What should I get next for my RS4?

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I recently purchased an HPI RS4 RTR from my uncle. This is about a year old. So far I love this car. This is my first nitro car. I am trying to figure out what should be my next hop up on this car. I am looking for a better response off the line and some more top end.


If it's the RTR, the first thing should be a new header and pipe. HPI makes some. Or try CEN. There are a lot of possibilities. Threaded turnbuckles will help to tune the car. You can also get a 2-speed. HPI makes one as does Ofna. So you can get it to cruise a little better. You may want to consider belt tensioners. That will help keep them on the pullies. They do skip sometimes. OH, and some new tires. If it still has the general purpose radials, you may want to get something stickier. Their slicks are nice. Or the X-Patterns. Also check Pro-Line and Treadz. Alot of possibilities.
Candyman, its an RS4 2. the engine is mounted differently then in the 3, due to the belt drive. But I agree a good pipe, header, and an OS carb! Does the card on a RS4 2 have one or two needles? And no doubt a two speed!
Yup, it's a transverse mount. Just like a GT. Shouldn't be hard to find a header that will bend around the engine. The carb is the standard single needle. So that could be upgraded. A lot of potential.
That carb is a piece of JUNK! That would definately be my first choice of hop ups. I honestly cannot believe the difference that OS 10e carb made on my RS4 :D Quick off the line, no more loading up at idle, more top end, and I dont have to constantly mess with my throttle trim just to keep it running anymore. I was going to sell mine until I did the carb and header, now I am loving this thing. I have used it more in the last week then I have since I bought it in April. Next up for me will be the two speed :banana:
Thanks for all of the ideas.

Candyman - Yes I am running X-Pattern tires. These are the only ones I have used so far. I have been pleased with the grip they provide. I will keep that in mind when I get a 2-speed.

I think I am going to get a pipe, header and carb first. I will run that for a few weeks and then go from there. I am at HPI's site right now. It looks like I can get a pipe and header as a package. Now I just need to find the carb. I will check TowerHobbies.com tomorrow to see if they have it. Is it pretty straight foward replacing the carb? Any thing I might need to keep my eye out for?

That is what it looks like. I went to HPI's site today and found a great walkthrough on how to replace the carb. Now I just need to find the carb. :) If you don't mind me asking what did you pay for your used one? What should be the ball park figure for a new one? TIA.

Actually I got it from a friend, we traded. I traded him a brand new aluminum air filter for it. But I see them fairly often for about $20 - $25. And YES it is well worth doing. Like I said before I would definately do that first! It will make such a huge difference in the performance and adjustability of your RS4. I will look where I had seen one before and if the guy still has it I will let you know. Or find someone selling a blown OS engine with one on it if you can get it for the right price. Then just take the carb off it and trash the rest.
Well, I have an RS4. Mine like your's was a ready to run car. These guy's are steering you inthe right direction. There doing such a good job that I can't add much more. However, I can tell you this there is a difference in after market pipes. So do yourself a favor and dont buy an mip pipe or the one at HPI's website. Oh sure they'll be a huge improvment from the one you have now, but the most bang for your buck will come from a Paris Pipe. HPI's 2 speed tranny works well for me and ofna is good also . I'm running HPI and have no complaints. I'm running a .12 O.S. cvr in my car and it is way more motor than the .15 FE that is in your car even after you add an O.S. carb and the purple heat sink head and the performance exhaust. I would like to see you spend the extra money on a better engine. Youll be half way there after you upgrade the .15 FE, but youll still only be makeing a little over half the power. Good luck
Rouge, please don't take this the wrong way but I just want to point out a few things. Remember this guy is fairly new to nitro too, so imo it would be better to learn on the engine he has now as opposed to an expensive high performance after market engine. Even if you buy a new OS engine (approx $140 - $150) engine your still going to have to buy a new pipe and header, correct? You still have to get the two speed, correct? so why not start with a used OS carb for like $25 and maybe a pipe and header for about $50, which would be needed anyway, and for $75 it will perform waaaay better then the setup he has now, run it until it needs an engine, you can then do the two speed while running that FE which will also work with a new engine. Then you already have the pipe and header and two speed for the new mill, sell the carb or keep it for a backup (which is what I would do) Or do it your way, get rid of a good working engine, spend $150 on an engine and run it with the stock pipe and header, or add another $50 to that for the pipe and header and now your at $200 and thats without a two speed. If you have alot of money to spend at once mcvickj a new mill and header and pipe and tranny is a great idea. If not just start with a carb and header, believe me you will notice a tremedous difference.
Thanks for the idea Rouge. But as NCNitro pointed out I am new to the nitro world. I would like to see what I have first before I get rid of it. As he also pointed out all of the hop ups that have been suggested will still work with the new engine when i do decide to get one. I have some money for this project but I am not looking to drop another $250 at this moment.

Well Nothing in my post was contidictory of the fact that signifigant gains in power would be noticed by hopping up the current engine with a carb and pipe and header. I personnaly dont think that it's hard for a guy to figure out a high performance engine. I mean lets face it you guy's were suggesting that he put an O.S. carb on his current engine. Ironicly the only thing tricky about any engine is the carb. and on the hpi engines that problem is solved with there simple 1 needle carb which he is being urged by you to change. quote from you ""That carb is a piece of JUNK! That would definately be my first choice of hop ups. I honestly cannot believe the difference that OS 10e carb made on my RS4 Quick off the line, no more loading up at idle, more top end, and I dont have to constantly mess with my throttle trim just to keep it running anymore. I was going to sell mine until I did the carb and header, now I am loving this thing. "" Sp what if the guy is new that doesn't mean he's stupid. All I'm doing is posting my opinions based on real life expirience and letting HIM decide. Oh! and dont worry I didnt take you post the wrong way. It was meant to make yourself look good and I think we can all see that. The problem is that if the guy is new and you truly care about saving him the frusteration of tuneing an engine. Then you shouldnt suggest putting another carb on his current engine because thats the only thing that makes it simple. :mad:
Rouge, I put an OS carb and header on my stock .15 FE engine, as did Divine are we both "stupid" for not just buying a brand new engine because of a lacking carb and header. Did you jump right in, pull out a perfectly good engine and buy an OS just so you can say I have an OS in my RS4. ( my guess is you got it used with an OS already in it) Alot of people have trouble tuning a nitro engine. I never implied the guy was stupid, only that he should learn the basics of nitro engines and tuning before buying an expensive engine. What happens if you lean it too much? BOOM. I'm sorry you feel the need to be confrontational when we were just telling him a good starting point. And if you think HPI solved anything with a one needle simple carb, well then more power to you, I'll sell you the one I took off since you think they are so great. So why does HPI show a two needle carb upgrade right in the maual that comes with it? That carb is junk, how can you possibly tune the car to idle well, take off good, and have good top end with one needle, there has to be a compromise, maybe you can explain this to me? Is it simple to contantly have to mess with the throttle trim just to keep it running, is it simple when it sits at idle, loads up a chokes on excelleration, hmmmmm I think not. So exactly how is this one needle simple carb better? BTW you are not the only person here with "experience" and from your post and your tone I seriously doubt how much experience you actually have. And you DID take my first response to you wrong, I guess some people just can't handle constructive criticism
mcvickj, thanks buddy. OS is a great engine I have one in my T-maxx, which I put in after I blew up my TRX. And I will put an OS in my RS4 3 once my HPI engine goes. But for now I am using the HPI engine and with just a used OS carb and header off my T my RS4 3 is running GREAT now. Like I said before all the hopups we recommended will work with a new mill and would be needed whether or not you got the engine first. Good luck with your HPI and I'm sorry about where your thread has gone, but trust me if you want to start off with just a few bucks and want the car to run right you NEED a two needle carb. Just ask anyone but rouge what they think of (rotflmao) HPI's "simple" one needle carb, you don't have to take my word for it.
As I stated in my previous post. I am just putting out my opinions Based on real life experience. Haveing said that I Hopped up my .15 FE as much as a person can and then bought the O.S. CVR. And from experience can tell you that even with all the hop ups the engine still leaves some to be desired. As far as being confrontational goes. I was just replying to your post. Your guess about me buying the car used with the O.S in it is way off so I would be a little more cautious with my guessing if I were you. The affects of leaning your engine out are greatly incresed with a carb swap. I never said the carb that was on it was better ( you didnt pay attention) I said it was simple. Simple doesn't mean better, unless your stupid. The one needle carb is desighned for the unexpirenced. Why? ( I'll answer it for you because I know your guessing is Bad.) ease of operatin, better Idle etc..... You suggested that he replace the carb and I'm in total agreement. But then you say He's new to nitro. THEN DONT CHANGE THAT CARB IF YOUR AFRAID HE WILL LEAN OUT HIS ENGINE. I will admit to one thing that probably would have prevented all this. I didnt pay very close attention to his first post. All I noticed was a new rs4 rtr from his uncle, and what to do to hop it up. I missed the part that said he was new to nitro. Otherwise I probably wouldnt have posted anything at all. While I was typing my last response he posted that he didnt want to drop another 250. at this moment . Hey thats great man it's all good you know just read the post and make up your own mind. Thats what it's all about. As for my experience, I've been at a long time and there are those out there who have been at it longer than me but I seriously doubt that NCNitro is one of those people.
ease of operatin, better Idle etc.....

BETTER IDLE, man you can't be serious, rotflmao, they idle like crap with that carb! Do you even have an RS4? Second you don't even know who I am so how can you make an assumption that I have not been at this longer than you. I was a small engine mechanic for many years, and I repair RCs for a local hobby shop, and since I am about ten years older then you I know I have more experience then you, straight up. Maybe next time you should read the post thoroughly before just putting any old response up. :mad: :mad: So when you get ten more years experience come back then!
Dude. You seriuosly arent going to try to tell everyone that that single needle carb wasn't made for beginners. Are you? It' s whole purpose is to be simple no low end adjustment. It 's job is not to be high performance but to just perform. idle and go . thats about it. It idles well and it goes like its supposed to. It doesn't surprise me that you work in a hobby store. Dont get me wrong all of us are trying to stay young in some respect and alot of people look at us R.C. car people as inmature kids. But dude get a real Job. Oh! and since you want to compare Dicks. Here's Mine! I'm 27 years old, I have an assosciate's degree in electronics, and My Airframes and powerplants license. I work for Garret aviation. I work On Corporate and Private Jets. ... Hmmm. Looks Like Mine is Bigger. This will be my last post as I'm finding the effort required to respond to your ignorance far outweighs my desire to respond. I know thats Kind of weak But some one has to be the Bigger man and call it quits. I'll go first
Once again mr. big peepee you did not pay attention to the post, man are you dumb. Who said I worked in a hobby shop? where does it say this? Where did I say a single needle carb was not for beginners? I fix nitro RCs for a guy who owns a hobby shop. I am a professional photographer for a nationally published motorsports magazine if you really must know, as well as for the Associated Press. I spent many years as a small engine mechanic. Why do you dance all around the issues. I never asked or cared what you do for a living, it is totally obvious to me you don't know half of what you think you know. You want to turn this into something personal come to NC and I'll turn it into something personal, Man dont post unless you read the thread you keep making youself look more stupid with each post.

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