Fiream

HI guys,

I'm new to this board and the hobby R/C racing. I do alot of Parkinglot racing at my local hobby store, I'm having trouble with grip. Let me star by telling about the track. The track is not level nor smooth since it is in front of a store it slops down hill, ther also is a very large bump in the center. The bump is not my problem, the problem i'm having is the turns, the car will not stick in the turns. Well, I shouldn't say that it will get around the turn but it's very loose in the back end. I'm currently using "I think" V-Groove Pro compound HPi tires. Could the problem be that the slop of the hill in relationship to the track(I.E. the track is horizontal to the northern downhill slop, meaning turn #1 is downhill) Most people have told me to go with foam tires, i'm not sure if I want to go with foams. Is there any way i can get rubbers to grip, maybe a softer compund or some kind of traction compound like they use in drag racing?

Any help would be great,
Rob

asd

foams are a "must" for racnig, unless u want to do 360's each time u make a turn
if u want to run good rubbers that will stick better than the rest, i recommend looking into take-off tyres, ask the ppl at ur track what tyre combos they're running and that should give u a goo general idea of waht U should be running

Fiream

Most guys at the track are running "foams" I'm not having that much trouble running rubber, it's just I can't get the rear end from stop kicking out...

Jack Moss

If you are running on an asphalt surface trust me foams are the best way to go you can drive yourself crazy trying to get a HPI on rubber tires to hook up on asphalt. Foam tires are usually much cheaper than rubber too.

www.kustomrc.com

Im2lazy

If you have those vpattern tires, that is your problem. For rubbers, ask if there is anyone around that is fast with rubber tires, and use the type they have. Don't be shy. Take-offs are good, but I am of the opinion that Sorex's are the best (at my track for sure). Those HPI Pro compound stuff is a bunch of BS. Stick with real racing slick compounds, the ones that are temperature specific. It may be beneficial to use slightly softer inserts in the rear, but most likely not.

Foams are also an option. Foams are worth about 1/2 a lap to a whole lap faster per five minute qualifier at my track. And these laps are about 22-24 seconds each, so foams are definitely faster than any rubber tire setup, but if you are just starting to race, i suggest a good set of rubber tires. The reason is that if your track is made of 4x4's or anything else solid, you are going to chunk your tires a lot more often than an experienced racer would. Sure you can run on chunked tires, but there is the chance that you will make a chunk in the tire that makes it unusable.

Just get going and make it around the track without hitting anything and you will soon become much faster than if you focus on racing the fast guys every time you hit the track.

V-One S

Another problem you could have is that you don't have enough rear toe-in or too much camber, my v-one s is setup so the rear is a bit loose, so i have to learn to catch the tail and if i learn to drive like that, i can become faster then people who have a stable car then has heaps of drag down the straight.

But just try a a degree or 2 more reear toe-in or less camber, and also check your front caster, you's as much as you can get.

Im2lazy

i believe he has a nitro rs4, so he can't adjust the rear toe.

However, you should not need to put the rear toe much beyond two degrees. 2.5 seems fine, but, beyond that, your compensating for a problem elsewhere.

Firearm, I want to know, when does your car spinout, entering the corner, exiting the corner, braking or accelerating?

It is not likely there will be many cars like yours on the track, but I would again suggest you talk to a nice track rat and have him help you figure it out. there should be people nice enough to take their time to help a new racer.

Another place that may be your problem is the diffs. Make sure there isn't too much diff action.

one piece of caution, Rs4's are notoriously hard to get running perfectly.

V-One S

Sorry im don't really know many cars well at all, really only my own car since i've only really just fully gotten into this hobby in the past few months, but i've had a crap old electric for years.

Fiream

Im2lazy,

Car really hasn't ever spun out, but i've almost spun out many times. Acellerating and braking are not a problem, entering corners are not a problem, alittle understeer, just the way i like it, but exiting the corner is where i'm having problems. If i get on the gas even alittle it will try to kickout. I'm running about -1.5° camber in the rear. I was think, what if I get a set of wider tires for the rear?? It work on real cars.....


Rob

V-One S

Can you adjust your camber on the rear?

if so i'd try running 0.5 degree. to stop wheel spin, but if it is actually getting grip and pushing the rear-end with out wheel spin i'd go to around 2.5

Im2lazy

I think I may have it.

Okay, where is your rear camber links located? In the RS4 that I ran, this was a very important adjustment. Don't put the camber link on the top hole of the rear hub carrier. This causes the rear to roll excessively and not want to square back up fast enough.

So, it's like your car keeps leaning over like it wants to keep turning even when your not. I'm not suggesting a rear roll bar because HPI's roll bars have no effect on the car if it is lowered to race height.

If this is not the case, then, as I said, it is your diffs or your tires.
Make sure your rear diff is a step softer than the font diff.

Fiream

I put a picture in to give some idea of the track condition, and yes i've tried 0.5° it helps very little, i've even tried postive camber.

V-One S

I think my car is set-up with positive camber so that when im entering, am in, and leaving a corner the car is rolled over further so that it gets even more rubber towards the ground, but im not positive since i didnt do the actual set-up i had a guy who races a V-One R and works at my LHS set it up.

Just try a few different setups, maybe even less camber on the front, it is 4wd right? so then the front will pull out of the corner instead of the rear pushing, and have u accidentally put in the rong gears/pulleys and created underdrive in the car?
I'd play with your set-up a bit before buying new tyres, and if u do get new tyres go for a softer compound then what you have, and Take-offs are great i've been told, just bought a set for my car for when i get down teh track next time.

Im2lazy

No, I'm not talking about the camber angle, (1.5 should be good) I'm talking about where your camber link is attaching to the rear hub carrier. The hub has 4 different holes to adjust your roll center. If your car has the camberlink attached to the highest hole on the rear hubcarrier, the rear end of your car will roll to much in the corner and also want to keep rolling by the end of the turn.

Fiream

Yeah my car is 4wd, i'm running 0° of camber in front. I guess i could put more camber in front making more understeer, that would work too.....