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PostPosted: Mon Dec 18, 2017 12:10 pm 
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Thanks for the early posting of the Race rules and the time/effort all of you put into these rules.
Even when we don't say it - we do appreciate the time and effort . . .

Now to the Question:
Is there a definition for "Redline" used in the Average Horsepower calculation process ??

When we look at the car's tach there is a redline placed by the car manufacture . . . but in these race classes most engines
don't have a real redline except for maybe the rev limiter selected by the car owner or engine builder.
Our rev limit was selected during the modified engine Dyno tune process.
Is this what the rules intended for the "Redline" for our car ??

Thank you in advance for some further clarification of the rules use of the term "Redline" .

Regards,

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PostPosted: Mon Dec 18, 2017 2:30 pm 
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Sboxin wrote:
Thanks for the early posting of the Race rules and the time/effort all of you put into these rules.
Even when we don't say it - we do appreciate the time and effort . . .

Now to the Question:
Is there a definition for "Redline" used in the Average Horsepower calculation process ??

When we look at the car's tach there is a redline placed by the car manufacture . . . but in these race classes most engines
don't have a real redline except for maybe the rev limiter selected by the car owner or engine builder.
Our rev limit was selected during the modified engine Dyno tune process.
Is this what the rules intended for the "Redline" for our car ??

Thank you in advance for some further clarification of the rules use of the term "Redline" .

Regards,


Rules still say this in regard to Dyno testing:
"All Dyno graphs must show decreasing power for 1500 rpm from the peak horsepower level, or the car must reach the rev-limiter during the Dyno testing."

So, "redline" could potentially be either endpoints (but has nothing to do with the red mark on the OEM Tachometer).

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PostPosted: Mon Dec 18, 2017 2:38 pm 
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davidfarmer wrote:
I have no issue with adjusting for mis-sized tires, I DO have an issue with tires being deemed illegal because I can't afford to buy new wheels. Just because the sidewall bulges out on a particular rim has nothing to do with the tread width or performance.

A 245/40/18 Hoosier is going to be very close to 266mm on my rims

That's not true to begin with, because the larger wheel DOES make the tread width and the section width wider because of the design of the tire shoulders.
And, if the car weighs more than 3100 lbs, you can still use the same size wheel and tire---not "illegal", just won't get the "cheater" Mod Factor for a tire that is essentially a hair smaller than the 275. Or, you can use those wheels with the 275's, and be a bit larger than the 245's. It's called "closing a loophole".

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PostPosted: Mon Dec 18, 2017 2:41 pm 
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JCathers wrote:
BFG doesn't have a time trials contingency.. these changes to TT4 really seem to be trying to force hoosiers out of TT instead of leveling the playing field with Toyo/BFG - pushing an american company that produces great tires with a great contingency program out of TT because their tires run wide...

These rules don't force Hoosiers out of TT one bit. They force supersize wheels expanding tread and section width out of getting inappropriate Mod Factor perks.

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PostPosted: Mon Dec 18, 2017 5:33 pm 
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Greg G. wrote:
JCathers wrote:
BFG doesn't have a time trials contingency.. these changes to TT4 really seem to be trying to force hoosiers out of TT instead of leveling the playing field with Toyo/BFG - pushing an american company that produces great tires with a great contingency program out of TT because their tires run wide...

These rules don't force Hoosiers out of TT one bit. They force supersize wheels expanding tread and section width out of getting inappropriate Mod Factor perks.


Greg - then why not let the cars under 3100 lbs run the wider wheel/tire combo then if they so choose? They of course would have to apply the correct modification factor based on NASA Section Width, but this way they would still have a choice to use the wheels they purchased based on last years rules?


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PostPosted: Tue Dec 19, 2017 7:54 am 
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Greg G. wrote:
That's not true to begin with, because the larger wheel DOES make the tread width and the section width wider because of the design of the tire shoulders.
And, if the car weighs more than 3100 lbs, you can still use the same size wheel and tire---not "illegal", just won't get the "cheater" Mod Factor for a tire that is essentially a hair smaller than the 275. Or, you can use those wheels with the 275's, and be a bit larger than the 245's. It's called "closing a loophole".


How is it a cheater loophole if the tire in question is available to everyone? Because some cars can run wider wheels than others?
If that's the case, it seems only logical that it would have been a lot easier to limit wheel size. No?

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PostPosted: Thu Dec 21, 2017 7:36 am 
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Because then we would just come out with "cheater" wheels :lol:

We all know what NASA is doing with the section width rule - they needed to come up with a rule that ensured that no one would come in with a overly wide tire for the size stamped on the sidewall. Weather it's from a plus sized tire like the Hoosier 255 or weather it's due to us stretching the tire by putting it on a wider rim. Yeah it sucks that some of us will have to buy new rims but in the long run it's a good rule and one that guards us from future tire issues. And seriously has anyone ever really had an issue selling wheels? Finding good used wheels isn't always easy but selling good used wheels - not too tough.

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PostPosted: Fri Dec 22, 2017 6:22 am 
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Hi Greg,

Could you elaborate on the combinations tested. Maybe a table of the combinations you/NASA collected. I think this data will save a lot of us a headache or money on combinations we cannot afford to order for trial and error purposes.

In your testing did you test a 255/35R18? If so on what rim width? I would like to step up to 18's for caliper clearance/wheel offset.

Currently I have is 275/35R17 R7 on a 10" wheel and they are an exact fit for the 282 template.

Thanks,

Nick


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PostPosted: Sun Dec 24, 2017 11:48 pm 
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Thethreefitty wrote:
Hi Greg,

Could you elaborate on the combinations tested. Maybe a table of the combinations you/NASA collected. I think this data will save a lot of us a headache or money on combinations we cannot afford to order for trial and error purposes.

In your testing did you test a 255/35R18? If so on what rim width? I would like to step up to 18's for caliper clearance/wheel offset.

Currently I have is 275/35R17 R7 on a 10" wheel and they are an exact fit for the 282 template.

Thanks,

Nick

Nick, someone started a thread in the Race Craft section of the Forums, but it hasn't gained much traction yet. Our data won't be posted, because as soon as someone buys some other wheel, or runs a different tire pressure, etc., they will complain that "we told them...."

I'm comfortable stating that the 275/35R18 R7 should fit the 282 template on a 10" wheel. I know the 255 won't come close even (290+) on an 11" wheel--probably won't fit 282 on a 10" wheel, but not confirmed.

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PostPosted: Wed Jan 03, 2018 9:31 am 
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As a general question. What was the basis of the template using 30mm for the sidewall? Having a shallower number (25 or 22mm) would focus approved or not approved status on the tread width more than where some tires are very square at the sidewalls, or if a rim is slightly wider than the tread of the tire.

Is there a noticeable performance gain by installing a tire on a rim where the sidewall is flexed outwards to the rim?

Just questions from the peanut gallery....Thanks


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