Whats SXS for rallycross?

Heres a link to that video. I wonder if that is on the stock suspension arms and shocks?

https://www.youtube.com/watch?v=27_WkGVARbw

However, doesn't seem like it takes much to put these on their top. The factory "roll cage" is also not even close to up to snuff for real rollover risk prevention, it seems a real roll cage or roll bar would entirely necessary:

https://www.youtube.com/watch?v=B3AOEpTbd20

fidelity101 (Forum Supporter) said:

ProDarwin said:

fidelity101 (Forum Supporter) said:

ARA has them as a class as well but its very limited participation. Also some states don't allow you to plate the SXS so that makes it harder to transit on public roads. 

I feel like by "some" you mean "most".  Is plating a SXS common?

 

Yeah some I do mean Most, 

 

plating a SXS is common up north in michigan.

I was in Sedona AZ and Moab UT few months ago. They were plated and on the streets EVERYWHERE. 

In reply to engiekev :

Says ini the video it's lowered with shorter shocks. Looks like the arms could be stock.

Are there restrictions on shifting to 1st on a motorcycle style sequential transmission?  I like a clutch pedal as much as the next guy but it could be interesting to put really low gears into a Yamaha, get the paddle shift version, and stay in gears 2-6 after launch.

Are there any vehicles with a traditional all wheel drive system?  The best I can find is a locked rear and open diff front.  I assume 4wd isn't what we want most of the time.

Note: that has an overall width of 64", the track width is much narrower.  By at least the width of the tire, if not more (hard to tell if fenders stick out beyond tires or not).  It would not be legal under the proposed rules.

Its also 68" tall (this is the lowest # I've seen).  For reference, that's 20 inches taller than a Miata and 12" taller than a Subaru.

Edit:  The one in the video looks like the suspension was lowered ~3-4" (and wider track as a result) and the tires are shorter.  Big help.

ProDarwin said:

Note: that has an overall width of 64", the track width is much narrower.  By at least the width of the tire, if not more (hard to tell if fenders stick out beyond tires or not).  It would not be legal under the proposed rules.

The ruleset I saw listed a minimum for the overall tread width, not the center to center track width.  Because not only is that easier to measure in the field, it is also the dimension that we should be caring about.

My RX-7 has a track width of 56", tread width is a bunch more.  This is the other critical point, we are asking these vehicles to run in the same courses as cars, and vise versa, and ruts and cleaned tracks will happen, it is safer if everything is roughly the same size.

I dont quite get all the resistance to the CVT. I mean, I autocross a F500 with the snowmobile CVT and while it may sound irritating, its kinda awesome for the task. You are never off the powerband and can dig out of slow corners with more authority. 

Tuning the Nth degree out of it is about the same as Nth degree carb tuning. You can get it close enough and not worry too much. The Dakar build in Racecar engineering still used the CVT and only had a bit of supplemental cooling as I recall, and thats Dakar. 

I'm just saying, I wouldnt discount it so quickly. 

https://can-am.brp.com/off-road/us/en/can-am-world/dakar.html

Can-am X3 has won dakar 3x running with their CVT

the big boy can-am maverick x3 x rs turbo rr is 72" wide and 68.5" tall, makes 200hp and weighs 1600lbs

MrChaos said:

the big boy can-am maverick x3 x rs turbo rr is 72" wide and 68.5" tall, makes 200hp and weighs 1600lbs

that thing looks absolutely mean as hell.  I believe that's the one Ken Block is ripping in most of the time.  Unfortunately, out of my league price-wise.

Pete. (l33t FS) said:

The ruleset I saw listed a minimum for the overall tread width, not the center to center track width.  Because not only is that easier to measure in the field, it is also the dimension that we should be caring about.

Ah, correct.  My mind keeps going to track width, because its what's used for autox.  And constructors class.

I predict rollovers if people are running these stock.

Apexcarver said:

I dont quite get all the resistance to the CVT. I mean, I autocross a F500 with the snowmobile CVT and while it may sound irritating, its kinda awesome for the task. You are never off the powerband and can dig out of slow corners with more authority. 

I love CVTs, but I would hate to rallycross one unless it was computer controlled and not simply load/RPM.  At least with a rear driver, and I assume 90% of these things are rear wheel drive, the throttle is as much a control input as the steering wheel is, maybe more.  Braking mid corner usually makes the front end go wide so you need to tuck the nose in with throttle lifting.

So I can see a CVT that drops the engine speed to idle when lifting being a suckfest to drive, unless you were driving the corners at low intensity and powering out, or had tires that had all the grip.

Lof8 - Andy said:

MrChaos said:

the big boy can-am maverick x3 x rs turbo rr is 72" wide and 68.5" tall, makes 200hp and weighs 1600lbs

that thing looks absolutely mean as hell.  I believe that's the one Ken Block is ripping in most of the time.  Unfortunately, out of my league price-wise.

i mean that is more than i paid for my veloster N

Pete. (l33t FS) said:

Apexcarver said:

I dont quite get all the resistance to the CVT. I mean, I autocross a F500 with the snowmobile CVT and while it may sound irritating, its kinda awesome for the task. You are never off the powerband and can dig out of slow corners with more authority. 

I love CVTs, but I would hate to rallycross one unless it was computer controlled and not simply load/RPM.  At least with a rear driver, and I assume 90% of these things are rear wheel drive, the throttle is as much a control input as the steering wheel is, maybe more.  Braking mid corner usually makes the front end go wide so you need to tuck the nose in with throttle lifting.

 

So I can see a CVT that drops the engine speed to idle when lifting being a suckfest to drive, unless you were driving the corners at low intensity and powering out, or had tires that had all the grip.

What if you left foot brake in a CVT? Will it continue to maintain higher load and RPM? Assuming there isn't a throttle cut-out for when both brake and accel pedal are applied, or it is bypassed.

As someone who used too assemble these things I wouldn't trust the factory roll cage in a high speed roll over! 

In reply to engiekev :

When CVTs were adopted to motorcycles, people would drag the brake so they could keep on the throttle mid corner to keep the revs up.  

Lifting mid corner usually tucks the nose in, but because the front wheels of a rear driver lock so easily due to the lack of drivetrain inertia, braking mid corner usually makes the front end go wide.  A trick I have used a couple times to avoid a cone when I got more turn-in than I'd expected, and it felt really cool when it actually worked according to plan 

If course if you drive more aggressively and enter the corner sideways so the only way out is more power, then great, but that is not a way I would want to drive something tall and tippy.  And it rather relies on you being able to enter a corner with speed, something some course designers love to not give you   

I am watching that video you posted upthread and it looks awesome... on a table smooth dirt oval with nice long straights to get up speed before corner entry.  I wish I bought my Garmin sooner, but it looks like the "fast" courses never seem to top 45mph (60-70 with wheelspin) with constantly running at 25-30mph in corners, with lots of bumps and crossing over old ruts and stuff like that, because we are an amateur sport and can't afford to have the sites tilled and rolled between events. 

Pete. (l33t FS) said:

Apexcarver said:

I dont quite get all the resistance to the CVT. I mean, I autocross a F500 with the snowmobile CVT and while it may sound irritating, its kinda awesome for the task. You are never off the powerband and can dig out of slow corners with more authority. 

I love CVTs, but I would hate to rallycross one unless it was computer controlled and not simply load/RPM.  At least with a rear driver, and I assume 90% of these things are rear wheel drive, the throttle is as much a control input as the steering wheel is, maybe more.  Braking mid corner usually makes the front end go wide so you need to tuck the nose in with throttle lifting.

 

So I can see a CVT that drops the engine speed to idle when lifting being a suckfest to drive, unless you were driving the corners at low intensity and powering out, or had tires that had all the grip.

Much of that can probably be addressed through driving style and clutch tuning. 

As long as you don't drop below the engagement RPM for the primary clutch you will get engine braking. Even on a 2 stroke snowmobile, as long as you keep the throttle up enough for the primary to stay engaged you will have engine braking.

Proper tuning (ramps and springs) in the secondary will allow it to back shift to provide lower effective gearing and more torque out of the corner. 

Just like anything else I would expect a learning curve, and it may require a two footed driving style to keep the rpms from dropping too much and more aggressive transition to throttle before completely letting off the brakes to ensure the clutches load properly.  

dropstep said:

As someone who used too assemble these things I wouldn't trust the factory roll cage in a high speed roll over! 

Aftermarket cage will be one of my first upgrades

Lof8 - Andy said:

dropstep said:

As someone who used too assemble these things I wouldn't trust the factory roll cage in a high speed roll over! 

Aftermarket cage will be one of my first upgrades

+1

there are specific rules on cage building to prep these vehicles for stage use and it makes complete sense. 

No Time said:

Pete. (l33t FS) said:

Apexcarver said:

I dont quite get all the resistance to the CVT. I mean, I autocross a F500 with the snowmobile CVT and while it may sound irritating, its kinda awesome for the task. You are never off the powerband and can dig out of slow corners with more authority. 

I love CVTs, but I would hate to rallycross one unless it was computer controlled and not simply load/RPM.  At least with a rear driver, and I assume 90% of these things are rear wheel drive, the throttle is as much a control input as the steering wheel is, maybe more.  Braking mid corner usually makes the front end go wide so you need to tuck the nose in with throttle lifting.

 

So I can see a CVT that drops the engine speed to idle when lifting being a suckfest to drive, unless you were driving the corners at low intensity and powering out, or had tires that had all the grip.

Much of that can probably be addressed through driving style and clutch tuning. 

As long as you don't drop below the engagement RPM for the primary clutch you will get engine braking. Even on a 2 stroke snowmobile, as long as you keep the throttle up enough for the primary to stay engaged you will have engine braking.

Proper tuning (ramps and springs) in the secondary will allow it to back shift to provide lower effective gearing and more torque out of the corner. 

Just like anything else I would expect a learning curve, and it may require a two footed driving style to keep the rpms from dropping too much and more aggressive transition to throttle before completely letting off the brakes to ensure the clutches load properly.  

Well, from the pavement side on the F500, you have to left foot brake (no other option, footwell size) and you kind of waffle the throttle mid corner to keep it engaged. You can do some of the left foot braking as described. Now, there is some clutch setup voodoo (springs and such), but its really not impossible to learn. 

Lof8 - Andy said:

dropstep said:

As someone who used too assemble these things I wouldn't trust the factory roll cage in a high speed roll over! 

Aftermarket cage will be one of my first upgrades

Fortunately at a rallycross they will be all low speed rollovers, relatively speaking.  Of the few I have seen, they tend to stop once upended, or even just on their side without going all the way over.  Hollywood physics does not apply, vehicles don't keep tumbling for a hundred yards without shedding any momentum 

It was always at tight low speed corners too, not the "high" speed ones.  Extrapolate from that what you will.  (My take? Not going fast enough to slide)

Here's what my dreams are made of

YXZ supermoto

Lof8 - Andy said:

Here's what my dreams are made of

YXZ supermoto

what about this https://www.youtube.com/watch?v=UOekvbHL7DY

In reply to MrChaos :

That's cool too. But I much prefer the corners and surface changes. 

So the Yamaha uses a turbo 3. Is the reason that they don't use the R-1 motor just because they want more low-end grunt?