139 replies to this topic

[FTodaro]

Be creative, there are a front and back side to a radiator.  Ding, Ding, Ding, any radiator.

I can tell you have never done this or you do not run a fan on your car.

[Bench Racer]

If you have a KOYO radiator, it's a vertical flow and if you have a Springfield Dyno radiator it's a cross flow. You most likely removed one of the cooling fans/frames therefore you have half the rear side of the radiator to tape/cardboard/block. Or because the radiator may be any radiator add a spacer between the cooling fan frame and the radiator (spot weld the spacer, therefore the spacer is part of the any radiator) and slip the cardboard between the radiator and the cooling fan frame. Did it that way on my Spec7 car. Todd as a shop owner, instead of piling on why not jump in and help Frank work through/around the rules.

[Pete Maerz]

There is no Aero advantage, if someone says different show me the data.

 

Frank,

Care to speculate why Mr. Montoya's crew chief taped up his radiator for qualifying? You think it was to keep his coolant temps warm? By the way, it was in the 70's the day this photo was taken.

 

[Todd Lamb]

Completely different animal.

 

When does a Spec Miata average 190mph over the course of a lap? Or go 170mph in a turn?

 

Also, they are taping the flat front of the car, not the back of the front bumper inlet.

[Todd Lamb]

Mainly because we have people like you introducing complicated work-arounds and providing erroneous information about aero advantages, trying to sway the public opinion just for something to do. It creates a lot of work/hassle/headaches when it comes to making things happen. You do realize this, right?

 

 

 

If you have a KOYO radiator, it's a vertical flow and if you have a Springfield Dyno radiator it's a cross flow. You most likely removed one of the cooling fans/frames therefore you have half the rear side of the radiator to tape/cardboard/block. Or because the radiator may be any radiator add a spacer between the cooling fan frame and the radiator (spot weld the spacer, therefore the spacer is part of the any radiator) and slip the cardboard between the radiator and the cooling fan frame. Did it that way on my Spec7 car. Todd as a shop owner, instead of piling on why not jump in and help Frank work through/around the rules.

 

[Steve Scheifler]

I was taught to not believe everything you read but if its on the internet, it MUST be true. I don't try to get facts from Wikipedia because we know its very accurate.

NA- .38
NB- .36
Chevy Astro Van- .40
VW Euro Van-.37

Something doesn't jive.

Maybe you should also look up "coefficient".

[SaulSpeedwell]

I was taught to not believe everything you read but if its on the internet, it MUST be true.  I don't try to get facts from Wikipedia because we know its very accurate.

 

NA- .38

NB- .36

Chevy Astro Van- .40

VW Euro Van-.37

 

Something doesn't jive.

 

Cd is just a shape and "slipperiness" coefficient, it gets multiplied by FRONTAL AREA and speed^2 and air density and a 0.5 to arrive at "aero drag force".  It is an idealized equation, but you can't escape that more area is generally always bad, and that pesky exponent on the speed is why 1200HP Veyrons go "only" 30-50 mph faster than a bunch of 400-500HP cars. 

 

Anyway, does anyone know the frontal area of an NB?  Looks bigger than an NA to my eye! 

 

As for this grill mesh rule, it goes beyond silly for an important reason - by forcing the mesh to be "attached to the air guide" (as opposed to where the A/C condenser mounts), you are choking flow and raising coolant and intake air temps.  We tested this to death on cars with marginal cooling on hot (for Ohio) days.  

[Pete Maerz]

Todd,

Nascar average qualifying speeds at Martinsville are in the 90's and they still tape up the radiators. You don't need to go 190 mph to realize an aero effect from closing off the radiator inlet.

 

If you have an overcooling issue, hear me out here, you could run a thermostat.  

[MPR22]

Todd,
Nascar average qualifying speeds at Martinsville are in the 90's and they still tape up the radiators. You don't need to go 190 mph to realize an aero effect from closing off the radiator inlet.
 
If you have an overcooling issue, hear me out here, you could run a thermostat.

Thermostats fail on a regular basis on these cars. Fail shut, by by new engine, fail open and by by HP on cool days. No thermostat=custom temperature control for about .10 per application.

[Todd Lamb]

So your belief is that taping off the entire front end in NASCAR for a 50 second qualifying run (2 laps plus out lap) to gain .1 sec before the car spews water all over the windshield is similar to taping the opening behind the front bumper on a Spec Miata?

Also, considering anyone is free to do it, and it is free to do, your belief is that it should not be allowed?

Just trying to understand your logic here.

[Pete Maerz]

Hi Todd,

I'm just refuting the statement that's there's no aero advantage. If legal and if I were running at a track like Daytona I'd at least experiment with it. When a car approaches terminal velocity these things can be significant. Of course if it works everyone will be looking for larger and more exotic radiators in order to get a hot lap in qualifying without overheating.

 

I don't believe it's necessary in Spec racing; same goes for a lot of the seemingly "innocuous" allowances in the SM rule set that have caused complications.

[LarryKing]

Agree with Pete. Added complexity in a spec class. I've run thermostats for years, never had a failure. What happens if you tape too much?

[SaulSpeedwell]

I ran Stant "heavy duty" 180F units and no failures.  WIth April/October races in the 30s, 40s, and 50s (degrees F), I always considered a thermostat mandatory. 

 

The one time I tried tape and a gutted thermostat housing, when I saw coolant temps going TOO HIGH, I was like:  "oh great ... now what .... pull into the pits and rip it off?".  No more tape attempts for me after that.   We're talking Ohio weather here, though.

[Caveman-kwebb99]

I am not even half as smart as Saul and I have taping down to how big of a piece to tear for several different temps in Ohio. My engine builder does not want me to run a tstat so I don't. I will be writing a letter to support franks stance to go back to taping the grill rather then the stupid raditor which is probably an aero advantage in itself although .5 of what it is to tape on th e grill.

[FTodaro]

I have been trying to post a picture of what i "used to do" but for what ever reason i can't get the file small enough to be allowed.

 

The 4 to 6 inched of tape needed in the front recesses of the radiator intake screen to adjust temps, its hard to understand how restricting air flow on the inside of the funnel is an aero advantage, the logic would be it would hurt. We are not taping across the front of the bumper such that air is not entering the funnel.

 

I would explain why running a thermostat in a 99+ car is not optimal, but then i would have to Kill you.

 

You guys kill me. Its almost like any idea is a bad idea?

 

No proof of an aero advantage, or logic to support the belief.

 

No cost to class.

 

You want to run a stat run one or some expensive duck tape on your screen. Your choice. 

 

But let the debate continue on speculation and conjecture.

[Dave D.]

In regards to taping the stock car nose,I think the advantage they are getting has to to with the fact that there is a large splitter there and taping the rad inlet increases pressure on the large surface area for more downforce as well as reduced drag. I recall a conversation where a crew chief mentioned that the difference between loose and a push was one width of tape on the grill in the right spot.

[ChrisA]

 

 

You guys kill me. Its almost like any idea is a bad idea?

 

 

 

Surely they warned you about getting any bright ideas.

[Tom Sager]

 

You guys kill me. Its almost like any idea is a bad idea?

 

 

Your idea is a good one.  We should be able to install a screen of any material and of any size and we should be able to tape over that or the bumper opening itself however we want.  

 

Others should write letters supporting this and hopefully it won't take until 2016 to get it approved.  It would be nice to see a "rule change" that is beneficial and common sense get through the entire cycle and to approval quickly (couple months).  Managing the temp on my '00 is a pain in this part of the country with sub-50 degree days to 90+ degree days.  

 

As for someone getting an aero advantage  , well ,   you're only some tape away from a level playing field. 

[Pete Maerz]

No proof of an aero advantage, or logic to support the belief.
 But let the debate continue on speculation and conjecture.

Here's some more conjecture and speculation:
http://media.gm.com/...0810_cruze.html

.5 mpg improvement from grille shutters on a Chevy Cruze.

I don't really feel strongly about this rule. I'm just pointing out that the claim that there is zero aero effect is false. By the way, shouldn't the burden of proof be on the rule change proposer?

[FTodaro]

Here's some more conjecture and speculation:
http://media.gm.com/...0810_cruze.html

.5 mpg improvement from grille shutters on a Chevy Cruze.

I don't really feel strongly about this rule. I'm just pointing out that the claim that there is zero aero effect is false. By the way, shouldn't the burden of proof be on the rule change proposer?

Yup I would say this is right on point with putting two strips of tape on a screen. From your link:

 

 

"Engineers used some of the proven approaches to making the Cruze Eco a gas sipper, trimming its overall weight and lowering the ride height. But the real innovation is behind the front grill where an automatic air shutter system allows the car to change shape and cut through the air more smoothly.

 

The air shutter system uses sensors to feel and sense wind and temperature conditions. The sensors are married to electric motors that open and close the shutters automatically.  With the shutters closed at high speeds, wind drag is reduced. At lower speeds, the shutters open to maximize engine-cooling air flow. The air shutter system contributes nearly half a mile per gallon in combined city and highway driving."

 

 

I submit there is a difference between taping off an air inlet so no air passes through, such that the air is diverted around the bumper vs. Putting tape into a recessed air inlet such that the air passing through has more restriction, and is not allowed to flow around the outside of the bumper.

 

We can agree to disagree on this one. I never said "there was zero effect", I said it was no advantage.