XRAY - Model racing cars

So I'm fairly new to the RC scene with @ 6 months under my belt. I picked up a pretty much brand new XT8 Truggy (08 Spec) and just love the Truggy! I'm running an LRP28R on it for a motor, a JR 650 for steering, and a JR 590 for throttle. Mediocre servos, but working my way up to the good stuff.

My local track is a fairly tight and technical track with some big jumps (3 triples, 2 doubles, tabletop, and a timing section) with a medium sized straight.

I just started racing it and getting faster with it, and I'm noticing a HUGE issue with it's handling (and I know it's not the Truggy itself, it's setup related for sure). When I go into 90+ degree corners, I actually have to slow down to get the Truggy around the corner without going off the track. It seems to have the turning radius of a dump truck at the moment, or it's severely pushing and working against itself.

I'm running the stock tires and wheels at the moment, but have tried a few different sets since I originally thought maybe the tires were just not biting enough to get the Truggy around the corner. After watching other Truggy drivers flick their rigs around corners like a buggy....I figured I had better start getting some advice.

I'll have to take a picture of my wheel setup tonight to post (I forgot before I left for work), but here is how it's currently setup.

Keep in mind these numbers are estimates since I don't have a true setup station or way to measure my setup. Just eyeballing it.

Rear: Toe in is @ 3-4 degrees, with @ 1 degree of negative camber (leaning TOWARDS the chassis).

Front: Toe in maybe 1-2 degrees, 3-4 degrees of negative camber

Now like I said above, setup is a completely new thing for me....but I'm thinking the toe in on the rear may be causing my issues. I have not touched the rear since I got the Truggy. I left it as the previous owner had set it up, but now....I need to be able to power through corners faster. I've upped my driving speed to the point where I feel like I'm putt putting through corners instead of attacking them....and I'm getting left in the dust because of it.

I have adjusted my steering Ackerman all the way to the rear since the manual said that will help with small tight tracks, and at first it did seem to help...but now I don't even notice it anymore.

Track is typically very dusty on practice days, and they keep it pretty moist on race days. It's a clay base track, so traction usually isn't much of an issue except on practice days.

Diff Fluid is 7K, 10K, 5K from front to rear, and I'm about ready to do a fluid swap in there....once I figure out what weight I want to try.

Any help would be GREATLY appreciated.

Thanks!

Hmmm....upon a little more research after I posted this....It's very possible my steering servo is underpowered, but I'm still not so sure since the problem is on power AND off power. The stuff I found was issues with on power steering and a 140oz/in servo.....still reading though!

You definately need a better servo, thats way under powered. For a decent priced servo i run a ds1313 from ace servo's. They run about 75 bucks

Oh no doubt I need a stronger one, but that shouldn't matter at low speeds much should it? I mean the wheels are turning to their stops without any troubles....yet it still has a HUUUGE turning radius.

I was actually planning to order a Blue Bird servo to give it a try. Pretty cheap and some good reviews.

I'd say it was your steering servo as well. Even at low speed if the servo doesn't have enough torque to hold the wheels then its not going to turn well. I use a Hitec 985MG and works great for about $60. I have a friend that uses Ace servos and they've been great too.

Well that was kind of my point. It's holding the wheels just fine I can understand at high speeds the servo won't have enough strength to effectively turn the wheels with the forces all acting against it....but even at 5mph it turns like a dump truck. Making me think the setup is off....

I guess I'll find a better servo and see if that fixes me up. I just hate throwing money at things I can't pinpoint as the exact problem

Good call Robin. I'll have to fill one out since I didn't do the initial setup of this guy.

Servo Saver is tight.

Here are a few pics of what I was talking about above at least. I'll get the setup sheet filled out as soon as I can. Don't mind the dirty pics. I ran yesterday and didn't have time to clean it as of yet. Darn work!

I just posted what I could for the setup sheet.

xform/index.php?act=view&ID=391&setup=xt8

I dont know a lot about the truck but 1. 140 is a little weak for a truck unless your really good it wil have problems eventually.2.those tires,old school with monster truck style sidewalls are causing the druck to be unresponsive maye not when out in a field by yourself but on a track with other new style tires you will see the difference in feel & visaual. If the servo is still in good enough shape ,hold the treads lightly & yurn the controller wheel. The rims will turn much more than the treads relative to others you race against.Set up may very well be part of the problem but normally I dont play much with setup on the buggy till I have the right tire package or your just fighting yourself. Propper tire package is 50% of the cars handling next is motor tune,if you cant count on your motor to be there when you need it you wont be able to drive then comes setup as a fine tuning tool,with the way most cars are today even a bad setup can run OK if your motor will adjust the truck when you need it too & you can cont on the tires to be consistant.Lastly from what I've seen & heard(I dont have a x-ray truck but do have the mbx5t) the last xt8 was just not up to par with newr trucks period.If your good you can compensate alot but dont expect your truck to drive arounsay, a mbx6t or AE truggy or even a kyosho its an unfair advantage of new style weight placement those trucks have.I would think if you want to handle the newer trucks the newer chassis would be the best setup upgrade.Seeing side by side pictures of the old & new chassis will help you under stand where I'm coming from.It's the same as going from my old school buggys to the new design style you cant really compair fairly.

Get some Low Profile truggy tires (look at the fast guys at the track) and take all of the toe out of the rear of the truck and it should be MONEY! Tires and toe pretty much make or break a truggy.

Always remember that tires are 80% of the setup!! You could have the perfect setup, but your car will be the hardest thing to drive....ever...without the correct tires!!!

You said you have a couple degrees of toe in on the front. Try going to one or two degrees of toe out. It will makebit feel more responsive at the turn in. The outside tire will turn just as far at the lock but the inside tire will turn farther and help get the truck into the corner better.

Also, not sure which set if ackerman holes you are using on the steering plate, but move them to the back for more responsive steering.

Softer front suspension or ligher front sway bar, lighter front diff oil and/or lighter center diff oil will also help with turn in. Also anything you can do to move some weight toward the front of the truck can help the front tires bite in the corners. I've seen people put the rx battery on the mud guard toward the front of the truck by the steering servo to relocate the weight from rear to front. Shorter wheelbase can make it feel more tresponsive too.

Of course ad others have said... A better steering servo can't hurt either.

Dont wait to test the servo. GET NEW TIRES!!!

For loose dirt I would say a set of medium AKA Ibeams. Or Cityblocks in the front if you need a bit more steering. Cant go wrong trust me.

I installed a JR9100T steering servo for this weekend's race and VOILA....she now turns properly Of course...3 laps into the main....I had the pin that holds the rear bearing carrier to the suspension arm somehow pop out of it's slot...so I DNFd anyway. Is there any kind of aftermarket pin set that works better than the stockers? I have had both rears pop out on me (even with the set screw in there) and one rear bent itself into a pretzel off a hard landing.

It seems like the end of the arm is flexing to the point where the pin is freed from it's slot and of course the pin pops out of one side....and I'm off the track in the weeds somewhere