139 replies to this topic

[LarryKing]

 

1.6 guys who don't want to tape their grille as they are worrying about heat soak, so likely would never tape their grille. I actually understand that point, one of the few I can at least understand the hows and why's

 

He knows.

[Jim Drago]

He knows.

who? Bo? Bo knows thermostats?

[MPR22]

They do a lot of things in Texas that are illegal in most states... Unfortunately most involves incest and llivestock

Says the Yankee living in the Hood in Tennessee. You are truly multicultural.

[Tom Sager]

Some people inherently distrusts people, yet the same people love big government.  I believe that is why Liberalism has be been called a mental disorder.  

I don't think the moderators around here care much for political speak but I couldn't agree with you more.  Now if we had a place on this site for political banter, there would be quite a bit to add to your discussion.

 

Taping a radiator would seem to be an area of political common ground given that everyone has access to affordable low cost tape (or even free if you get it from your rich buddy's tool box or ask someone if you can "borrow" it), but SM has more than 2 political parties to appease.  

[ChrisA]

Some people just enjoy being "Pro-Anti".

Or is it "Anti-Pro"?

[Ron Alan]

Some people inherently distrusts people, yet the same people love big government.  I believe that is why Liberalism has be been called a mental disorder.  

Spoken like a true Savage! Hard to persuade free though....

[Cnj]

I was recently reading up on some tax law in an effort to make sure our company was compliant. This rule is reminiscent. A rule to have a rule and rules piling on rules.

Sometimes common sense and simplicity should lead. The quote that Jim pulled above indicates that the racing authorities believe tape provides areo advantage. Really? Based on what research/data/test/evaluation on a Miata? I'm pretty decent at understanding fluid dynamics based both on study and profession - and I don't buy that a couple strips make a competive difference. Perhaps a total seal will (maybe) but good luck keeping temp down for three perfect laps (the mimimum possible for quali) without overheating.

I never saw anyone use more than one or two strips of tape before this rule and so those looking for problems (complete seal) are dredging up problems that don't exist. All it means is that people like Jim will develop expensive solutions such as shown on the radiator above - instead of a few cents of tape.

Change the rule.

CNJ.

[Caveman-kwebb99]

I am all for changing the rules to catch compression ratio and the extra str work that was going on but when it comes to a strip of duct tape to regulate temps we need to all take a reality check and let those that don't want to risk running a tstat tape instead.

[Cnj]

Will do

Cnj

[Pete Maerz]

Sometimes common sense and simplicity should lead. The quote that Jim pulled above indicates that the racing authorities believe tape provides areo advantage. Really? Based on what research/data/test/evaluation on a Miata?
CNJ.

Craig, although not specific to Miatas, here's some information pertaining to the aerodynamic drag contribution of a vehicle's cooling system. It's a simple concept: air going through your car causes more drag than air going around it.


A couple Google references:
http://papers.sae.org/2006-01-0342/

Abstract:
"Engine cooling systems are usually designed to meet two rare and extreme conditions; driving at maximum speed and driving up a specified gradient at full throttle while towing a trailer of maximum permitted mass. At all other times, the cooling system operates below its maximum capacity with an incurred drag penalty.

In this work it is being suggested to design the system using the existing methods and then vary the area of the cooling air intakes to permit the minimum amount of cooling air for adequate engine cooling. A full-size, Australian made Ford Falcon car (a large modern 'family' saloon) was tested at the Monash University Aero-acoustic Wind Tunnel. The cooling air intakes of the vehicle were shielded progressively until fully blocked. Four different possibilities of shielding were investigated with the aim of determining the variation of drag reduction with the shielding method employed.

Results from these tests found the optimum method for shielding the cooling intakes for minimizing the drag coefficient was vertical strips. This enables the airflow to be attached smoothly to the body. For a sealed cooling system, the drag reduction achieved was about 7% which corresponds to a prediction of about 2.9% and 1.7% in reducing fuel consumption on highway and urban driving conditions respectively."

https://books.google...ic drag&f=false

The above source indicates that the cooling system accounts for 15% of total vehicle aerodynamic drag.

http://www.stockcarr.../#ixzz3SdiOSpY1
"As a rule, you never want to give up any more grille area in the frontof the car than necessary. Taping over the grille is one of the few ways you can improve aerodynamic downforce and also reduce drag on a racecar. The best way to keep the smallest grille opening is to build themost efficient cooling system possible. That doesn't necessarily meanyou can simply install a larger radiator, because if you cannot supply asteady, cool flow of air across every inch of the radiator's surfacearea, you are wasting its capacity."

You guys keep saying "a couple strips of tape has no significant aero effect." Hmmm...then why does your cooling performance change?

A Miata generates around 50 hp worth of aero drag at 100 mph. If blocking off the radiator is worth 7% that's 3.5 hp. Yeah, under normal conditions the car would probably overheat totally sealed. However, what about a cold day on a high speed track? Maybe you could block off 2/3rds of it for a 3.5% improvement. This kind of benefit would be tempting to a front runner.

Like I said earlier, none of this matters to me personally as a casual racer. I'm just trying to point out that taping the radiator inlet has a real aero effect. I believe the current rule is adequate as written. Tape the radiator all you want but don't block the opening. This is a Spec series; keep the variables to a minimum.

[FTodaro]

Pete this is pretty typical of screen tape to put heat in the car.

 

does this look like it would be a measurable benefit?

 

Without more information about your study about where the air was diverted, and other aero feature of the car, its hardly an apples to apples analysis.

 

I find it hard to accept that this is an advantage.

 

http://s300.photobuc...w=recent&page=1

 

 

[LarryKing]

 

This is a Spec series; keep the variables to a minimum.         

 

Yep

[Jim Drago]

 All it means is that people like Jim will develop expensive solutions such as shown on the radiator above - instead of a few cents of tape.
CNJ.

And Jim had no issues with tape

[Bench Racer]

Pete is doing such a fine job, I should stay out.

 

Frank, my 2013 Ford Edge has maybe 40% of the grill opening blocked within it's design, can you say areo to improve fuel mileage.

[Cnj]

Pete,

Good research and measured input to the topic. I have thoughts in response - but have to make a living today so will get back to you.

Walter,

Yes it's a spec series, but keeping variables to a minimum does not mean adding rules to control everything. So for example - in the interests of total spec and parity would you support rules that define tire pressures, camber and caster angles and insistence that everyone start quali and races on new sets of tires? Others can add multiple other variables that we have access to in our series that have a far greater performance impact than tape could have.

CNJ

[Caveman-kwebb99]

No way my tape is worth 5hp!

[Bench Racer]

Shucks, I was sitting here thinking and I know a guy that might cover the bumper/grill opening with an advertising decal and call it legal.      Naw, he doesn't live in Wisconsin.

[Jim Drago]

Shucks, I was sitting here thinking and I know a guy that might cover the bumper/grill opening with an advertising decal and call it legal.       Naw, he doesn't live in Wisconsin.

It was legal.. the rule came in after that and because of that!   Thanks for reminding me.. One of my favorite pictures East Street Racing 1-2-3!

 

[MPR22]

Pete is doing such a fine job, I should stay out.

 

Frank, my 2013 Ford Edge has maybe 40% of the grill opening blocked within it's design, can you say areo to improve fuel mileage.

 

Yep the grill is all about the aero on the cute little brick of a car.  Can't have anything to do with aesthetics.

[MPR22]

 

Yep the grill is all about the aero on the cute little brick of a car.  Can't have anything to do with aesthetics.  They even strategically yet SM illegaly mounted the license plate holder forward of the grill to push more wind around the car.