I attached the larger o-ring (971031) on the bottom of the shock body as indicated. The smaller o-ring (970050) floats loose on the shock shaft once I undo the bottom cap and start slowly pumping the shock piston.

sounds like these shocks are a bit of a pain
but i hear they work ok.

Use which engine in your NT1 bester ?

Thanks!

Hey R/C Market, I use a Max Power SL3 Engine. It has awesome power and is super reliable. It will idle for as long as i want it to. I think it's just as fast as the Novarossi Plus 12-3CT. Deffinately the best motor i have ever owned.

Regards, Ryan

I ran the car today and was very impressed with it's performance out on the track. Much better than I expected for a first run. The car was totally hooked up with the stock setup! Really easy to drive and fast. Stratus 3.1 body, K-Factory tires and TZ 3-port (stock). Front trackwidth was 196mm and I had a ton of steering. I am going to race the car in this configuration next month when our club races again.

I do have a question though... Where/what is that whirling/twirling chirping sound coming from when the car is on-throttle???

Just FYI... The rear diff leaked today. The front diff leaked even before I put it in the car and I did end up using Permatex to seal it.

http://www.nitrokb.com/images/nitrokb.com_nt1.jpg

I think max uses nova engines but he tweak the engine a bit....stock vs modified?:blush:

Glad you like it. I've been really happy with mine. Mine also makes the "whirling/chirping sound". Remindes me of a turbo with a blowoff valve:nod: I think it must be the clutch.

As for the diffs, mine leaked the first time I built them, but after changing the diff oil a few times I think I was able to get the o-ring in place better and haven't had a leak since. I do wish they had a more conventional gasket though. I hate having to replace the o-ring everytime I decide to try a different diff setup.

I built a few extra diffs for the car, so doing quicker setup changes isn't as time consuming, but I hadn't had any leaks. Much better than the MTX...mine ALWAYS leaked, even with extra sealant. The whining sound when you hit the throttle and let off, mine did that for a while, but went away after a while, think it might have something to do with the brake disk.

I too had front and rear leaking problems after my first build but that was because I over filled the diffs, after fully following the manual it never leaked. hmm I think I need to try a different diff oil :cool:

After racing mine for the first time, I put my MTX4 on the shelf! ;);) My diffs don't leak, however my pivot balls and pivot ball cups continually re-adjust while driving. I put in some thread locker, so hopefully that prevents it from happening anymore. :confused:

Any other short-comings anyone else has witnessed, so I can be better prepared for my next race? I did purchase CVD's, which was one of the short comings.

I believe the hard front foam bumper helps protect the body a bit more at the cost of some weight but other than the front cvd's this kit is really top notch.

I did manage to have a wheel come off with no impact (with one of the kawahara gnarled lock nuts installed with the grip of death) and I lost the plastic wheel hex, roll pin and one bearing so the aluminum hexes may help you out to at least keep everything together.

The two guys who tried the car were, "Hey! What's that sound??" and I told them, "Who knows? Don't worry about it. If there is something wrong with it, it's too late now!" :lol:

Gasket like the MTX-4 would have been better. :nod:

Having extra diffs is really the way to go. If that sound is the brake disk, then I guess I didn't leave enough of a gap between the pads.

Hmmm... would like to get to the bottom of what it is.

The diff seals do suck but with a bit of practice they can be built so they don't leak. To ensure a good seal you must use a new o-ring, proper fill level, and the right amount of tension. With the process below I haven't had any leakage problems with mine.

1. Fill to the indicated fill level and apply the cap w/o the o-ring seal.
2. While holding the diff cap side up work the diff with to pull the oil into the crevasses and air to the top. A drill with a cut dog bone works great.
3. Open the diff case and refill to the manual fill level.
4. Repeat steps 1-3 until the oil level remains holds steady, do not fill beyond the indicated mark or the diff will leak.
5. Install the seal in the cap w/o oiling it so that it contacts the outer lip and sung the screws down evenly in an X pattern. Do not over tighten or you will damage the seal, they only need to be snug.


For the twirling sound I would suggest you check your side belt tension and rear side pulley. With the 25T side pullet you will need to run the side belt tension at maximum to keep it from skipping under braking and hard acceleration. The belt may also bounce and slip if your side pulley gets gummed up with debris. Should the belt check not resolve the problem check your rear brake setup. If your brake screws are too tight (light drag) or too lose (lots of play) the brake disk with float and squeal. There is also potential for the pins on the brake pulley to rub the bulkhead if it is shifted all the way towards the spurs on its set screw key. A digital servo can also make a similar sound when the fets overheat from being used in a throttle application. The last thing to check is your 2spd assembly, make sure it is assembled correctly and the shoes are not spread too far rubbing on the gear adapter.

Mark

On the shelf! At least I can relegate my RRRs to the Outlaw class. ;)

IMO, the mating surfaces don't provide enough friction to keep the pivot balls from backing out. With thread lock, the nuts go right on with no effort - and the pivot balls screw into the suspension arms (no thread lock) like butter.

I would suggest building 40 & 60K rear diffs and a 40K front. The 40K rear speeds up the car through mid corner and helps plant the rear on exit in low to med grip levels. In higher grip conditions the mid corner bog with the 60K goes away and pulls harder on exit. A light front diff gives good turn-in and scrubs less than the conventional stagger. Go softer than 40K in the front and you are likely to lose some breaking on entry and harder setups like 60 or 80K sacrafice scrub like a spool on entry.

Mark

I can't even get it right on my RRRs. It's Permatex for me. :nod:

I don't have my side belt tension set to the max. Hopefully it's just that.

XRAY needs an addendum to the manual to state what the correct starting gap should be. :sneaky:

Another addendum. The length of the shaft extending out of the left side of the bulkhead when you tighten the brake pulley key.

Can that happen as soon as you put the car on the track? Right from the get go, it starts making that sound.

Will do.

Thanks for all the advice Mark. :nod:

Here is a quick update on tire wear at the nationals track, have any of you guys tried using a harder tire on just one side? Does it drive oddly enough to worry about it? Is there anything I can do setup wise to help this out? The nats surface will have enough traction to require 45 shore rear tires and I've had an extremely hard time finding any harder than that.

This was for a 15 minute main and maybe 3 minutes of warmup.

Twister tires, 40 shore @ 58mm fronts and 42 shore @ 60mm rears.

56.9mm RF
56.1mm LF
55.7mm RR
57.6mm LR

..

Make sure the brake cam post isn't rubbing on the brake disc.

Ok you guys have been way to nice on the topic of screws backing out.

So what is the deal with this anyone have a solution, 6 races, and I have been take out every time by something in this car backing out, this past weekend the freaken nuts on the wheels backed off, put it back together using blue locktight and 2 mins of running pow, again. I have used blue and red locktight thought this car and even CA in some places... But no matter what, this thing seems to vibrate to the point, that something is going to fall off. I'm really trying to work with this car, but short of CA every freakin screw, nut, etc. nothing has worked.

Any ideas from the poeple that make it trough a 20 min main with out the something backing out? Yes, I use blue locktight, red locktight, and CA glue... But nothing seems to work... :confused: I'm running CVDs in the front, Nothing bent, and dogbones in the back, nothing bent...

No way!! :eek: Really?? :weird:

Are you suggesting that I may have to shim the bulkhead side brake pad?

Haven't you heard??? You need to buy the new option parts to fix that problem.

I'm just kidding bro. ;)

Nuts
 

The only nuts that I have found that don't back off are the Kawhara ones.

They have them in Silver and Black.

Mark

I prefer to use wheel nuts that have serrated flange, it cuts into the wheel rim when you tighten it, you'll never loose it again. Serpent has them as well, part #SER 801217.
For uprights and arms, I make scratches in the threaded holes with a small screw driver all the way around (try not to damage the first few threads), I don't use loctite on these parts and have no issues with pivot balls or nuts backing out...

The Mugen serrated wheel nuts work just as well. I'm finally going to switch all my cars to those. :rolleyes:

Hi Ryan,
But HK small this engine & parts,
If you choice Kyosho X312T or OS 12TZ spec 2 ?

Thanks!

I'm lucky enough to have a hardware store 3 miles away that has a drawer full of these at all times :D. Serrated M4 flange nuts are the way to go :nod:.

So long as the pulley isn't all the way towards the spurs the pins won't rub. Alternatively if you shim the play out of the shaft with the shims on the side pulley side it can't shift far enough for it to run regardless of the brake pulley placement.

The servo sounds wont occur immediately unless you have drag brake, too much throttle spring and/or return spring tension, or the fets have already been damaged. Digital throttle servos are just failures waiting to happen, a good analog servo works best. Keep the digital one for a steering backup.

You have 3 options you can:
A. cut your tires even left to right with your normal fr/re split and have a car that starts great and falls off all race.
B. cut your tires larger on the higher wear wheels so that they even out mid way through the race giving you a better car for at least the 2nd 1/2 of the main than option A. You will have asymmetrical handling at the start that balances in the middle before falling back off. If you have to cut 1mm or more difference you would probably be better with a shore stagger.
C. Run harder tires on the higher wear wheels to even out tire wear. This option generally give the most consistent handling but will be asymmetrical from start to finish. I usually try this before staggering my tire dia.

Depending on conditions you may need to do a combination of options 2 & 3 to get the best result.

For the wheels the stock nuts lose their nylon locks fast and should be changed. I am using HPI steel nuts on my car but the serrated nuts like Mugen offers are better. For other items like the shocks, camber & steering links just make sure you got them nice and tight before every race and they should easily make a 60min final w/o lock tight. Make sure you hold the screws tight w/ your 2mm allen when tightening the nuts with your 3mm.

If you have screws backing out of the composite parts you can try putting some thick blue threadlock (Tamiya stuff works best) on the screws but most likely the composite has been stripped out.

Mark

Have you thought about adding them to your store? There seems to be a good market for them.

Mark

No, I'm not. The brake cam post has a machined flat and you may have to extend it a little by filing off the shoulder on top so it clears the brake disc. There is a clearance, but it's pretty tight...

Thanks, I'll take a look at it. :)

Have you balanced your car yet?

Also, I'm surprised that your RF is wearing less (edit) than your LF given your RR tire wear. Anybody else seen that type of tire wear? Is that symtomatic of anything?

Only in Houston!

I had to edit my post. I meant "less", not "more". My mistake.

Sorry about that, I read my notes again and it actually reads the way you would expect.

56.9mm RF
57.6mm RR
56.1mm LF
55.8mm LR

It's odd for sure, my car should be perfectly balanced. I use the Xray balancing posts and then allow the low side to sit on a scale to measure the exact weight. Right and left are within 1 gram on the rear, and 2 grams on the front.

I then used the Xray tweak station to ensure everything was completely square there as well.

My setup was not quite ideal this weekend. Interestingly there were two left hand corners giving me a hard time where I felt like I needed more turn-in and usually ended up washing the front a bit which would have increased my RF tire wear. Toward the end of the race this eventually caused a slight spin as the tiny LR tire because the droop setting changed by so much.

Oh, and the track is resurfacing again today with a more aggressive sand mixture so I have no idea how we're going to make a 60 minute race at the nationals without some 50 shore tires.

I tried 42f/45r on this day, and just couldn't generate enough grip even though the tire wear was high.. Hopefully the new non-water based sealer will fix this problem.

Where can I get them?:)

On the uprights and arms, I like the idea, but I'm not sure I completely understand... Do you have a picture or something... :D