haplm

Certainly those tires were too much. I have changed them to HPI Rally / VR Pins for the rest of the race, as they were causing too much of understeer. To my defense, we were expecting heavy rain, so I mounted those as I was expecting mud.

Trying to go through the hairpin with standard steering angle and throttle is unreliable, and really slows you down. People who win these races are unbelievably fast, trying to avoid any kind of slide. Watch this (one of the top guys):
https://goo.gl/photos/rPuuohTWtTEixc8h7
https://goo.gl/photos/jkuXyEeP1LDZkgyD9

If you ever come, let me know. There is a race at least every other weekend spring-autumn, I can take you there. We've had 2 polish guys on this one ;-).

What's interesting is, that there are many tracks in the countryside (often very well equipped and maintained like this one), but nothing in the capital (where I live). So don't be jealous too much, because it is at least 1 hour drive for me as well ;-).

BTW - I've just realized, that my steering angle is so extreme, that I'm hitting dampers with zero offset wheels. So I had to order +1mm and +2mm wheel hubs...

fyrstormer

iTrader: (1)

It doesn't sound like "real" rally racing if they aren't sliding around corners. It sounds like touring-car racing on dirt.

haplm

I'll share that message with the fellow racers :-). It has some explosive potential :-). BTW, many of those cars are converted X-Rays (T2) and Tamiyas (TA-02), and with those, sliding around the corner might be a bit more difficult... Anyway, it is a lot of fun, and I like it much more than racing on track (I have SC truck as well, and driving it from platform comes nowhere near this).

Raman

iTrader: (94)

I used to be in the same boat as you when I lived in California. I lived in Culver City and had to drive down to Cal Raceway in OC.

Then we moved to Las Vegas and the only option I had was a parking lot race on Friday nights. As of January we now have an indoor carpet track, the owner switches between on and off road using movable ramps.

As luck would have it, the on road races take place Saturday's which I work! Lol.

as it is there are far too many classes at that track, to start rallye I would need a bit more support / interest.

fyrstormer

iTrader: (1)

Hey, it's not my fault they're all doing it wrong.

4roller

Desert stage rally!

Raman, at your track would anyone be caught dead driving an xv-01 in any of the classes except novice?

I know this car weighs a chunk, like 1600+, at least that's how much I guessed with a bathroom scale. I am guessing 300g is a lot of extra weight to throw around compared to people driving 1300g cars that have to add weight to keep it to spec.

I often wonder, how would the xv-01 fair against other more road oriented TC cars with tub chassis.

I know you placed 2nd or 3rd in a couple of races. And it seems like the earlier people in this forum had the same idea to race xv-01s in TC-like classes.

Does this car keep up? I often have dreams of showing up at a track and blowing away the regulars, only to have their heads explode when they find out that the flavor under the lexan is pure rally funk.

More RC stuff
My friend just gave me a crap load of HPI rims. I'll share them once I get them all sorted out. Some vintage bling that he had been sitting on and never used b/c he drives f1 mostly. He brought out his f1 and ta05v2 (albeit his beaters) and maybe its just his older electronics or dead batteries, but I gotta say, those cars should at least be as fast as mine. Neglect of tuning? Idk. I was just happy to cook some parking lot garage after work last night. Even if it was just for 15 mins. My first drive with another car!

fyrstormer

iTrader: (1)

There are videos of the XV-01TC running on tracks, but damn if I can find any of them right now.

4roller

Yes, the only ones I've seen are the go-pro runs with clear lexan bodies, and those are all only 1 car on the track.

Xv-01's vs the world!

fyrstormer

iTrader: (1)

I saw one that was supposedly an XV-01TC running against other touring cars. Can't find it right now.

4roller

#rimChoicesForDays

All except one set is HPI. The deep dish, ones are white centers and silver hoops. Kind flimsy, but hella bling.

The 5 spoke Tamiya rims are the 24mm narrows, that I finally remounted my salvaged Ride USGT tires.

I also got a 36mm Tierod which I installed, now I have more servo spline angle options.

haplm

Speaking of tires, I have just found what the Austar/whatever-name-you-get-on-ebay-for-this-knockoff Pirellis (and probably original HPI Pirelli as well) are good for - parquets! So if you are going to run in a school gym (at least we do from time to time, when it is freezing outside), these are the tires to get. They keep traction no matter what, and you even get a nice squeal while braking :-). I'm just afraid I have significantly shortened life of my belt, driving with these tires, modified steering, full throttle, and without slipper for like 5 minutes, grinning like imbecile :-).

BTW - speaking of belt, it really helps if you do this. Much better sound from the belt area...

4roller

haplm is posting in all these old threads, but I guess they are much more relevant to the topics that were created.

Today I ran the XV-01, with the Subaru body at the Bank parking lot. Smooth Asphalt, with that sealed glaze. It's slick and dusty, but very smooth. The kind of smooth that if it was wet, you'd slip.

After haplm's comments (about slow acceleration), I wanted to test out some different gearing. I switched out from 72/38 -> 72/32. The lot is small so top speed didn't really matter. I will say that between a solid 38T pinion and a drilled (lighter) 32T pinion, there are some advantages for acceleration. Yes the gearing naturally produces more torque, but also the spin up and wind down of the motor is also faster. Less rotating mass.

Anyway, I hand a great time. 4 wheel drifts doing 90 degree turns was my favorite. Nailed it every time. I was running the outer perimeter of a "L" as pretend course. So fun.


Tires:
I am using some cheap slick tires that I purchased on ebay from China.

These tires aren't light, in fact there are kind of heavy because the rubber is 2-3 times thicker than other tires. I think it is because they used this as the initial tire before cutting treads for different patterned tires. I bought other slicks from another ebay seller, and the tire carcass is much thinner.

Cons:
With 4 tires that are heavier than standard tires, it makes up for rotational mass, thus acceleration is reduced. The tires are thick, so they aren't as supple as a thinner walled tire carcass. The profile is rounder than say a competition USGT tire, which makes for less sideways grip.

Pros:
Very inexpensive for a set of four, $5-7 (shipped with rims and foams). Durable, because the tire is so thick, they last a long time, perfect for bashing. After 5 packs, I see very little wear. The durometer (hardness) must be higher.


I will say that the USGT tires turn WAY better. But for a basher tire, with the throttle pinned, who cares.

4roller

Do the Austar Pirelli tires wear well? how long do they last? I am thinking about getting a set since I have so many extra rims now.

haplm

They are reasonably durable. Definitely more than I would expect. This is the tire after few hard runs on tarmac:



Just keep in mind that my car is ±250g lighter than the standard XV-01, and I have an undergeared motor ;-). With your gearing, it might be a very different story, as the tire is sort of soft...

BTW - I've just started feeling like a tire collector. These are 2 new tires in my collection (on top of like 10 others I already have):



Both are VR Tyres, left are medium compound pins, right is soft rally block. I'm getting ready for a weekend race, so I will let you know how they perform once the race is over.

I have also ordered Kyosho 26mm Rally Tires. They look like HPI Pirellis, but with more spacious pattern. I hope these could actually work on mix of tarmac and gravel. However, since they travel from Korea, I won't have them before the race season is over. So I don't think I will be able to properly test them until next year (for which occasion I will finally buy HPI Pirelli S compound).

4roller

Today I installed the Tamiya TA06 one way 18t pulley on the XV-01



I decided to install the one way pulley on the rear end since this would allow the belt to come to a complete stop and the one way bearing to spin in its place. Rather than having the belt spin if installed in the front, this makes for less drag.

Summary
This set up produces 4 wheel drive while power is on. Off power, the rear wheels are freewheeling. When braking, the setup only utilizes the front wheels to slow down. Reversing, front wheels drive.

What are the implications for such a set up? So far from testing in a small area, the following is what I have observed.

Front wheel drive while in reverse
No big deal, we hardly ever drive the car in reverse, right? Reverse acceleration is slower because there is less traction.

Reduced braking power
Only the two front wheels are actively resisting motion when braking is applied. By only having front brakes, your braking is reduced somewhere between 20-40%. Front wheel braking is far more effective than rear wheel braking. However, coming from 4 wheel braking, stopping distances are increased.

Increased off power coasting
When the vehcile is coasting, the car travels further than it would in the standard 4wd setup. The rear wheels maintain their momentum, unaffected by motor's magnetic drag. This may cause push in corners.

Increased acceleration when starting from coasting
A surprising increase in acceleration is felt when throttle is applied when the car is already coasting. The rear wheels maintain their spinning momentum, when throttle is applied, less energy is required to bring all 4 wheels up to speed, resulting in a very direct a deliberate jolt of acceleration over the standard 4wd setup in the same situation.



This is not rear wheel drive car Here is an image of off power coasting. You can see the front wheels have already stopped rotating, while the rear wheels continue to spin.