July FasTrack posted

[Joe Harlan]

No I did not stop read travis. Once the car went OBD2 my money says it had a different production cod which made it a different model. I can show you S13 nissans that came out in 6 of 90 that were 91 models does that mean i can now race the early 91 in ITA with aa 4 valve motor because it was produced in 90? get real.

 

[Doc Bro]

Joe,

2370 (minus fudge factor) for the 128hp car and 2460 for the 133hp car. [/b]

Oh yeah, I forgot to mention the Z3 was ORIGINALLY clased at 2675....the adjusted to 2600....

Still doesn't seem remarkably different from a Miata to me....except the weight


Back to your debate.

 

[tnord]

never been in the draft of one have you?

if the miata aero is so good....why is bumpdrafting so easy/important? why can i run at about 80% throttle in the draft? have you looked under the rear bumper of these things? it's a big parachute. have you looked at how much the wheels stick out beyond the front bumper? have you calculated it's frontal area?

your using results to try and support your claim that the car needs weight, regardless of what is typed.

 

[Greg Amy]

And your data to support that they are "more aerodynamic than just about anything out there" is where?
[/b]

Andy, back at you: *I'm* not the one making the initial claim.

So, if you want to get into a semantics pissing match let's handle it this way: I rescind my statement that the Miata is aerodynamic, compared to other vehicles. Ergo, we are left with the original claim that the Miata has poor aerodynamics.

Prove it.

You guys just can't seem to accept that the world doesn't revolve around you...

 

[tnord]

You guys just can't seem to accept that the world doesn't revolve around you...
[/b]

...says the guy who's bitching because someone is faster than he is.


hey, you made it personal.


since this has quickly rescinded in to unquantifiable speculation and scare tactics....i'll take the express train back to rr-ax.com, and maybe stop at the vinyl shop to get some new "SM" markings on the way.

 

[Joe Harlan]

never been in the draft of one have you?

if the miata aero is so good....why is bumpdrafting so easy/important? why can i run at about 80% throttle in the draft? have you looked under the rear bumper of these things? it's a big parachute. have you looked at how much the wheels stick out beyond the front bumper? have you calculated it's frontal area?

your using results to try and support your claim that the car needs weight, regardless of what is typed.
[/b]

Travis, Please. ANy car will draft. That is a dumb ass statment on the aero advantage or disadvantages of any car. A freaking champ are will draft. Facts are facts and under the IMPROVED TOURING RULES the late car has been given a set of rules that it should not have. Or the Early car is getting the benefit of late parts that are NOT the same....The ITAC screwed this one up and the CRB whiffed at the curve ball. It should be fixed because if I vin a 94 car with an OBD2 system in it then we created a model that did not exist!

 

[Greg Amy]

never been in the draft of one have you?[/b]

Not lately, no...

if the miata aero is so good....why is bumpdrafting so easy/important?[/b]

1) Because in Spec Miata they're identical cars, and
2) In other categories they have a power disadvantage

...why can i run at about 80% throttle in the draft?[/b]

That's how "a draft" works, Travis.

...have you looked under the rear bumper of these things? it's a big parachute.[/b]

As it is very just about EVERY other production vehicle with a rear bumper, Travis. Including the supposedly "aerodynamic" NX2000.

...have you looked at how much the wheels stick out beyond the front bumper?[/b]

As it does on most other IT cars, Travis. Aren't you allowed a front spoiler/airdam? "Disadvantage" - if it exists - nullified. Aren't all Spec Miatas equipped the same? "Disadvantage" nullified.

...have you calculated it's frontal area?[/b]

Nope. Have you (remember, you're making the claim here)?

The question - that you have yet to answer - still stands, Travis: where is the data supporting the long-standing meme of the Miata as not aerodynamic?

You can keep trying to turn it back on me, but I'm not the one making the claim...

 

[Andy Bettencourt]

Andy, back at you: *I'm* not the one making the initial claim.

So, if you want to get into a semantics pissing match let's handle it this way: I rescind my statement that the Miata is aerodynamic, compared to other vehicles. Ergo, we are left with the original claim that the Miata has poor aerodynamics.

Prove it.

You guys just can't seem to accept that the world doesn't revolve around you...
[/b]

Actually Greg, I quoted YOU, remember. YOU said they were one of the best. Called out, you recind. If the common knowledge that the Miata has poor aero is what you dispute, what type of info would be acceptable since published Cd's seemingly aren't.

It cetainly isn't UN aerodynamic enough to be an 'adder'. I will try and dig up the info you request.

 

[Greg Amy]

...what type of info would be acceptable since published Cd's seemingly aren't.[/b]

A reasonable request. Find for me the measured Cd of a Mazda Miata - with the hardtop attached - and we can discuss the relative aerodynamics of the stock M1 (but, debating the relative merits of stock vehicle aerodynamics in the context of a spec category is nothing short of stupid silly.)

We'll then debate the IT-allowed aerodynamic devices and how they affect and/or negate any perceived or actual aerodynamic disadvantage of the Miata in relation to other classified vehicles.

I think we've set a new forum record for the number of topic drifts in one 24-hour period... - GA

 

[gran racing]

Dave I will sign the letter as well... but don't think your car wont get added to that list!!! [/b]

Right back at ya.

Golf III
Honda Prelude si
5 cyl. Audi

Kirk, just as a fyi, while I personally think the Golf III is too light, I have a hard time forgetting my previous discussions with the powers that be and the reasoning I received for a descrepency in weight between that car and others. "It was classed by the previous regiume and sure, it is underweight compared to how other cars were classed."

Would it be possible to put the cars through the new process even if it's only to shut me up if I were to write in a request? LOL

 

[Eagle7]

86-88 RX-7 - 146 HP

89-91 RX-7 - 160 HP

I want a weight break!

Oh, forgot I'm not at minimum weight anyway. Forget it. <_<

 

[Andy Bettencourt]

86-88 RX-7 - 146 HP

89-91 RX-7 - 160 HP

I want a weight break!

Oh, forgot I'm not at minimum weight anyway. Forget it. <_<

[/b]

Marty, you know as well as anyone that there are a TON of mechanical differences that make up that 16hp. Intake, AFM/MAF, compression bump, injectors, etc.

 

[Andy Bettencourt]

A reasonable request. Find for me the measured Cd of a Mazda Miata - with the hardtop attached [/b]

Here is what I came up with:

While maybe not applicable to the M1, the new MX-5 in soft-top form is a .38 while the hardtop version is a .37. We might be able to extrapolate those numbers to the M1 since it too has a CD of .38. CD of the NX2000 is a .32. So we could resonably say that the coefficinet of drag on the stock NX2000 is .32 and an M1 with a hardtop is .37. Seems significant to me.

Comparision:

Volkswagen Beetle - .38

McLaren F1 - .32

 

[Greg Amy]

You almost had me, right up to the point you inferred the Nissan NX2000's aerodynamics were comparable to the Gordon Murray-designed McLaren F1...



I personally believe the M1 is not the aero slug that everyone thinks it is. Nope, I've got no engineering data to support that, only a keen eye, some aero/mechE training, and experience in watching them. In addition, in the context of Improved Touring, any of the perceived aero problems (e.g., the ones Travis listed) are cured with the allowable IT mods, making the point moot. I'd suggest that if the M1 is truly a slug, it has a lot more to gain with the allowed IT mods than most other cars. Again, personal opinion.

However, how about you use that nifty DL-1 you have and do the coast-down data calculator? Yes, it'll derive a sum of both aero and rolling friction, but it's useful comparative info...plus, it will take in account the lowering of the car as well as any comparative disadvantages such as the front wheels sticking out and the rear valence.

Back to arguing why the 1.8L should have more weight.

 

[spnkzss]

You almost had me, right up to the point you inferred the Nissan NX2000's aerodynamics were comparable to the Gordon Murray-designed McLaren F1...



I personally believe the M1 is not the aero slug that everyone thinks it is. Nope, I've got no engineering data to support that, only a keen eye, some aero/mechE training, and experience in watching them. In addition, in the context of Improved Touring, any of the perceived aero problems (e.g., the ones Travis listed) are cured with the allowable IT mods, making the point moot. I'd suggest that if the M1 is truly a slug, it has a lot more to gain with the allowed IT mods than most other cars. Again, personal opinion.

However, how about you use that nifty DL-1 you have and do the coast-down data calculator? Yes, it'll derive a sum of both aero and rolling friction, but it's useful comparative info...plus, it will take in account the lowering of the car as well as any comparative disadvantages such as the front wheels sticking out and the rear valence.

Back to arguing why the 1.8L should have more weight.
[/b]

It could be true. The 1988 CRX HF had a cd of .29 while the F40 had a .34

 

[Andy Bettencourt]

Prove it.

You guys just can't seem to accept that the world doesn't revolve around you...[/b]

Ok, so the data is there that you asked for. Now it's your 'gut' that is telling you otherwise. No sweat, it's that same 'gut' that is telling you the Miata will wreck ITA...I'll take my chances with those odds.

It could be true. The 1988 CRX HF had a cd of .29 while the F40 had a .34 [/b]

...and a huge rear wing. That's why I though the F1 was an interesting comparison. Numers are numbers.

 

[spnkzss]

...and a huge rear wing. That's why I though the F1 was an interesting comparison. Numers are numbers.
[/b]

It all that air that gets sucked into that BMW V12... ~~~~~~~

 

[Greg Amy]

Ok, so the data is there that you asked for. Now it's your 'gut' that is telling you otherwise. No sweat, it's that same 'gut' that is telling you the Miata will wreck ITA...I'll take my chances with those odds.[/b]

OK, you want to go back to arguing, Andy? Fine.

You did NOT give me the info I was looking for. You presented information for a TOTALLY DIFFERENT car by the same manufacturer, that does not even have the same model name, and tried to imply it was the same.

Well, it's not, babe. Not even close (at least, not any closer than my NX2000 is to a McLaren F1! ) So, again, I ask you: what is the official Cd of the Mazda M1 Miata with the hardtop installed? Your implied answer thus far: "I have no effing clue."

That's why I though the F1 was an interesting comparison. Numers are numbers.[/b]

And you would think that that "interesting comparison" - that the Nissan NX2000 econo-coupe happens to have the same coefficient of drag as the million-dollar McLaren F1, a car designed in a God-knows-how-expensive wind tunnel by a race team - would be a clue as to the futility of using that unitless number for determining total aerodynamic drag. No, instead of coming to that logical conclusion, we simply ignore it and say "but...this one goes to ELEVEN!"

Enlightening, to say the least.


BTW, congratulations on doing your best to avoid the original debates on the classified weight of the M1 in ITA. Don't think we're not seeing right through it...

 

[Racerlinn]

 

[Andy Bettencourt]

Greg,

What I want you to do is admit you were wrong. You came out gangbusters claiming something wasn't true. You throw categorical generalizations around then recant. With no data, you ask US to disprove YOUR statement. With a reasonable effort, I did. Then you want to ignore the numbers I provide and go by your gut feel. It's a joke really.

(I see no reason why, for the sake of arguement, you can't take real data from an MX-5 and apply it to the M1 Miata...unless it doesn't work for your arguement. If the new Miata goes from .38 to .37 with the hardtop on, I would love to know how the M1 gets any more benefit. No, it's not the exact data you were looking for but it's CERTAINLY close enough to prove that your NX has a significantly lower CD than the Miata with a hardtop. I think you probably knew no data existed for an M1 with a hardtop when you asked for it, making it impossible to disprove the statement you made with no data to back it up)

Doing my best to avoid the original debate? Are you serious? I post TOO much. I explain everything. The only one avoiding questions is you. Maybe the entire post #29.

If you want to seperate the 94/95 from the 96/97, so be it but lets not claim the 94/95 didn't go through the Process, it did - just like the NX2000.