502x on carpet - Rear end to loose

[Netmav]

Can anyone help me figure out how to get more traction on the rear end, when running a 502x on carpet?
First of all, I'm new to racing, so I don't have very much experience with this. But I think it must be possible, because I see the B44.1's going around our track with a lot more traction on the rear end..

Here's my setup (at least what I remember now, as I'm at work ):
Ride height at 21mm
Schumacher Mini Spike tyres (with the spikes cut off)
Losi 40wt shock oil and 1.3x2 pistons. Tamiya Blue springs (Front)
Losi 30wt shock oil and 1.4x2 pistons. Tamiya Yellow springs (Rear)
Front toe-out at approx. 1
Rear toe-in at 2
Front camber at -1.5
Rear camber at -1.5
The diffs are both at "medium" tightness

I have the "gold" HL aeration dampers, alu front castor hubs (12 deg) and the rear alu 1 deg uprights on the car as well.

If theres any more info needed, just let me know.

Any help/tips/tircks/suggestions are greatly appreciated.
Thanks.


\Martin

[Jamie.T]

Are you running lipos? If so are they in the most forward position as there's a choice of forward and rear?

Also, i always run the front diff a little tighter than the rear.

[muratti]

I´d try rear camber at only -0.5 or even 0. When i began racing this was new to me, i thought more neg. camber means more grip but that´s not the fact.

[jamiew]

I would try a set of mini pins instead of spikes also why do u cut the spikes off??

[Jan Larsen]

Yes, go for minipins. I usually have ever so slight understeer on my 511 (granted, not the same car, but same suspension) even with full pins. I only trim the most outer row of pins to make the car a little more predictable.

Also, if the track is indoor like smooth, drop the ride height 2-3mm all around.

[Fredrik Emilsson]

Originally Posted by jamiew

I would try a set of mini pins instead of spikes also why do u cut the spikes off??

Maybe not allowed to use them on carpet. Wears out the carpet.

[Netmav]

Hi guys. Thank you for all the replies!

Yes, I'm running LiPo's. Team Orion Carbon Pro packs, and they are in the forward position. I have no wheights on the car, btw.

I've tried the front diff a little tighter than the rear, but that didn't help much..

I'll try it with less rear camber on saturday, at our club meeting.

The reason for running cut off Mini Spikes is because that's what I found when I googled for what tyres to try.. (as I said, I'm new to racing..). That's also what most of the other cars are running in our club, btw.

I'll also drop the ride height, but that would require cutting the rear springs. Is this "normal procedure"? I only have Tamiya springs available now..

Jan: What's the reason for cutting just the outer rows of spikes? What does that do?

There's no "rule" against tyres with spikes in our club, and the reason I cut them was, as I said, that's what I tought everybody else is doing..

So you guys think that Mini Pins, or even un-cut Mini Spikes are better for indoor carpet racing, than the cut Mini Spikes? Interesting..

Thanks again.


\Martin

[kayce]

As others have suggested -
* Batteries (or weight) further rearward equates to more rear traction (fwd position is to gain steering). If you think about it, it's just common sense.
* Front diff should always be tighter (or rear looser), as it allows the front end to pull the car through corners. A comparatively too tight rear diff makes the rear behave like it has a locked rear-end, which results in oversteer (or back of car wanting to swap ends).
* Cars "can" vary from one make to another as far as what they prefer in tyres - so while mini-spikes might be the choice of AE cars doesn't mean they'll be the optimal choice for your Tamiya. If what everyone else is using isn't working for you it's not reason to keep beating your head against the wall - so like others said, try mini-pins (or maybe even try them just on the rear, don't be scared to mix-&-mismatch).
* The reason for clipping off the outer set of pins is to make the car rotate easier (opposite of the problem you're having), and to keep the tires from allowing the car to "traction roll" on high traction surfaces like carpet. If you're car is not grip-rolling in the corners, then you don't need to clip off the outer row just because everyone else is doing it.


My other suggestions would be to ask a couple of things -
* what motor combo are you running? - since, especially if you're new to racing, having too much horsepower can often be disadvantageous and adding to the problem of the car wanting to swap ends. So a milder motor choice might be a worthy consideration.
* do you have softer rear springs? - being as softer rear springs will allow the rear of the car to roll more in the corners and make it less apt to swap ends.

[Jan Larsen]

Originally Posted by Netmav

I'll also drop the ride height, but that would require cutting the rear springs. Is this "normal procedure"? \Martin

For some odd reason, Tamiya has made the rear springs too long to achieve correct ride height and never made any attempt to correct the error. Us people who've been racing the TRF cars for a while are used to it, but for newcomers it may be confusing.
Yes, you need to cut one coil off the springs. We then bend the cut area back into something that resembles the end of the spring bit you just cut off so it sits correctly on the shock. Hard to describe, much easier to show. The cut end must face upward towards the blue adjuster, NOT the spring cup.
I've also seen both Associated and Kyosho springs used instead of Tamiyas.
This only applies to the rear springs, the fronts are fine.

But first and foremost; tires. The minipins are leaps and bounds better than spikes on smooth carpet.

[Netmav]

I'm running a Speed Passion Competition V3 6.5R motor on a Hobbywing XERUN 120A V2.1 ESC. 19T pinion and 79T spur.

I believe the red Tamiya springs are the softest ones? I can cut them, and try them on. Maybe that helps.
Anyway, the first things I'll try is adding some weight at the rear, and loosen the rear diff a little. If that doesn't help, I'll try the other springs, change the rear camber and maybe the rear toe angle.

Thanks guys!


\Martin

[Jamie.T]

Stick 60-90G between the lipos and run cut yellow springs on the rear and you should see a large improvement.

[kayce]

Originally Posted by Netmav

I'm running a Speed Passion Competition V3 6.5R motor on a Hobbywing XERUN 120A V2.1 ESC. 19T pinion and 79T spur.

That is a LOT of motor, to be running indoors/carpet.

[kidcongo]

My club is in its winter season, which moves indoors to a carpet track. For rear end traction, the biggest gains i have found are by stiffening the front suspension, and softening the rear. I am running 30wt AE oil in the rear and 40wt in the front. Also have more camber in the rear and some added weights. I have had no problems with rear-end traction.

[Netmav]

Hi guys.
First of all, thanks a million to all of you for helping me out!

I was at the track for 8 hours on Saturday, and the first thing I did when I got there, was to add some weight at the rear (I only had some "stick-on" lead bits, so all I could fit was 21g), and I adjusted the rear diff.
Man, what a difference!! I didn't touch anything else the whole day, I just kept going around our small track faster and faster, and with a bigger and bigger smile on my face!
I did one more change, when I think of it. Last time I was at the track, I used Schumacher Mini Spikes with the spikes cut off, and Schumacher foam inserts. This time I also used Mini Spikes with the spikes cut off, but with Pro-Line Closed Cell inserts.

Ok, so back to the weights. What do you guys use for weights? I know Rudebits make a "LiPo tray weight kit", but is there any other options out there, or do I need to make something myself?

Thanks again.


\Martin