June 2012 Fastrack
- Thread starter Greg Amy
- Start date
Andy Bettencourt
Super Moderator
ITA
1. #7633 (Christopher Childs) Increase weight of 1.8 ITA Miata
In ITA, Mazda MX-5 / Miata includes R (94-97), change the weight as follows: 2460
1. #7633 (Christopher Childs) Increase weight of 1.8 ITA Miata
In ITA, Mazda MX-5 / Miata includes R (94-97), change the weight as follows: 2460
erlrich
Super Moderator
Damn...we really need one of those little popcorn-munching smilies for this one
It is nice to see the ITS 240SX get a break, maybe we'll see a few more out there now.
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Quite interested to hear the back story and support behind it. - GA
JeffYoung
New member
Mostly started due to the CRB's disagreement with the use of the lower stock hp number for the car, and the inconsistency in doing that with the Miata versus all other cars in the ITCS.
I initially did not want to change this since it has been debated ad nauseum, but ultimately voted yes (I think the vote was unaminous).
There was no pressure from the CRB to do one thing or another, but they did raise the issue with us.
I initially did not want to change this since it has been debated ad nauseum, but ultimately voted yes (I think the vote was unaminous).
There was no pressure from the CRB to do one thing or another, but they did raise the issue with us.
Ron Earp
Administrator
Yessir. Being as how my car only needs to rev to 5200 RPM I propose 5200.
Jeebus, are we really going to have to read page after page of ITA Miata minutia (no offense to quoted poster)? The situation has been debated for years. Bridge, water under it, and all that. Other cars get processed at the highest rated hp, this one should be no different.
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Fair enough, and I agree. And the Miata will still be the kick-ass ITA car to have. It's what I would build, bar none.
I officially, formally, and publicly discontinue any and all bitching about the how the Miata weight was done in ITA.
- GA
Sorry for asking dumb questions, but what is the underlying reason for not allowing cars to run in different IT classes at different weights? I understand that there are potential problems that the driver would have to deal with in terms of wheel size between classes (ITA to ITB etc). But as long as the car is compliant, why does this keep getting shot down? It seems that if you wanted to run your ITA miata in ITS at a lower weight, go for it.
Is there some real reason for this or is it another washer bottle? I'm hoping somone can provide the cliff notes.
Is there some real reason for this or is it another washer bottle? I'm hoping somone can provide the cliff notes.
As someone who argued against double-listing, it's a solution to a non-problem, with lots of minor downsides that add up to make it more trouble than it's worth.
** Our classes are confusing enough as it is, without people having to figure out if that's an ITB Golf II or an ITC Golf II
** If (when) something like the ITS Nissan 240 weight changes, it would have to propagate to two classes rather than one. A change can't always be accommodated within the "bucket" established for a class (e.g., if it would make it too heavy for a given rollcage tubing size, or be impossibly low).
** We already have outlier issues, in terms of light cars or big engines, and dual listing will create more of them - cars already outside (or at minimum, right on) the limits of the class, made super-light or extra heavy to fit.
** At the end of the day, it doesn't give anyone anything they don't already have...
K
** Our classes are confusing enough as it is, without people having to figure out if that's an ITB Golf II or an ITC Golf II
** If (when) something like the ITS Nissan 240 weight changes, it would have to propagate to two classes rather than one. A change can't always be accommodated within the "bucket" established for a class (e.g., if it would make it too heavy for a given rollcage tubing size, or be impossibly low).
** We already have outlier issues, in terms of light cars or big engines, and dual listing will create more of them - cars already outside (or at minimum, right on) the limits of the class, made super-light or extra heavy to fit.
** At the end of the day, it doesn't give anyone anything they don't already have...
K
Andy Bettencourt
Super Moderator
So this is going to be a long post, and I ask everyone to read it and REALLY try and understand it. I also challenge any ITAC or CRB member to bring forth any reasonable arguments. Anyone who agrees with the philosophy of the change (like Greg), I would like to hear their arguments as well. Maybe I am missing something. It should always be the job of the committees to put in the work and class things as 'right' as they can.
First off, this classification is NOT inconsistent with the way other cars are classed because it is DIFFERENT. Read that again. It's different. I am going to lay out some generic scenarios for you in an effort to try and reduce the Miata bias.
Take car A. Car A had a body style run from 1990-1993. From 1990-1992, it had 130hp. In 1993, they tweaked the intake manifold and the cams and the new rating was 140hp. Now, if the 1990-1992 car was classed first, it would be classed based on the 130hp number. You would then have a choice as the CRB. Add another spec line because the cars are different, or combine them at the higher HP because the items that make the extra 10hp are not legal to change in the lower HP version - and then allow the UD-BD so that the lower HP car can actually make a real base number. Following me? It's a mechanical change that CAN be done to can extra HP in IT trim.
Now, take car B. Car B had the same body style run and the same HP change. But the extra 10hp came from a tuned set of headers and a low restriction exhaust. Are we saying that the new stock HP is the way to class this car. HELL NO. Why? Because those mods are already taken into account in the IT weight calculation. Follow this logic:
Lets say for arguments sake that there are 4 things that contribute to a cars 25% potential increase in IT trim (just using round numbers to make it easy. We know every car responds differently). Air intake 5%, exhaust 10%, B&B - port and compression 5%, and ECU 5%. There is your 25%. If a car gets a bump in stock HP SOLELY because of one of these, you have not increased it's potential HP in IT trim. You can not argue this. In the above example, all you did was erode the 10% increase in an optimized exhaust, you did not add 10hp to the baseline number. So you COULD use the higher number to class it but you would then have to reduce the potential % gain the car will get - netting the same original weight.
Take the 2 versions of the 2nd gen RX-7. One had 146hp and one had 160hp. That 14hp difference was made up of basically 3 key items. A MAF instead of an AFM, different intake manifold design and higher compression rotors. All three things that you can not change in IT. These cars COULD be on different spec lines with TOTALLY different HP in IT trim.
NOT true with car B above. Those cars have exactly the same HP potential in IT trim. There is nothing 'mechanical' that you can change that would bump the base hp of the early car up to that of the later car. When I say this, we need to be clear. This 'something' has to be a feature that is not otherwise allowed to be changed in IT. In other words, something you could UD-BD to that would bump the HP.
Another example. Let's say Nissan had a 240SX 'Type S' at 140hp and a 240SX 'Type R' at 160hp. All they changed was the exhaust and the ECU. The Type S is already classed. Then the Type R comes in and all it has is optimized equipment under the IT rules. There is NOTHING different in the two cars in built IT trim. You DON'T bring the bottom car up to the top car and THEN add the 25%, because you would be forcing the car to actually gain about 43% in order to make it's process power.
Even more simply (because this is very hard to explain), Car A has 130hp. Honda does a Type R version with a factory optimized IT package. It now has a rated 162hp. You wouldn't take the 162hp version and class it at 25% additional power because the Type R version has used up 100% of the IT gain and there is ZERO more to get.
So to bring it back to the Miata, this is exactly what happened. The 128hp car was classed, then later, the 133hp car was requested. When you look at the differences, the cars are identical except for an ECU tweak. Since this is an allowed mod in IT, it renders the improvement 100% moot when discussing potential in IT trim. And THAT folks is how cars are classed at the core level. Potential hp in IT trim. The change in ECU adds nothing to the base HP as it affects HP in IT trim. If it were a larger TB or something you could not legally change, then yes 100%. So if you wanted to use the 133hp number for 'consistency', go ahead, but you must compensate with a lower potential gain in IT trim, say using 20%...which gets you to withing 5lbs of where the car is classed now (figuring 2370 because of the old slush 10lbs). But this is silly because it would be very hard to pinpoint the % of one modification under the rules...so you simply use the standard 25% on the correct number.
One thing that should concern us all is that this line of thinking has been debated and voted on at the ITAC level. It is codified in the Ops manual and had seemingly been accepted by the CRB for over a year now. So effectively, the CRB has decided that (which is their right I suppose) that the Ops manual is out the window for this car but yet it holds firm on it even when it's wrong (see DW adder in ITR). Sweet. We should all be happy with the inconsistency.
So there is data that shows the Miata makes more than 25% but less than 30%. Ok, fine. A weight change based in THIS line of thinking is actually the unprecedented kind. 25% to 27% on a motor like this is 2.5 crank HP...or 2whp. Anyone who wants to adjust the weight of a car based on 2whp is nuts. Let's be real here.
This isn't a Miata issue, it's an issue about whats the right way to class a car. To the Miata, I am not aware of any dyno sheets that show the Miata to be capable of 25% on top of the 133hp number that already includes a % for ECU (as described above). Interestingly, 128hp @ 30% and 133hp at 25% are almost identical. So the Miata is getting classed at a number not yet represented in any dyno data and at a level that doesn't make sense.
It's obvious the Miata is a lightning rod but we need to be worried about classing decisions that make sense because we have put forth effort and thought instead of seeing what we think we see.
If you have a real need to add weight to the Miata, then do it in a way that is consistent and makes potential sense. It's probably more than the sum of it's parts...so add in another variable that not many cars have - like a rear DW adder. I proposed it, it was shot down. This would add an additional 50lbs to the Miata while legitimately trying to quantify a real difference in it's contemporaries - EXACTLY what an adder is suppose to do.
First off, this classification is NOT inconsistent with the way other cars are classed because it is DIFFERENT. Read that again. It's different. I am going to lay out some generic scenarios for you in an effort to try and reduce the Miata bias.
Take car A. Car A had a body style run from 1990-1993. From 1990-1992, it had 130hp. In 1993, they tweaked the intake manifold and the cams and the new rating was 140hp. Now, if the 1990-1992 car was classed first, it would be classed based on the 130hp number. You would then have a choice as the CRB. Add another spec line because the cars are different, or combine them at the higher HP because the items that make the extra 10hp are not legal to change in the lower HP version - and then allow the UD-BD so that the lower HP car can actually make a real base number. Following me? It's a mechanical change that CAN be done to can extra HP in IT trim.
Now, take car B. Car B had the same body style run and the same HP change. But the extra 10hp came from a tuned set of headers and a low restriction exhaust. Are we saying that the new stock HP is the way to class this car. HELL NO. Why? Because those mods are already taken into account in the IT weight calculation. Follow this logic:
Lets say for arguments sake that there are 4 things that contribute to a cars 25% potential increase in IT trim (just using round numbers to make it easy. We know every car responds differently). Air intake 5%, exhaust 10%, B&B - port and compression 5%, and ECU 5%. There is your 25%. If a car gets a bump in stock HP SOLELY because of one of these, you have not increased it's potential HP in IT trim. You can not argue this. In the above example, all you did was erode the 10% increase in an optimized exhaust, you did not add 10hp to the baseline number. So you COULD use the higher number to class it but you would then have to reduce the potential % gain the car will get - netting the same original weight.
Take the 2 versions of the 2nd gen RX-7. One had 146hp and one had 160hp. That 14hp difference was made up of basically 3 key items. A MAF instead of an AFM, different intake manifold design and higher compression rotors. All three things that you can not change in IT. These cars COULD be on different spec lines with TOTALLY different HP in IT trim.
NOT true with car B above. Those cars have exactly the same HP potential in IT trim. There is nothing 'mechanical' that you can change that would bump the base hp of the early car up to that of the later car. When I say this, we need to be clear. This 'something' has to be a feature that is not otherwise allowed to be changed in IT. In other words, something you could UD-BD to that would bump the HP.
Another example. Let's say Nissan had a 240SX 'Type S' at 140hp and a 240SX 'Type R' at 160hp. All they changed was the exhaust and the ECU. The Type S is already classed. Then the Type R comes in and all it has is optimized equipment under the IT rules. There is NOTHING different in the two cars in built IT trim. You DON'T bring the bottom car up to the top car and THEN add the 25%, because you would be forcing the car to actually gain about 43% in order to make it's process power.
Even more simply (because this is very hard to explain), Car A has 130hp. Honda does a Type R version with a factory optimized IT package. It now has a rated 162hp. You wouldn't take the 162hp version and class it at 25% additional power because the Type R version has used up 100% of the IT gain and there is ZERO more to get.
So to bring it back to the Miata, this is exactly what happened. The 128hp car was classed, then later, the 133hp car was requested. When you look at the differences, the cars are identical except for an ECU tweak. Since this is an allowed mod in IT, it renders the improvement 100% moot when discussing potential in IT trim. And THAT folks is how cars are classed at the core level. Potential hp in IT trim. The change in ECU adds nothing to the base HP as it affects HP in IT trim. If it were a larger TB or something you could not legally change, then yes 100%. So if you wanted to use the 133hp number for 'consistency', go ahead, but you must compensate with a lower potential gain in IT trim, say using 20%...which gets you to withing 5lbs of where the car is classed now (figuring 2370 because of the old slush 10lbs). But this is silly because it would be very hard to pinpoint the % of one modification under the rules...so you simply use the standard 25% on the correct number.
One thing that should concern us all is that this line of thinking has been debated and voted on at the ITAC level. It is codified in the Ops manual and had seemingly been accepted by the CRB for over a year now. So effectively, the CRB has decided that (which is their right I suppose) that the Ops manual is out the window for this car but yet it holds firm on it even when it's wrong (see DW adder in ITR). Sweet. We should all be happy with the inconsistency.
So there is data that shows the Miata makes more than 25% but less than 30%. Ok, fine. A weight change based in THIS line of thinking is actually the unprecedented kind. 25% to 27% on a motor like this is 2.5 crank HP...or 2whp. Anyone who wants to adjust the weight of a car based on 2whp is nuts. Let's be real here.
This isn't a Miata issue, it's an issue about whats the right way to class a car. To the Miata, I am not aware of any dyno sheets that show the Miata to be capable of 25% on top of the 133hp number that already includes a % for ECU (as described above). Interestingly, 128hp @ 30% and 133hp at 25% are almost identical. So the Miata is getting classed at a number not yet represented in any dyno data and at a level that doesn't make sense.
It's obvious the Miata is a lightning rod but we need to be worried about classing decisions that make sense because we have put forth effort and thought instead of seeing what we think we see.
If you have a real need to add weight to the Miata, then do it in a way that is consistent and makes potential sense. It's probably more than the sum of it's parts...so add in another variable that not many cars have - like a rear DW adder. I proposed it, it was shot down. This would add an additional 50lbs to the Miata while legitimately trying to quantify a real difference in it's contemporaries - EXACTLY what an adder is suppose to do.
lateapex911
Super Moderator
I'm trying to think of examples Jeff, where there has been a car that was classed at X power, then a later version was classified with X +5hp (or 10, 15, etc) that was the result of a change of an IT allowed mod.
I'm coming up empty. Clearly the CRB and the ITAC have examples, or there would be no claim of inconsistency. Can you cite them for us?
shwah
New member
ITB Golf 2? Was classed at 100hp. Later available as 105hp. Now classed as 105hp with 30% expected IT gain. Or at least that's the story. The weight never really changed, but the multiplier was presented when weight clarification was requested...
shwah
New member
OK. What the heck is "required wiring rendered redundant by allowed modifications (i.e. engine management harness)"?
Can that be translated into English. Is this the same body that seems to think that you can physically change the wires and where they go to and from in the engine wiring harness, to enable sequential fuel injection, whether wiring supporting such was there from the factory or not?
The request was simple. If the wires DO NOT DO ANYTHING ON A LEGAL IT CAR let us take them out. Why not leave it simple?
Can that be translated into English. Is this the same body that seems to think that you can physically change the wires and where they go to and from in the engine wiring harness, to enable sequential fuel injection, whether wiring supporting such was there from the factory or not?
The request was simple. If the wires DO NOT DO ANYTHING ON A LEGAL IT CAR let us take them out. Why not leave it simple?
Ron Earp
Administrator
Just build your car like that and call it a day. Motor legal, suspension legal, drive line legal, race over min weight - go have fun.
I have no idea why the wording can't be simplified to something that does what every IT-builder ends up doing. If I were IT Czar there wouldn't be a rule on wiring beyond something like "Cars need wires, use some." All that said, I probably have more wires than the average IT car since mine still wears a tag and will continue to wear a tag.
But, make sure you're using the rules to the full advantage, examples:
*AC systems can be removed in part or entirely" - In a Mustang the entire assembly of heater core, evaporator, etc. is called "Air Conditioning". Wires make that make any of that work are part of the AC, therefore, they are part of the system and can be removed.
*Mustangs without power windows, theft systems, ABS, aux lights, and other optional equipment exist therefore I can remove all the wiring on my car because there are examples that don't have those items.
As you know pulling apart the harness is a major pain in the butt. But it is worth it. We got about 11 or 12 lbs out of optional crap on the first pass. There is 1.5 to 2 lbs I left in because I was afraid to pull due to the safety/theft interlock system.
to avoid unforeseen issues. remove wiring to items you are allowed to remove, effectively allowing you to remove that entire system from the car. you got what you wanted.
but with allowed ECU and related engine wiring harnesses, as well as the existing open rules for wiring of fans, switches, gauges, and the like, we wanted to be sure that the minimal harness being used (you can debate the legality of that specific harness separately) doesn't result in the full stock harness being removed. the last thing we want to see is a squirt on a harness and a small loom for the datalogger and driver controls, with 6 or 7 wires from the stock chassis harness sticking around to connect to the head and tail lights. it's still IT.
JLawton
New member
<warning: This is all about ME>
RE: Miata weight........... We hashed this out years ago. Lots of bitterness, anger, name calling (and I'm not being dramatic here). I admit, I was one of the early complainers........... so after years and years of battling Miata's in ITA and getting my ass kicked, I finally break down and buy a Miata. And fucking two months later weight might be added????? You.....have ........got......to.....be.....shittin'..........me..............
RE: Miata weight........... We hashed this out years ago. Lots of bitterness, anger, name calling (and I'm not being dramatic here). I admit, I was one of the early complainers........... so after years and years of battling Miata's in ITA and getting my ass kicked, I finally break down and buy a Miata. And fucking two months later weight might be added????? You.....have ........got......to.....be.....shittin'..........me..............
Andy Bettencourt
Super Moderator
V8's are an anomaly. The CRB at the time was deathly afraid of them, requiring 30% on top number no matter what and this was before the policy was written. Any 'extra' arguing on the V8's could have lead to their non-inclusion. I, for one, hope that the ITR V8's get cleaned up.
What cars are you talking specifically about Chris?
gran racing
Super Moderator
Oh man. THIS is going to be a good thread, I can just feel it.