Lower Grill Filler?

[PHeller]

Does anyone make a solid grill insert for the lower grill opening? Say out of something like Lexan or solid aluminum that could be painted?

I'm looking to reduce front end drag for better mpg.

[Fordboy]

nope all of the grills made for our car is mesh, not solid
you would probably have to do something custom

[NYRichyone]

It WILL create more drag...think about it.

The other BIG problem is cooling, I had one of those Flame cut-out grills a few years back, it did look great, BUT, the car ran ALOT warmer. These are just FYI',s....:biggrin:

[PHeller]

Running warmer isn't a big deal.

I don't think it will create more drag...it smooths the flow of air around the front of the car, not into the radiator...why do you think some of the most efficient cars have very little in way of grill openings?

[NYRichyone]

Running warmer isn't a big deal.

I don't think it will create more drag...it smooths the flow of air around the front of the car, not into the radiator...why do you think some of the most efficient cars have very little in way of grill openings? Ok.

You are the expert.:?

[MellowedZX2]

:)Running warmer isn't a big deal.

I don't think it will create more drag...it smooths the flow of air around the front of the car, not into the radiator...why do you think some of the most efficient cars have very little in way of grill openings?

Running warmer is a big deal, engines have NORMAL operating temps for a reason... Show an efficient car w/ minimal grill openings? :)

Joel

[Texas Tracer]

I've seen guys overheat pickups after putting aftermarket grills on their trucks.

[simplicity05]

Here's some pictures of some race cars. Lets see what they look like:

http://formula420.com/MYSPC/NASCAR_6968.gif

http://www.motorsport.com/photos/lemans/2006/24h/lemans-2006-24h-eg-1878.jpg

http://origin-lab.com/blog/wp-content/uploads/2007/06/9611ch.jpg

They all have nice sized openings to let the air in for cooling and induction.

[1981gMachine]

Here's some pictures of some race cars. Lets see what they look like:

http://formula420.com/MYSPC/NASCAR_6968.gif

http://www.motorsport.com/photos/lemans/2006/24h/lemans-2006-24h-eg-1878.jpg

http://origin-lab.com/blog/wp-content/uploads/2007/06/9611ch.jpg

They all have nice sized openings to let the air in for cooling and induction.

Ok, nascar, what do they do to create more downforce and let them go faster? Duct tape over the grill openings.

Lambo, cuz a ZX2 is just like a lambo, just a lil cheaper. Let's not forget they have scoops in the rear to suck air into the rear mounted engine.

Drifting? Yeah cuz those cars reach high speeds, they are not a ture race car . They are built to slide with lots of power. Of course they have a big opening, looks cooler.


The least you could of done was post viable pics of race cars that support this "big grill" idea.

[1981gMachine]

Drag Coefficient

The shape of a car, as the aerodynamic theory above suggests, is largely responsible for how much drag the car has. Ideally, the car body should:

* Have a small grill, to minimize frontal pressure.
* Have minimal ground clearance below the grill, to minimize air flow under the car.
* Have a steeply raked windshield to avoid pressure build up in front.
* Have a "Fastback" style rear window and deck, to permit the air flow to stay attached.
* Have a converging "Tail" to keep the air flow attached.
* Have a slightly raked underside, to create low pressure under the car, in concert with the fact that the minimal ground clearance mentioned above allows even less air flow under the car.

All of this reduces drag, increases top end speed and over the long run better mpg



Now the question on hand:
I'd take a piece of poster board and make a template for the opening. Then transfer it onto a sheet of plastic. Something thin yet rigid. You could glue some "L" tabs on the back of the cover to attach to your grill opening. If anything I would try it closed off at 1st. Temp rises maybe open the 2 center holes up or get a different thermostat with a lower temp setting.

[TTFOWIA]

dude, even if "no opening in the front" would reduce drag like you're saying. it is NOT with a perfectly vertical WALL that it will happen. maybe removing the opening would (in general). but not on our application. cuz the only way to do that is a. custom bumper. b. VERTICAL WALL.

[1981gMachine]

Everyone is missing the point, the "wall" is still less drag then air getting trapped in the engine compartment.

[TTFOWIA]

air will still get caught in the engine compartment unless you put a FLOOR under your engine.

[1981gMachine]

air will still get caught in the engine compartment unless you put a FLOOR under your engine.

Well no shit sherlock but where does the bulk of the air come in at? Umm Umm the grill opening. If there is a cover where is that air gonna go??? Around the car not into the engine bay. So how does this NOT reduce drag? Maybe you should reread what I wrote. I said reduce not eliminate. There will always be drag but you can reduce drag in many ways.

[1981gMachine]

4.Interference Drag

Interference drag is that that comes about because vehicles are not single bodies without appendages. And unfortunately, when different shapes are combined to form a practical vehicle, the total drag is always greater than the sum of its parts.

For example, the drag of a wheel (even when covered in a fairing) and that of the car body will be greater when they are joined that when they are measured individually.

In effect , the flow over one surface interferes with the flow over another surface.


Goro Tamai, in his book The Leading Edge (from which the above table is taken), suggests that the priority order for reducing drag should be as follows:

1.Reduce separation pressure drag (ie size of wake)
2.Reduce Induced Drag (ie downforce/lift drag – normally, it would be reducing lift)
3.Reduce Interference Drag (eg sealing holes, contouring junctions, etc)
4.Reduce Viscous Drag


http://autospeed.com/cms/A_110351/article.html

[1981gMachine]

Article written by someone at an engineering school. Basically says less drag = better mpg

http://gcep.stanford.edu/pdfs/ChEHeXOTnf3dHH5qjYRXMA/10_Browand_10_11_trans.pdf

[TTFOWIA]

Okay, I will let you try an experience yourself in your head. lets say you take a pepsi bottle. you cut the top half. You now have a big "air catcher. try catching air in front of a fan with it. for SURE its going to be huge. the drag of the bottle will be amazing cuz of course, the bottle catches ALL the air and does NOT let it out. if you put a WALL in front of this opening. it will STILL be kind of huge. hovever, if you remove this wall, and cut the bottle in half horizontally, the air will be "catched" but released at the bottom. it will be LESS resistant then the wall. this is exactly what is happening with the car. the air enters the engine bay, but can escape easily at the bottom. the resistance this wall will create is worst than the resistance air will create entering the engine compartment and exiting as soon its in.

[1981gMachine]

I can you sit there and tell me that if someone were to block off the bumper, where the lip is around the opening, it wouldn't reduce drag?

see the lip? Now use you imagination an picture it flush the whole front of the bumper. Last time I checked the ZX2 was a flat front bumper. There is curve to it

http://img237.imageshack.us/img237/5739/cid0426081830apj1.jpg


What's the best aerodynamic shape? A tear drop with the wide part the leading edge.

[TTFOWIA]

w/e. try it. then rent a drag testing chamber and let us know.

[1981gMachine]

w/e. try it. then rent a drag testing chamber and let us know.

It's called a wind tunnel dumbass. You've done nothing to prove closing a grill will cause more drag. I've provided a few links that state lower drag increases mpg. And the one said by closing holes. wtf is a grill opening?

[Kilroy]

this thread is retarded... obviously if you closed the grill off the car would be more aerodynamic, but your radiator wouldn't be getting the rush of cool air it needs to keep your motor running at ideal temps.

[1981gMachine]

this thread is retarded... obviously if you closed the grill off the car would be more aerodynamic, but your radiator wouldn't be getting the rush of cool air it needs to keep your motor running at ideal temps.

glad I don't have to explain to you that. It's common sense a few on here must me lacking. Same reason why nascar teams only put so much tape on the grills. More tape = more heat

[TTFOWIA]

It's called a wind tunnel dumbass. You've done nothing to prove closing a grill will cause more drag. I've provided a few links that state lower drag increases mpg. And the one said by closing holes. wtf is a grill opening?

yeah I had a blank about the wind tunnel name lol...

and I NEVER said lower drag would NOT increase mpg. I am totally for this statement. I said I am sure, ON OUR car, blocking the grill would NOT decrease drag.

[1981gMachine]

yeah I had a blank about the wind tunnel name lol...

and I NEVER said lower drag would NOT increase mpg. I am totally for this statement. I said I am sure, ON OUR car, blocking the grill would NOT decrease drag.


There is a curve to the bumper. Air will in the dead center build up a high pressure spot but the bulk will go around the car.

[TTFOWIA]

w/e... im not too sure about that.

[JohnP]

Back in March '74 Car & Driver had a project car : "Crisis-Fighter" Pinto , this was to see how much they could increase the mileage . Yes gas prices were getting crazy , $2.00 I think .

They increase the mileage by 25% for less then $15.00 , made a pretty slick looking car while they were at it . Mileage went from 14 to 18 mpg @ highway speeds , 55-70 mph.

It all comes down to Aerodynamics , less wind resistance ,rolling resistance . They made a Air Dam/Spoiler for the front bumper , covered the headlights with plexi , blocked off Part of the grill , added a rear spoiler and changed tires(harder higher pressure) .

The ZX2 already has most of the features the project Pinto had . All you need to do is increase the size of the front air dam/spoiler , block off Part of the grill , go to a Low Rolling Resistance tire with higher pressure .

I had a post on the old site about how to make three different kinds of front air
dam/spoiler , two were fixed ,one was adjustable . Spoiler has to be as close to the ground as you can run it . A stock size tire in LRR with high pressure , like 42F / 40R will increase the mileage , run the stock tire at a higher pressure .

Blocking the grill to see how much you do need to leave open , use Duct Tape , cover it completely . Drive it till it starts to get hot , remove a couple of strips from the center , drive it and see what happens , keep doing it till your comfortable with the engine temp . Once you have the opening size figured out , make a couple of inserts to fit inside the grill opening .

I guess you could call this the "Crisis-Fighter" ZX2 , everything comes Full Circle . At todays gas prices if you can increase the mileage by a few or more by spending less then $20.00 , think it might be worth it . I have the old magazine , but I just checked to see if anything was on the internet and found the Pinto , good pics and info . , checkout the site .

http://forum.ecomodder.com

[CJW]

There is no need for name calling. And why does everything have to turn into a debate.

He asked
Does anyone make a solid grill insert for the lower grill opening?

Not
Hey I already know what I want to do, does anyone know where I can find something like this? Feel free to argue amongst yourselves, not helping me, and start calling each other names.

[PHeller]

I shall experiment with painters tapes and cardboard for starters. Also will try to run something covering the area from the where the bumper ends to the lower radiator support.

Basically, I'm wanting better gas mileage, and the more time and effort I put into trying to get it...the more I'll attempt to slow down to achieve best possible mileage. No worries though, I'm not doing anything crazy like fender skirts or rear teardrop...

[JohnP]

Skirts , I knew I forgot something . You can attach a side skirt along the pinch weld under the rocker panel . Skirts and Air dams can be made using Vinyl lawn edging , comes in different widths . With a low air dam and side skirts , you will create a low pressure area under the car . I did all this stuff 30 years ago , it does work great for mileage .