hookem34

iTrader: (17)

So I mounted up my 16mm pistons with the 2.5mm hole for my Kyosho shocks. They had to be threaded on the shock shaft, and ended up mounting crooked. I think the 2.6mm hole version is the better fit for Kyosho shocks.

Anyone else have this issue?

Imbue

iTrader: (1)

Dan,

I replied to your email, but I wanted to address the issue on the forums as well.

I apologize to those who may have had sizing issues. It's one of those teething issues, and I think we've got them sorted out now. Obviously needing to force them on isn't right. 2.6mm is the right ones for Kyosho. We've actually relisted all 2.5mm brands into the 2.6mm category. We had some issues with our sizings being wrong. We relied on some 3rd party measurements from a source we trusted, but they've been off on more than one brand.

I am really particular about having a piston fit properly. One option was to follow the current trend, oversize the center hole and just let the consumer live with the poor fitment. This was not acceptable to us, as it could cause inconsistent performance and uneven wear on the sealing band. So we opted to offer as many sizings as we can, so that your pistons will fit perfectly centered.

hookem34

iTrader: (17)

Thanks Todd for the email. Sent you a reply.

pickle311

iTrader: (31)

I finally got to test the pistons out today and was thoroughly impressed. Fit and fish were top notch. I noticed the movement was very smooth in the body. Setting the rebound was a bit different from normal. I'm guessing this is a result of the piston having an oring on the outside that makes contact with the inner wall of the shock body. That's ok for me though, I don't use much rebound.
On the track, I was blown away by the difference in my car. The track was low traction and dusty. I had been fighting all day to get enough traction.
As soon as I got up to speed, you could actually see the difference in the attitude of the car. Immediately I had traction. It made the car very responsive and predictable on a loose track.
I was running 35wt front and 30wt rear and it really felt good. I wanted to go up a touch but it started raining before I got to try it.
Overall, these pistons were a game changer for me in these conditions. People watching even came up and told me they could see a huge difference in my car and asked what I changed.
Now I need to try them on a high bite track and see how that feels. I'll certainly be ordering another set for my truggy.

hookem34

iTrader: (17)

I second that vote of confidence Sean! I ran the pistons in my K car and they were a marked improvement over the ever so popular 1.3x 8 hole pistons.

In this Texas heat I ran 525 front and 400 rear and the car was absolutely planted. The biggest difference was after large(ish) jumps. The car never bottomed and I could immediately get back on the power. Was also silky smooth in the ruts and off camber corners.

Thanks again to Todd for correcting the order so quickly and getting me the new pistons. Remember to order the 2.6mm holes for Kyosho shocks.

madweazl

iTrader: (12)

The piston is substantially heavier which should decrease how responsive it is to small bumps but it somehow is better through the small bumps but then provides more damping in areas that use more travel?

I'm just not understanding how this works?

Imbue

iTrader: (1)

It all has to do with weight and shock shaft velocity.

Over the rough, with a really responsive shock package, your wheels are going to try and follow the ground, up and down into and over every divot, rut and bump. This causes your suspension to work in overdrive and your car can become unstable as your suspension is going every which way to follow the terrain. With the heavier piston, your shock (and wheel) is obviously going to be moving slower, no matter what, causing the wheel to trail behind the bumps and divots. This allows the car's suspension to skip across the holes or from one bump to the next, instead of trying to follow every contour.

Over large jumps, the heavier weight increases the force it takes to compress. Very simple F=MA. If the force is constant (you're taking the same jumps in a buggy that weighs the same, etc), then the increased mass will slow down the acceleration. This creates the "pack" feeling. It's not real pack, it feels better.

razo125

Is there an advantage to having the extra unsprung weight on the pistons vs having them further out and down low on the hubs?

Imbue

iTrader: (1)

I really don't have an answer to the technical "why", but comparing them back to back, the pistons felt better overall, they felt more direct. The weights on the hubs seemed to make the car a bit lazier.

razo125

That makes sense, the pistons weights are higher and have a more centered CG vs the hub weights, making them feel more agile while the hub weights would feel more lazy. or stable I imagine each would be good tuning options depending on the track conditions.

I'm also liking the oring seal and different valving options.

speedy2

iTrader: (1)

Wonder if are there products that could degrade the o-rings, like fuel or the oil while cleaning the car ?

pickle311

iTrader: (31)

Why would you have methanol in your shocks?
I don't know what the compound of the orings are, but certainly there's something that will break them down. It's highly doubtful that it will be a chemical commonly used in RC Racing, especially inside a shock.

madweazl

iTrader: (12)

Left rear soaks up a lot of exhaust and I imagine that was his concern (mostly oil at that point though). Perhaps cleaning solvents during shock rebuilds? Nothing I've ever really been concerned with though.

Jaz240

iTrader: (52)

Silicone swells O-rings but I can only imagine that will just give a better fitting over time. I would think just like many other things on our cars it would be a good idea to change them every so often. Either way these pistons look awesome and feedback seems to be on par with that assumption.

speedy2

iTrader: (1)

the new Soar buggy uses the same pistons but in aluminium
and his handling seems great too