SPM rules question / help me class my car

M

mtm68

Member
hello folks,

I'm a newbie to the PNW, with some experiencing racing cal club, sfr-scca, and nasa nor-cal. I know I raced against some of the conference folks in the 25 hours in 05/06/07/08. We finished 2nd in E2 in 06/07 with our Kumho sponsored Miata, and won E2 in 08 with Evil Genius.

I'm reading and learning about conference, getting my licensed issued, etc. and ran into a rules question regarding new car I'm building. After running the relatively restricted rulesets for years in pro7, sm, it7 and ita, i decided to build a run a 'fun' car and let the classing fall where it may. I know, its not the smart thing to do..
After reading the rules, and corresponding scca rules, i believe the car I describe below fits into SPM; your thoughts are highly encouraged.

Chassis: 93 Miata, with low front crossbar cage (scca prod style roadster cage)
Motor: turbocharged 1.6 miata
Aero, stock body with wing and splitter.
The gotcha: stock fuel tank.

Here is my read of the rules... Conference rule 1313, tel me SP cars must meet safety regs following 1303A and are classed using a formula of displacement x 1.4 for forced induction, that gives me a net engine size of 2.24, putting me in SPM.

1303A says SP cars will race according to Oregon region SCCA rules.

Following those (curiously found in the sups, as opposed to a standalone ruleset)
from here: http://www.oregonscca.com/media-library/documents/roadrace/2011/2011 general supp regs 1-26-11.pdf

Page 6, letter D it says to be legal follow gcr sections 9.3 (general safety) and 9.4 (GT and Prod cage rules)

Off to the gcr from scca.com
gcr page *92 section 9.3.27 says I need a fuel cell, unless otherwise specified in the GCR.
page 102 9.4- cage rules. no issue there. car looks like every other SCCA FP style Miata.

So, now we are off to find out if we are 'otherwise specified in the GCR'
On page 495. section 9.1.5(prod rules) #11, we are allowed to use the stock fuel tank as long as its between the frame rails and wheelbase.

So, if you've followed along this far. .what do you think? SPM legal?
related SPM Q- I see no restriction on tires to DOT only. Am I reading that right? real slicks would be fun.

thank you, I look forward to meeting folks at the track. I'll be wandering around the 8 hours of the cascades in a couple weeks.
 
well how much does the car weight. there is another class you could run too. ST with ICSCC is basicly anything goes with a min weight and a power to weight ratio and a DOT tire, some GT2 cars will also run spm and run true slicks. i say you are spm legal. ive run spm with my ITA car just because i wanted to run in that run group to practice for the enduro's the car does
 
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Marcus,

Regardless of how this discussion turns out RULES WISE, I'd URGE you to install a fuel cell!! Just a WAY WHOLE bunch safer then a production car gas tank.

We have had very, very few crash/fires in ICSCC racing and we'd really like to keep it that way from a Turn Workers standpoint.

Relative to the potential loss.. fuel cells aren't that costly compared to the entire car.
 
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I'd put in a cell, too, but you're not required to have one in either SPM or ST. Yes, you can run whatever tire you want in SPM (DOT-only in ST).
 
Thanks for the ST suggestion, I don’t see it as legal for ST, based on these factors:
1324 B 2 (IT rules in SCCA GCR 9.4 don’t specifically allow the low roll hoop cage, only Production and GT)
1324 C 2 (The front and back window angle and shape must not be changed) This is impossible since it doesn’t have a windshield 

Otherwise, ST looks like it would be great, I’m not sure about HP output, since the motor is still on the engine stand. I was also hoping for quite a bit less than 2400 lbs (ST minimum I would be shooting for), obviously post completion, I could ballast it up to that.


the_driver said:
well how much does the car weight. there is another class you could run too. ST with ICSCC is basicly anything goes with a min weight and a power to weight ratio and a DOT tire, some GT2 cars will also run spm and run true slicks. i say you are spm legal. ive run spm with my ITA car just because i wanted to run in that run group to practice for the enduro's the car does
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Richard / Steve,
The Miata gas tank is actually extremely safe;its very well protected by the crash structure in the car and additionally once a cage is installed. The options for installing a fuel cell would put it hanging out the trunk, and without significant crash reinforcement there (think dirt modified), it would actually be less safe than the stock tank. The 'best' option for a fuel cell install into a Miata is actually the area where passenger seat (was). There are quite a few folks running in SCCA with that setup. I haven't yet convfinced myself that having the cell next to me is very safe either (or atleast safer than the stock location). I haven't ruled out a cell, but the logistics in a Miata chassis aren;t as straightforward as other cars.

Thanks Mike! I can't wait to get up and running.


Marcus
 
I haven't yet convfinced myself that having the cell next to me is very safe either(...)


Tell that to open wheel guys sitting on the damn thing :)
 
mtm68 said:
Thanks for the ST suggestion, I don’t see it as legal for ST, based on these factors:
1324 B 2 (IT rules in SCCA GCR 9.4 don’t specifically allow the low roll hoop cage, only Production and GT)
1324 C 2 (The front and back window angle and shape must not be changed) This is impossible since it doesn’t have a windshield 

Otherwise, ST looks like it would be great, I’m not sure about HP output, since the motor is still on the engine stand. I was also hoping for quite a bit less than 2400 lbs (ST minimum I would be shooting for), obviously post completion, I could ballast it up to that.


Marcus
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Are you planning on running it as a convertible? If so, you're still good for ST rules. Also, I use a cell for reasons other than simple safety, but YMMV and all that. Finally, we (the ST guys) submitted a rule change to lower our minimum weight to 2200 from 2400; it's very likely to pass (class-specific rules that don't seem to impact safety almost always pass).
 
The 2200 pound weight limit would sure open the class up more . There are a lot of IT cars that would fit in and allow them some HP mods :)

Steve Adams said:
Are you planning on running it as a convertible? If so, you're still good for ST rules. Also, I use a cell for reasons other than simple safety, but YMMV and all that. Finally, we (the ST guys) submitted a rule change to lower our minimum weight to 2200 from 2400; it's very likely to pass (class-specific rules that don't seem to impact safety almost always pass).
Click to expand...
 
Steve Adams said:
Finally, we (the ST guys) submitted a rule change to lower our minimum weight to 2200 from 2400; it's very likely to pass (class-specific rules that don't seem to impact safety almost always pass).
Click to expand...
One of the things that made ST attractive is that without a lot of changes an American Iron car transplant could finally compete in ICSCC in a class similar to AI.
These cars tend to be closer to 3000+ pounds than 2000. Having cars with half a ton difference in weight IS a safety issue.
Even though the power to weight is the same the weight to tire loading is not, giving an advantage to the lighter car.

If this passes -- which I hope it doesn't -- I'll have to totally rethink engine choices and this will only cost MORE money.
 
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FWIW, the impetus for the change was several Spec911 cars that wanted to run with us this year but couldn't. Ditto for some lighter-weight cars (Alfas and the Nissan 240sx, just to name a couple examples) that simply don't have a hope of being competitive ballasted up to 2400lbs.
 
Steve Adams said:
Are you planning on running it as a convertible? If so, you're still good for ST rules. Also, I use a cell for reasons other than simple safety, but YMMV and all that. Finally, we (the ST guys) submitted a rule change to lower our minimum weight to 2200 from 2400; it's very likely to pass (class-specific rules that don't seem to impact safety almost always pass).
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Yep. It looks similar to this http://www.springfielddyno.com/forsale/forsale.htm

A lower weight would make ST more appealing, as this is likely closer to where the car will end up power wise, and adding 200+ ballast wouldn't be very appealing.

What other reasons are you using a cell for? I could see a couple others, very endurance specific (additional capacity, and dry break fueling). Are there others?

Marcus
 
I don't think the car would be ST legal without the windshield, as Marcus pointed out.

The ST min weight change will allow Spec911 cars to crossover more easily and maybe a few other cars. I would like to think a low horsepower car could be the match of a 3000# E46 M3, but I'm not gonna hold my breath. The beefy amount of rubber and brakes allowed still favors the heavier/more powerful car, IMO.
 
mtm68 said:
.... The Miata gas tank is actually extremely safe;its very well protected by the crash structure in the car and additionally once a cage is installed.... Marcus
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Well you're probably right.

BUT our last 'big bad crash big fire' WAS a Miata!! Pro 7 WITH a fuel cell in place of the factory tank. Cell was semi crushed and tore off a fuel line which allowed HUGE fuel flow onto the hot exhaust (even though car was inverted). Not a pretty picture.. sigh
 
Richard Broadhead said:
Well you're probably right.

BUT our last 'big bad crash big fire' WAS a Miata!! Pro 7 WITH a fuel cell in place of the factory tank. Cell was semi crushed and tore off a fuel line which allowed HUGE fuel flow onto the hot exhaust (even though car was inverted). Not a pretty picture.. sigh
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It was an SPM/RS-classed RX-7, which is definitely not the same as a Miata.
 
eric_krause said:
I don't think the car would be ST legal without the windshield, as Marcus pointed out.
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Why not? The silhouette of a convertible is pretty much the same (with the top down) with the stock window or no window at all. Or are "top down" convertibles not legal for ST, full stop?
 
mtm68 said:
What other reasons are you using a cell for? I could see a couple others, very endurance specific (additional capacity, and dry break fueling). Are there others?

Marcus
Click to expand...

I suppose the ease with which to relocate it would be another. Having a smaller capacity is probably a plus for some people. (And you can have a dry-break with a stock tank. :p)
 
Steve Adams said:
I suppose the ease with which to relocate it would be another. Having a smaller capacity is probably a plus for some people. (And you can have a dry-break with a stock tank. :p)
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touché! I've just found it easier to adapt when adding a cell :)
I'm not against cells either, some of my previous cars had them.
Marcus
 
Steve Adams said:
Why not? The silhouette of a convertible is pretty much the same (with the top down) with the stock window or no window at all. Or are "top down" convertibles not legal for ST, full stop?
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"front and back window angle and shape must be maintained"
My unofficial opinion is that removing the windshield is not retaining the same angle and shape. I could see an argument that there is no rear window so running as a convertable might be okay, but there definitely was a front window.
 
eric_krause said:
"front and back window angle and shape must be maintained"
My unofficial opinion is that removing the windshield is not retaining the same angle and shape. I could see an argument that there is no rear window so running as a convertable might be okay, but there definitely was a front window.
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Exactly where I ended up. So, I guess the ultimate answer is it looks like I'm good in SPM. That'll be a tall order, but I'm game to try :)
 
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