If you modify for zero rear toe, your next thread will be "Help, my car spins out when it turns"

Have you done the basic setup? I'm betting you haven't. Check and set camber, castor, droop, ride height, toe front and rear? That would be the 1st step before redesigning suspension components.

Trying to not be rude ...... but I can't imagine why you think you know more about car design than HPI? Do you think that they have been doing it wrong for 20+ years?

Running on slippery tiles is not giving any grip, for sure not with the stock tires from HPI. The car can become unpredictable First of all the question if it is also the problem on asphalt and get some better tires.

That's what confuses me too. Look, I havent been runing on high speeds (10-20 km/h) and I do more of a rally car driving that has its grippy and drifty moments while the surfaces are pretty slippery even the asphalt we have here. I like the amount of drifting the stock tires give, of course there's not much traction but I like it. I don't know what would happen at super high speeds, but at the speeds I go the car was at last going as it should after my mod. Other people on youtube having the same car, got the same issue, they speak about unpredictable behaviour...

About the mod, It normaly wouldn't let me do it, but I removed the suspension arms shafts at about 80%.

I really don't want to upset you guys and I am sorry if I do , but it is things I've tested and worked, I wish you were here to witness it too! Maybe if I use softer tires it won't choose a side to grip more and have both tires pushing to the center all the time, cuz mine tends to get grip from one side and then happens what I showed you in the videos ( https://we.tl/UkFqjnDPu4 ) of the previous reply...

Bob - it seems you know more about R/C cars than all of us combined. There is no sense in posting more help requests when you clearly won't accept any. Best of luck to you.

Just to throw in another suggestion. Check your diffs, it is possible that the rear diff is unloading and only one wheel is providing power in the rear.

I'd take a look at the hub and differential bearings at all 4 corners of the car. If one (or several) of those bearings are binding, the car will most likely track unpredictably. I'd also check to make sure that none of the axle assemblies are binding, as that would create a similar effect.

Rear toe contributes to directional stability - that's certainly not the problem in this case.

I've posted videos showing the problem in a couple of my posts, it is not drifting from both sides, one side is gripping, the other drifting.

So I guess toe is a matter of personal style and my style is somewhere inbetween, that means I need to reduce my toe

For you guys say my diffs might be faulty I checked that too and they are fine, and because after reducing the rear toe I had the results I was looking for so I am now looking for a way to do it permanently...

Here's a short video I made when I started...
https://www.facebook.com/bob.corey.5...2829479403971/

I am about to make more videos when I setup my car to my liking!

So tell us, are you an experienced driver or is this your first (real) RC car?
Do not get me wrong but the Sprint is already an 20 year old design with no real racing blood (devellopped by racers while racing). The RTR comes with a cheap radio and tires and is assambled with less care. But in the base the car itself is good.

You will be amazed what some heat in the tires and some good tires can do
If other guys experience the same thing, is it the car or also the experience level of those drivers? Well... No experienced driver would buy a Sprint if he can build a car with a much better chassis for a same price.

Again, Toe-in, even 3 degree is a normal thing, no need to mod it.

You have tested in a way no one would drive the car like that. It is like water skiing with 10km/h, Also then you would mount air tanks on the ski's to make them float.

This is my first real rc car and bought it for a super discount half price to have fun in free time but seems I start to like it, my goal is to do FPV races and videos. I made some 3D printed roll cages for the cameras too! I haven't tried any soft tires yet or any super grippy surface, here all asphalt is slippery and cold.

Haha that last one made me laugh, but I did the test trying to show you guys what's happening. I could max it and shoot it with a drone or something to see that the same thing happens on the street as well, making you loose or even spin out (I guess because of my slippery tires)

The races I am planning to do are kinda low speed in parks, concrete, asphalt or even indoor places so the traction is usually very low, but I need to be able to drift at lower speeds so it feels more like a real car.

(In the box I found some rear hubs for 2 degree rear toe in :-D )

I agree!

Trigger and SteveM I am not trying to pursuade you about anything, the models are made so anyone can modify them to suit their needs and style of driving and conditions in general. You might have super fast RCs with good tyres and all but not me, and since I know what I am lookig for I asked you guys if you know how I can get adjustable rear toe...no offense eh...

(Of course I am not saying this is going to be right for everyone)

With a little bit of slip angle, the car tries to center hence 3 degree toe in helps.

Bob, these guys are very knowledgeable and trying to help you. No need to be stubborn. Leave the toe alone. Something's binding like I said. Check the drive train. And take the car out on asphalt where traction is better and run it there to see if same happens. You might just need to change tires and driving surface.

You mentioned you're planning on doing low speed drifting. Less toe might actually be a good idea for that use case, but I'd still check all the binding and traction suggestions first to verify the car is functioning properly.

Yep I did so, bindings are good I can tell you the car is very carefully used and never crashed Traction where I live is very bad everywhere! And with my stock tires if you go higher than 10 mph you probably loose control and spin out. Only the stone block street next to my house is grippy and there the car goes mostly straight but turns because of the stone gaps

Have you taken the car completely apart and checked every bearing? Just because the car has been carefully driven and never crashed does not mean you do not have a bad bearing or binding somewhere in the drive line. I would personally take the entire car apart and inspect every bearing, hinge pin, shock, suspension arm, suspension links for damage and make sure all these parts go back together as they should.

You seem pretty hell bent on changing the toe even though many people with years of experience here, not to mention the engineers at HPI, all agree on the need for rear toe. On my Tamiya TT02 the stock hubs have 0* of toe and the car was a total handful until I installed hubs that have 2* of toe in, it made a world of difference in the stability of the chassis.

I too run on unprepared tarmac, actually tennis courts, but they are always dusty and very slippery. In the 6 months I have had the car I have used 5 different sets of tires trying to find something that will provide a bit more traction. My current favorites are the Ride 26MM Radials and the Tamiya Super Grip Radials. They both offer a bit of tread and a pretty sticky compound for this sort of use.....the Tamiya's seem a bit stickier but seem to be wearing quicker than the Rides.

Before you start reinventing the wheel I would tear down the car and look for any issues and carefully reassemble it make sure everything is even side to side. I would then try new tires. Are the tires you are using original to the kit? How old are they? Even through the tires might have plenty of rubber left on them does not mean they are not dry and hard and that can start to happen pretty quickly depending on where and how they were stored. I can tell you there is a reason why every competitive chassis on the market has toe-in built into the chassis.

Cheers,
Jim