Yokomo YZ-2

[Zahir144]

Thumbs up for MB Models. They were the only store that I could find online that had the YZ-2 (and supporting spare parts) readily in stock this week. There's little benefit in having rock-bottom prices but limited or no availability.

On a separate note, has anyone else noted the not insignificant amount of 'play' that the front (black anodised) hinge pin brace has between its location and the front bumper on the YZ-2? If not, perhaps it's just me.

[PaulRotheram]

Mine has a little play, but its not important. it's there for strength on a hit to that would affect the bulkhead.

[Plasmag]

What springs / oil for shocks would you recommend for running on carpet and then astroturf?

[Ashlandchris]

I have set mine up exactly as kit standard and I have to say it is awesome.
I run it on slippery indoors (Batley and Cullingworth), high grip carpet indoors (Manor), and sandy astro outdoors (Batley / Spenborough).
Except for changing tyres (mostly Minispikes or minipins - Yellow) I find the set up awesome.
I bought 2 extra sets of springs to allow me to either stiffen or soften the shocks, but so far there has been no need to even undo the packaging.

Never had a car like it for "straight from the box".

[ralphee]

Did something bonkers on mine for last nights meet. Went back to kit springs front and rear after a shock rebuild, 450 front oil, 400 rear, and, decided to man up and fit the geared diff.
Initial punch was a bit high on my first outing, with the geared diff aggression it made it way lairy, so i knocked the punch down for the next heat, and bam, car felt great, went where i wanted it, much more mellow, and managed 4th in the A final, albeit a scruffy final for me.
Rear was rolling a tad when the grip came up though, so may need to tinker with rear springs.
Wanted to ask, any tips on limiters in the shocks for carpet, does seem to have a lot of droop in kit?
Anyway, a bit of a back to the drawing board meeting with it, but a good step in the right direction,think ill be sticking with the gear diff now, car jumped like a beast too!

lee

[Allan1875]

Originally Posted by ralphee

Did something bonkers on mine for last nights meet. Went back to kit springs front and rear after a shock rebuild, 450 front oil, 400 rear, and, decided to man up and fit the geared diff.
Initial punch was a bit high on my first outing, with the geared diff aggression it made it way lairy, so i knocked the punch down for the next heat, and bam, car felt great, went where i wanted it, much more mellow, and managed 4th in the A final, albeit a scruffy final for me.
Rear was rolling a tad when the grip came up though, so may need to tinker with rear springs.
Wanted to ask, any tips on limiters in the shocks for carpet, does seem to have a lot of droop in kit?
Anyway, a bit of a back to the drawing board meeting with it, but a good step in the right direction,think ill be sticking with the gear diff now, car jumped like a beast too!

lee

I'd stick with kit droop and harden your springs.

[ralphee]

Ill stiffen up in moderation then, thanks Allan, reckon Yatabe Orange would have been the ticket but lacked the time to change running two cars, ill try it next week.

lee

[Zahir144]

First impressions: a really good buggy. I ran the YZ-2 (my first foray with 2wd) with Yatabe black & yellow springs at Swindon earlier today on a slippery astro track and it went well. Looking forward to racing at Mendip for the first time next Sunday.

[MHeadling]

Has anyone tried the rear roll bar on astro/carpet??

[adey]

Originally Posted by ralphee

Did something bonkers on mine for last nights meet. Went back to kit springs front and rear after a shock rebuild, 450 front oil, 400 rear, and, decided to man up and fit the geared diff.
Initial punch was a bit high on my first outing, with the geared diff aggression it made it way lairy, so i knocked the punch down for the next heat, and bam, car felt great, went where i wanted it, much more mellow, and managed 4th in the A final, albeit a scruffy final for me.
Rear was rolling a tad when the grip came up though, so may need to tinker with rear springs.
Wanted to ask, any tips on limiters in the shocks for carpet, does seem to have a lot of droop in kit?
Anyway, a bit of a back to the drawing board meeting with it, but a good step in the right direction,think ill be sticking with the gear diff now, car jumped like a beast too!


lee

Yes Lee, it was very difficult to get the power down cleanly. Still, at least i got it round faster than Birdys xray lol

[Cosworth]

Should come to Midlands Raceway. Jamie will help you out with all your Yz2 needs

[ralphee]

Originally Posted by adey

Yes Lee, it was very difficult to get the power down cleanly. Still, at least i got it round faster than Birdys xray lol

You were only a lap off your fastest time with your hybrid i think Ade, on a car you had never driven before on pretty much kit settings, just 4mm of Ackerman spacers haha, so you know it can be quick, and its not all that punchy after i turned that down some.
Ive stiffened it up some for friday, see where that takes us.

lee

[discostu]

Mark

Yeah I tried one and felt the car doesn't need it but saying that certain tracks it may come in hand

[timoxx4]

Whats the idea of 4mm of Ackerman spacers ? Dosent that make the steering more aggressive ? I would have thought 0mm Ackerman spacers would be the go ? To calm things down.

[Allan1875]

Originally Posted by timoxx4

Whats the idea of 4mm of Ackerman spacers ? Dosent that make the steering more aggressive ? I would have thought 0mm Ackerman spacers would be the go ? To calm things down.

No, 4mm = less aggressive.

[timoxx4]

Originally Posted by Allan1875

No, 4mm = less aggressive.

Hmm, I have always thought moving BACK on the Ackerman is calmer steering. Kyosho RB6 guys will know all about this.

So how is it opposite on the YZ-2 if someone can explain that would be fantastic as I just don't get it?

[Allan1875]

Originally Posted by timoxx4

Hmm, I have always thought moving BACK on the Ackerman is calmer steering. Kyosho RB6 guys will know all about this.

So how is it opposite on the YZ-2 if someone can explain that would be fantastic as I just don't get it?

Hi mate,

Confused over this now as I 100% agree with what you are saying and on my BMAX4, further forward = less ackermann, which is more aggressive.

I read somewhere ages ago that when shimming a bellcrank it was the opposite way round but now that I have been sitting thinking about it, not sure that actually makes any sense? Been googling frantically to try and find what I read ages ago but with no luck.

When I go home tonight I am gonna stick it on the workbench and change it and just view it by eye, it will be the easiest way! If I do find it before I finish work today, I will post it up here.

One thing I will add, is that ackermann is obviously dependant on the angle of the steering arm. Every car will be slightly different depending on kit standard setup. If anyone has anything to add, feel free as this is going to do my head in until I get home tonight.

[Allan1875]

So, I just spoke to Lee Martin as this was bugging me.

He confirmed that for the 2wd, it is opposite. Further forward = less aggressive.

I am still going to mess with this at home, can anyone provide any further info or find any documentation on this? I noticed you mentioned the RB6 above, what was the story with this?

Edit: Just been thinking about this more and the only difference can be the mounting point of the inner ball stud in relation to the ballstud at the wheel and the angle, or lack of which creates this difference. I think parallel is more ackermann and less aggressive, where as the link more angled is less ackermann and more aggressive.

I'm really not going to be satisfied until I get home tonight ha!

[RichyUK]

I believe its because the 2wd crank pivot point is in front of the rack, where as a 4wd is behind.

[timoxx4]

Originally Posted by Allan1875

I noticed you mentioned the RB6 above, what was the story with this?

Yeah the RB6 has a ackerman plate that everyone was reversing to place the ball studs back more to calm the steering down as its a rather twitchy car to begin with. I pushed mine one step further and made a alloy one on the milling machine that placed the ball studs even further back and it made the steering even more settled down.

I also race 1/8th nitro buggy Mugen MBX7R and its the same. Ackerman links back = calmer steering. Its just how those particular cars work I guess. And I have just always thought that's how all cars react to ackerman changes in the same way but I guess it can be opposite.