tires on the inside. weight on the left side. sway bar staggared lots of camber lower weight springs and shock oil in the inside if you know tell us.
cool, i will do the best ican. bear w me ,not fast at typing. first it depends if u r turning in both directions as far as sway bars go. but the main problem with the 4tec is how easily they bottom out and that must be eliminated w out killin the performance. this particular track i run on pulls down hard gs and can sheer the bottom off in one tank; so put 3-4 slim cut vacuum line slivers in between the shock seat and the shock stock to limit shock travel to your liking.road course racing will not recquire so much effort. you cant put anything solid to limit travel cuz u will be back to the flintstones suspensions. once u get your car from bottoming out its time to balance how it turns and slow down steering servo throw by relocating the screw that holds the very first linkage right off the servo and bolt the arm as close to the center as poss. this reduces speedpand throw enabaling the supersensative steering to be more predictable and plain easier to steer. my cars go left so putting anything on the left is abetter balanced . i took the factory battery holder and relocated between the eng. and l/r tire it stands upright perfectly with 2 peices of velcro and a 4 or 5 inch peice of mechanics wire routed over the top bolting it to the left diff. carrier and the other end to a hole u need to drill.this holds the batt. pack tight even in a hit.before u strap it in may i suggest making a true heat shield by cutting a pepsi or beer can logo of your choice that will cover the three exposed sides of the batt. pack;but first coat the inside w real rubber like liquid electric tape or just good silicone. this will keep exh. heat off the batt. make sure u use vacuum lineoround the mechs. wire in spots thatso wont rub into batt. also zip tie or large o-ring around batt. pack to ensure no batt. ejection if u take a hit. man this looks prof. and puts weight right where its needed to go left.sway bars must be snugged to control arms to be effective. the hold dwn. hrdwr that comes is lame for the sway bar kit cuz the holes are already too big,so i order 2 kits and use 2 pieces on each control arm at the same time i zip tie the bar to the arms. a sway is not effective if its not attempting to move the other side. leaning to the right makes the sway barutilize the left side and if it is strapped on correctly,it will attempt to squat the car which enhances stability in a tight corner w sign. banking. i also know great way to keep entire car cool even heavy accel by using body reamer putting 20 or so holes in windshield and side windows. usually wont weaken body integrity.this really runs the car so much cooler and ultimately a longer lasting car. stock tires with the little black spacers is perfect grip for concrete and the abuse . the rims are perfect because the 3mm offset is just the right width and stance. rear downforce and a serious little dampening return trick to the inside ofthe shocks with fliud flow and one way flaps allowing flow in only one direction but a flap that opens another hole as the shock is being pulled back to leangth allowing xtremely fast tire return to the road keeping the assend glued.more to come , this is all intended to help those in need of grip and stability. oh i use 20 50 oil in shocks
most of that makes alot of sense for left turn only. I don't really haved a place to run like that. I wish I did because it is one heck of a looking track.
Actually I just found a group of people that runs in the local Wal-Mart parking lot. Prolly mostly drag racing runs.
If they do run some left'ys I will be sure to use some of your info. I am intrested on your shock setup though. how do you use the one way flaps. That makes so much sense on how that would work. but how
you 20w 50 are you using regular motor oil
man its fairly simple after u do one, but explianing it will take a min.so let me grab some grub and smoke. this will be worth reading it really does keep the wheels planted. i"ll tell u bout a super sticky tire and what to put inside before u assemble perfect for asphalt and concrete
ok. first before iforget,these cars come witha 1.5 degree toe in-rear hub,or axle/baering carrier.traxxas installs these cuz they know its going straight 2 a parking lot and get dogged back and forth. these hubs do benefit straihgt cuz it eliminates pulland one wheel from overtaking the other.however,turning even on flat surface ,forces the wheels 2 fight .therefore it cant make its mind to grip or slip.so, sh can the 1.5 hubs and put the 0 degrees in.eliminates the guess work to say the least. this deal wasted alot of my time.makes the car bouncy and twitchy. the shocks u completely dissassembl leaving only the top c clip on;remove what i call the disc, by removing c clip closest to threads.once u have the disc u notice 1 hole. make another 180 deg. as close 2 edge just like fact.the bit u need must b exacto 2 fact. hole. sand all burrs and clear holes where u can c right thru them.next u need very small sheet of plastic;lets say,the thickness of a tarp or plastic a car part comes in .as long as u cant put your finger thru it. iwill post this and come rihgt back to fin
yes 20 50 eng.oil. expl. later its adv. over silicone shock oil, even if its thick
lay disc on the plastic ,take new razor blade cut perfect circle of disc diameter, no overhang,will only keep flap lifted.once cut, lay against disc and take same drill bit in hond and poke center hole for shaft staying center is crusial @this point. the bit will have the hole undersized so u will need 2 ream it out with say a penpoint not 2 big,must slide snug up shaft.once u feel the flap is ready slide it carefully toward the top c clip u left in.just b4 it reaches clip let the disc do the rest making that once against clip,no wrinkles appear. @ this point flap clocking position is not important;but that the flap covers disc perfect especially where fluid is 1 direction.install lower clip and b checking for snugness where flap resistant 2 rotate.actually, the upper clip opening should face the hole u drilled.take new blade cut notch in flap at clip opening exposing that hole for the 2 way fluid flow. see fliud is packed on both sides so the factory hole u keep covered opens up while its beingforced apart by spring now u have fluid traveling thru 2 holes,but only in 1 direction,on the way out allowing the spring to sustain car weightuder heay cornering.always b careful not 2 rotate shaft and foul up alignment of notch u cut for 2 way flow.if u get the align. off ,u will cover both holes and the shock wont want 2 compress.once the shock is assembled, leav spring off and move shock slowly upand down even pressure both directions;if built correctly,it will have half the resistance when u pull it out making a speedy return.....
hi im trying to clean up my 4tec 2.5 and i want to remove the fuel tank any idea how i can do that??
Just got a used 4 tec. I have 2 t maxx,s but wanted to try a car. This thing is a blast, But i think i might need a new piston and sleeve. I read the post up top and thats helped out alot just wanted to say thanks. Oh Ive had it for one week and killed one set of tires, rear shock tower, and today I busted the rear a arm. If i dont get better at driveing the car its going to brake me befor i can brake it
IF IT AINT BROKE, HIT IT WITH A BIGGER HAMMER
you can repinch the sleeve and get some more life from it as long as it hasnt eaten a bunch of dirt.
it will get you another gallon or so out of it if done properly, which is long enough for you to get some $$ and buy a new engine in the meantime.
Im no expert. i just play one on the TRX forums
I feal stupid for asking this.please forgive me since I also have a Maxx..my question is..why dose the clutch bell have 2 gears on it that connect to 2 spur gears?? I dont get how it works when 2 gears are turning at the same time??? when the Maxx has one gear on the bell and its own tranny for 1-2 gears.the 4tec looks more complated then the maxx.is there a tutorial that explains how 2 gears work when they turn at the same time??
if you notice the first gear closest to the motor on the clutch bell moves the rear and the front gear moves the front.....pretty simple
"My Ideas always work sometimes"
this is interesting, my question is, how hard would it be to convert a new nitro 4tec to electric? what special motor mount would i need or anything like that, or is a straight up swap?
rustler vxl 2.4
http://monster.traxxas.com/showthread.php?t=463593Originally Posted by rustler09
Best example I've seen so far...with pics!
If you can't beat it....destroy it!
hmmm sems easy enough, thanks.
rustler vxl 2.4
HHmm Ok I am new to the RC world (put down the 360 controller and picked up a receiver). I recently purchased a brand new 4-tec as my first car. I know, I was told shortly after by another shop that may not be a great first car and to take my time. Well I have taken my time as best I can. I broke it in down to the seconds and was running great. I say "was" because I took it to an athletic track to see how it did because my street was not really smooth enough. Well long story short I hit the 4 inch wall that runs around the outside of the track at almost full speed...not head on but on the right side, put it this way the only thing holding the front passanger wheel together was the glue (more of a stress ball now). Um well I fixed everything I broke on it the only thing I have noticed is that when I start it up (still starts right up) it starts to idle then the RPMS just climb like someone is slowly pulling the throttle. It gets to the point where I just have to cut it off. I adjusted the LSN to the point where it is 1 turn from bottom (1/8th turn) but it cuts right out. Should I just try and take it somewhere to get it tuned or is there something else probably really wrong with it?
well the LHS was right the 4tec is only for expericened drivers only as it is rated for skill 5 under traxxas guidelines due to the speed or the nitro at 70+mph. well its a bummer that it wrecked on your first real speed run. if the idle keeps going up and the tune of the HSN and LSN are ok then lower your idle screw down a bit to lower the RPM's down. i would go so low on the LSN as it will be too lean at the setting bring it flush with the outer ring and set your HSN where you had it at when running it. good luck with the car and have fun always
i didnt mean to discourage anyone or wasnt trying to say that. i was going to say what WH20 said but was talking and doing something else at the same time and like stated it can be a great car and tremdous fun if the throttle is carfully pushed
The 4 Tec is not a terrible first car. Anyone can tell that they are going just a little to fast. You just have to use some throttle control and be aware that this car is waaaaay too fast to get crazy with. Everyone crashes and everyone breaks something. That's why we have this forum. To help eachother out and keep our RC's on the road/dirt. Not that we laugh when someone crashes their RC (cause we all do it) but we love to see pictures of the carnage! So if you have a disaster like this, post pics! As far as your motor, it could be a few things. The easiest would be to retune the motor. Start at factory setting and adjust your servos so they are balanced at 0 trim with your transmitter. First check your idle gap. Since it's reving high RPMs, make sure the idle gap is about 1mm, the thickness of a credit card. Make sure your carb is sliding smoothly back to the closed 1mm gap. If that's not the problem, then set the motor to factory settings. Turn the HSN counter clockwise until it stops. Don't force it when it stops, it doesn't have to be tight. Then turn it 4 complete turns clockwise. As for the LSN, makes sure the hed of the screw is flush with the hole. So turn it so you can only see the top of the screw sticking out, not the side of the head of the screw. This is the best starting point for tuning your motor. If that doesn't solve your problem, it could be an air leak. If you hit pretty hard, try taking the fuel tank off and see if it's cracked somewhere. Leave the fuel lines on, pinch one line and blow hard into the other. You can submerge the tank in water when blowing to see if any air bubbles come up when you blow in the lines. If there is an air leak, you need a new tank. Inspect the motor. Make sure the cooling head is tight, your glow plug is tight (not crazy over tight), and check the bearings in the clutch and block. Make sure your carb is tight as well. Just be careful when tightening the screw(s) on your carb. There are rubber O rings in there and you will destroy them if you over tighten. Inspect the clutch shoes and spring. Make sure your spring didn't break or pop off and make sure the shoes are in good shape. An air leak can cause the motor to do crazy things. Check the fuel lines in case they were pinched and/or got cut somehow. If none of these work, let us know. I'll keep brain storming to come up with some other ideas. But hopefully this works for you. Best thing is to NOT get discouraged. We all tear our RCs down, we all break them and we all crash. In my opinion, Nitros take a lot more work to keep on the track than electrics. If you learn to enjoy tearing down your RCs as much as you enjoy running them, it won't be bad at all. This will give you a chance to see how it's put together so when the next crash happens, it will be a quick rebuild. You can also give it a propper cleaning while it's tore down. Personally, I love tearing my RCs apart. It gives me something to do when it's too wet or too cold or the wife is nagging in my ear (like she is right now). So just be patient, ask questions (that's what we are here for), and we will get you back out on the track. Hope this helps and keep us posted!
If you can't beat it....destroy it!