Mid West Council SM2 Class: Spec Miata on 200tw tires
#21
Posted 03-09-2021 08:49 PM
#22
Posted 03-09-2021 09:31 PM
The NA6 gets to add a header.
Authorized ModificationsSM2 cars will adhere to all rules as listed in the Midwestern Council of Sports Car Clubs GCR for Spec Miata with the following exceptions.4.1Engine4.1.1Exhaust System4.1.1.11.6L (1990-1993): May use exhaust header, part number #56005, from Racing Beat. This is the only approved header and is allowed for 1.6L engines only.4.1.2Tires4.1.2.1Tires must be size 205/50R15with a tread wear rating of 190or higher.
Anyone know what that adds in terms of power?
NA8 get to run with no plate and 2350 pounds.
If there are split starts that should put SM behind SM2
Will be interesting to see how this does as a class, although I still favor cheap power enhancements for the 1.6 along with a little extra weight and a slight weight reduction on the NA8 (2375) to bring all the cars to even better competitive balance in a single class.
The tire rule 190TW or higher could be a big plus once the tire choices are sorted out.
Interesting they went with the RB header. It's CONSTANTLY on backorder including right now. While a very nice piece and fitment compared to others is great, the net benefit is negligible, like barely over a ported manifold.... plus with no heat shield, underhood air temps for the afm are through the roof.
it's basic physics....the 1600 car suffers from lower torque compared to the 1.8 liter cars. either displacement and/or compression are real world solutions.....that and forced induction.....
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Marc Cefalo
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#23
Posted 03-10-2021 08:38 AM
How about a turbo and sequential gear boxes?
Apples and oranges and you know it. My suggestions were about keeping the power the na1.8 has under the current spec and not laying down due to hydraulic lifters when hot. Keeping the valve seat pressure we deserve when we have to trim a seat. Being able to put a standard valve in when we need head work but cant get valves.
Yours were about adding power. I'll argue in good faith if you will.
#24
Posted 03-10-2021 09:08 AM
so little talk about the important thing here ... tires.
im curious, like most racing ideas, this will probably actually work for mid west council. because ideas like this work pretty well until someone, somewhere pulls out the checkbook and decides they want to win more than anyone else. we are talking shaved tires, different sets of street tires for qualifying (yoko a052) and racing (RS4?), and what happens when the next generation of tires comes out? the fast folks now have to test and run setups for all the new tires to find out how quick they are and where they are good.
street tires is not the cakewalk easy button many folks think it is to lowering costs. for the casual it might be a bit cheaper. but for anyone who wants to win, even at the divisional level, it got way more complicated.
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Gordon Kuhnley: Driving miata's in all conditions, courses, and motorsports that I can.
#25
Posted 03-10-2021 09:21 AM
so little talk about the important thing here ... tires.
im curious, like most racing ideas, this will probably actually work for mid west council. because ideas like this work pretty well until someone, somewhere pulls out the checkbook and decides they want to win more than anyone else. we are talking shaved tires, different sets of street tires for qualifying (yoko a052) and racing (RS4?), and what happens when the next generation of tires comes out? the fast folks now have to test and run setups for all the new tires to find out how quick they are and where they are good.
street tires is not the cakewalk easy button many folks think it is to lowering costs. for the casual it might be a bit cheaper. but for anyone who wants to win, even at the divisional level, it got way more complicated.
It would probably be better if a specific tire was spec'd. That narrows the experimentation variables a lot.
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#26
Posted 03-10-2021 09:29 AM
Apples and oranges and you know it. My suggestions were about keeping the power the na1.8 has under the current spec and not laying down due to hydraulic lifters when hot. Keeping the valve seat pressure we deserve when we have to trim a seat. Being able to put a standard valve in when we need head work but cant get valves.
Yours were about adding power. I'll argue in good faith if you will.
James, There is no arguing with you . You know that
You don't get the rules set.. you constantly want changes outside class philosophy and what suits you and your needs and not necessarily what is is in the best interest of the class. And then is all of the unintended consequences of many of your ideas..
East Street Auto Parts
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#27
Posted 03-10-2021 10:10 AM
It would probably be better if a specific tire was spec'd. That narrows the experimentation variables a lot.
that does help quiet a lot, but it also ties the success of your class to a fickle thing, like when a company decides they no longer want to make your spec tire, and you have to pick a new one.
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Gordon Kuhnley: Driving miata's in all conditions, courses, and motorsports that I can.
#28
Posted 03-10-2021 10:28 AM
I'd bet less than than 3. Maybe only you. That's like the trashing the 25 pounds back and forth for the 1.6 a few years ago.
Good to see David and Jim on the same page Now if we can just get James it will be one big happy party
And I too say what is 25lbs...Ironically the SMAC did not agree
I bet I can go back and find some moaning when the VVT went from 2400 to 2425...silly people!
Ron
RAmotorsports
#29
Posted 03-10-2021 11:04 AM
I bet I can go back and find some moaning when the VVT went from 2400 to 2425...silly people!
it should have been 50.
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#30
Posted 03-10-2021 11:10 AM
that does help quiet a lot, but it also ties the success of your class to a fickle thing, like when a company decides they no longer want to make your spec tire, and you have to pick a new one.
I don't think it would be too tough to get the manufacturers to confirm that they're building a tire for 2 or 3 or 4 years.
#31
Posted 03-10-2021 11:31 AM
I don't think it would be too tough to get the manufacturers to confirm that they're building a tire for 2 or 3 or 4 years.
im just saying i've seen it happen before in spec tire classes on street tires where the popularity of the class ebbs and flows based on how good the spec tire is. when its a good tire that everyone likes, they like it, when its not a good tire, the class suffers. SSC did this when they ran teh 615k+, the class hated that tire, and it showed. and then when the replacement came, the 660, everyone liked it again.
and thats a bit different than a non-street tire, because hoosier isnt going to up and stop making a tire, because they are race tire company that makes race tires, they get the business model. but bridgestone, a multi-billion dollar company chaired in another country, for example just recently decided to stop making the re71r despite it still being a very popular and very competitive tire. why? dunno. they just did. whatever math whereever made them decide not to make it anymore.
im just saying, a spec street tire is a bit more variable and problematic than a spec race tire is. you are that the whim of much larger forces.
Gordon Kuhnley: Driving miata's in all conditions, courses, and motorsports that I can.
#32
Posted 03-10-2021 11:42 AM
I bet I can go back and find some moaning when the VVT went from 2400 to 2425...silly people!
probably, but I was not one of them
East Street Auto Parts
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#33
Posted 03-10-2021 03:53 PM
We are going through it right now in champ car. Our favorite 200 TW tire has been discontinued. Now we have a lot of different tires to buy and a lot of testing. Oh and 200TW are always faster when shaved. Our fastest lap times are always at the end just before cording.
V2 Motorsports
#34
Posted 03-10-2021 05:11 PM
We are going through it right now in champ car. Our favorite 200 TW tire has been discontinued. Now we have a lot of different tires to buy and a lot of testing. Oh and 200TW are always faster when shaved. Our fastest lap times are always at the end just before cording.
And dont ask now.. 200 tw is also VERY subjective
East Street Auto Parts
Jim@Eaststreet.com
800 700 9080
#35
Posted 03-10-2021 07:33 PM
Whats the big deal about the tires?
Are 200 tw tires going to offer more heat cycles than a Toyo RR?
#36
Posted 03-10-2021 07:35 PM
Whats the big deal about the tires?
Are 200 tw tires going to offer more heat cycles than a Toyo RR?
yes, in theory
East Street Auto Parts
Jim@Eaststreet.com
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#37
Posted 03-10-2021 08:37 PM
Whats the big deal about the tires?
Are 200 tw tires going to offer more heat cycles than a Toyo RR?
#38
Posted 03-11-2021 09:43 AM
What I ask for is crazy but you guys putting in place na's with nb uprights, intake plenum changes, etc, etc, well that's so much different and very good for the class.
Of course I argue for my gear and not yours. You do that well enough. You guys are the ones that told me that it is the owners of those years that have to do the arguing for it. And Bench has shown me the way on how persistence in message pays off.
Tell me why solid lifters for the na 1.8 head is contrary to the spirit of the class? Present me with something sound and why this simple thing shouldn't be considered and I'll drop it.
Na 1.8 guys, why should we not get the same max lift from our spec cams as the 99/00 get? The max lift numbers for our cars is a joke if you cant achieve throughout the session.
#39
Posted 03-11-2021 09:52 AM
oh, and slotted control arms to get camber where you werent getting it before without having to buy an upright or subframe. Thats cool and money saving but shims, a bridge to far from the spirit of the class I guess. Non concentric head jobs. I feel like I am the spirit of the class based on the examples set by others.
#40
Posted 03-11-2021 09:53 AM
Also, RR's ain't that cheap. There's some 200tw that are nearly half the cost
dunno if this a joke, but the fastest 200tw are nearly equal in cost and likely have less competitive heat cycles. https://www.tirerack...052XL&tab=Sizes
a052 is 152 a tire, rr is 190
Gordon Kuhnley: Driving miata's in all conditions, courses, and motorsports that I can.
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