Project Uncontrollable Missile - RJ Speed Nitro Funny Car build

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johnnydmd

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My weekend of testing my monster trucks on my track and getting dimensions finalized took a hit thanks to Henri's spitting rain on us most of it. Bummer. So I decided instead to work on my RJ Speed Nitro Funny Car build...this will be a long post with a lot of steps and commentary.

After some drag racing last weekend, as I mentioned in my other thread, I wanted to get one of these things. I really like having two of everything I race. So I ordered it, and some other items I needed, and I already had a ton of spare parts and engines to use. It came in a few days, and I had already devised a logo and paint scheme, so not long after I unboxed it, I had the logo afixed to the inside of the body.

239153258_10221592322260855_2754583877614158398_n.jpg


My immediate reaction when I opened the box was, this looks pretty cool, and a lot of fun. Very different from your typical kit - it's very spartan, and uses a number of "tricks" so to speak to accomplish things from standard parts. I read through the instructions, some things seemed a little daunting at first, but really they were not. RJ Speed is a very small American company, and I loved how the kit felt like that.

240316015_10221592322580863_5031480172590778641_n.jpg


I was going to try and stuff a Kyosho .26 in there, but very quickly saw that would not be possible given the width of the vehicle. That's ok - because this thing is pretty small, despite it having a 13 inch wheelbase. It's very narrow, and very, very light (more on that later).

240376699_10221592321900846_6099173445851200742_n.jpg


I got everything organized, and started running through the steps. Pretty soon I had a chassis started.

239279029_10221592321060825_7405185674479107900_n.jpg


From this pic you can see that I broke the flange on one of the bushings that hold the axle. Those were, by design very difficult to press in. The chassis is made of lightweight fiberglass parts, completely. Everything was very precisely cut I must say! (except one thing, which I'll mention). As for the bushings, I really have to ask why? I've already ordered bearings from Boca that are direct replacements. Clearly I'm not the only one wondering why use bushings when bearings are readily available. The idea is to get power to the pavement, not waste it on resistance from metal on metal.

239183470_10221592320700816_5173582129730406481_n.jpg


The rear end wasn't hard to assemble. I'm not sure how it'll hold up though, because the hubs are held on by set screws onto a smooth stainless steel axle. I've also noticed that RJ Speed sells upgraded hubs and axles, so that's likely on my list. The upgraded parts are all aluminum, and use a clamp.

239300784_10221592320060800_4455567730635387328_n.jpg


I fitted the engine, and left on the rotostart. Soon realized that the rotostart had to go - as the wheels would not fit with it there. Bummer. Well this is a "mule" engine anyway, so for now it's gonna have it's OWB shaft exposed with no cover. Not a big deal I suppose. I say this engine is a mule because I don't think it's a good choice - again, I'll explain later.

240409990_10221592319460785_4863923915168476980_n.jpg


The rest was a little trickier. The gas tank confused me at first, but got it figured out. Not real sure how good a seal the rubber stopper makes, I guess it was decent enough. The steering, hump pack, radio, all held down with the servo tape they provided. The steering linkage uses collars on two linkage bars to adjust - kinda "hacky" but pretty cool actually in that "raw kit" way. Does make it easy to adjust. Now, now sure how long that servo will stay, I do have an aluminum bracket that would work very well there. The throttle servo was a bit harder to work with - I had to dremel the hole out significantly to make it fit. That's my only major complaint with the kit - otherwise the fitment was all incredibly precise. I don't have a balancer (yet) - but I think overall I got the car pretty balanced with the hump pack and servo offsetting the engine.

239903533_10221592318940772_7836186418207877023_n.jpg


I put the wheelie bar on (that was ordered separate from the kit), and fitted the body. Right away I realized that the spoiler would require some standoffs/posts.

240501484_10221592318460760_2678332187655746933_n.jpg


I didn't have an exhaust yet, because I really wanted to see how things laid out first. So I figured I'd test by using the one from my nitro Slash to see if that shape/style would work. (That was also the style recommended in the manual). It most worked - but as the manual mentioned, you might need the optional engine shim kit to raise the engine a little. As it was, I needed it to be a hair higher, as the manifold flange was rubbing very slightly on the tires. This would also allow me to angle the pipe downward slightly. I will have to cut away some of the rear of the body of course to make room for the pipe, but it should be fine and look pretty cool I think. I went ahead and ordered an exhaust from RD Logics for a nitro 4-Tek car, which looks like it'll fit perfectly.

Next it was on to painting. I wanted to do a burgandy/brick color, with ghost flames.

238830132_10221592318020749_817936387335335184_n.jpg


It came out a little duller than I was expecting, I should have used a more vibrant red base, and should have hit the flames a little harder with the white backing in the front of the car, but overall I was at least close, and know what I'll do when I paint the next body, lol (I am certain I'm going to go through bodies like candy).

So now I'm just waiting on the exhaust, the engine shims, and bearings. Guess I'll need a starter box too :) Will continue on the next post...
240533843_10221593729016023_1130200372388338787_n.jpg


Overall, I really enjoyed this simple little build. It was cheap enough, and I think it's going to be a very, very fast car. Surely it's only good for outlaw classes and such, but it'll be cool to shock some of these guys running monster electric outlaw setups. The videos of these cars I've seen are insanely fast. The car with engine and exhaust weighs in a "whopping" 2.5 lbs! I'm sure I'll have to add weight to get it to hook up.

That also being said - the engine - the Dynamite .19 is not really ideal. I'm just using it because it was either that or a TRX 2.5 I had to get this thing set up, and an idea of how it'll run. The .19 is going to probably be way too torquey, and not enough high end. If this car runs straight and well, and I really like it, I'll splurge for an O.S. Speed .12 which is a serious high end screamer with about the same peak HP as the Dynamite .19, but much, much more of a top end powerhouse.
 
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WickedFog

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My weekend of testing my monster trucks on my track and getting dimensions finalized took a hit thanks to Henri's spitting rain on us most of it. Bummer. So I decided instead to work on my RJ Speed Nitro Funny Car build...this will be a long post with a lot of steps and commentary.

After some drag racing last weekend, as I mentioned in my other thread, I wanted to get one of these things. I really like having two of everything I race. So I ordered it, and some other items I needed, and I already had a ton of spare parts and engines to use. It came in a few days, and I had already devised a logo and paint scheme, so not long after I unboxed it, I had the logo afixed to the inside of the body.

View attachment 131538

My immediate reaction when I opened the box was, this looks pretty cool, and a lot of fun. Very different from your typical kit - it's very spartan, and uses a number of "tricks" so to speak to accomplish things from standard parts. I read through the instructions, some things seemed a little daunting at first, but really they were not. RJ Speed is a very small American company, and I loved how the kit felt like that.

View attachment 131539

I was going to try and stuff a Kyosho .26 in there, but very quickly saw that would not be possible given the width of the vehicle. That's ok - because this thing is pretty small, despite it having a 13 inch wheelbase. It's very narrow, and very, very light (more on that later).

View attachment 131540

I got everything organized, and started running through the steps. Pretty soon I had a chassis started.

View attachment 131541

From this pic you can see that I broke the flange on one of the bushings that hold the axle. Those were, by design very difficult to press in. The chassis is made of lightweight fiberglass parts, completely. Everything was very precisely cut I must say! (except one thing, which I'll mention). As for the bushings, I really have to ask why? I've already ordered bearings from Boca that are direct replacements. Clearly I'm not the only one wondering why use bushings when bearings are readily available. The idea is to get power to the pavement, not waste it on resistance from metal on metal.

View attachment 131542

The rear end wasn't hard to assemble. I'm not sure how it'll hold up though, because the hubs are held on by set screws onto a smooth stainless steel axle. I've also noticed that RJ Speed sells upgraded hubs and axles, so that's likely on my list. The upgraded parts are all aluminum, and use a clamp.

View attachment 131543

I fitted the engine, and left on the rotostart. Soon realized that the rotostart had to go - as the wheels would not fit with it there. Bummer. Well this is a "mule" engine anyway, so for now it's gonna have it's OWB shaft exposed with no cover. Not a big deal I suppose. I say this engine is a mule because I don't think it's a good choice - again, I'll explain later.

View attachment 131544

The rest was a little trickier. The gas tank confused me at first, but got it figured out. Not real sure how good a seal the rubber stopper makes, I guess it was decent enough. The steering, hump pack, radio, all held down with the servo tape they provided. The steering linkage uses collars on two linkage bars to adjust - kinda "hacky" but pretty cool actually in that "raw kit" way. Does make it easy to adjust. Now, now sure how long that servo will stay, I do have an aluminum bracket that would work very well there. The throttle servo was a bit harder to work with - I had to dremel the hole out significantly to make it fit. That's my only major complaint with the kit - otherwise the fitment was all incredibly precise. I don't have a balancer (yet) - but I think overall I got the car pretty balanced with the hump pack and servo offsetting the engine.

View attachment 131545

I put the wheelie bar on (that was ordered separate from the kit), and fitted the body. Right away I realized that the spoiler would require some standoffs/posts.

View attachment 131546

I didn't have an exhaust yet, because I really wanted to see how things laid out first. So I figured I'd test by using the one from my nitro Slash to see if that shape/style would work. (That was also the style recommended in the manual). It most worked - but as the manual mentioned, you might need the optional engine shim kit to raise the engine a little. As it was, I needed it to be a hair higher, as the manifold flange was rubbing very slightly on the tires. This would also allow me to angle the pipe downward slightly. I will have to cut away some of the rear of the body of course to make room for the pipe, but it should be fine and look pretty cool I think. I went ahead and ordered an exhaust from RD Logics for a nitro 4-Tek car, which looks like it'll fit perfectly.

Next it was on to painting. I wanted to do a burgandy/brick color, with ghost flames.

View attachment 131547

It came out a little duller than I was expecting, I should have used a more vibrant red base, and should have hit the flames a little harder with the white backing in the front of the car, but overall I was at least close, and know what I'll do when I paint the next body, lol (I am certain I'm going to go through bodies like candy).

So now I'm just waiting on the exhaust, the engine shims, and bearings. Guess I'll need a starter box too :) Will continue on the next post...
View attachment 131548

Overall, I really enjoyed this simple little build. It was cheap enough, and I think it's going to be a very, very fast car. Surely it's only good for outlaw classes and such, but it'll be cool to shock some of these guys running monster electric outlaw setups. The videos of these cars I've seen are insanely fast. The car with engine and exhaust weighs in a "whopping" 2.5 lbs! I'm sure I'll have to add weight to get it to hook up.

That also being said - the engine - the Dynamite .19 is not really ideal. I'm just using it because it was either that or a TRX 2.5 I had to get this thing set up, and an idea of how it'll run. The .19 is going to probably be way too torquey, and not enough high end. If this car runs straight and well, and I really like it, I'll splurge for an O.S. Speed .12 which is a serious high end screamer with about the same peak HP as the Dynamite .19, but much, much more of a top end powerhouse.
I would love to build an RJ Speed kit. They do look like a lot of fun. Thanks for sharing your build so far!
 

johnnydmd

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Sigh...waiting on my tuned pipe from RD Logics, and they seem to be uh...non-responsive. Found another on Ebay that would work, so might get that instead.

Anyway, this is how I plan to cut the rear which will allow for the exhaust.

withpipe.jpg
 

johnnydmd

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Here's an RJ Speed nitro vs an electric and taking the win in an event finals in 2011. By my stopwatch calcs, that's about a 1.65s run!

 
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johnnydmd

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Update on this little project:

240704365_10221620395002656_4867917607239611762_n.jpg


Got the exhaust installed. It was a tight, tight fit. Literally millimeters of clearance - which is ok with the rigid rear suspension and foam tires.

240844716_10221620395402666_1054819300633006668_n.jpg


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240844716_10221620395402666_1054819300633006668_n.jpg


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I got it started and running, and immediately had some problems. One, the tank was leaking badly. This was because Johnny Can't Read. Doh. Yeah, missed a step about tightening the screw in the stopper cap. I remember even thinking, why would you not tighten it all the way, that makes no sense? Yup, that was dumb.

After fixing that, it was running a bit better, but not great. Kept cutting out as if it was starving for fuel when I revved it. After listening to some people insisting that it was because the gas tank was in the rear and how the acceleration would "push" the fuel to the carb if the tank was in the front(which my physics senses told me that was uh..."not a thing") - to humor them I moved the tank and it still did the same thing. (I also mentioned to these experts that it was doing this while revving the engine with car in my hand - but they insisted, so I obliged). I was going to replace the tank with one off of one of my other cars when I decided to open it up and take a peak. Ok, so the fuel line from the tube to the clunk was somehow severed, lol. I ditched the tube/clunk setup and just ran the brass tube method. I mean, it's not like this car is going to be upside down(at least not on purpose anyway!). No need for the clunk setup.

Moved the tank back to the rear, got it running, now it was revving really good. Got the engine tuned better and I've got it running, good temps, but it's cutting out after I give it a good launch. Not sure if it's starvation or bogging down, but I think bogging down. Dynamite .19 needle settings seem to be somewhat of a mystery - factory is supposedly 2/2 - but none of mine were set to that (their manual strangely omits the .19). I think I have them pretty good, but last night after posting about idle gaps, I thought, hmmm, I don't think I looked at that with this particular engine. Sure enough, the idle gap was so small the carb was nearly closed. That might be why I needed my LSN out 4 turns to even get the engine to start. I'll play with that some more if it ever stops raining. One other reason is that there is quite a bit of resistance in the drive train due to the axle being housed with bushings, of all things. My bearings are on the way. I still can't believe this kit comes with bushings for that. These guys have been around forever, from BoLink days, so while skimp out on this part of the kit? I also lengthened my fuel lines some, not sure if that would help any.

I will say this though - the car is so light that with that bottom-end MT engine, it pretty much goes into full-cyclone mode when launching with any amount of throttle! Definitely going to ditch this "mule" engine and replace with a high quality .12 top end screamer. I've got about 3 weeks before the next big drag race event, hoping to have it ready by then. I still need to test the new gearing in Invader as well....
 

johnnydmd

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Sounds like you're making progress at least :)

Yup, this one has been a little interesting for sure, had a few missteps. My buddy wants to build one, so he's kinda waiting to see how mine goes so he knows what not to do, lol.

I've been debating on the engine to put in this thing. Part of me wanted to put in the OS Speed .12 but I cannot bring myself to spend 500+ dollars on an engine. I thought about a Novarossi .12, but their status and future is uncertain at best (currently defunct, but rumors of return). I was looking at the OS Max .12tg, and comparing it to the SH .12 Rxt, and pretty much had it narrowed down to those two engines, but was pretty torn. I ordered the SH, then changed my mind and cancelled. Went with the OS instead. I think my experience with the Dynamite .19 tuning soured me a little on the SH, which seems to be essentially a smaller less powerful version of the .19 that I already have. I do love my big block SH's though...but the OS is just better quality IMO. I think they are both probably similar in range/power, but the OS carb is definitely better from my experience and that's gonna matter with staging and what not.
 

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Long time no update, but I have been working on this car some. I got my OS .12tg and set it up. Not sure if anyone noticed, but I actually had this exhaust set up with a "rookie mistake" that didn't even cross my mind, lol. After some wondering as to why the new engine wouldn't run right, and seeing my fuel turn from pink to brown(oil) in the tank, I realized that you cannot run the exhaust pipe upside down, haha. Duh. All the oil in the pipe winds up back in the tank. Whoops. Fixed that, and got back to breaking in this little monster.

20210903_221345.jpg


Have had a hell of a time breaking it in too. The pinch is just insanely tight. I've had the thing flat out lock up at TDC a few times, and need a pair of channel locks on the flywheel to free it. I've gotten about 6 1oz tanks through it or so, and it's just starting to loosen up some, at least to where I can get it to idle through a tank without stalling. Small throttle still making it stall, but I'm a little hesitant to lean it out too much just yet until the dang thing isn't so ridiculously tight. Anyone ever have an engine so tight like this? Man. The little .12 does sound nice though. Can't wait to get it going.

Here it is with the exhaust right side up...

20210916_183616.jpg


Oh, and I really disliked the "stock" snubby looking blower intake, so replaced it with a big ole scoop.

20210916_193642.jpg
 

Greywolf74

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LOL, I didnt notice. I bet you were like WTF is going on here?!

Are you heating the engine too around 200F before starting and then keeping the engine around that while breaking in? If you are then I can't say I've ever experienced that.
 

johnnydmd

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LOL, I didnt notice. I bet you were like WTF is going on here?!

Are you heating the engine too around 200F before starting and then keeping the engine around that while breaking in? If you are then I can't say I've ever experienced that.

Yeah, lemme tell ya, the frustration level was getting close to 10 until I figured it out!

I heated it, but probably not to 200, I didn't measure though, just felt fairly hot to the touch. When running it was mostly around 170, and rich as hell, spitting fuel out quite a bit, so I leaned it slightly on the LSN and it got to 190-200 and held. I was using a hotter (but still "medium") #5 plug, but it was pinging a little, so going back to the #4 on my next go-round. The engine felt slightly looser and ran through the full tank, so I think I'm slowly getting there.
Looking great, although the driver won't be able to see whare they are going now 🤣

I would have rather used the same one I had on my vette, but I also wanted to use up some of these scoops that came in the proline scoop pack :D
 

JCsRCcar

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That thing looks awesome and love the idea of nitro over electric. Dumb question: why not gear it to take advantage of the torque?
 

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If you are refering to 2 speed tranny ,the shift upsets the car when it shifts ,I have a car
that has a 2 speed an when it shifts ,it becomes unstable to control with that much power!..:hehe:
 

johnnydmd

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Yeah these cars don't even have a transmission, it's just a gear on an axle shaft. Super simple design. I'm actually not even sure what clutch bell tooth count I have on there, need to check. I have a bunch of higher ones to test if needed. My plan was to try a few different ones to see what times I could get, etc.

I decided to ditch the big ole scoop, I remembered I had an RPM blower, so I mounted that instead and cut a piece of foam I had to rim the hole. Just need to put some red stickers on the intake flaps yet.

20210930_224027.jpg
 

johnnydmd

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Sooo....this is related to some things I was doing with Invader. I was still struggling with the fuel mixture, and as with Invader, I ditched the 1oz Sullivan tank for a Jato 2.5oz tank. Viola. By now I felt I'd run the thing enough in the factory settings (LSN 4 turns out, HSN 2.5 turns out) that would barely allow the car to move without flooding. It was definitely better with the new tank though, so I started doing a little more rigorous running, though still nothing more than 1/2 throttle and pretty low RPMS. I ran a couple of tanks more, then started tuning for performance, and getting the idle right. This day it was 3 turns out for LSN, and 1.8 turns out for HSN. Though the engine is still pretty tight and needs quite a bit more running before truly letting it rip, I was at least able to get an idea of what it'll be like. I was using an 18t clutch bell, and a 3 shoe aluminum HR clutch that is unmodified. I was pretty blown away by 1) How responsive the car was with just the tiniest throttle blips and 2) That without tire sauce, the car would spin out at any speed with more than 1/2 throttle. Gonna do a little more running around before I get to true testing. Probably start with 66 ft runs first because I'm actually a little scared of this thing's power. I'll post up some GNSS screens of that.

20211007_191724.jpg


I also need to install some lights, not sure yet where I want them, I guess where headlights would go, lol.
 
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