Need helping tuning HPI RS4 RTR3....

[TheLazyOne]

I currently own a HPI RS4 RTR3. The car currently has a 2-speed transmission, cvec pipe, headers, 12 fin heads & a 2-needle carburetor. The car is sluggish at takeoff. Once the car hit’s second gear, it starts to gallop. I’m sure the car isn’t properly tuned do to the fact that I am still a newbie. What areas of tuning will allow this car to be quick off the line & have a nice mid range punch? Will the proper tuning allow this car to hit at least 50 mph? Someone told me at a shop by me that this is not possible unless I get a new engine. I’m also looking at replacing the suspension. What areas should I start looking to replace? Thank you all for your suggestions. :confused:

[PhillyNitro]

Low end may be to rich.

[TheLazyOne]

With the proper setup, can this car even hit 50mph? I want to get the most out of the stock motor before I buy a new motor.

[RCRACER2471]

Ya your low end is too rich and isnt reaching peak rpm quick enough. No i doubt your car wil reach 50mph using the stock engine and the 2 speed. You'll need a new engine for that. There are alot FASTER engines compared to HPI's stock one. You can replace the suspension with threaded aluminum shocks.......

[TheLazyOne]

Thanks for the tip...

[TheLazyOne]

What would be a good engine to gain speeds over 50 mph? thanks....

[RCRACER2471]

how much are you willing or can you spend???

Sirio .12
Traxxas 2.5
HPI .12R SS
Fantom .12
O.S. 12.CV-RX
those are some i can name off the top of my head for right now... but the majority of all engines you'll like....

[TheLazyOne]

HPI has a program called the engine exchange program. I could trade in my .15FE & $99 for a .15SS. But then I figured why not just try selling the engine off with all the hopups i've added & get something better. I'm not really sure what I should do at the moment but what I do know is that I want a more that is going to push my car over 55mph.

[brassmonkey1234]

I would reccomened the sirio. I don't have it myself, but on RCCA, they said the sirio domiatied the back stretch of straits while keeping up everywhere else.


BTW: The sirio .12 is only $149, but you need a starter box.

[RCRACER2471]

HPI engines are good for beginners to get familiar with them. After than i odnt think you'd want to own one anymore. you could do the HPI exchange program but there are way better engines out there besides that... Sirio is a good engine to save up for. Especially since its known for a lot of speed and horsepower. If you have the money to afford it, get one......

[KyleSch]

Don't get a sirio if your still somewhat of a newb, they dont last long especially if its not tuned right. I would get a 15SS for your next upgrade since you can get it on the exchange program. You probably can hit 45 with that engine. you probably aren't hitting past 37mph with your stock engine.

[TheLazyOne]

I just bought an O.S. .12cvr for my HPI RS3. It cost me $180. Did I get taken? I bought the engine from the shop I got my car from.

[RCRACER2471]

yes you did. THats the retail price of the same version but just with all pulstart, which is what im getting soon at my LHS for the same price. You can get it for atleast $60 cheaper, if not more!

[TheLazyOne]

I could of gotten the .12 CV pull start for $110. Then their was a .12cvr bump start for $135. I trusted the guy's opinion on the motor. Where could I have gotten this motor cheaper? I was also told the the motor I have pumps out 1HP which he was correct & the cv doesn't. thanks for you advice.

[davehyde]

we run the os 12 cvr in our truck[gt]
its the best engine we have ever used
its a crack engine....
we paid 150 british pound[about 210 dollars]
but things cost more here.....:D

[TheLazyOne]

what is the best .12 engine on the market?

[TheLazyOne]

I am now running the OS .12 cv-r with a cvec pipe & 2-speed tranny in my RTR. For the amount of money I spent on these parts, I could of went out & bought another car. Major newbie mistake. I should of saved myself the hassle & gotten a impulse or a yokomo instead of the HPI. oh well......

[TheLaxPlayer]

If you have the pollstatr .12cv-r, which is named, but not labeled the .12cv-rx, then $180 is not a bad price. Tower sells it for $180. If it is the bump start, it should have been about $125.


I got my .12cv-rx for $125, but it was on sale at tower.

For newbies, the best is the .12cv-r(x). For expert tuners, probably some overpriced siro or novarossi.

[TheLazyOne]

Bumpstart was going for $130. I wasn't sure if i was over paying for the motor i bought.