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Old 11-12-2002, 03:17 PM   #1
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Angry WHY,Why,why....? is Hpi junk? This thing is starting to @#$%!me off!

I got the Nitro MT RACER, and a Fantom Fr15 with airtronics servos... I love the thing, it is fast, it handles well, and it breaks EVERY time I take it out!!!! ---Guys, I am not stupid, I can drive, and I'm not bashing it to hard--2-3 foot high jumps is all that is doing these things!--landed correctly!I have gone through 3 ball ends(the actual metal ball breaks at the threads leaving threads in the hole) on my camber links, each at different times, two front a-arms (one was running into a dumpster with my 7yr old son at the wheel-so that doesn't count ), my shock caps wont stay on the rear shocks, and I just hapened to break the outdrive for my left front CVD (the thing coming out of the diff that the cvd is held on by)... This is going to drive me insane...I like to tune, I dont mind a fix, but EVERY tank and a half???? What problems(weak spots) Does the MT have so I can get rid of them?--Or is it just the whole thing is a peice and I should look at somthing else more durable?--I thought that "HPI makes a great product"--everyone says...and it is, but why all the breaking?---Sorry had to vent... ANY HELP OR SUGGESTIONS ARE APPRECIATED!
Thanks

Last edited by Zuperfastone; 11-12-2002 at 10:01 PM.
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Old 11-12-2002, 08:26 PM   #2
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Default Nitro MT Racer

WOW, that IS alot of problems. I was thinking of getting one if I got back into Nitro off-road.

Change the Ball-cups to RPM or Losi (the same).
If you are breaking the metal ball-ends then try Robinson Racing, Ti ends.
You can Boil the suspension arms in water for 20 mins to make them more flexible.
As for the shock caps and the rest of the stuff. It sounds like hard landing damage. Try some heavier shock oil if you are doing alot of jumping. Maybe some 60 wt. in the rear at least. You can put a 1/4'' piece of fuel tubing on the shock shafts between the lower eyelet and the shock body. If the caps come off it's usually from the shock piston pushing it off during a hard landing.
On the outdrive, did it actually break into pieces or maybe just the "E"-clip came off inside the diff.

Hope that I gave you some Ideas to try.
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Old 11-12-2002, 09:33 PM   #3
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Thanks popsracer,
I am using trinity 45 wht oil w/hard springs in the fnt
and 50wht oil and med springs in rear-- all with the stiffest piston I could find (small 2 hole). all the plastic is boiled for 10 min., and I have RPM ball cups. I will try the Robinson TI balls, and the fuel line trick sounds like a great idea!--how much would you recomend? 8mm or so?-or more-less? Heres some pics of the damaged diff.. I think they have stronger ones available, I also noticed the center dog bone is TWISTED! the one that goes from the slipper to the front diff. I am ASC sertified and I will be damned if the thing is not together right!--someone sugested the engine might be to powerfull for the drivetrain...It putting out a little under 1.5 hp, maybe the 42,300 rpms?---Well, in the pics you will see the diff, just above the diff you will see how I rigged the ball into the tower(after buying my 2nd tower---due to the threaded part of the ball still being in the hole---I figured I had two good towers with the threads stuck in them and I desided to dig the metal out and fit a new ball on the towers I had rather than buy new ones again and again)----the last pic is my rear cap-both look the same--they won't even thread on now that they have poped a few times---time to go aluminum I guess. thanks for your help....
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Last edited by Zuperfastone; 11-12-2002 at 10:05 PM.
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Old 11-12-2002, 09:34 PM   #4
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I didn't clean it, I just wanted away from it...for a few...I always clean my stuff...
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Old 11-12-2002, 09:36 PM   #5
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cant I post more than one pic per post?---and why dont they show up?hmmm oh well here you go ---one more...
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Old 11-12-2002, 09:38 PM   #6
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Last one....these were SMALL jumps, average 1-2 feet- maybe 3ft on a couple, but the small ones did the damage, and every bit of damage was done on a picture perfect landing!---I just don't get it.
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Old 11-12-2002, 10:14 PM   #7
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Default Damage control

I've never seen an outdrive split apart like that before. May have been over-hardend during the heat treating process. Get the HD outdrives from HPI. They come with a 72??? part # not a "Z" or "A" number. (sorry, don't have part #'s handy)
Maybe your dampening is TOO stiff. Try the #3 pistons all around with the same oils your using now. If it's (dampening) too stiff, the oil can act like a solid object between the piston and the shock cap. Normally the grooved shock caps won't pop off that easily.

The Fantom shouldn't be any more strain on the drivetrain than a Novarossi. I've seen several NMT's with them and no complaints from the owners. The twisted dogbone was probally caused by a pebble in the drivetrain. Something had to give.

How about Graphite shock towers for that problem.

On our T-Maxx, I have problems with the caps poping off once in awhile. I use RTV on the shock body threads and this seems to help quite a bit. 8 shocks for a T-Maxx $100+.

BTW, it's "Popsracer"

Last edited by popsracer; 11-12-2002 at 10:17 PM.
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Old 11-12-2002, 11:47 PM   #8
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thanks a bunch, I would be one of the last to tell you not to get the racer---but sheesh! this has been wearing me out--I feel as though I AM racing cause everytime I go out I end up scrambling the thing back together just to have fun for a few more minutes!! I will try the 3's and see whats up, I just ordered the hotbodies threaded T-Maxx shocks (2) for the rear, and I hope they work!---Please don't tell me they are junk -they were all aluminum, and threaded for the same (or less) money that the aluminum hpi (bodies only)were...anyway thanks for putting up with the longest topic dealy in the world!--
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Old 11-14-2002, 08:11 AM   #9
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hey there Zuperfastone i have a nmt and have done a bunch of mods to the thing so i think i know the car fairly well.

first of all ditch those darn plastic shocks. once they pop off the first time they will keep doing it indefinetley look at the threads at the top of the shock body see how the threads point up thats why. replace them with super shocks all the way around.

replace the stock diff shafts with the heavy duty diff shaft i believe they are made of stainless steel

i assume you keep breaking the metal balls on the front a-arms. try using a small nylon locking nut on the part of the ball that is exposed on the other side of the a-arm. i have never had any problem at all

as far as the a-arms them selves you are s.o.l. they are prone to breakage and there is not much you can do other than boil them.

hope at least some of this helps
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Old 11-14-2002, 11:18 PM   #10
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Default Metal Balls

Boy!, I wish I had metal b___s.
I think i read somewhere that a metal washer between the hex and the arm helps spread the load out better. Then use a nut on the other side of the arm/knuckle as HARLEY187466 suggested.

When I had my RC10GT, I used to make a ramp in the front yard with a 4 ft long board on top of an empty 5 gallon bucket. The truck would probally get about 3 feet of vertical air and 15-20 feet in distance. NEVER broke a thing.
With the T-Maxx, Both me and my 7yr old Son race it off-road. The only problems are the shock caps and 1 broken body mount. That's alot of tumbles too. Oh yea, and a few rear bumper brackets.
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Old 11-15-2002, 08:16 AM   #11
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cool, guys !!
I think the washer thing may help, I am actually breaking the balls on the shock--tower side where the camberlink attaches to the shocktower. I will washer and nut all the ti ones I put in though and try to rid myself tof the problem completly. Here is a link to the shocks I ordered from tower wow they sure are nice!--I should have got the purple ones, then I could easily match them with another set for the front----but noooo, I got the blue T-maxx threaded ones! and now I cant find a blue 3.5" threadded set for the front...any Ideas?



http://www2.towerhobbies.com/cgi-bin/wti0001p.pgm?Q=1&I=LXANU1&P=7

at this point, I have ordered all these goodies for the car, and now, I have this broken outdrive and I spent all my money!!

So, I removed the cvd bone on the side that has the broken out-drive, then I desided to do the same for the otherside to get it it fixed---Now I am a 2-wheel drive!---I set it up for street (street tires, snubbers on the shocks<gas line> and my "street" pipe) so I wont be breaking any more stuff here are some pics---blue T-maxx header is on the way....

as dirt car-pre outdrive mishap
both breaks the outdrive and a rigged ball mount
The front snubbers at work, with the 2wd street set up
the street set up
My son--who wanted his pic on the internet--He's the best hop-up yet!
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Old 11-15-2002, 11:23 AM   #12
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If you continue to break (which will be most likely), dump the NMT and get an RC10GT or a cheaper 1/8th buggy.

Seriously, I've put at least an extra $200 in my NMT in parts alone to make it stronger, tougher, and more durable but I was still breaking stuff. I now have an RC10GT and MBX4 XR. The XR may be too expensive but I had an Ofna Worlds 2 before that and it was just as durable. The RC10GT rarely breaks and 1/8th buggies are just bomb proof!

If you can, get one. They may cost more at first but they're very cheap to keep running.
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Old 11-15-2002, 11:38 AM   #13
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Default 1/8th buggys!

I think the 1/8 buggies look so awaome!--skin on or off! I would love one, but I really dont know wichone to get---the 9.5 looks awesome and well to tell you the truth they all look the same to me...at this point anyway, a little reserch is always good, what about the XTM with the 24-7 engine?---you need to show us your buggy NOW!! and the RC10 is a 2weeldrive?--right?-we must stay with the 4x4... well, cant wait till fantom comes out with their .21, then maybe the time for a buggy- and Ill just do piddly stuff on the mt....BTW do the buggies jump as good as the trucks?- -Thanks bud..

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Old 11-15-2002, 11:48 AM   #14
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Default My sons T-Maxx

Sorry not a very good picture.
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Old 11-15-2002, 11:50 AM   #15
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Default Posting pictures

Zuperfastone;
Could you tell me how to post my pictures so they open up in the message like yours did.

Thanks,
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