XRAY - Model racing cars

Hi,

Firstly is the picture on the website the right way round to mount them? i would of thought the taper would be facing upwards?
I tried the new pistons at the weekend, 1.3*8 hole with schumacher 50wt oil which should equate to around 600 cps(?) and grey spings which i think is pretty much the same Bren Ralls clanfield setup i think, i found that the damping was far too soft and the car was bottoming out very easily, this was at pendle which was hard packed soil and while the track isnt blown out its isnt smooth either.
What would be the first line of attack, up the oil thickness or 1.2*8 holes?
Given that changing the oil is easier than changing the pistons, i would assume oil first however what sort of affect is changing the piston verses the oil?
Basically im looking for more pack would even going back to the old pistons be better?
These pistons did feel better on the smoother areas but bottomed out to easily over the jumps.

My personal idea of shock tuning direction would say to go to a smaller hole piston. I look at some of the setups that guys are running with the 6-hole 1.4s and I have no idea how they drive the cars that soft. I currently run the 6 hole pistons with the optional 1.2 in the front and the 1.3 in the rear.

As for the 8 and 10 hole pistons I am not sure because like many of you. I didnt even know they were coming out till they were released on the website

Can someone explain the advantages of the new 8/10 hole pistons?
What is the difference in performance to the 6 hole pistons, because I can generate different pack-effects with the standart pistons as well?
So in my opinion it is the same effect for example with an 6 x 1.4 and an 500 oil compared to an 8 x 1.3 with 700 oil.

Please tell me if I am wrong!

Greetz

Markus

This is curious. I guess its so sme racers can use really thick oil.


The 1.1x10 pistons should be the cats meow. Offering tons of pack but still be plush over the small bumps. The 1.3/1.4x8 pistons don't look like they're going to offer anything we cant allready do with the 6 hole pistons.


When I had my AE Rc8 we were experimenting with the 1.4 hole pistons. They were too stiff in turns but had nice pack in jumps, maybe too much pack.

So we made 1.4 pistons with 2 extra holes drilled in them. 1.1 holes. When useing 30-40 wt fluid with 1.4 and 1.1 holes you'll be softer on small bumps and rebound will be quicker. But 1.1 holes do not flow fluid very fast on big hits. They have a ton of pack.

Since 1.1 holes flow fluid so poorly, I'd expect the 1.1x10 to work well with thin fluids to give good pack but soft suspension feel in the corners. Side effect: maybe too stiff for sharp edged bumps like speed bumps or washboards.

THX for the answer, that makes things clear for me now.
I think you are right, the 1.1 x 10 pistons are worth a try. Lots of pack but still smooth for bumps the only thing is if the rebound is still fast enough.
Does anyone know if they are already available in Germany?

Don't forget, the thicker the oil you use, the bigger the viscosity change when it warms up during a race.

Managed to try the 10 hole pistons today and they worked really well, 50wt in the front with silver springs, 40wt in the rear with the blue/grey springs, found them to be really supple in the fast sweepers and packed nicley on landings, tried the silver springs on the rear but found the rear just to bouncy.

Where can i get these 10 hole pistons? amianhobbies.com? Couldn't find them and they have alot of Xray parts. (don't say ebay)

Hi Bren, can you explain how to use the grafic, I don´t understand how they find the numbers, and how to use them .

Thank you !!!

few!! thought i was going mad in my maths so see how figures differed. Some interesting points on edges & how it alters pack, adds some more science to piston/oil choice. Cheers Razo for the info

Thats really interesting!

When i first filled the shocks up i used 60 front and 50 rear but the rear initially felt a bit harder than the front, that could be explained by the thinner oil offering more initial pack???

Awesome thread! Bookmarked it!!

I am getting a set of 8/10 holes tapered shock piston. Can some recommend a base setup (oil and piston) using this piston set? I am running the stock silver springs on short, bumpy grass track, minimal loose dirt.