newbie here, RS4 questions, etc....

[ryboj]

Ok, I bought a new RTR dominator .21 8 port the other day for the local track, but they don't allow 1/8 nitro. So that's going bye bye. :nono:

Anyhow, I can still have fun on the street.....because at my parents house I have a 2.5 year old? RS4 Nitro Rally 4WD belt driven .15FE with an Airtronics controller, and it was NOT RTR.

Can anyone tell me what model it is exactly? I don't have the car in front of me to know.

It was barely broken in, and then it's been sitting ever since, so just over 2 years sitting. I did buy the HPI 2-speed tranny, and that was it.

However, we all know how "entry level" the .15FE is.

I've been reading some posts here, and it seems, for the money, to get the most reliability and performance, O.S engines do the trick. I realize there are some powerhouses out there like the NR's etc, but they are costly to buy.

How much engine can my 4wd RS4 2-speed tranny car handle in it's current condition? Can I just add an engine and leave it alone and be happy?

OR...

If I do upgrade the engine to a fast .12 or some .15/.16 or something, what parts need to be upgraded? How much on avg are these parts if I needed all of them?

I'm basically trying to figure out how much it's going to cost to get my car up to speed, no pun intended, and I will not be racing it, just doing stuff out in front of my house, etc. Looking for the best bang for the buck in terms of engine. Reliable, easy to tune, start and good power.

Let me know what you guys think! Thx!

 

[Mugen-Racer]

HPI Nitro Rally, eh? Well, basically you can put a .12 or a .15 engine in it. Just make sure the shaft is what's needed like a Standard shaft, SC, or a short shaft. I would go for a slide carb instead of a rotary carb for better response. As for engines brands, you can go with the reliable OS. I hear good things about Fantoms. They turn a pretty high RPM. I never really understand Rally because you still can't go in grass with it. Maybe some smooth dirt area, but can't really go outrageous.

 

[ryboj]

Mugen-Racer: Yeah, that's funny. You're totally right. When I first bought that thing, I went in blind, just bought it off tower and said this ought to be cool, a rally 4wd, do a little dirt, you know...gosh....the street is almost too burly for it...
:nono:

Anyhow, what does "SC" stand for? The shaft on the .15FE seems "long", at least to me. Maybe it's not, but it sure protrudes out there.

Is the carb I have now a rotary style?

When you buy a new engine, it comes with a carb too, no?

So, either the OS or Phantom?

If I were to go with the OS engine, which model or one could I just install with zero issue and no need for any other upgrade?

Or, if I do any of them, will I need an upgrade?

I really don't want to spend more than $125 total to get this thing crazy fast/reliable. Is that possible? Or is it going to cost me more?

 

[Mugen-Racer]

Not sure on the OS engines as to the model numbers. I'm a Novarossi fan. The standard .15FE engine you have is most likely a rotary style where when you hit the throttle, the arm on the carb rotates clockwise/counterclockwise. Slide carb would slide in and out. I think SC is standard. I'm trying to remember on my old HPI onroad. Used the same engine. If you take the clutchbell off and it's got threads all the way, it's a standard. Let me see if I can find a diagram with the different kinds of shafts.

 

[ryboj]

Thanks mugen, I'll have my dad send me a pic of the car and what the original box says, that way I know exactly what I have.

I could likely find a deal on a used NR on ebay or something.

I just need to know what this car can handle, and what it will take to handle more. Or, would I just be wasting money trying to make it better when it's not designed for more power....

 

[Mugen-Racer]

I haven't really seen a rally car run, so I can't really say what it can and can't handle. I made my HPI RS4 run so fast and it was fine, but the handling wasn't the greatest.

http://www.osengines.com/engines/car.html

Here is a OS site. The 12TR pictured is a SG shaft. Smooth at the end and then some threads. CV and the .12CV-R shows the Short shaft. Standard would be threaded and the length is the same, or close to, the SG. Those are the typical 3 different cranks. Some manufactures make all 3 for different apps. Just get the one that is designed for your car, otherwise, customizing will be in order.

 

[ryboj]

Mugen, yeah, I've been looking at that page. Will I need to buy different motor mounts, pipe, etc to make this work? Would you go .12. or .15 with the OS. I mean, I think my stock engine was about .6hp or something....with 1.0-1.1hp, it's almost double.

They make the touring engines too.

Wonder which one I should be looking at here?

 

[Mugen-Racer]

I think you're pretty much going in the touring class. If you go with a non pull start engine, you're going to need different engine mounts. Otherwise, the stock should work. You probably would end up needing a new header and pipe to go with the new engine. HP is good and everything, but I tend to look at the RPM's and how much it can turn. A typical good engine maxes around 36,500 or higher. Phantoms are around low 41,000 or so. You'll be amazed at the difference from the stock .15FE to something like the OS.

 

[ryboj]

No, I definitely want a pull start engine! Would I still need a new header pipe and muffler if I do a pull start engine? Basically, the new engine will need one? Only a .15/.12 HPI engine could reuse the same stock muffler stuff, no?

I tend to agree with you. The more RPMs, typically the more power will be made. But a lot times these engines don't have a lot of low end....but in a car, you're just looking for mid high typically.

The cost of the phantom engines, they are higher priced than the OS engines no?

So, do you think I can $125 or less and make this RS4 kick, or is it not worth it? Will it end up being a money pit?

 

[Mugen-Racer]

Most likely you'll need a header pipe. I would suggest a pipe, too. Dynamite has a header/pipe combo around $40. Phantom is a little more expensive I believe. Total investment if you get a new engine will run around $150 minimum. Rough estimate. You can use the stock pipe, but will actually hold back the power of the new engine.

 

[ryboj]

Mugen, appreciate the helpful information.

Sounds like $150 could become close to $200 after something might break and need an upgrade.

I need to reconsider my options here. Again, appreciate the help.... :burp: