kevetz99

My Feedback: (3)

Check this out:

Supercharger

I know this has been talked about alot, but I have never actually seen any type of pictures or production of them. It basically just rams air into the intake. Personally, I do not think it works, because ramming air into the intake would just lean out your engine. Tell me what you think though.

-Kevin

packfan88

My Feedback: (2)

now now kevetz it says no spamming the link to outwar.
dont make me report you

kevetz99

My Feedback: (3)

Oh Packfan...lol shhhhh.

GeorgeKelp

My Feedback: (1)

yea, go to www.rbinovations.com they have a supercharger, which i belive works, and they have a custom system that stores the air from the exhaust that comes back to the fuel tank, and uses it later, also If you have the rb supercharger you may also get aditional tubing and create and splitter; the air coming fromt he exhaust into the gas tank is split, and then the slit and is pluged onto the aux line in the supercharger. thus creating more air flow, much like a turbo charger

AznAbyss952

Does the super charger boost top end power too? Max speed? Or just acceleration? From what I read, it gives me the impression of just acceleration.

KyleSch

If it does what it says it would give you more power, wouldn't directly give you more top speed but would give you the potential to use taller gearing and still have decent acceleration.

I really can't see how this would work though, since if you force air into the engine it just blows right back out the other side since the intake and exaust are open at the same time.

kevetz99

My Feedback: (3)

I really don't know. I don't even know if it works.

Unstable

it MIGHT work with a well tuned pipe, but I can see it being a nightmare if its not tuned right. I have also seen theses on RC dragsters at the WRAM show in NY. those things look cool.

as for the comment about leaning it out, you just richen it up... the whole idea is to force more air so you can dump more fuel which makes a bigger bang.

it would be really cool to try on a 4 stroker though... I think you really see an advantage there.

I have seen a RC turbo unit but I cant find out any info about it. anyone know of a link?

nitroman88

My Feedback: (5)

I dont think the supercharger is worth 170.00 bucks. you can get a high end engine for that much,

shoehead

I second everything unstable said. Especially the importance
of a well tuned pipe to keep the charge in place.
I also believe that a 4 stroke would be easier to get good
results from. But not necissarily better results. I just think
it would be easier.
Along this same line, I was thinking it would be cool to use
those co2 cartridge size nitrous bottles like for whipcream
to nitrous inject the engines. It could be controlled with
a 3rd channel some radios have.

kevetz99

My Feedback: (3)

Shoehead,
They already have that. Check out www.jagrc.com

shoehead

That is awsome! I gotta get that!
What about intercoolers? has anyone tried little
intercoolers to cool down the charge?

WhiskyVR-4

to avoid cross-posting, I'll put up a link to the post I made tonight about that "supercharger"

I think its a cool idea, but I'm still highly skeptical of that particular unit.

I explained in morbid detail here:
http://www.rcuniverse.com/showthread...736#post896555]

WhiskyVR-4

A turbo unit? Rad. It would obviously have to be a 4-stroke, but it would still be pretty slick.

A superchager is just about the only way to add a forced-induction system to a 2-stroke because a turbo would destroy the exhaust pulses that 2-strokes depend on to run properly.

I don't really consider the RB unit to be a "supercharger" its more like an air "accelerator." I explain that abit mroe in my other post (the one I linked).

That JAG Nitrous kit looks pretty killer though, thats a great idea. I mean, yer going to shorten the life of your engine, but its going to die anyway, 2-strokes are made to wear-out.

I also totally agree about the fuel issue. You could easily run a supercharger on a carburetor, people have been doing it for ages! You just richen it up some to accomodate the extra oxygen. Remember, while you might need 14-15 parts of air for each part of fuel with gasoline, you need less than 2 parts of air to burn 1 part of nitromethane! And Nitromethane brings some of its own oxygen too (unlike gasoline). Of course, we don't run pure nitro, but you get the idea.

Actually, this brings up another issue with turbocharging an R/C car. With a turbo, you have different boost levels at different engine loads. Because the rpms and boost levels of a turbocharger are not directly synchronized with any other part of the engine, it would be VERY hard to tune a turbocharged R/C car (no sensors or ecu to control the fuel). But thats not a problem with a positive displacement supercharger (like a whipple charger).

shoehead

To avoid a lean condition with a nitrous setup you could
have the nitrous pull in
extra fuel when the nitrous is introduced. Like they do
on non fuel injected real cars. You could make a needle
valve setup to adjust how much extra fuel to pull.

KyleSch

Or maybe you could just have fuel mixed in with the nitrous, if that would work?

shoehead

I am pretty sure you can't have it pre mixed. but
you could make a nozzle that was 'Y' shaped that
would pull fuel through it as the nitrous went through.

AznAbyss952

I am definently going to check about getting a nitrous kit for my new rc this summer. Depending on price though. Any estimate the price?

shoehead

Not yet. I saw a thread on another forum where a guy was
makink crazy guesses. But the actual guy who is making them
discounted the guesses. It was pretty ridiculous, the whole
thread except for the guy who makes them, everyone else
seemed like they had never heard of nitrous injection. I even
started to wonder if they know what words mean!!

AznAbyss952

Oh...I would really need to acomodate the money I need to get if I wanted to get the nitrous for the rc too. I cant wait to hear some reviews on it.

WhiskyVR-4

Nitrous Oxide produces power in 2 ways.

First, and most significantly, it adds an extra part of oxygen to the mix, and therefore allows you to burn more fuel in the combustion chamber, thereby increasing power output per stroke.

Second, liquid N2O has an exceptionally low boiling point, so as a result, if liquid N2O is introduced into the airstream and flashes to vapor, the reaction draws most of the heat out of the air, thereby increasing air density (and again, adding power)

Without an injection system, however, you couldn't really run a "wet" system on an RC vehicle, but you can cetainly run a dry shot and compensate with "fuel enrichment" (just a fancy term for dumping fuel at a very high rate, most cheap nitrous kits do this, which is partly why the are potentially very damaging to the engine)

I think the whole thing is pretty cool, actually. I've got a series of 1:1 performance parts I am trying to adapt to RC right now (doing the CAD work, hopefully I can get some parts machined) and if I can get them built, I will certainly make them available for as cheap a price as I possibly can.

Incidentally, nitromethane fuel also brings some of its own oxygen to burn, whereas gasoline does not (gasoline is C8 H16, nitromethane is CH3 NO2). This is part of why nitro is so powerful (that and it only requires about 1.8 parts of air to burn one part of nitromethane, unlike gasoline at about 14.7:1 stoichiometric).

Unstable

"hey, you think I am running a bit lean?"
"don't know, hit the nitrous"
*whaaaaaAAAA BANG!!!! rattle rattle*
"yup, a little lean."

WhiskyVR-4

Haha, totally! I'll tell you what though, its a hell of a lot funnier with RC engines than real ones.

We did that to my buddy's AE .15 RC10GT rtr engine. It had had a good life, and we dediced it was time to see how much it could take, so we leaned it way out, got ourselves a big long peice of parking lot (at the mall, actually) and let it fly. Those dinky AE engines FLY when they are about 1.5 turns too lean and running over 400 degrees F (as measured by raytek temp gun). Thats a great sound though, its not even a waaaa sound, its more a waaaaaAAAAAAAeeeeeeeEEEEEEEEE......... clink clink clink. We wanted a bang but didn't get one, it just quit right at that high-pitched weeeeEEEEEEE.

It was somewhat less amusing when we blew a piston out the side of a block on the dyno in a 1:1 car, but another case of "a little lean?" "yeah, a little lean"

SiLPHEED

While it is true that the RB website only provides vague info and no real tech data to back up their SC, it IS possible to supercharge a 2-stroke engine -- kinda.

We will assume that this little thing can move enough air to cause a positive pressure within the cylinder. We will also assume that the said engine can handle the increased heat and pressure.

The 2-stroke engine will expel exhaust gasse when it is in the BDC (bottom dead center) position. Once it moves up slightly to begin the compression stroke, the incoming air and fuel CAN be forced into the chamber without blowing right out the exhaust. This is because the exhaust port would be closed at this point.

I think the better idea would be to supercharge specially designed 2-strokers that would be able to benefit from forced induction. Of course, the best idea would be to leave FI to the 4-stroke variety of engines. For ALL engines, the best upgrade would be a fuel injection system.

duffman

I would really like to see a fuel injection kit avaliable for nitro R/C motors, one that just came with a little throttle body, engine temp sensor, rpm sensor, computer, and maybe exhaust sensor. In my tower hobbies catalog there is two fuel injected nitro motors that are made by O.S., the hardest part it seems would be to put the temp sensor in the head or the kit could just come with a head that has a built in sensor either way im sure it could be done. It would be really nice to never have to worry about tuning your motor and you would get a nice smooth power band. If a company started making FI kits im sure they would start selling like hot cakes.