INVADER - Nitro Slash drag car

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.

Register Log in

johnnydmd

RCNT Racer
Messages
91
Well, I fired it up last night, man that is one nasty, mean sounding engine :D I shoulda taken a video, I will next time. I can tell right away just by a couple of very light throttle blips, that this thing is packed with power.

Had a little trouble at first due to a faulty glow plug, but once I put in a good one, it started easily. Not sure I mentioned the mechanism, but I used a Redcat rotostarter, and rigged up a Traxxas Easy-Start connector to attach to the wheelie bar with just the plug wire and ground to use a Traxxas starter wand to heat the plug. Since the body doesn't have an opening to stick anything on the plug when the body is on, this was a necessity. Works really well. I ran about a tank idling lightly, few very slight throttle blips.

The only other issue I had was with the Hot Racing 3 shoe clutch. There are 3 little washers that go under shoes, but what I noticed is that with them there it makes the shoes slightly higher than the posts on the flywheel, which in turn push the shoes into the clutch bell a little, causing the clutch to drag pretty bad making the car creep a lot. I suppose the washers to keep the shoes from touching the flywheel when they flip outward, but really this seems a little unnecessary to me, and so I removed them and re-tested. Much, much better. Gotta say, that clutch is really, really nice when working correctly. I will probably get a few of them and drill the shoes out to test higher rpm slams.

Oh, and I found aluminum beadlock rims for the front that match the Mickey Thompson rear beadlocks very nicely! (Vanquish makes them).
 
Last edited:

johnnydmd

RCNT Racer
Messages
91
Full parts list and price breakdown. Though I had free shipping on quite a few items, I'm sure it added a few hundred extra to the total....kind a got a little queasy adding this up, but it's only a little more than expected...and totally worth it :)

Integy steel drive shafts 40.00

Traxxas Screw set 14.00

Big bore aluminum Shocks 40.00

Traxxas 2055 Servos (2) 44.00

Traxxas Slipper clutch and spur gear – 20.00

Traxxas Fuel tank – 8.00

Traxxas fuel tank holder – 6.00

Traxxas upper chassis plate – 10.00

Traxxas receiver box – 3.00

GPM Servo arm and linkage – 15.00

Hot Racing X shaped alloy servo arm – 9.00

Traxxas turnbuckles – 22.00

Integy full suspension kit – 140.00

Integy front bulk head – 22.00

Traxxas gearbox – 12.00

Integy alloy Gear case – 20.00

Hot Racing 3 shoe clutch and flywheel – 38.00

Traxxas Throttle and brake linkage – 9.00

STRC steering bell cranks - 16.00

Traxxas Suspension pin set – 6.00

Xtreme Racing CF chassis plate – 90.00

STRC engine mount – 19.00

Integy body mounts front and rear – 60.00

Integy rear suspension mounts 20.00

Ball Bearing kit - 14.00

Integy hubs/nuts 12mm - 15.00

Venom hump pack – 20.00

FlySky Radio and Receiver – 40.00

O.S. .21 Engine – 280.00

THS Tuned Pipe – 55.00

Pro Line Hoosier Drag slicks – 29.00

Mickey Thompson bead lock rear wheels – 60.00

Pro Line Hoosier front tires – 22.00

Vanquish bead lock front wheels – 65.00

STRC Wheelie bar – 30.00

Parma 55 Chevy Body – 41.00

Pro Line Headlights – 25.00

PETG .60 sheet 24x18 – 10.00

30 small sheet metal screws – 2.00

Dubro green nitro fuel line – 3.00

Nitro exhaust deflector – 5.00

Traxxas EZ Start harness – 5.00

RB Innovations air filter – 30.00

RPM Zoomies – 9.00

LOSI 2 pin connector – 1.00

Total – 1442.00
 

Rolex

Hoof Hearted
Staff member
Supporter
Military Veteran
Messages
34,574
Location
In my recliner
RC Driving Style
Bashing, Flying
That's quite a parts list. Keep us posted on the progress.
 

johnnydmd

RCNT Racer
Messages
91
I can tell this thing is gonna be snappy :) Just barely touch the throttle, this thing revs fassssst. I also put on the Vanquish OFM Outlaws(one, lol). I thought I was ordering "pairs", turns out it was parts for one. Then I went to order the other, and there were out of the center clamp rings! Doh! Scoured the net and couldn't find any. I kinda was resigned to either waiting for them to make more, or ditching the idea altogether. I was a little concerned about the weight, the wheels were around 90 grams alone. Then I got to thinking...why not 3d print the center ring? My Mickey Thompson's on the rear have a plastic center ring, presumably to save weight(and it's totally inside where you cannot see it, so I did the measurements, made the model in Meshmixer, and printed it out. That original ring was 40 grams of the weight, so good opportunity to make the weight a bit more reasonable. Worked like a champ :)

 
Last edited:

Tunedpipe

RCNT Qualifier
Military Veteran
Messages
157
Location
Beautiful Idaho.
I bought a Tornado s30 nitro 3 months ago just for a mod platform and I have yet to break it in because of weather. I don't want to break it in and then have it sit for another 3 months so I'll wait.
 

johnnydmd

RCNT Racer
Messages
91
Construction is finally 100% done(at least until testing). The last piece of the puzzle was the front wheels, which I finally got the second one delivered and was able to put together last night. I compared the weight of the Proline Pomona rims, and adding the Vanquish rims with the clamp ring being 3d printed wound up being a net weight gain of .25 lbs(120g). I can live with that, and the total is now at 6.6lbs, still a pretty light vehicle given the power output of the OS .21tm. The additional weight is a decent trade off for how much tighter and precise the Vanquish wheels are. Man those Pomona's had some real slop in them.

120338


Have to wait a bit to finish breaking in the engine, it was only 21 degrees this morning :O I really am pretty anxious to start doing test runs, and tuning/modding the clutch and gearing.
 

johnnydmd

RCNT Racer
Messages
91
Got a chance to burn two tanks this weekend while it was 50 degrees out :) That weather didn't last unfortunately, now it's back to 30 and snowing, lol. Still running at factory needle settings and being very ginger with it. Ran with the lid on too keep the heat in. Might insulate with foil and run some if it doesn't warm back up. Couple of little half-throttle blips on the third tank from a stop, and the rear slicks easily broke loose. Power to weight looks pretty good, and just a guess, but likely I'll be changing the bell and spur gears out to get more top end. Bottom end is really strong with the 72/20 setup. 65/24 might be where I need to be. Pretty sure I'm going to drill out my clutch shoes too, but won't know until more testing is done.

Just for fun I did a build sheet for an "express" version of this car. Using stock chassis/arms/towers/bulkheads/steering/servo arms/linkages, but still a beefed up drive train and rear wheels. Engine would be Dynamite .19, and front rims would be the ProLine Pomona's. 875 was the final tally for that version, so would have been quite a bit cheaper.

Once this thing is broken in and I start tuning for real, I'll post some vids of runs, and hopefully the ET's are where I expect them to be.
 

johnnydmd

RCNT Racer
Messages
91
Little while since an update, but I've been toying with this thing the past couple of weeks nonetheless. I didn't get a chance to record a video, but will soon once I have it where I want.

I got the engine about 3/4 the way broken in, but haven't messed with the needles just yet. My next outing I will start dialing it in some. First I had to fix a couple of glaring problems.

The first problem is that the 3d printed attachment for the wheelie bar was just not stiff enough, far too much flex. Even with my rich settings, launching the car(tested at half throttle), the front wheels came way up(when it actually got traction). So I started thinking of ways to brace it, and came up with using Jato turnbuckles and a strip of .60 PETG mounted to some handy existing screwholes in the shock tower.

120557


120558


The second problem is traction loss. I was testing on my parents driveway while visiting them, which is probably a little smoother than typical no-prep road/parking lot surfaces(it's sealed blacktop). After launching, I gunned it briefly, and it spun out of control. Nearly hit my mother's car!

I'm running 72/20 gearing, with an unmodified hot racing 3 shoe clutch. Given that the stock Nitro Slash runs 50-55 mph top speed with 18/72, I'm thinking that I should be around 60+, which is probably plenty to compete in typical no-prep SE classes, or Pro Mod RCDRL rules, but I'm thinking of switching up to 65/24 gearing, and either lighting my shoes by drilling them out, or trying to find a clutch system with different spring choices. I know Reds makes a fantastic clutch, but it's 1/8 scale. I'm guessing a 1/8 clutch and bell isn't gonna work. Anybody know, or ever tried? Or are those clutches the same size? Bottom line is, if I gear this thing up, I think I need to tune the clutch to hit at higher rpms to prevent bog and get up further in the power curve. That gearing should add quite a bit of top end I think, and still have tons of power.

Speaking of which, does anyone really know the hp of the O.S. .21? I know the .18tz was dyno tested at 2.4 back in the day. I wonder if the .21 is pushing 3? Feels vastly stronger than a TRX 3.3(saw that tested at like .97 hp), and the Dynamite .19(which is rated at 1.7 I think).
 

cbaker65

Hardcore RCNT User
Messages
3,376
Location
Kern county ,Calif.
I think that it is best if you wait until your engine is fine tuned to leaner conditions before you start changing the clutch shoes!

The fine tune of the engine will effect the way that it takes off from dead still to full WOT on the starting line ,if you just start
making sudden changes now ,it will only confuse you!

Yea ,you can change the timing of the clutch ,but ,I would also look into a good slipper spur ,allowing the slipper to slip a
little will help on take offs!
 

johnnydmd

RCNT Racer
Messages
91
I just have the stock slipper currently, which is the one with the little plastic pegs. Are there some better options out there? I see some ones with actual pads, etc, but not sure they will work.
 

cbaker65

Hardcore RCNT User
Messages
3,376
Location
Kern county ,Calif.
I just have the stock slipper currently, which is the one with the little plastic pegs. Are there some better options out there? I see some ones with actual pads, etc, but not sure they will work.
The friction style does burn out faster ,the Mgt trucks uses those as well ,at one point ,I was modifying my spurs gears an drilling
the peg holes out a little to install ball bearings in there place ,it caused the gear to wobble around ,so when I touched the gear
with my fingers ,the gear would move from side to side ,but it never did effect the runs like that ,to me ,it actually helped shed
any debris off of it like little pebbles!....:cool:

My spur gear mod!





 

johnnydmd

RCNT Racer
Messages
91
How does that work with the ball bearings? Wouldn't the disks spin on the bearings?

I've got this thing broken in, and am starting to tune. Gradually leaning int out, it's still pretty rich. I have to do something about the brakes, they just don't work all that well, tried some adjustments to no avail. Bad enough that twice I tapped into a curb at low speed, but enough speed to wreck my steering servo(no servo saver, or front bumper for that matter on this).

Definitely have to do some suspension tuning as well. The wheelie bar mod is working great though, but when I gun it the right rear wheel tends to lift up pretty hard and make the car spin to the left quite a bit. So I am thinking the shocks need to be adjusted to be a bit stiffer...gobs of insane power though! I can easily brake the tires free even when moving 10-20 mph. Can't wait to race this against some of the local 2s electric guys who think nitro isn't fast enough :D:D Just a couple of test runs of 132 feet and timing in my head, I can already see that this thing can fly. Still need to do a full top speed run to decide if I want to change gearing, but I might actually be ok with the 20/72 set up.
 

cbaker65

Hardcore RCNT User
Messages
3,376
Location
Kern county ,Calif.
How does that work with the ball bearings? Wouldn't the disks spin on the bearings?

I've got this thing broken in, and am starting to tune. Gradually leaning int out, it's still pretty rich. I have to do something about the brakes, they just don't work all that well, tried some adjustments to no avail. Bad enough that twice I tapped into a curb at low speed, but enough speed to wreck my steering servo(no servo saver, or front bumper for that matter on this).

Definitely have to do some suspension tuning as well. The wheelie bar mod is working great though, but when I gun it the right rear wheel tends to lift up pretty hard and make the car spin to the left quite a bit. So I am thinking the shocks need to be adjusted to be a bit stiffer...gobs of insane power though! I can easily brake the tires free even when moving 10-20 mph. Can't wait to race this against some of the local 2s electric guys who think nitro isn't fast enough :D:D Just a couple of test runs of 132 feet and timing in my head, I can already see that this thing can fly. Still need to do a full top speed run to decide if I want to change gearing, but I might actually be ok with the 20/72 set up.
That spur set up is like what is in most rear trans on 2wd models an the way they work ,most trans. are set up on a bunch
of bearings inside of a gear an a thrust screw runs through the out drive cups to tighten the pressure ,in which allows a
certain amount of slippage ,the slippage helps save the gears on torque loads an during rough terrain & jumps that is
hard on the gears!
 
Thread starter Similar threads Forum Replies Date
D Nitro RC 22
Rubendb Engines 42
>BD Nitro RC 1
S Electric RC 4

Similar threads


Top