45 replies to this topic

[949Racing]

949 RACING

Spec Miata 15x7 6UL

First production run just arrived, available for immediate shipment.

http://mazdaracers.c...c-miata-wheels/

 

[Caveman-kwebb99]

Ok maybe im confused the max allowed offset is 25 for SM if I remeber right, but the offset of these is 24???  that would make them illegal for SM use, is the 24 offset a mistype on your site?  

 

Very curious about this?  Not that +/- 1 offset will win or lose a race, but we all know tech guys see black and white not shades of grey...

[speedengineer]

No max allowed offset for SM, just a max allowed track width.  People say that 25mm offset is the max you can run such that you don't have to worry about busting track width measurement.  I'm sure there is more than 1mm of fudge factor in there, but I haven't measured it myself. 

 

Wheels look great Emilio, and a great price.  Do they happen to come with valve stems?

[949Racing]

No max allowed offset for SM, just a max allowed track width.  People say that 25mm offset is the max you can run such that you don't have to worry about busting track width measurement.  I'm sure there is more than 1mm of fudge factor in there, but I haven't measured it myself. 

 

Wheels look great Emilio, and a great price.  Do they happen to come with valve stems?

Visit our website for item details. Valves not included.

 

And yes, 1mm is a long way from the trackwidth limit considering there a lot of cars set up with +25 wheels and spacers. I am guessing there is at least a fair chance the Extended Lower Ball Joints will be allowed by SCCA. They have a direct effect on track width so the trackwidth rule will have to be adjusted. NASA has already approved the ELBJ's and I believe SCCA is looking at them for autocross classes. No more ah, "crash damaged" tubs or subframes to get -3° on the NA's

[Jim Drago]

if you run 25 mm wheels you can not run spacers or you will not pass track. There is enough room for 24 mm offset wheel with no spacer IMO as we set spec with 25mm offset and added a little fudge factor, but it will be close.
IMO, the likelihood of extended ball joints in SCCA is not good.

Wheels look great!
Jim

[949Racing]

if you run 25 mm wheels you can not run spacers or you will not pass track. There is enough room for 24 mm offset wheel with no spacer IMO as we set spec with 25mm offset and added a little fudge factor, but it will be close.
IMO, the likelihood of extended ball joints in SCCA is not good.

Wheels look great!
Jim

 

 

 

 

 

I assume you mean 5mm spacers? Has anyone ever been measured? Has anyone ever failed trackwidth? Hard to imagine the measuring rig is accurate +/- .079"

[steveracer]

Are they any stronger than the earlier versions?

 

I have a small pile of wheels with bent inner beads from curbs...

[davew]

Around here, we get track measured regularly. As stated in another post.

 

As one of the people who measured cars and wrote the rule, the spec is based off 25mm wheels with no spacer. the fudge factor is very small. I doubt the extended ball joints would create a legal track with 25mm wheels.

 

Remember any wheel spacer must be used on both sides of the car, thus a 5mm spacer become 10mm of track

 

Dave

[949Racing]

Are they any stronger than the earlier versions?

 

I have a small pile of wheels with bent inner beads from curbs...

Gravity cast T4 Gen 1's from 2007 are not even in the same league as the current flow formed T6 wheel.

[949Racing]

Around here, we get track measured regularly. As stated in another post.

 

As one of the people who measured cars and wrote the rule, the spec is based off 25mm wheels with no spacer. the fudge factor is very small. I doubt the extended ball joints would create a legal track with 25mm wheels.

 

Remember any wheel spacer must be used on both sides of the car, thus a 5mm spacer become 10mm of track

 

Dave

Two different topics. Extended ball joints and an extra 1mm of offset. ELBJ's push the wheel out a good 15mm per side so clearly a huge change. Not the topic of this thread though.

 

It appears the trackwidth rule is written with +25 wheel + 5mm spacer and nothing more. That means a bent spindle, subframe, tub, tolerance stack on hub, rotor or wheel that increases one side more than .039" will be illegal, if I am to understand the assertion. So the status quo is run 5mm spacers but check your trackwidth because your car is on the limit.

 

OTOH, run a +24 wheel with 3mm spacer and have a 3mm (.120") fudge factor for bent parts or tolerance stacks. 

[Ron Alan]

^^^^Someone doesnt read other posts very well by the guys who wrote the rules. 25mm without spacers is what the measurement is based on. My guess is these 24mm wheels will be ok but right at the limit...Time will tell.

 

They are good looking wheels...thanks for offering up another option! 

 

 

Can someone point to the measurement and how it is measured in SM? 

[davew]

I was chairman of the rules committee and Jim Drago was the CRB liason when we wrote the rule. It is based off of 25mm offset wheels with no spacer. We built in very little tolerance. I remember we measured at least 20 racecars when we determined the spec. These wheels will probably pass the spec. but if anything is off, you have used up the built in fudge factor. Even a 3mm spacer would be non compliant.

 

Nothing against the wheels quality, apperance or price. But it may cause an illegal situation if used in SM. Buyer be ware.

[Jim Drago]

Two different topics. Extended ball joints and an extra 1mm of offset. ELBJ's push the wheel out a good 15mm per side so clearly a huge change. Not the topic of this thread though.
 
It appears the trackwidth rule is written with +25 wheel + 5mm spacer and nothing more. That means a bent spindle, subframe, tub, tolerance stack on hub, rotor or wheel that increases one side more than .039" will be illegal, if I am to understand the assertion. So the status quo is run 5mm spacers but check your trackwidth because your car is on the limit.
 
OTOH, run a +24 wheel with 3mm spacer and have a 3mm (.120") fudge factor for bent parts or tolerance stacks.

The rule was written to accommodate 25 mm offset wheels with NO spacers. From memory, I think we added 3 mm to that spec. Several of us on SMAC at the time measured a few of our cars to come up with the spec. I believe the wheels will pass if there are no spacers on the car and nothing is bent. But they will be close. I am ordering a set, so IMO, they will pass.
Jim

[Todd Lamb]

Extended lower ball joints were not approved by the SMAC.

[949Racing]

Extended lower ball joints were not approved by the SMAC.

Good to know going forward. NASA approved them so that will require some setup juggling by racers who double dip.

[Todd Lamb]

Well Xavier (NASA) and I (SCCA SMAC) made an effort to align the rules, but apparently NASA approved that one on their own. First I had heard of it was a few days ago from Flyin Miata.

[Mark]

Is there an 'unlike' button somewhere? 

[Mike Collins]

We measured multiple cars with multiple sets of wheels...believe it or not, not all 25mm wheels measured the same.  It was close but not the same.  The rule was set with no spacer and 3mm of fudge factor.  Depending how these "24"mm wheels actually measure it will be close. Yes! I have seen cars measured for track width and I have seen cars fail because of spacers... Buyer be ware, they may pass but you are flirting with the edge of the rule and trusting your 80 year old tech official with bi-focals to get the measurement right... ( the good news is they probably will, its the young guys that get wrong more often then not and then can't accept that...hmnn Runoffs.... )

[FTodaro]

I apologize for posting off topic, but this thread illustrates the point. If there already was an agreed upon approved method for obtaining camber (offset bushings) approved by both clubs, available for all drivers at a reasonable price. Why in the world would NASA go off on a tangent, and approve another method of Camber enhancement?

 

First as we see this additional method is in conflict with the SCCA rules. Next its application may put the competitor in jeopardy of a violation on Track Width. Third, it now provides the racer with options which is going to cost drivers MORE money because you know teams with test each method to see if one has an advantage over the other. So the net result is that it will cost the class even more money.

 

As I have posted before, if you’re going to provide multiple options, then why even have a spec, why not just leave camber open, Including Bent spindles which were expensive in their own right.

 

I am not really seeing the logic of this anymore?

 

Rant Over.

[Tom Sager]

I apologize for posting off topic, but this thread illustrates the point. If there already was an agreed upon approved method for obtaining camber (offset bushings) approved by both clubs, available for all drivers at a reasonable price. Why in the world would NASA go off on a tangent, and approve another method of Camber enhancement?

 

First as we see this additional method is in conflict with the SCCA rules. Next its application may put the competitor in jeopardy of a violation on Track Width. Third, it now provides the racer with options which is going to cost drivers MORE money because you know teams with test each method to see if one has an advantage over the other. So the net result is that it will cost the class even more money.

 

As I have posted before, if you’re going to provide multiple options, then why even have a spec, why not just leave camber open, Including Bent spindles which were expensive in their own right.

 

I am not really seeing the logic of this anymore?

 

Rant Over.

I'll take a stab....

 

1. Someone thinks the extended ball joint is a better mousetrap compared to bushings

2. There is an intent to make it more difficult for competitors to run events put on by the other organization.