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MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 3:28 p.m.

https://www.scca.com/announcements/181-rxb-welcomes-utv-s?fbclid=IwAR0mDgGatLB9mAkSdqdAO7-6wpZu9XQFAz8zj6byCzDlhM7PJhzLABlsrnQ

2020 Rules with SxS/UTV rules.

Biggest non SxS change I see is the new tire rules.

3.2 F now states 

Tires must be in good condition, with no cord or belts showing or cracks in the tread or sidewall. A space-saving wheel designated by a manufacturer for temporary low speed use and for transiting a short distance may not be used for competition regardless of the type of tire installed. The load index/rating for non-automotive tires must meet or exceed the weight of the vehicle.

 

That looks like to me it will open up a whole lot of tires for the cars that can run 15" wheels and smaller as most SxS's weigh as much as miatas.

MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 3:33 p.m.

Here are the big rules

10. Minimum width is 64 inches measured from the outer edge of the wheels. Minimum wheelbase is 83 inches measured from the center of the wheels.

11. Maximum ground clearance measured at the base of the frame rails at both the front and rear of the vehicle is equal to one half of the diameter of the tires fitted to the vehicle. It is strongly recommended that the vehicle be lowered to the greatest extent possible.

FooBag (Forum Supporter)
FooBag (Forum Supporter) GRM+ Memberand Reader
7/1/20 4:23 p.m.
MrChaos said:

That looks like to me it will open up a whole lot of tires for the cars that can run 15" wheels and smaller as most SxS's weigh as much as miatas.

That's an interesting point you have there.  I'm wondering if that wasn't the intent of the RXB, especially as that's a major change less than two months out from the National Championship.  I pointed out your interpretation of the rules (which is quite valid, IMO) to the RXB for confirmation.

 

As for the addition of UTV's/SxS, I'm cautiously optimistic.  With 35 cars being a large event for Iowa Region, I'm all for adding more racers.  Time will tell if they will cause course problems or lead to incidents. 

dps214
dps214 Reader
7/1/20 4:31 p.m.

I didn't read the rules but like most things scca, I assume these changes go into effect for next season, not immediately.

ojannen
ojannen GRM+ Memberand Reader
7/1/20 4:42 p.m.

12-ply UTV tires generally have a load rating around 1,000lbs.  I think that is enough for an early Miata.  I think the fast guys have tires figured out though.  Especially now that Alpha Racing Tyres has a US distributor.

MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 4:49 p.m.
dps214 said:

I didn't read the rules but like most things scca, I assume these changes go into effect for next season, not immediately.

Regional programs may begin allowing eligible UTVs to participate in RallyCross events effective immediately.

EvanB (Forum Supporter)
EvanB (Forum Supporter) GRM+ Memberand MegaDork
7/1/20 5:00 p.m.

From what I saw while looking briefly, utv tires cost as much or more than rally tires.

MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 5:28 p.m.
EvanB (Forum Supporter) said:

From what I saw while looking briefly, utv tires cost as much or more than rally tires.

but they are a little easier to source 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/1/20 6:02 p.m.
ojannen said:

12-ply UTV tires generally have a load rating around 1,000lbs.  I think that is enough for an early Miata.  I think the fast guys have tires figured out though.  Especially now that Alpha Racing Tyres has a US distributor.

Early Miatas weigh more than 1000lb.

 

The supposition is that you will have the car effectively on one tire at some point, and that is the absolute worst time to have a tire failure.  The tire load rating must be that of the entire car, per tire, by the way the rule is written.

 

 

ojannen
ojannen GRM+ Memberand Reader
7/1/20 7:33 p.m.

In reply to Pete. (l33t FS) :

I missed that part.  Do you know if the vehicle weight includes the weight of the driver?

At ~1500lbs, can any of the SxS use tires designed for them?

MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 7:47 p.m.

I mean a standard Blizzak in 195/50r15 is only a 84 load range tire which means 1102lbs of weigh capacity. 

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
7/1/20 7:51 p.m.
ojannen said:

 I think the people with a lot of money have tires figured out though.  

lol....."Figuring out" the tires isn't rocket science. it's pretty widely-known what the top tires are for various conditions.. It's just that the vast majority of rallycrossers aren't going to (or can't afford to) truck around with $5000 worth of wheels and tires for every conceivable condition like some of the people who are chasing national trophies (and seem to have relatively unlimited budgets) do. 

In our large region, there seems to be an unspoken agreement that nobody t in the highly-contested classes goes crazy with the $$ specialty tires, even if some could definitely afford to.. Pretty much it's just gravels or Maxsport RB3s. Nobody wants to waste money on a tire arms race. . 

In any case, hopefully they clarify that rule, else RX is going to continue down the autocross path of "finding all the rules loopholes" or "outspending everyone else on specialty stuff," which will decrease compeition, not increase it. One woudl think that the spirit of the rule is to apply to SXSs and not to car classes. 

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
7/1/20 7:58 p.m.

As to the subject at hand, will be interesting to see how it plays out. Hopefully it will help some of the smaller programs struggling to stay afloat, especially in some of the more rural regions. I tend to doubt many of the large regions (Detroit, DC, New England) will add SXS to current rallycross programs since they're already hitting entry caps consistently, but I've been wrong before. 

MrChaos
MrChaos GRM+ Memberand SuperDork
7/1/20 8:03 p.m.
irish44j (Forum Supporter) said:

As to the subject at hand, will be interesting to see how it plays out. Hopefully it will help some of the smaller programs struggling to stay afloat, especially in some of the more rural regions. I tend to doubt many of the large regions (Detroit, DC, New England) will add SXS to current rallycross programs since they're already hitting entry caps consistently, but I've been wrong before. 

I mean they do state in the rules that organizers can limit it to log booked utv's sxs'

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
7/1/20 8:12 p.m.
MrChaos said:
irish44j (Forum Supporter) said:

As to the subject at hand, will be interesting to see how it plays out. Hopefully it will help some of the smaller programs struggling to stay afloat, especially in some of the more rural regions. I tend to doubt many of the large regions (Detroit, DC, New England) will add SXS to current rallycross programs since they're already hitting entry caps consistently, but I've been wrong before. 

I mean they do state in the rules that organizers can limit it to log booked utv's sxs'

Maybe I didn't read closely enough, but my impression was that basically it's up to regions whether or not they want to allow SXSs at all - only that they are "allowed to" now. 

EDIT: "Each Region will have the option to allow UTVs at local events." So, not a requirement. 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/2/20 6:59 a.m.
MrChaos said:

I mean a standard Blizzak in 195/50r15 is only a 84 load range tire which means 1102lbs of weigh capacity. 

That is also a tire meant for passenger cars.

Lof8 - Andy
Lof8 - Andy GRM+ Memberand SuperDork
7/2/20 7:10 a.m.

I'm certainly digging the mid season rule change.  I thought I was going to be waiting til '21 to be doing much rallyx with my YXZ.   

 

ojannen
ojannen GRM+ Memberand Reader
7/2/20 7:34 a.m.

In reply to irish44j (Forum Supporter) :

I am thankful that our local surfaces are high grip and don't turn into mudfests in the rain.  Our venues don't really have the dew covered grass issues on early runs either.  It means that tire choice almost doesn't matter.  The indysport mud tires only last one or two events due to lugs getting ripped off on the drive wheels.  I run Maxsports mostly because they lighter than full gravels (and they are cheap).  The only real question for me is how long to run tires after the edges of the tread blocks get rounded off.

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
7/2/20 8:03 a.m.

In reply to ojannen :

Yeah we are mostly in the same boat where Max sports are generally a little bit faster than gravels but the really extreme tires probably would not provide huge additional advantage, since our surfaces are predominantly hard packed clay and gravel, And we don't often run when it is wet because it's pretty much like an ice rink. We have very little driving done on grassy areas, And definitely none of that loamy farm field stuff. I think the super gummy tires would probably be a little bit faster than anything most people are using, but they would definitely wear down really quick on our surfaces. Probably the other reason nobody is bothering with them. 

I would say most of our modified cars are running on Maxsports these days, but I am not really convinced theyre much faster than gravels since we are on fairly high speed courses and a lot of our cars are pretty high power in the first place. I think the main reason is cost. And we also have some events when it is close to freezing out in which case most people just have snow tires on.

collinskl1
collinskl1 GRM+ Memberand Reader
7/2/20 8:58 a.m.
Pete. (l33t FS) said:
ojannen said:

12-ply UTV tires generally have a load rating around 1,000lbs.  I think that is enough for an early Miata.  I think the fast guys have tires figured out though.  Especially now that Alpha Racing Tyres has a US distributor.

Early Miatas weigh more than 1000lb.

 

The supposition is that you will have the car effectively on one tire at some point, and that is the absolute worst time to have a tire failure.  The tire load rating must be that of the entire car, per tire, by the way the rule is written.

This is a poorly written rule. There is no reason a single tire needs to be rated for load carrying capacity of the entire vehicle. That's not how tires are validated and certified.

The rule should require tires to be rated to meet or exceed the actual weight of each corner of the car, as raced - or front/rear axle weight as a pair of tires.

Using GAWR loads of the vehicle would be the easy way out, but isn't applicable to motorsports as the cars aren't raced at full loaded capacity, and are often modified to be lighter than the OE curb weight.

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
7/2/20 9:17 a.m.
collinskl1 said:
Pete. (l33t FS) said:
ojannen said:

12-ply UTV tires generally have a load rating around 1,000lbs.  I think that is enough for an early Miata.  I think the fast guys have tires figured out though.  Especially now that Alpha Racing Tyres has a US distributor.

Early Miatas weigh more than 1000lb.

 

The supposition is that you will have the car effectively on one tire at some point, and that is the absolute worst time to have a tire failure.  The tire load rating must be that of the entire car, per tire, by the way the rule is written.

This is a poorly written rule. There is no reason a single tire needs to be rated for load carrying capacity of the entire vehicle. That's not how tires are validated and certified.

The rule should require tires to be rated to meet or exceed the actual weight of each corner of the car, as raced - or front/rear axle weight as a pair of tires.

Using GAWR loads of the vehicle would be the easy way out, but isn't applicable to motorsports as the cars aren't raced at full loaded capacity, and are often modified to be lighter than the OE curb weight.

I agree it's a poorly written rule.

The rule should simply state that it applies to UTV class only and that automotive classes still have to use automotive tires as it has always been.

GAWR or load ratings should not come into the equation (since it's not like we can measure a competitor's car's weight to verify, anyhow) - automobile classes should have to use automobile tires. UTV classes can use UTV tires. Seems simple enough - leave it to SCCA to bungle up the wording and make it complicated. 

 

MrChaos
MrChaos GRM+ Memberand SuperDork
7/8/20 5:52 a.m.

talked to someone on the RXB and they are going to clarify the rule. The rule will say basically the load rating of all 4 tires combined need to meet or exceed the actual weight of the vehicle. just like car tires.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/8/20 6:06 a.m.
collinskl1 said:
Pete. (l33t FS) said:
ojannen said:

12-ply UTV tires generally have a load rating around 1,000lbs.  I think that is enough for an early Miata.  I think the fast guys have tires figured out though.  Especially now that Alpha Racing Tyres has a US distributor.

Early Miatas weigh more than 1000lb.

 

The supposition is that you will have the car effectively on one tire at some point, and that is the absolute worst time to have a tire failure.  The tire load rating must be that of the entire car, per tire, by the way the rule is written.

This is a poorly written rule. There is no reason a single tire needs to be rated for load carrying capacity of the entire vehicle. That's not how tires are validated and certified.

The rule should require tires to be rated to meet or exceed the actual weight of each corner of the car, as raced - or front/rear axle weight as a pair of tires.

Using GAWR loads of the vehicle would be the easy way out, but isn't applicable to motorsports as the cars aren't raced at full loaded capacity, and are often modified to be lighter than the OE curb weight.

Counterpoint:  People are routinely told to inflate their tires up to and beyond the maximum pressure to prevent debeading.  And that doesn't always work, either.

 

The tire load rating is at a certain pressure and varies with the pressure in the tire.  It's a lot higher at 50psi than 35.

Lof8 - Andy
Lof8 - Andy GRM+ Memberand SuperDork
7/8/20 7:09 a.m.

I'm kind of surprised that the legality of SXS is not getting much attention.  These things can be a huge performance bargain if you find the right deal.  My YXZ is off-the-wall exciting to drive and the options for places to legally drive it are much greater than places where you can rip on a rallyx car (at least around me).  Got mine all set up for this weekends Port St Lucie event. 

dps214
dps214 HalfDork
2/12/21 2:30 p.m.

Bringing this back up...we just collected our new rallycross mobile today.

If it's worth doing it's worth overdoing, right? 170hp and 1500lbs should be entertaining at the very least.

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