Anyone Into Nitro R/C Cars

84CAB · 01-30-2005, 05:20 AM

Any of you gus into this stuff? I posted a few pics the other day and got a few responses.... I am looking for someone knowledgeable about the tuning/running of these things. This is my first one, I have owned it for about 2 weeks and it has been a PITA to tune, I can barely keep it running. Is this normal...or can I expect it to improve on warmer days? (It has been in the 30's-40's)Is there a forum similar to this for these cars? The store I bought it from has been less than helpful.I have found a few tips on the net but am getting pretty discouraged with this thing. I wish they were made in Germany instead of Japan.

audi2.7t · 01-30-2005, 06:39 AM

http://nitrorc.com/ these little buggers can be a real PIA to tune and are sensitive to temps.

lendaddy · 01-30-2005, 06:45 AM

To properly tune these you need an IR temp gauge. Basically you tune by head temp. There are boards just like this for RC Nitro which will be very helpful to you. FWIW, many would say it's a little cold for nitro right now.

Also, the motor you have blows. Sorry, but it just does. I have the same one and could never get it to hold a tune. Now I run RB Concepts engines and couldn't be happier. Do you have an IR temp guage?

84CAB · 01-30-2005, 07:15 AM

thanks guys- lots of help.. I do have a temp guage, I think your right about the engine, all I seem to do is tune it - over and over...

84CAB · 01-30-2005, 07:24 AM

lendaddy - i have a lead on this engine - RB .28 5 port pull start engine - do you know if is a doable ( easy) transplant??

mikester · 01-30-2005, 08:18 AM

I've got nitro RC airplanes...

bryanthompson · bryanthompson's Garage

I have a Nitro RC boat, but I haven't ever run it. I have all of the pieces, but I want to get a better engine.

cstreit · cstreit's Garage

Tuning them isn't that difficult.

The basic principle is the needle valve operation.

Turn out the needle valve about 2.5 turns. Run the engine up to full throttle. Turn int he needle so that the engine speed increases. Once it starts to decrease or cut out, you've passed over the optimum mixture into lean territory. Back the needle valve out abotu 1/4 to 1/2 turn from there.

Now - Adjust the idle air bypass to get a good smooth idle.

Once that's done, let the engine idle for about 15 seconds. Then jam the throttle wide open. If it bogs down under throttle transition, lean out your low end a bit more (if you have a seperate low end adjust, otherwise turn in the main need valve slightly). If it wants to cut out under high RPM, you're too lean. If it burbles and missed at high RPM, you're too rich.

It's fairly straight forward once you get the hang of it.

If you REALLY get fustrated, take it to your local R/C flying field. The guys that fly planes tend to be better at tuning motors than the car guys because they can't afford to lose power....

I've got a number of planes as well.

1/4 scale Piper Cub with 25cc gas motor
Ultimate Biplane with 4 stroke .75 cc OS motor
Extra 300 stunt plane with .60 OS supercharged motor
...and a number of hi-speed pylon racers...

Jay Auskin · 01-30-2005, 10:49 AM

Yeah, I couldn't get my nitro car to start up today (first time trying it). It's only about 35F, so that might have been an issue. Plus, the engine which came with my car (used) might not be good anyway. We'll see. A new one is on it's way.

rob justice · rob justice's Garage

Bought on for my son for christmas - used it once and its knacked already - every time you rev it - it jumps out of gear. Reckon the dif or gearbox is shot.
Good news is parts are cheap to replace.

cstreit · cstreit's Garage

Jay,

Cold weather and nitro engines don't mix real well... Especially if you are trying to hand start.

Jay Auskin · 01-30-2005, 06:22 PM

Yeah, I was hand starting. Everything was kept inside, and then I brought it outside, filled it up, and tried to start. We'll see when it gets warmer. I bought a new engine before trying this one anyway. It has a crappy engine in it. Plus I recently sold an RC boat engine for crazy-eddie money, so I figured I'd treat myself

Maybe I'll take my old engine apart. Anyone know the procedure to set the cam timing??

bryanthompson · bryanthompson's Garage

Ack... I am one email away from ordering a 3.5cc, 1.3 hp K&B Outboard for my boat. I was happy letting my project hull gather dust in the basement, but then this thread had to come along and get me all excited for a new project. Why do you guys keep doing this to me? I really gotta get out of OT land before you people bankrupt me.

Anyway, here are some pics of the hull with measurements. I'm on the lookout for a radio and some servos, as well as some throttle/steering cables.

bryanthompson · bryanthompson's Garage

She's expected to do 40mph with that 1.3hp engine... plenty fast enough for my first boat. I gotta start looking for a name and color scheme. I'm thinking about using a classy scheme using the Sable Brown Metallic from the 944 with a couple Copperflint pinstripes. That should look really good.

mikester · 01-30-2005, 09:05 PM

More pictures...

kmhemi · 01-30-2005, 10:24 PM

I started out with Nitro Airplanes. A friend showed me a 4wd truck and I was hooked. Now I have forgotten the planes and since bought a Kyosho Mad force 4wd truck, .21 Nitro and a 3 speed auto trans that rides wheelies to around 40mph. Top speed is in the 50's. I have a Mrs Bud Hydroplane with a BIG nitro outboard and just bought my first 6 channel Helicopter. What a ***** those are to fly !! Tuning isnt that bad. You just have to go real slow. Especially when it's cold. I always tune mine by ear and feel. Nothing special. you'll know when it's right. 1/4 turn of the valve is a MILE.. tiny steps.
Email me if you need any help..I am not claiming to be anywhere near expert but it's all about fun in the first place.

84CAB · 01-31-2005, 03:58 AM

Thanks for all the info guys.. your all correct the adjustment seems really simple but for some reason I can't get right. I think it has to do with the weather of course and am also questioning the OEM motor after what lendaddy said. You guys have some great looking models.Maybe that is the answer to Waynes question on sagging sales; he needs to sell R/C parts as well!

lendaddy · 01-31-2005, 04:43 AM

The motor isn't THAT bad, it's just grossly underpowered for its size IMHO. If you are chasing your tail real bad you may have an air leak at the joint between the carb and jug (this is fairly common).

bryanthompson · bryanthompson's Garage

kmhemi - do you have any pics of your helecopter?

mikester · 01-31-2005, 06:10 AM

To adjust the motor do you have the instructions?

It's really pretty simple...

You have to set the high speed (wide open throttle) first. To do that start the engine with the needle valve open maybe 2.5 turns. With the engine running WOT pinch the fuel line for just a bit, if the engine Runs faster during the pinch then the mixtrue is rich, give a little turn (maybe 1/8th turn) in and pinch again until the engine doesn't run up with the pinch. At that point you'll want to back the needle out so that when you pinch it, it runs up just a little so that it is a little rich. LEan is bad - if it is a brand new engine you'll want to run it a little more than a little rich.

Now the low speed is set really the same way. Bring it down to idle and pinch the fuel line. If it runs up - it's rich, if it quits it's lean. Depending on the type of carb (twin needle or air bleed) adjust accordingly. IF it is a twin needle you'll turn it in if it running up with the pinch and out if it quits. If it is an air bleed then you'll turn the screw in to richen and out to lean. Once the idle is set you'll want to set the WOT one more time (might require a minor adjustment) and then set the idle again after that.

That SHOULD do it - that's how I set my airplane engines. Wtih the temp guage you should keep and eye on the head temp but I don't know the numbers you're looking for with the car.

Try this web site www.rcuniverse.com, there are forums there that I'm sure can help you out a little more.