Kyosho Big bore tapered pistons

[Nick]

Now available Kyosho Big bore taper pistons! I have a couple of sets out on test at the moment with Tobys & NJC11 on her. Toby ran his FS2 yesterday at NDOR mid east regional which is a low grip astro track very bumpy with very large jumps! I believe he ran 5 holes 1.3mm front with 5 holes 1.4mm rear car looked real good all day.



http://www.gurnellrc.com/ForumImages/Pistons/Pistons.jpg


There is a choice of 3, 4, 5, & 6 holes pistons with 1.2 mm,to 1.65mm holes in 0.05mm steps.



Please PM me if you are interested in purchasing a set. I’m selling then at £6 a pair with free postage but as they are made to order, please expect delivery in approx 3-4 days for delivery.

http://www.oople.com/forums/images/misc/progress.gif

[chricke]

it seems like i cant send you a PM (0 messages in sent)
but i want to buy 4 pistons from you!

[Nick]

i sent you a pm mate

[Nick]

Hi all just to say all orders have been packed and are in the post tomorrow! Also I have sent some out for testing to the Uk team so some setup should start to come through with the big bores in the next couple of weeks.
:thumbsup:

[Nick]

Hi just to say thanks for the orders and they have all been posted at lunch :thumbsup:

[quarter throttle]

remember to bring me a set to worksop tomorrow ;)

Ash

[Nick]

Just to say all pistons ordered before 11 last night have just been posted:thumbsup:
Many thanks for the orders and happy New Year

[Nick]

All piston orders have been posted. See you all at area 51 guys :thumbsup:

[RudeTony]

Highly recommended by all the Kyosho Team

[RogerM]

Nick, I hope you bring some spares with you.

I am impressed by the quality of them and they are definitely getting the job done!!! :D

[DJFlyinbin]

Do you do tapered pistons for the small bores too?

[Nick]

sorry no only big bores at the moment

[Nick]

Hi all just to say all orders have just been posted:thumbsup:

[mikeyscott]

Hi

What are people using these days?

I am trying 1.4 rears which feels good

[Nick]

I have been selling a large range of sizes! i think on the 4wd 1.3x5 front 1.4x5 rear still seems to be most popular

[RogerM]

Nick,

did you get my e-mail from a few days back???

1.3x5 & 1.4x5 will work just about anywhere in my experience but I am playing with a bit more pack in the front at the moment and liking the 4x1.2 option with circa 37.5wt oil.

I am still experimenting with the rear of the 4wd but am struggling to get much better than the 5x1.4 option ..... maybe that's just where the balance point is at! Will keep everybody updated as I find better options (Assuming I do)

For 2wd I am currently 4x1.4 at both ends of the car running 35/30wt oil Fr/Rr.

All oils are AE by the way.

[mikeyscott]

I need to order some 5 x 1.3 at some point.

I'll also check out the 4 x config for the Vega etc.

I'm running Losi oils, which I think are thicker.

[Nick]

Hi all! All orders was posted out last night :thumbsup:

[RogerM]

Even my monster shipment mate?

Seriously though, Nick is sending me a vast selection and myself and my merry band of helpers will get the big bore shock setups sorted out before the season starts :)

[Nick]

Sorry Roger yours are going through this week :thumbsup:

[RogerM]

No worries mate, plenty to work with this weekend anyway ... we are nearly there with the Lazer anyway :D

[Windy]

Hi guys

Is anyone getting closer to a definative setup for the big bore shocks? Also are the tapered pistons a nice to have?or do they improve the shocks even more?

Cheers

Windy

[RogerM]

They are not essential but they do allow you to run a bit more roll control via damping without slowing the "squaring up" of the car out of the corner ... it is possible to go too far with the normal pistons and get a fair amount of over rotation.

I have a crew in place and am working as fast as we can to get something for the "typical" driver to use as a starting setup ... all set ups need a bit of personalisation to individual drivers IMHO.

The problem we are having is the weather, it's so cold it's hard to know if what we have ATM will still hold true when the temperatures turn positive again!

[Nick]

Hi just to say all orders have been posted. Roger yours are almost donehoping to post tomorrow:thumbsup:

[NitroArgi]

It seems to me that the Lazer is pretty much dialed with this tapered pistons combination....what about the RB5? Any testing in rear motor on outdoor tracks?

[njc11]

Im back messing with the 6 hole tapered..

FS2

Front - 6 x 1.1mm 37.5wtAE yellow spring (1.5mm spacers to reduce droop)

Rear - 6 x 1.2mm 30wtAE red spring

Other pistons set up is front 4 x 1.4 40wt Yokomo green, Rear 5 x 1.4 30wt red spring

MCS

Front - 5 x 1.3mm 40wt Red Spring

Rear - 5 x 1.4mm 32.5wt red Spring

Also running the car with an unpinned slipper.. made it much better in rd4 at chadderton at the weekend... took abit to get used to it mind and still am lol! unpinned for worksop/chadderton lots of surface changes with ripples, jumps etc.. Pinned - flat/smooth grippy carpet.. :thumbsup:

[mikeyscott]

I haven't tried the unpinned slipper yet and certainly something for me to think about when I get time.

Also need to re look at tapered pistons again as I'm back with standard at the mo.

[RogerM]

It's going to be a matter of personal preference and track surface but I've found outdoors that the 4x1.2 and 6x1.2 are both too high pack to reap the benefits of the big bores.

We (Adam & I) finished sunday on Fr 4x1.2/32.5wt AE/ Losi Green spring, Rr 6x1.2/25wt AE / X-gear red (or Losi Yellow), that is with LAW43 on the back.

Based on the feel we need to go slightly larger holes and up in oil, not 100% sure where we will end up but we are closing in!

Nick, I think the pistons are waiting for me, I've got a "signed for" ticket last night but I was way too late to get to the post office. Will let you know.

With the 2wd I must admit that I am less certain we have identified the optimum working area.

Will keep you posted.

[adam_u]

We (Adam & I) finished sunday on Fr 4x1.2/32.5wt AE/ Losi Green spring, Rr 6x1.2/25wt AE / X-gear red (or Losi Yellow), that is with LAW43 on the back.

It was actually 30wt AE front and 25wt AE rear with pistons as above that we ran in the final - we noticed some inconsistency in the AE oils as Rog was using the older bottles of AE for the 30, not the newer twisty-spout ones meaning that his was a little under damped up front and was a bit of a handful - car felt really soft on the bench but it was really responsive on track, albeit packing up a bit too much over the big ruts and bumps - less piston/heavier oil to achieve the same sort of feel should be pretty good :thumbsup:

[/tobys]

I've found that unpinned seems much more consistent over bumps etc - especially if you need to steer through them. I found pinned felt faster but was certainly more inconsistent and more difficult to drive = slower lap times. I also felt you could get the power on earlier unpinned, especially in bumpy sections.

Rog/Adam - does your FS2 BB shock setup stop the front rolling about so much? I've gone back to using the Front Roll bar to keep the front in check around the twisty sections.

Nick - are you running LAW43?

[njc11]

Yep im running LAW43...

Will be playing with shocks at worksop on sunday.. will let people know

:thumbsup:

[RogerM]

Toby, the higher pack front end and the change (shortening) of the front camber link does help control the roll.

We are not quite there with the piston combination yet as Adam states but are getting there.
I deliberately put the setup I did as I felt it was better at normal temperatures than what we ran in the finals of the freezing Kidderminster meeting it Adam was refering too.

As Adam also said I personally feel that both pistons pack up too quickly on a rough track for my tastes so will most likely be going up slightly on piston hole area.
As soon as the piston arrive from Nick I will get stuck in .... need to speak to Mr Caro about bulk discounts on shock oil LOL

[Nick]

Hi all just to say thanks for all the orders. They have all been sent :thumbsup:

[RogerM]

And I must say thank you for filling my parts boxes with pistons Nick .. they are getting everywhere!!! :D


I've been doing a lot of work with these pistons recently and I can say I am getting seriously close to achieving, my interpretation of, perfection with the FS2-sp running some of Nick's pistons. Will post it up here once I have had a few more drivers try it out and feedback.

The tapered pistons really do seem to transform the response of the big bore shocks and I now have a car that not only handles like a dream but feels alive and responsive too, it actually feels more direct than on my old small bore set up but MUCH more consistent.

The only unfortunate thing is that the extra volume in the shocks, although bringing potential benefits, makes them a fair bit more sensitive than the small bores which will mean you you probably will want to carry 3 sets of front and 3 sets of rear pistons with you to suit all track conditions (from smooth flat + big jumpa carpet tracks, through "typical" multi-surface off-road to "surface of the moon")

[Robocop]

Any more info on the pistons,ran the car yesterday car felt good but a little to slow response other rb5 running small bores

[RogerM]

I need to check a couple of measurements off a VEGA but I was running 4x1.4 front (35wt AE oil & losi orange front spring which is very close to X-gear gold) & 4x1.45 rear with x gear red springs & 30et oil. I was definitely up on pace compared to small bores & could monster c4.1s & cougars through the rough stuff. Played with pistons a lot and settle back to these every time as great balance of pack/response/bump handling

[Gayo]

OK, after reading so many good things about Nick's tapered pistons, I bought some to try. Crazy fast postage BTW, thanks mate!
But so far I get a really soft damping, is that normal?

Here is my setup :

MCS with Kyosho BB : 3x1.5 holes on front (40WT), 3x1.7 holes on rear (32.5WT). Damping is really soft, I think I would have to use something like 50/45WT to get the same feeling I had with the stock pistons and 40/30WT shock oil.
I also tried with 5x1.3 on rear. Slightly better but still too soft for my bumpy grippy astro track, the car is tossed on every corner. Damping is good for the bumps on the straights though, the wheels reacts really quickly and follow the track ripples nicely.

Same thing with my FS2 with Kyosho BB. 5x1.3 (40WT) on front, 5x1.4 (35WT) on rear. The car is too soft, crazy reactive to steering and throttle inputs.

I checked the pistons to see if something was off, but the holes are of the correct, specified size, and the piston diameter is only 0.05mm smaller than stock parts.

So am I doing something wrong? Or is it my track and driving that need more damping?
Any help welcome. :)

[njc11]

On my MCS im using Front 5 x 1.3 42.5wt Red Spring, Rear 5 x 1.4 32.5wt Red Spring

FS - Front 35wt 6 x 1.2mm Yellow Spring - Rear 6 x 1.2mm 27.5 wt red Spring

:thumbsup:

[mikeyscott]

On my MCS im using Front 5 x 1.3 42.5wt Red Spring, Rear 5 x 1.4 32.5wt Red Spring

FS - Front 35wt 6 x 1.2mm Yellow Spring - Rear 6 x 1.2mm 27.5 wt red Spring

:thumbsup:

I will give these a go for the FS :thumbsup: as at present I'm getting on better with the small bores.

[njc11]

Be prepared to go up 2.5wt and up one spring rate to Orange

Let me know what you think

:thumbsup:

[sime46]

Small bores rule.

[SimonW]

I've finally decided that 2x1.3 and 2x1.4 per piston is what i will use in my vega front and rear. After filling 1 of the holes in the stock 5x1.3 and not changing the oil weight a quick bench test felt a little too stiff ( pack) and too slow but only just for my taste, on the track the car was alot better than with 5 holes. Past experiences with shocks i thought the 4x1.4 will be close but a little soft so i went for the mid point. HTH's

[RogerM]

Right guys, I am still not in the position where I can say that this is definitively the best setup for either car but we have now put something like 30 hours running (our poor cars would be destroyed by now if any other brand) and 75 hours at the track tinkeing and have settled on the following as the starting base setups for each ... although this may evolve over the next few weeks as we get more and more feedback from other drivers. We have had 28 different pistons to work through and drained about 12 bottles of shock oil between up even being methodical about our testing order. All testing has been done against the clock and so isn't what feels fast it is what is fast (for us at least).


2wd (Scorpion & VEGA tested, sadly no MCS available but I can't imagine it to be far off ...)

4x1.40 front (35wt AE oil as a starting point and tune from there, remember 2.5wt is a big step on the big bores), X-gear Gold springs with staggered ribs / minispikes, Reds with minipins. That is shocks out on wishbone and mid on original tower
For those running Losi springs that is Orange
4x1.45 rear (30wt, 32.5 if you like a livelier rear end) and X-gear red or Yellow springs depending on how much rear roll you like form the car.
For those running Losi springs that is Pink.
That is shocks inside on wishbone and middle on Scorpion stinger tower, 1 in from outside on Vega.

Because the stock RB5 runs much more inclined rear shocks than the mid motor cars I would expect that you will be wanting to reduce pistons 4x1.4 and maybe even then still go up 2.5wt in the oil. Sadly we have not had the opportunity to do much testing with a rear motored car.

I tried 3,4,5 & 6 hole combinations but to get the front end geometry to really work and feel alive, responsive & stable at the same time you need to have a little bit more instantaneous roll than you can get with 5 or 6 hole pistons but not as much as 3 hole pistons give you.
I hate to think how many combinations we put across the cars to arrive here but each time we moved from the 4x1.40 fronts we found ourselves back there a few logical tuning steps later. The rear sort of followed the progression of the front end tuning with the key objective being balance, that said we worked all around the various combinations in that region and kept coming back to the 4x1.45.


With the FS2-sp it was just as mammoth task but at least we had the 5x1.3/5x1.4 setup to use as a base line from last season and the 4x1.2/6x1.2 setup we settled on for the big jump strewn indoor carpet tracks.

After much work it became apparent that the front and rear of the FS2 are so superbly balanced that you didn't have to push one far away from the sweet spot before it started to show up very apparent weaknesses in the setup. That is great because you can get almost instant validation to a change at one end of the car.

Up until yesterday evening I would have said that I was happy with the setup as we finished with it a couple of weeks ago but Nick sent me through some extra pistons to try based on the requests & feedback I'd given him earlier in the week. Cutting a long story short a change of front pistons highlighted that we were too soft at the rear, a couple of hours tuning time later and we had a car that was fast, confidence inspiring and a pure joy to drive ... even let you get away with the odd wheel on a track marker type error at full speed without getting unsettled.

Front 5x1.2/35-37.5wt AE oil with a Losi Green spring (mid hole on front wishbone), 3rd in on tower
Rear 5x1.35/30wt AE oil X-gear red or yellow rear spring (or Losi Pink which is similar to X-gear yellow) inside on LAW43 and middle on tower.

Now I am convinced by the above setup but there were only two of us at the track last night testing and light was failing so I have nobody else to get an opinion from other than what they saw. The comments I got back where that the car looked to be stable and stayed relatively flat throughout the lap and it was certainly quick on the clock too.
It is great over the bumps (with ride height set 18 to 19 ... use 19-20 if track is REALLY rough) and just holds it's line no matter what the surface throws at it.
Be warned, this setup generates a LOT of steering and as such you might find its a bit of a handful until you get used to it then you will love the fact that it will turn inside any other 4wd car out there, nothing will be sneaking up the inside of you in a final for sure :)
If it is too much all that should be required to calm the nose a little is to stand the front shocks up one hole and/or go up 2.5wt in front oil (try all combinations to find what suits your driving style).
I know I have said this repeatedly but it still holds true, IMHO the Lazer FS platform is as close to perfection as a 4wd car can be.


As I say work is still continuing but I believe that both of the above setups will give very good starting points for your own individual tuning.

I hope to be writing a full breakdown of the trials very soon and hopefully there will be a full on article covering damper tuning on oOple soon ;)

[Gayo]

:thumbsup::woot::thumbsup::woot::thumbsup:

We have had 28 different pistons to work through and drained about 12 bottles of shock oil

Now that is nuts :lol:

I will try your findings ASAP, now where is Nick?:lol:

[njc11]

Sounds good Roger... :thumbsup:

Im racing tomorrw, just MCS though, so may if i have time try your shock settings!

:thumbsup:

[RogerM]

Nick,

been trying to find time to give you a call all this week but life has been chaotic .... not helped by all the testing LOL. Will try to get hold of you tonight buddy.

[RogerM]

:thumbsup::woot::thumbsup::woot::thumbsup:



Now that is nuts :lol:

I will try your findings ASAP, now where is Nick?:lol:

Well the other options were either guessing or not bothering at all .....

To my mind you either do a job properly or not at all :thumbsup:

Now, remember that I am not on the pace of Kev Lee's etc. BUT running those settings on the 2wd last weekend I was able to monster all other cars through the rough stuff and wasn't loosing out anywhere on the infield sections and my times through the runs were very consistent and faster than those I am normally racing for places. I do however need to remind myself that no run is improved by over driving the first lap .... my ability to stick it on it's roof on the out lap was the only thing more consistent than the other lap times :woot:

[Nick]

Hi just to say thanks for the orders and the have all been posted :thumbsup: Also if anyone need any at the national i will have some with me! See you all at the weekend.

[RogerM]

Hi guys, just a quick update. I've had the week off work and have made it out a couple of times to try some more stuff.
The short story is that I keep coming back to the shock setups listed above, there are other combinations that make the cars feel easier to drive but all seem either slower or less consistent against the clock.

I have found with the above setups all that I am changing for different tracks / conditions are;

Inner ball stud spacing (typically starting at 1mm both ends on the Lazer, 5mm [use the ball studs with the 2mm shoulder to prevent them pulling out] front & 2mm rear on the 2wd)

Upper shock mounting position (in when more roll needed, out when less wanted)

front hub height (run the front AXLE low for buckets full of front end bite, axles up if you want to calm the car down) ... this is a powerful tool, especially on the FS2!



Just to clarify the rear shock tower position on the 2wd; they are mounted at distance apart that is equivalent to the width between the middle holes on the Lazer rear tower.


Hopefully that will help some of you ... lets put the small bores to bed for good ;)

[Nick]

Hi all just to say thanks for all the orders and they have all been posted

Also many thanks to Roger for all the hours of hard work on the shock setups for everyone to use! So far I have heard very good reports about how good the setups are.

Also i have just swoped to a RB5 Vega so will start working on setups as well as soon as i get a set of big bores for the car.

[RogerM]

Nick I will be in touch over the weekend to discuss VEGA big bore setups.

More testing tonight, maybe tomorrow as well ... we aren't standing still on making the big bores quicker around a lap than the small bores .... for me they already are, significantly so!!

[Honeybadger]

So which way are you meant to mount the pistons in the shocks?

Tapered side up or down?

[RogerM]

tapered side down :)

[Honeybadger]

tapered side down :)

Thanks Roger, I'm on it now. I'll get the Laser out for a blast in a bit. :thumbsup:

[Nick]

Hi all just to say all orders have been posted out yesterday :thumbsup:

[RogerM]

Just a note to say that in the brief spell of warmer weather we got I found both cars were a bit too soft on the oils quoted above and ended up +5wt in the front of both and +2.5wt in the rear of both.
Still sure I have the best piston combination in there for both cars.

Going to do a few runs with the DB1 on small bores to get a feel of Kev's set up then will start working on a big bore set up for her.

[tomtom]

Going to do a few runs with the DB1 on small bores to get a feel of Kev's set up then will start working on a big bore set up for her.


You got me interested ! :drool:

[RogerM]

Some extra testing has suggested that a higher pack setup works better on the 2wd cars (still happy with the Lazer setup once the oil grades where upped a little when the weather warmed up).
Will post details of the revised setups once they have been properly tested by a couple of different drivers.

Work has begun on the DB1 setup.

[Rebelrc]

tapered side down :)

Makes absolutely no difference at all, fact!

[RogerM]

Makes absolutely no difference at all, fact!

Absolutely incorrect I am affriad ... that is how they work, all about the change in effective section along the length of the hole. It's a very common flow biasing tool used in many different engineering genres.

[Rebelrc]

Sorry Roger I ment
It makes no difference at all to pack and rebound speeds:)

[RogerM]

No it does make a difference.

The area of the hole on the flat face (which is of course circular) is smaller than the area of the hole on the tapered side (which is oval). Although a little over simplified you can think of it as a change in speed of the fluid as it passes through the hole.

From big hole area to small hole area the fluid will have to speed up (same volume displaced, smaller area for it to flow through at the exit so it has to travel faster to get through in the same time). This change in fluid speed changes the point at which the shock 'packs up' relative to the other direction.

With the tapper down effectively the pack point on the compression stroke is lower / earlier than that on the return stroke. This is also exaggerated by the fact that in use the return stroke will always be slower / lower energy than the compression stroke due to the balance of forces (this is also the reason you can't accurately gauge the pack point by bouncing the car on the table ... you need to drive it as you will never bounce it as fast as the suspension tries to move when hitting a bump on track).

Tapered pistons mean that you can get a faster return Vs. bump stroke thus allowing you to use more pack than you could normally without slowing the direction change down as a parallel bore piston would ... with is why I say for our tracks tapered pistons are essential to get the performance out of the big bore shocks.

There are lots of design considerations around pistons (even in our relatively crude rc shocks), they are far from a flat disc with a few holes in :)

Nick's pistons transform the Kyosho big bores, try the same piston sizes in straight and tapered back to back on the same track, same day same car .... I have a couple of piston related things I am working on which I will be talking to Nick about soon ;)

[Battle_axe]

surely though this all works the wrong way arround you want really fast up travel in the shock and to be able to control the rebound. in reall life the last thing you want is any kind of pack or lock up i think the mip pistons are the propper way to do this

[RogerM]

We control roll AND big jump landings with our shocks and the cars use quite a large percentage of their suspension travel just in roll in a normal corner ... if they returned slowly it would take an age for the car to return to center let alone start rolling the other way.

Have a think about what we are trying to achieve with our very simple shocks and how our surfaces and track designs affect the car differently to say a 1:1 rally car.

[discostu]

We get what you mean roger however I would say the shape of the piston is forcing more oil around the piston rather than though a very slightly oval hole and this is why they seem to rebound quicker. Ive also done some back to back piston runs they both produced pretty much the same lap times but the tapperd IMO feel less consistant.

I would say don't waist your money on tapperd pistons unless your are at the top of the time sheets where those drivers can really tell the difference.

[Neal]

Hi Nick,

can i please order a tapered pistons set (4 pieces) for 1/10th kyosho big bore shocks?
with 4 holes of 1,3 mm each please..

can u please pm me? your mailbox is full...........

[danmurphy]

Also trying to get in touch with Nick for some Kyosho big bore tapered pistons but his message inbox is full :(