Yamaha Yamaha YXZ 1000 Chronicles?

[badassmav]

The way the lower front mount appeared higher than the rear lower mount I dont know if it would get to the point of going forward, but if my eyes aren't deceiving me I assume Yamaha did it for a reason. The front reminds me of what Honda use do to on their 250R quads angling the front control arms up in front about 5% or so. They sure handled nice.

Regarding the rear arms, the lower a-arm pivots on a tighter arc than does the upper arm, pushing the bottom point of the rear bearing carrier/upright outwards more than the top point during bump. This causes a negative camber gain, and counteracts the body roll while cornering to keep the tire contact patch flat. It appears that the lower a-arm connects to the upright using a double shear joint, which indicates that it locates the the upright, and therefore, the direction that the rear tire is pointing throughout the travel. From what I can tell in this pic, the relationship between the two a-arms will cause the rear wheel to toe outwards, while at the same time increasing the negative camber as it bumps. This will assure a car that over-steers into corners instead of under-steers, which makes sense because the last thing you want to give a novice driver is a car that under-steers. The consequences of losing control while cornering with this arrangement is that the rear of the car will most likely come around, backing you into the wall. Compare that to the front end pushing out, causing you to go head on into the wall. I'll take choice "A" anytime.

I believe you are already aware of what I am about to say, but I will include it anyhow for the benefit of those who aren't.
In the example of the front suspension on the 250R quads, the inclining upper arm would be for the purpose of creating caster gain as the suspension bumps. Positive caster is what causes your steering wheel to return to center when you let go of it after a turn. It is created in a front suspension by positioning the top ball joint rearwards of the bottom ball joint, relative to the direction of travel of the car. The effects of negative caster can be felt while backing up, where letting go of the steering wheel only allows the tires to steer sharper. Too much static caster set in a front suspension makes the steering feel heavy, and scrubs excessively while turning, causing excessive wear to tires and components. Just look at any old Ford twin I-beam pick up truck with its lofty setting of 5-8 degrees of positive static caster at ride height when turning the tires, and you can see the results of excessive caster settings. Not only is it seen through the wear pattern on the tread of the tire (an uneven wearing of the tread, otherwise known as "cupping"), but the inside tire literally lifts that corner of the truck off the ground by nearly an inch or so when the wheels are turned full lock. This is due to the massive caster. But, because caster inhibits the "return to center" characteristics of the front end, we need it for stability. With parallel mounted upper and lower arms, when the front end "dives" under braking, it causes the steering axis inclination (an imaginary line drawn in between the center of the top and bottom ball joints, referred to as SAI in the automotive industry) to rotate forward, negating any positive caster there was dialed in at ride height. If the static setting is minimal, the caster will become negative, causing the front end to wander more than one would like under braking. Inclining the upper a-arm pivot axis towards the front of the vehicle simply moves the upper ball joint rearwards as the suspension bumps, while the level bottom arm keeps that ball joint in location (fore and aft speaking). This causes the caster in the front to remain positive throughout the wheel travel with out excessive static settings. Positioning the upper arm as described above is also referred to as "anti-dive" geometry, and is built into most any modern day automobile, and all properly designed race cars.

I'm sure glad I didn't have to give that explanation out loud. I would have confused the hell out of me and you!

 

[badassmav]

Reid do you plan to get into racing? Building this car for an investor to race? You need a wheel man I would like to sit in the seat and give it a blast

Hey Adam! No racing for me! You know I'm not a willing participant. If I can't go to the races with beer and camera in hand as a spectator, I'd rather stay home. Besides, you know there would be beer coming out of every hole in my head after only a few miles of racing. I always hated having to ride in the car when we tested, but it was necessary in order for me to understand the car, and help set it up.
The short side of a long story is this: I am building the car for a friend who wants to campaign it with his son in select desert races next year. He's the investor of the equipment I will be using to fab up my junk. This is why I have not yet decided on how far to take the kit because they wont be able take 100% advantage of it , and I am also working on an all out kit for a RZR xp1000, similar to the one I built for the BAM, that needs to be done asap. It is what will be required to combat the RG Wildcat coming out next season. Now that's going to be one Badass ride! As delivered in stock trim, I bet it will be hard to beat in the right hands.

 

[badassmav]

Does anyone know if there would have been some kind of patent infringement on Polaris or Arctic cat if they would have used similar suspension mounting points? Maybe that's why they did what they did and then just fabricated up a story to sell it better.

Dimensionally similar mounting points by themselves would not constitute an infringement, unless the type and/or layout of the components used was similar (i.e. a trailing arm with one forward pivot that mounts to a rear wheel hub/carrier, with 2 rear lateral link bars as locating devices).

 

[Glamisfan]

Good point on the OEM design having springs that weight more then on your set up with the proper angle and motion ratio! I ran the 2 inch fox air shocks on my race rhino. I believe they weigh under 7 pounds apiece and I always loved that fact!
If I get one of these Yamaha's I'm going to do the keep it simple method. When I built my race rhino, I bought it for 11 grand and put another close to 9000 in it doing Molly cage and made my own long travel for it. I personally don't ever want to have to change Half of the OEM equipment to make the vehicle good enough for me again. Also, I sold the race rhino for $6300. Don't want to take that kind of a loss again. Even though I could build something like what you build and it would be nice to have everything perfect, i'm just not going to spend the time or money on a side by side like that again. Your builds do have my admiration, just as much as I admire what Geiser and Jimco build! If there's any way that you decide to build the long travel that can reuse the stock shocks I would be interested in purchasing that. Here's a couple of photos of my past builds. I built the pre-runner first using just an arc welder. Built the rhino in 2007. And I did airbag suspension on the back of my super duty a few years ago and I need to get off my butt and link and bag the front of it.

That last one is what the rear arms on the YX Z look like

 

[badassmav]

About the heavier coil springs, I want to say that I was running 150# over 250# on the front of Marc's Polaris racer, and I noticed when I was either at Queens, or at the UTVWChampionship races in Laughlin, that the stock shock lengths that Lonestar runs on their +3 1/2" kits (same width as Marc's)needed 300# over 450# springs to do the same job. That being said, you can see that the total loading on the shock mounts is much higher with poor motion ratios because of the higher spring rates to fight off the increased leverage. Now, were making beefier shock mounts as well ion order to handle significantly higher loads. There is definitely a multitude of considerations when keeping with the stock shock mounting positions. Too many consequences for me to want to deal with.

Yeah, those yellow arms that you posted are strikingly similar to the Yammy's. What were they off of?
Airbags, huh? Never tried wrapping my brain around running them. Once set up, the airbag on the prerunner must have been a pretty plush ride. It seems like the abrupt release of energy that a steel spring provides would be more instantaneous, and so much more violent than an airbag returning to its shape after a hard bump. Were there rebound issues, or problems keeping the rear tires in contact with the ground in the rough?

It sure seems like it would either be too stiff at full bump, or too soft at full droop. Is the "spring rate" of the airbag linear, or is it inversely proportional to the air displaced as it compresses?
Was the rebound valving in the shocks much lighter than it would've been with steel springs?
It seems like if it was soft enough not to buck on hard, unexpected g-outs, that it would run out sufficient air pressure during droop to offer enough rebound force for the shock to dampen, and to keep the rear tires planted to the ground. Please, elaborate on the accommodations you had to include to make an airbag perform satisfactorily throughout the entire range of wheel travel. I need to know!

 

[Glamisfan]

Those yellow arms above were posted by lonestar and they're off of the Weller racing Yamaha.

Airbags have a very extreme rising rate. At ride height I was running around 100 pounds per inch spring rate. When you bottom them out, since the air is compressed, it winds up being something like 1000 pound. The valving was similar to valving any other shock. I had coil overs on the front and I do my own shocks so nothing fancy needed for the air valving.
On my super duty as I'm remembering the valving is fairly light. But I do have a 16 inch bypass on the back that's mounted directly to the axle so it's a one to one ratio so of course that always pretty soft! Marty coin here in the Imperial Valley had a friend from the Mickey Thompson races come down to the cycle center in the late 80s when I worked there and he had a pre-runner with airbags on the rear and when he aired down, I fell in love with it!

There's also a neat thing about airbags. I always build it for the lightest possible spring rate. And then if the spring rate feels too soft, then you pour automatic transmission fluid into the airbag, A measured amount of coarse, and that does not eat up the rubber at all, and what it does is it displaces air which then requires you to run more air pressure to get the same ride height, so you increased your spring rate. I remember in the pre-runner I had 1 quart of transmission fluid in each airbag. I think in the super duty I don't have any. Also, on my super duty I have a backup camera, so whenever I back up to a trailer I lower the truck enough in the rear and then watch the camera, back right up to the hitch, and air the truck up and I'm hooked up.

 

[kmb760]

backup camera, so whenever I back up to a trailer I lower the truck enough in the rear and then watch the camera, back right up to the hitch, and air the truck up and I'm hooked up.

That is a awesome way of doing things solo

 

[tatum]

My buddy has a Funco sand car and I believe they had antifreeze in the airbags.

 

[NIKAL]

As I read this all I see in my head and hear as I read out-loud is the Reid from the Old Rick & Reid days! I can feel the excitement in his words, just like when he & his brother were tapped to build Scott McMillins class 8 truck. Just like when he worked on my Grandfathers 7s truck.

I know no one besides me knew Reid Johnson "Badassmav" before reading is arrogant posts on UTVU a few years back. But I can tell you he & his brother were the Geiser Bros of there days as they were on the forefront of off road truck technology with funding like McMillin had. I also know the past several years were not good for Reid, and he was in a dark place in life. But I'm telling you, this shows me Reid might be coming out of the dark and seeing new light. So if this is happening again with his new partner client, then you all better hold on to your hats & butts, cause this could be one hell of a ride!

I know Reid does not know this but when I was just a kid, going to his and some other shops with my Grandfather or other racers I knew, I would get to see the future creations in those shops. These guys were my hero's. my dad passed when I was 12. My grandfather stepped in to help fill that void. He was and still is my John Wayne. But guys like Reid, Rick, Mike Julson @ Jimco, Robby Gordon, Ivan Stewart. These were my hero's, like most kids would look at a baseball or football player as his. Whats even better is Ive met all my hero's, and to this day I still speak with them all! How "F"ing cool is that?

Also I just got back from 3 days in Baja with the UTV and did another 580 miles. This was the first thing I have read since coming home last night! Story to come!

 

[tatum]

Reid, do you know when you are getting your Yamaha?

 

[badassmav]

Reid, do you know when you are getting your Yamaha?

We were told late this month or early October. I heard that Motoworld has one on their floor as I type. I'm stopping by tomorrow at lunch for some spy footage. I'll fill you all in tomorrow afternoon.

 

[NIKAL]

We were told late this month or early October. I heard that Motoworld has one on their floor as I type. I'm stopping by tomorrow at lunch for some spy footage. I'll fill you all in tomorrow afternoon.

Reid, a buddy of mine went by Motoworld on Saturday to see the Yamaha. He said Motoworld only had the Yamaha for a few hours on Saturday as Yamaha only has 3 vehicles to show, so they are touring them around. I got an email last week from Chaparral that they too would have one on (9/5 Saturday, same as Motoworld), but only for a few hours. Maybe check Yamaha's XYZ Facebook and see if they post where they will be next. Maybe another San Diego dealership will get one for a few hours this coming weekend?

 

[badassmav]

Reid, a buddy of mine went by Motoworld on Saturday to see the Yamaha. He said Motoworld only had the Yamaha for a few hours on Saturday as Yamaha only has 3 vehicles to show, so they are touring them around. I got an email last week from Chaparral that they too would have one on (9/5 Saturday, same as Motoworld), but only for a few hours. Maybe check Yamaha's XYZ Facebook and see if they post where they will be next. Maybe another San Diego dealership will get one for a few hours this coming weekend?

Unfortunately Todd, I don't do f-book. They are evil, and like Google, there is something greater going on there, and it is not in our favor. People will realize someday, sooner than later, that broadcasting themselves to the world has been an irreversible mistake. Thanks for the notice though, and the kind words. I must say that you are one of the most well rounded guys in these forums. You are well versed in every topic you comment on, and am almost a bigger windbag then myself! If they ever agree to form a committee of sorts to represent our class, you got my vote.

I didn't realize they are "parade-ing" the YXZ's from store to store. If someone would tip me off as to where the next parade might be, I'd parade my ass on over there and gather some desperately needed data. Isn't the S&S show next weekend? I need to be there for sure. It's been awhile since I've done some idea shopping. I wonder if they allow coolers of Stout to be walked in? Hmmm. I'll be the one wearing the Groucho Marx mustache glasses. I hate crowds.

 

[badassmav]

Hey Reid, how long do you think these mods are going to take you to get to production?

Now there's the $64,000 question. I'm not sure at this point Hans, because I am committed to first completing an all out race kit I've been working on for the xp 1000. I've got to get that done, and on a car for testing ASAP, so there is time to refine any oversights prior to the end of the year. I have already committed my full testing and race support to that cause for the 2016 season. We will take delivery of the Yammy far before the Polaris kit is done. I expect it to be a 4-6 week window of time to hammer out the prototype kit for the YXZ, and I wont be able to start that kit for at least 3-4 weeks from now. I do have a 40 hr./week regular job, and live a half hour away from where the fab and design work will be taking place.

I hate to say it, but it looks like it will be early December at best before I can have the first Yammy kit done. My partner in crime decided he wants to go all out and have me build a kit to the best of my ability. That means a +6" kit, longer shocks, a-arm reassignment, front steer conversion, and most likely stretch the wheelbase by 6-7" (if the stock frame and diff layout says that is practical to do so. I doubt that it utilizing the stock pivot points). I've felt ever since designing the Monstermav that the wheelbase in these cars needs to be right around 100", and the 77" max track needs to be realized. After all, these cars will be seeing almost 100 MPH before the end of next year. I don't know about anyone else, but that's too damn fast in a car less than 6' wide, if you ask me.

So, the first kit I complete for both brands of cars, will not be be high in public demand. Therefore, if I'm in this to sell to the masses, I need to try and develop 2 kits for both the Polaris and the Yammy. Right now, I'm being tugged at from every corner, but vowed to myself to never again work 100+ hour weeks for anybody, including myself. I'm to effen old for that shit! The next few months ought to be very interesting. I'll share it all here, like always.

Man, am I glad you only asked one question, and I don't even think I answered it clearly. For now, my wonderfully frosted pint of Guinness is done, as am I. Good night all!

 

[Glamisfan]

The SSSS isn't this coming weekend, it's the following. I'll be there on the 19th. And I completely agree the wheelbase should be around 100". 90" is too short. 95" like the Wildcat is desent. And the 4 seater wheelbase's are too long for me. On the rzr's they have front a arms that are + 2" forward with the stock width. If you could push the a arms on the YXZ just 2.2" forward and rearward, that plus the stock 90.6" wheelbase would net 95".

 

[tatum]

The YXZ front diff is forward in the chassis with the axles swept back so it should be fairly easy to gain a few inches of wheelbase in the front.

 

[CSG]

CSG, your opinion, and all others for that matter, are welcomed here. If you race a UTV in the dirt, we both have a lot in common.

I was just curious on what brand of UTE you are racing that the front outside tire toes out when compressed? Unless it's an Arctic Cat, any rear steer car I've worked on to date always toes in when bumping. Typically, rear steers toe in while bumping, and front steers toe out while bumping, hence the static toe out settings on the XP 1000. The problem with a rear steer configuration is that it is very difficult to achieve both good ackermann steering and bump steer characteristics simultaneously. This is due to the fact that where the outer tie rod end needs to be located to achieve good ackermann characteristics, makes for a tie rod length too short to realize low to no bump steer. By all means, fill me in if your setup proves otherwise.

About the larger tires, I have concerns on the reliability of the transmission running tires larger than 29". They deliver a car they know is going to compete in the pro 1900 class, yet they sell it with only 27" tires. The ads call 12.9" of ground clearance "respectable", but I beg to differ. With 16"+ of wheel travel, that number should be closer to 14", and can be if one wants to sacrifice droop travel to get it. That (tire diameter) is a big red flag for me. The fact that there is a clutching upgrade available from the dealer tells us something. I think 32" tires have no credibility as of yet in our class, until which time they can be ran in numbers, in a racing environment, to gather data. Thanks for posting!

My 08 RZR 800 is the only machine that I have measured the bump steer on. It is using a heim at the spindle so the mounting height is slightly different than stock. I assumed that most others are the same way as car manufacturers typically do this on purpose as well to save people from an oversteer condition.

 

[Glamisfan]

The YXZ front diff is forward in the chassis with the axles swept back so it should be fairly easy to gain a few inches of wheelbase in the front.

Ohhhh.......good to hear!

 

[JoeyD23]

Reid do you need your name changed to BADASSYXZ now?

 

[Kalop]

Reid do you need your name changed to BADASSYXZ now?

I'd say BadAssReid would be most appropriate.