bgsteve523

I have a nitro rs4 with a .12ss engine. I replaced it with an OS .15 really powerfull. My problem is that every time i take off from being stopped with full power I spin out of control. This never happened with my .12! any ideas if its the diffs or what and if it is what kind of diffs can i get to help with the extra power. The tow is good! Diff's? Slipper clutch maby? Sway bars? I am lost please help out.
Sincerly,
Steve O

AMGRacer

A 15cv or cvr is not so powerful you need different diffs. This I would check first:

1. Wheelnuts are not overtightened
2. What tires are you using? No grip = spin
3. Do you know how to check tweak? Tweak = spin.

bgsteve523

The tires have good grip brand new
I do not know how to check tweek please explain?
the engin is a OS .15 CVRX its a lot more powerfull than the hpi .12 i had in it. Please get back to me i need help.
New diffs? or just work?

bgsteve523

OHHH one more thin it only spins out to the left side opposit of the exaust. I don't know if that helps my car is apart right now and the diffs look good but i am wondering if they can't handle the power of the engine or there is something else i can do hope someone can help. IF I DO NEED NEW DIFF/S WHICH ONES DO I GET???????? Thats the next big question i guess an do I do both rear and front or just rear?
Sincerly,
Steve O

AMGRacer

OK so your wheelnuts are not overtightened huh?

Are the tires spinning? Ie. are you breaking traction on the surface?? If you are get more grippy tires. What type/brand are you running and what is the surface?

Tweak is kinda tough to explain easily. http://www.rccaraction.com/rc/articles/untweak.asp

Read the above link CAREFULLY and make sure you do it. Diffs are not going to help if the car is tweaked.

bgsteve523

I didn't check if the wheelnuts are over tight! Why would that change anything??? Please explain I alway understood you wanted them as tight as possible. Please get back to me I appreciate it thank again!
Sincerly,
Steve O

bgsteve523

The real strange thing is that if I ease into the gas its fine it only happens if i gas it all the way from a stop I don't know if that helps but I figured I would share.
Sincerly,
Steve O

bgsteve523

so any other ideas? I hope that works, and what does over tightning your wheels do? thanks again

AMGRacer

So did you check the tweak as shown in the above article?

If you want help you have to provide detailed descriptions of what you are doing. So far I know nothing except that your car is spinning out. Answer the above questions:

1. Are your wheelnuts too tight and are binding the axle rotation?
2. WHAT TIRES/BRAND ARE YOU RUNNING ON WHAT SURFACE?
3. Have you checked the car for tweak?

popsracer

Steve;

HPI's are not too sensitive about over-tightening the wheel nuts. Snug them down good and they should be fine.
What will cause your problem is having MORE pressure on one of the rear wheels. Make sure that your shocks are exactly the same length. The more accurate the measurement the better. Then make sure that you have the exact same spring clips on each shock side to side.
The more power that you put to the chassis the more these things become important.

Keep me informed and I'll keep working on it with you.

PS; My E-mail address is in my profile.

bgsteve523

Thanks guys ill check it out. I will look at my springs and all. I am running the stock tires and rims that came with the kit but they are brand new great looking tread on them. My buddy with the same set up is running foam tires does that make a difference? Ill see whats going on ill test this weekend. Guys keep me infored if you have any other ideas. Do foam tires make a difference? I am not new to the nitro world just the on road part I have been into off road for so long this is tweeking my brain a little. Thanks again and please get back to me on any more input.
Sincerly,
Steve O

AMGRacer

YES!!! They make an enormous difference. If you are running on any sort of non-dusty surface foam tires will hook up well. If you are trying to run foam on a dusty surface they are terrible. That why I was asking about the tires. The kit tires are frankly pretty terrible once you start getting some horsepower on board. I would recommend foams for almost any application apart from a dusty surface.

AMGRacer

On my old RS4 Racer 2 this was one of the biggest problems I had when I knew absolutely nothing about these things. My hex had become damaged and was binding badly. It is worth checking.

popsracer

Usually the reason a wheel hex is damaged, is from having a wheel nut come loose. Associated cars/trucks are very finicky about how tight the wheel nuts are. HPI's are not.
Use a drop of threadlock in the nuts to keep them from loosening during a race.
Running Foams will not correct your problem. The car should run straight when accellerating in a straight line no matter what tire you are using.

AMGRacer

LOL I have not had any HPI junk for over 2 years, and I finally did sort that damaged hex issue thanks

Tires are super important, I used to bash around on a very dusty and dirty area with my ole HPI. The car would not hook up in a straight line with my novarossi CX12 for anything when I wrenched on the throttle, and I had removed all the tweak. Turns out that foams suck on dusty surfaces. Got some yokomo slicks and the car was dialled. Can't make assumptions as to where people run their cars