I think that something's wrong w/ my 3.3 rustler. As it stands right now, the performance is around that of w/ the 2.5 that came with it years ago. Yes it will do wheelies, but I can tell that it's missing something. I know how to tune the engine just fine, been doing so for 8 yrs now. I kept trying to lean it out until there was still visible smoke, and even then it didn't have full on performance. Running 20t/72t. Any suggestions on what to look for? Car is nearly all carbon fiber, so it weighs next to nothing, and with this large engine, it should be uncontrollable....but it isn't. Ayudame!

Make sure your brakes aren't dragging at all and that the drivetrain isn't binding.

Is the slipper clutch slipping? Is the ball diff jacked and slipping (not sure if Rustler has ball diff)? What kind of clutch/springs are you running?

That thing should be uncontrollable, you are right. What kind of controller do you have? Hopefully not the stocker. After 8 years I would hope that you graduated to a radio with end point adjustments and better response. When you open the throttle up, does the slide carb fully open? What kind of throttle servo do you have? Sometimes a faster transitioning servo (with a better radio) will give snappier response.

Pretty sure that the brakes aren't dragging, and I don't think anything is wrong in the drivetrain. Slipper is set 1/4 turn out from full lock. Does not have a ball diff anyway, and I had horrible trouble with clutches and had to resort to the stock shoes and spring after frying 3 sets of aluminum shoes and CBs and cannot figure out how to hook up my MIP spring. Controller is the stocker unfortunately. I don't really use this for anything but bashing, as most of my RC money is spent into the RS4 which is rollin with an mx-3. Throttle servo is the stock 2018, and the carb does open all the way. The problem is that the car is LESS wild than it was with the 2.5. Something just isn't right, and I mean with a rich setup with this high of gearing, it should be flipping over left and right. Dunno what else is goin on!

Idears?

if it's a relatively new 3.3, those engines won't really wake up until a good quart has been run through them, unlike the 2.5.

there's soooo much compression, it's really gotta loosen up in there before you see any serious speed...the 2.5's didn't have this problem nearly as bad as the 3.3 does.


Same thing happend to me with every one of my 3.3's when they were new. just be patient, after you get through about a quart or so, it'll wake up and run like a scalded ape.

It's a brand new engine, ran 6 tanks of breakin, so maybe 12 tanks tops through it.

I've got a 3.3 in my rustler and yes it is completely uncontrollable. I'm in the processing of switching to almost all aluminum and widening the truck just to help. You said you tuned based on smoke, have you tried tuning based on temperature? After you have a good tune, check the temp...

Yep, running around 230-250 all the time.

To ze top!

The traxxas engines are so so engines, not the best and not the worst. The one thing I did to my traxxas was replace the pos plastic carb with a os .18tm carb. Remember this was on a 2.5r engine, but Im thinking the 3.3 and the 2.5r use the same carb.
Thats the first thing I would do. The OS carb made the so so engiine into a stable running engine. I picked a carb up off ebay for 20 bucks, now the only issue I have is trying to turn fast enough to catch the cats.
The carb swap will solve many issue and make race day alot easier.

...The engine runs fine, and it shouldn't need a new carb. I'm asking why I can't seem to get the performance that I want, and I'm thinking it's drivetrain related.

Could be your diff

Old fuel, bad plug, air leak, clogged carb, bad fuel line, leaky fuel tank, (crappy plastic exhaust?), drivetrain bindage, bad clutch, loose slipper, loose diff, servo doesn't open carb all the way, poor break in, not enough break in. If all of that checks out clean, then you got a lemon my friend.

changer your gearing

22CB,and 66spur(revo)
that should give you the power

Buy something else

Fuel is brand new odonnell 30%, plug is a new OS A5, carb is clear, fuel line is new, fuel tank is straight, exhaust if high-tuned pipe from Associated, could be a problem, could also be a problem, ran it loose and tight with no difference, could be that, already fixed that, did 6 tanks of breakin without ever exceeding half throttle until the 4th tank IIRC, could possibly be that as well.

I think it's a drivetrain issue though, but I don't know what it would be.

Think about what you just posted. One, the chance of that gearing even meshing well is very low, and most importantly, if I can't get it to wheelie, why the hell would I go to lower gearing?

Top this baby off.

I'd keep running it for a little bit. The 3.3 takes more than 6 tanks of break-in in a stadium truck. There isn't as much load on the engine as their is on an MT, so they don't break in as fast. A lot of those engines come really tight from the factory too.

you won't notice much of a differance with the 3.3. i put the 3.3 in my smaxx and only got a 2 mph increase and more touque over the stock 2.5.

Hmm, alright I guess I'll let it go for a little while longer and then see if it isn't a drivetrain or other problem.