Restrictor Plate Racing 450 Supercross - Rag in the Airbox

enketchum
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Edited Date/Time 3/2/2018 1:44pm
Weege, JT, and Matthes were talking about 450s being too fast for Supercross tracks.

Weege brought up the bikes being the selling point for the factories and that the displacement could not be changed without massive blow back from them.

Then he brought up restrictor plates for the bikes and how well the AMA could implement and enforce this. Then he jokingly brought up stuffing a rag into every air box. That was my favorite part.

What do you think about restricting air box flow for 450s to slow them down ?
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Derpin' DJ
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2/27/2018 1:32am
Dunno how effective it would be without totally choking the engine. It will either have minimal effect at midrange in order to restrict top end, or completely choke the top end to properly restrict the midrange, as pressure loss is proportional to air flow squared.
JMX82
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2/27/2018 1:52am
I think using restrictor plates would not really solve the problem. 450's would be still heavy bikes with a lot of rotating mass which in my opinion is causing the large amount of injuries we are seeing today. Even the pro riders aren't using all the power that 450's have on the supercross tracks anyway

I think only logical solution would be making 250's the premium class for supercross and bringing back the 125's as a support class
#434
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2/27/2018 3:13am
Yes, the rotating mass is the problem when something goes wrong not the power. I had a 14 YZ450f and and a 15 YZ250f (both even had the same suspension settings) and the difference in getting them back when they stepped out was huge. One part was the sheer weight, but IMO the big crankshaft had an even bigger effect.
MxKing809
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2/27/2018 3:34am
A restrict or plate will never work. The factories will still be able to engineer the motor to perform as good or better with that plate than a stock bike.

I think the simplest and easiest thing to implement would be stock bikes with suspension. No super gnarly 3 gear tranny’s, no 72 HP factory bikes, no ECUs, just bone stock bikes that any privateer can buy and race.

It would be simple to check all of that.

The Shop

JMX82
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2/27/2018 4:14am
Fully stock 450's will just adds more weight to the bikes and won't solve the problem... Greater mass equals greater forces that equals more injuries. Try riding early nineties 250's be amazed how much lighter they are than the current bikes. For example 1990 Honda CR 250 weights only 205 pounds in stock trim compared to 2018 CRF 450 which weighs 248 pounds...
Asimo
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2/27/2018 6:44am
Won't matter since SX isn't WFO all the time. They cant understand F1 isn't selling F1 cars and NASCAR isn't selling Camrys either, or that Monster trucks don't sell pickup trucks, or 90% at a SX have never ridden and will buy beer and cigarettes before a bike.

Also, too slow it down they either need to go to less power overall, or make the jumps way bigger.

Ie instead if the standard 65 foot triple stretch it out 20 feet.
Now the double is smaller, and only a few will go for it on the triple.

Or just go back to 2 strokes. Nobody really likes 4 strokes anyway.



Stuntman949
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2/27/2018 7:37am
150f's and 350f's indoors, anything goes outdoors. Booooooooooom
Homey55
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2/27/2018 7:53am
Just put everyone on 250's indoors. Find a way to make the regional class more of a spec class and the premier class can do what they want with the 250. The 450 is hurting too many people.

Outdoors can go back to the 450, but I think the racing would be better if it were all 250 as well.
ML512
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2/27/2018 7:59am
MxKing809 wrote:
A restrict or plate will never work. The factories will still be able to engineer the motor to perform as good or better with that plate...
A restrict or plate will never work. The factories will still be able to engineer the motor to perform as good or better with that plate than a stock bike.

I think the simplest and easiest thing to implement would be stock bikes with suspension. No super gnarly 3 gear tranny’s, no 72 HP factory bikes, no ECUs, just bone stock bikes that any privateer can buy and race.

It would be simple to check all of that.
Well, that’s pretty close to what a Factory KTM 450 is...remapped stock ECU, race fuel, stock cam that’s re-timed, head is lightly cleaned up...not much to see in there. There’s a lot of Factory 450s out there that are just lightly massaged, that’s not the injury cause...the inertia they produce is what bites you more than the actual power output.

The Factory 450s I’ve gotten to try the past couple years are insanely smooth and not the rocket ship that some would think.
Johnny Depp
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2/27/2018 9:13am
Open class for the Pro's. Open class with a nickel sized exhaust restrictor for the wanna be's.
10000hrs
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2/27/2018 9:31am
How about limiting power by putting a rag in the muffler ... ie quieter bikes.
ML512
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2/27/2018 9:39am
10000hrs wrote:
How about limiting power by putting a rag in the muffler ... ie quieter bikes.
We've gone quite a bit quieter over the past few years and now we're getting into an area where we start to see too much heat retention in mufflers...thus causing them to fail much earlier.
Homey55
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2/27/2018 10:37am
What about a fuel restriction or a spec fuel injector that teams must run?
eGGz
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2/27/2018 10:39am Edited Date/Time 2/27/2018 10:48am
Its not the bikes, its the tracks. The injuries are due to the absurd spectacle that SX has become. Feld's motivation has never been to "grow the sport." Their motivation is solely to grow their profits. True racing fans don't need to experience pyrotechnics, screaming announcers, tracks that have the riders in the air half the time. These elements are a sadly successful attempt to pick the low hanging fruit. The riders are merely an expendable commodity.
Johnny Depp
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2/27/2018 10:41am
eGGz wrote:
Its not the bikes, its the tracks. The injuries are due to the absurd spectacle that SX has become. Feld's motivation has never been to "grow...
Its not the bikes, its the tracks. The injuries are due to the absurd spectacle that SX has become. Feld's motivation has never been to "grow the sport." Their motivation is solely to grow their profits. True racing fans don't need to experience pyrotechnics, screaming announcers, tracks that have the riders in the air half the time. These elements are a sadly successful attempt to pick the low hanging fruit. The riders are merely an expendable commodity.
Brilliant synopsis. Really.

brocster
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2/27/2018 10:53am
The bike’s capabilities has superceeded the obstacles that can be put in front of it in a supercross setting. Quite the opposite of what supercross was built as during its inception.
Markee
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2/27/2018 10:54am Edited Date/Time 2/27/2018 10:54am
First you would have to have a governing body that is worth a shit. I don't have confidence the AMA could regulate any mechanical regulations when it comes to HP.
mxtech1
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2/27/2018 10:54am
I think most of you are confused in thinking that Feld and/or the AMA cares about what you think.

Nothing will change until an OEM needs them to change. Alta will be the next big development on the Horizon for Pro Racing.

It wouldn't be that difficult for the AMA to say "by 2023 max cc displacement for AMA competition is XXXcc." This gives the OEMs nearly 5 years to conform. They would conform, but the AMA doesn't want to ruffle any feathers.

Look at how F1 and NASCAR work. The governing bodies dictate the platform by rules and regulations. The AMA basically says build whatever you want to build and we will figure out how to adapt the rules accordingly.

Most of you jack wagons complain on the boards about how fast and over-powered 450s are for Pro racing, but then you turn around and gloat anytime you speak with your wallet and buy a new 450.

You want 450s out of pro racing? stop buying them! if they can't sell them, they won't make them! You all think it's about the AMA and Feld, but it's not! It's all about the average joe who keeps buying.
Wells423
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2/27/2018 11:12am
mxtech1 wrote:
I think most of you are confused in thinking that Feld and/or the AMA cares about what you think. Nothing will change until an OEM needs...
I think most of you are confused in thinking that Feld and/or the AMA cares about what you think.

Nothing will change until an OEM needs them to change. Alta will be the next big development on the Horizon for Pro Racing.

It wouldn't be that difficult for the AMA to say "by 2023 max cc displacement for AMA competition is XXXcc." This gives the OEMs nearly 5 years to conform. They would conform, but the AMA doesn't want to ruffle any feathers.

Look at how F1 and NASCAR work. The governing bodies dictate the platform by rules and regulations. The AMA basically says build whatever you want to build and we will figure out how to adapt the rules accordingly.

Most of you jack wagons complain on the boards about how fast and over-powered 450s are for Pro racing, but then you turn around and gloat anytime you speak with your wallet and buy a new 450.

You want 450s out of pro racing? stop buying them! if they can't sell them, they won't make them! You all think it's about the AMA and Feld, but it's not! It's all about the average joe who keeps buying.
you have a good point but unfortunately from what I’ve witnessed this isn’t how our sport works. Teams and pros quit racing open class 2 strokes and the masses followed. No R&D went into the half liters for the last years they were produced. Same thing ultimately happend to 2 strokes. The 4 strokes came on strong and 10 years after Doug hit the track on his works bike 3 of 4 Japanese manufactures had pulled the plug on 2 strokes. Fans want to ride what the pros do. Honestly if oval track amateurs had access to nascar type equipment that’s what they’d be driving. It’s just an odd part of our sport that we can ride really similar equipment to what the best guys in the world ride.
2/27/2018 12:18pm
Wouldn't choking down power hurt a bigger guy like Pieck and favor a smaller guy like J-mart on a restricted 450?
yz133rider
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2/27/2018 2:01pm
Lower the weight minimum. Ktm could be lighter especially at pro level but arent allowed.
Fresh
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2/27/2018 3:46pm
yz133rider wrote:
Lower the weight minimum. Ktm could be lighter especially at pro level but arent allowed.
Wouldn't that make the inertia of the motor more agressive?

What about just doing a complete switch on the purse for both classes. 450's would be getting the current 250 purse and 250's would be getting the current 450 purse. More privateers would be attracted to the 250 class, and so would the factory teams.
doghouse
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2/27/2018 4:05pm
ML512 wrote:
Well, that’s pretty close to what a Factory KTM 450 is...remapped stock ECU, race fuel, stock cam that’s re-timed, head is lightly cleaned up...not much to...
Well, that’s pretty close to what a Factory KTM 450 is...remapped stock ECU, race fuel, stock cam that’s re-timed, head is lightly cleaned up...not much to see in there. There’s a lot of Factory 450s out there that are just lightly massaged, that’s not the injury cause...the inertia they produce is what bites you more than the actual power output.

The Factory 450s I’ve gotten to try the past couple years are insanely smooth and not the rocket ship that some would think.
While there are certainly myriad issues in SX, this is exactly what the 450 problem is. The bikes have an insane amount of inertia.

I almost killed myself last year when I stepped off a CR500 and onto another guys KXF450 because of not being ready for the inertia.
Johnny Depp
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2/27/2018 4:45pm
One day we'll look back on all this and laugh when electrics are the norm, with less inertia.
And I don't think having less inertia in a CR500 is the solution, you need a flywheel weight.

Let's not forget a few (recent) attempts to harness the laws of inertia that are no longer with us:



Maico's chain driven mainshaft used inertia to weight the front wheel





731chopper
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2/27/2018 5:54pm
Markee wrote:
First you would have to have a governing body that is worth a shit. I don't have confidence the AMA could regulate any mechanical regulations when...
First you would have to have a governing body that is worth a shit. I don't have confidence the AMA could regulate any mechanical regulations when it comes to HP.
Something could absolutely be done. Most every other form of motorsport requires post race tech inspection that can be very extensive. Supercross should have a post race tech inspection. Every bike leaving the track (with or without the rider) gets impounded to tech. The bikes can be retrieved from tech the following day no later than noon.

Something should be done to slow the bikes down and make them lighter.
Crush
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2/27/2018 6:24pm
20-30 years ago they knew 500s were too much for indoors and then too much in general...

Why we're here again is a result of some rules reflecting old technology, made redundant in one engineering cycle... We're like 5 cycles later and the rules still haven't been updated because people have their heads up their ass.

Fuck em off. Race 250s as your premier class. Amateurs and the "entry" pro class become two strokes. Cheapen the base level of the sport to encourage participation – which is 100% the biggest problem facing the sport today.

It's not hard. It just has to be done. Yes it will cost money, but this is a long, like forever long game.
Hcallz5
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2/27/2018 6:53pm
Unlike NASCAR we have the ability to make the tracks slower (more technical) which is what you saw last weekend with that big sand section. I think it's a great idea, a low risk addition for the riders that is difficult enough to also be entertaining for the fans.
71Fish
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2/27/2018 6:59pm
eGGz wrote:
Its not the bikes, its the tracks. The injuries are due to the absurd spectacle that SX has become. Feld's motivation has never been to "grow...
Its not the bikes, its the tracks. The injuries are due to the absurd spectacle that SX has become. Feld's motivation has never been to "grow the sport." Their motivation is solely to grow their profits. True racing fans don't need to experience pyrotechnics, screaming announcers, tracks that have the riders in the air half the time. These elements are a sadly successful attempt to pick the low hanging fruit. The riders are merely an expendable commodity.
That doesn't make sense. In your opinion, how does feld only care about profits when their "expendable commodity" is in limited supply?
Plus, the have to widen their fan base if they want to "grow the sport" and increase profits.
Take a business class, bruh.

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