Landracing Forum
Bonneville Salt Flats Discussion => SCTA Rule Questions => Topic started by: SteveM on November 24, 2015, 05:34:09 PM
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The tires I have on the front of my Rampage (H/DT) are Federal Formozas, marked as 165/50R15, 73V. They are the perfect diameter for the engine and trans I'm using. (21.5" calculated diameter)
There's a chance that the little green truck will be able to run on the high side of 150mph in 2016.
Section 2.F of the Rulebook for 2014 (don't have my 2015 book handy) states that VR and ZR rated tires are good for up to 200mph.
Since my tires have both a V and an R in the rating (although not immediately adjacent to one another in the form of "VR"), does SCTA consider these to be "VR" rated, and therefore eligible to run faster than 150 mph?
Your educated opinions are being asked for here. I know it's not an official ruling until I get something from SCTA in writing, but I'm just trying to get my level of understanding raised about tire speed ratings.
Steve.
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Steve,
All you need to know is here:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35
Good luck in 2016!
Geo
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Thanks for the link. Yes, I was familiar with the DOT rating system.
The issue I'm trying to figure out is that the DOT ratings don't seem to match up with the speed ratings in the SCTA-BNI rulebook.
SCTA says VR and ZR rated tires are allowable up to 200 mph.
There is an EXTREMELY low likelihood that my Rampage would ever see 200 mph. If I ever get anything close to that, I'll buy dedicated racing tires, as per the rulebook.
It is entirely possible that it might run a tick over 150 with the current drivetrain setup, though. I'm hoping someone will chime in about how SCTA might interpret the rating of my current tires (165/50R15 73V).
Steve.
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The term VR and ZR first appeared in the rule book around 1989-1990. That designation has not changed since as far as I can see though other sizes with allowed speeds have been added, generally a few mph greater than the mfg rating. For instance a U rated tire is 124mph but allowed to 130 by SCTA. If you read the tire rack site carefully you will see that the speed designation in the tire size ( for instance 205/75VR-15) has not been used recently ( supposedly since 1991) and the load/speed rating is separate= the 73V in your case. As I understand, the "R" in your tire size designates a radial as opposed to bias ply tire and doesn't mean anything from a speed standpoint. Therefore the 73V designation says you have a V rated tire (read "VR") in your question, and so you should be good to go.
My interpretation of course; better ask SCTA-looks like Jim Dunn, page 196 of the 2015 book.
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Looks like those tires are V speed rated which is up to 149 mph. Probably okay if you're looking to go "around" 150 mph.
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Looks like those tires are V speed rated which is up to 149 mph. Probably okay if you're looking to go "around" 150 mph.
Nathan, the mfg rating is 149. The rule book uses the (I think obsolete) "VR" designation and indicates it is good to 200. The rule book also clearly says there is some leeway in the mfg ratings. That is the point of the OP's question. If he has a "V" rated tire (old VR), the rule book clearly says he is good to 200. I think you are an inspector, right? Do you have a different interpretation?
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Interesting, Comparing the car and motorcycle tire speed ratings in the 2015 SCTA rule book.
An H rated tire is rated up to 150 mph for a car and 130 mph for a bike?
Nathan, I know the manufacturers recommendation for a V rated car tire is up to 149 mph but I'm not seeing that in 2.F, page 26, 2015 rule book.
What am I missing? Jeez just when I thought I knew everything. :-P
Dang it Jacksoni, you type faster than I do. :-D
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VR and V are not the same rating AFAIK. I would do what any other inspector would do: google "V tire speed rating". Multiple online sources say 149 mph. I see nothing that says V and VR are the same and I'm pretty sure that they're not. Newer high speed tire ratings are Z, W and Y. As far as I can tell, VR meant rated to at least 130 mph.
Unless someone can show otherwise, I'd fall back to what's readily documented and available to the public.
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VR and V are not the same rating AFAIK. I would do what any other inspector would do: google "V tire speed rating". Multiple online sources say 149 mph. I see nothing that says V and VR are the same and I'm pretty sure that they're not. Newer high speed tire ratings are Z, W and Y. As far as I can tell, VR meant rated to at least 130 mph.
Unless someone can show otherwise, I'd fall back to what's readily documented and available to the public.
As Jacksoni said his tires have the V (not VR) in the speed rating portion of the tire's service description (73V) ....
The tires I have on the front of my Rampage (H/DT) are Federal Formozas, marked as 165/50R15, 73V....
... as is the procedure since 1991 so as to be rid of the confusing older methods of labeling the tires such as ..
Over the years, tire speed rating symbols have been marked on tires in any of three ways shown in the following examples:
225/50SR16 225/50SR16 89S or 225/50R16 89S
Since the V is only in the speed rating area for the tire it is a V tire, speeds up to 149, so if the rule book says that a V rated tire can be used up to 200 (out of town with no rule book) then if it was my car I would argue the tire is legal and take along a copy of the article here...
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35
... that explains the confusion between old and new markings on tires...
Beginning in 1991, the speed symbol denoting a fixed maximum speed capability of new tires must be shown only in the speed rating portion of the tire's service description, such as 225/50R16 89S.
Sumner
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Rule book doesn't specify SCTA allowed speed rating for a V tire therefore...
Unless someone can show otherwise, I'd fall back to what's readily documented and available to the public.
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Rule book doesn't specify SCTA allowed speed rating for a V tire therefore...
Unless someone can show otherwise, I'd fall back to what's readily documented and available to the public.
But Nathan, there is no such thing as a "VR" rated tire since 1991 as has been pointed out. It is an obsolete usage. Those tires became "V" rated. If we strictly stick to what is in the rule book (here is a spot where a change is in order) the only tires allowed are up to "H" rating at 150 MPH. And SCTA with all the other, lower rated tires, allows some speed over the MFG recommendations. ie; the Above H tires is allowed to 150 but is 130 rated.
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Seems nobody mentioned the vehicle has to be legal and running all the gear, minimum requirements for the speed in the class for which they are running in..looks like at ElMo and Bonneville the records are less than 106 mph..in the HDT class..
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But Nathan, there is no such thing as a "VR" rated tire since 1991 as has been pointed out. It is an obsolete usage. Those tires became "V" rated. If we strictly stick to what is in the rule book (here is a spot where a change is in order) the only tires allowed are up to "H" rating at 150 MPH. And SCTA with all the other, lower rated tires, allows some speed over the MFG recommendations. ie; the Above H tires is allowed to 150 but is 130 rated.
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Jack, I don't see anything anywhere that says a V tire is a VR tire. Yes, VR, which was 200 mph rating, went away but a V tire has a very clear published rating of 149mph that anyone with access to the internet can find. There is no specific speed allowance in the rule book for a V tire (and nothing that states a V rating and VR rating are the same). Therefore, I'd put limit at published speed rating. Does not matter that there is leeway in other tire ratings. V is not specifically listed therefore all an inspector can do is reference manufacture ratings - unless specific testing has been done to validate that a certain tire can be run beyond it's speed rating. That hasn't been done for a V tire.
Rule book says ZR is allowed up to 200. AFAIK, ZR is still a current rating.
Show me something that says that VR rating is now V. I don't think your assumption is correct. Higher speed ratings are Z, W and Y. No V's that I see. The other thing you're not getting is that I can't sit on the witness stand and testify that I "allowed" Racer Joe Blow's car to run with V rated tires to 200 mph which resulted in a tire failure, crash and death or dismemberment because Jack Illiff says VR is the same as V. If there isn't a specifically stated speed limit printed in the rule book for a certain tire, I'm always going to refer to the lowest published speed rating that I can find. Case closed, end of discussion. A V tires is NOT a 200 mph tire. V rating is 149 mph. Competitor presents something that says otherwise from the manufacturer and it'll be a different story. Make sense?
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Thanks Nathan. I appreciate your thoughts and input.
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But Nathan, there is no such thing as a "VR" rated tire since 1991 as has been pointed out. It is an obsolete usage. Those tires became "V" rated. If we strictly stick to what is in the rule book (here is a spot where a change is in order) the only tires allowed are up to "H" rating at 150 MPH. And SCTA with all the other, lower rated tires, allows some speed over the MFG recommendations. ie; the Above H tires is allowed to 150 but is 130 rated.
Jack, I don't see anything anywhere that says a V tire is a VR tire. Yes, VR, which was 200 mph rating, went away but a V tire has a very clear published rating of 149mph that anyone with access to the internet can find. There is no specific speed allowance in the rule book for a V tire (and nothing that states a V rating and VR rating are the same). Therefore, I'd put limit at published speed rating. Does not matter that there is leeway in other tire ratings. V is not specifically listed therefore all an inspector can do is reference manufacture ratings - unless specific testing has been done to validate that a certain tire can be run beyond it's speed rating. That hasn't been done for a V tire.
Rule book says ZR is allowed up to 200. AFAIK, ZR is still a current rating.
Show me something that says that VR rating is now V. I don't think your assumption is correct. Higher speed ratings are Z, W and Y. No V's that I see. The other thing you're not getting is that I can't sit on the witness stand and testify that I "allowed" Racer Joe Blow's car to run with V rated tires to 200 mph which resulted in a tire failure, crash and death or dismemberment because Jack Illiff says VR is the same as V. If there isn't a specifically stated speed limit printed in the rule book for a certain tire, I'm always going to refer to the lowest published speed rating that I can find. Case closed, end of discussion. A V tires is NOT a 200 mph tire. V rating is 149 mph. Competitor presents something that says otherwise from the manufacturer and it'll be a different story. Make sense?
First off, let me make sure everybody understands where I am coming from:
I Love Landracing.com and Jon & Nancy are awesome for providing this venue for all of us to ask questions and discus issues.
But when it comes down to the definite and final answer and call, I have to agree with the statement DW made many times:
Contact the appropriate person listed on the SCTA website or rule book.
In this case I would send an e-mail to the "Car Technical Chair" Lee Kennedy at Lee.Kennedy@avmetrics.net
and CC the "Chief Automobile Inspector" Steve Davies at cartechscta@gmail.com
Something to that effect:
Lee & Steve,
Can you please answer following question for me.
I am trying to run a Federal Formozas tire, marked as 165/50R15, 73V. Manufacturers Speed rating is 149 Mph.
Is this tire considered to be a VR tire as specified in the 2015 SCTA Rule Book on page 26, Section 2.F Tires ?
Will I be allowed to compete with this tire during SCTA Sanctioned events (El Mirage / Bonneville) to a stated
Top Speed of 200 Mph ?
My vehicle is a Rampage Pickup and runs in H/DT. Current Records are in the 130 Mph area, but I am hoping to
get within 160 to 170 Mph.
Thanks in advance,
.............................
That's what I would do. But I am just a bystander in this discussion.
AND, if you get the desired answer, make sure to print out the e-mail and include it with your log book.
There may be a chance, that an Inspector will want to see documentation of this conversation with Lee & Steve.
More than likely, they will not remember what they told you. They are getting requests like this daily.
Hope to see you out in Bonneville in 2016. Good luck with your quest.
Mike Spacek
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When were the tires manufactored?
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Honestly, this is a pretty simple question with a pretty simple answer. The tire in question is a 165/50R15, 73V. The fact that there is a R and V in the tire description doesn't make it a VR tire and doesn't make it a 200 mph tire. It's pretty clear that 73V is the load and speed rating. Load rating is 73, speed rating is V. The R in this case and pretty much all other cases where it comes between the aspect ratio and the wheel size denotes that it's a radial tire and that's it.
This is definitely an "inspector-level" type question IMO. No real need to ring up the big guns for such a minor question. If there was something to contest and a decision was needed then yeah, hit them up but I don't really think that's the case here. One problem with only contacting someone within the association and not posting here is that someone else with the same or similar question doesn't get to see the answer or the discussion therein.
BTW I've already been down the V rated tire road with Excelsior Comp-V tires. They're sold as a vintage style "competition" tire but only have a V speed rating. Car that showed up with them was limited to 150mph.
Sometimes I speak from experience.
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Seems nobody mentioned the vehicle has to be legal and running all the gear, minimum requirements for the speed in the class for which they are running in..looks like at ElMo and Bonneville the records are less than 106 mph..in the HDT class..
The Bonneville record is 135.003 mph in H/DT
The ECTA record (Ohio Mile) record is 135.624 mph in H/DT
I currently hold both of those records, and certainly hope to push both of them higher in 2016.
The El Mirage record is still 104.8xx mph, held by Pat Manghelli.
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When were the tires manufactored?
2013.
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Also, FWIW, when it comes times for rule change submissions next year, I'll put one in to update the street tire specs. The old and outdated specs get over looked because there aren't many competitors running street tires. There's been a pretty big push to require that competitors follow manufacturer specs for safety equipment (seat belts and head and neck stuff comes to mind) because the manufacturers obviously know how their equipment is to be installed/used better than the SCTA does. I have a feeling that allowed speeds for certain tire specs might drop to the manufacturers published speed rating should the current SCTA spec be higher. Doing otherwise opens up the association to liability risk.
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Nathan,
Thanks for taking action on this.
Don
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I don't know what the official ruling with be with respect to allowable speeds for current V-rated (As opposed to pre-1991 VR rated) tires, but this table from tiresafety.com seems to indicate that the ratings are equivalent....
http://www.tiresafety.com/sizes/passenger/speed.asp
I have submitted an inquiry to SCTA requesting clarification on this issue.
Thanks, everyone.
Steve.
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I don't know what the official ruling with be with respect to allowable speeds for current V-rated (As opposed to pre-1991 VR rated) tires, but this table from tiresafety.com seems to indicate that the ratings are equivalent....
http://www.tiresafety.com/sizes/passenger/speed.asp
I have submitted an inquiry to SCTA requesting clarification on this issue.
Thanks, everyone.
Steve.
Yep, the difference between a VR and a V tire is in name only, just like now we call a Datsun a Nissan :-). They just got rid of the R part after 1991. Same specs., has to pass the same lab certification and so on...
Sumner