pics of my grille block experiment...
 

Rough template:
https://home.woh.rr.com/slurp812/gb1.jpg


first cardboard total lower grille block:
https://home.woh.rr.com/slurp812/gb2.jpg

Stuff I used to make up the aluminum one:
https://home.woh.rr.com/slurp812/gb3.jpg


Here is the aluminum one on the car, ready for my drive to work tomorrow!:
https://home.woh.rr.com/slurp812/gb4.jpg

With the first cardboard one, it got kinda warm after a short trip, so I went with the small opening. i didn't even measure it yet. It looks to be about 5x7 inches...

let us know how it does tomorrow :thumbup:

That looks really good, let us know how much better your FE is

That's really nice looking! I enjoy seeing ideas I can use on my own car.

That looks awesome. I'd love to see a picture in daylight from further away, I bet it's barely noticable.

it does seem to do a little better, but Iv changed the spark plugs also. And just recently had a trip about 5-600 miles, and messed up on filling up at foreign pumps. My numbers have been erratic. But usually now around 37. But weather has been warmer also. so many variables. But small steps in the right direction...

I have a question,

if you place that block further in (not flush) will it still improve aerodynamics??

I want to know because I want mine as inconspicuous as can be...

probably but its really hard to say and it all depends on how far back you place it.
i honestly didnt see much mpg with the grill block. but i also go over 65 for maybe 20 miles in an entire tank.

it will help

... insightful...

well it has on my truck

What do you think the difference is between flush and further back?? 1mpg at most??

Personally, looking at that I'd have gone with a full upper block and maybe 1/6 to a quarter width each side on the bottom. IMO it's the upper grille blocks that are more aerodynamically effective.

its probably a little late for suggestions but I have seen where people have relocated their front plate lower (under the bumper) and used it as part of the grill block.

it gives the front of the car a cleaner look. may not be good for your application if you are already getting too warm for comfort.

You know, that's kinda funny you mentioned that. I bought the car from a state that doesn't have a front plate. so I had to buy the front plate mound from Honda. So when I first got it, the plate was down there, but on this car, it doesn't quite fit right. I thought about fiddling with my own custom mount, but I just wanted to have it look correct, and not attract any law enforcement...

I have been lucky I guess to live in a state that doesn't require a front plate.

I wonder how much leeway there is with where the front plate is placed. I have seen them in the windshield of the passenger side. not sure if it is legal.

I think most laws clearly state that the plate is to be mounted to the front bumper. Enforcement tends to be pretty lax, though; mainly people only get any enforcement activity if they completely lack the plate. Still I'd rather not attract attention by having it too far from where it's expected. I'm happy with my partial lower grille block license plate...

someone asked for a better daytime pic of my grille block....
https://home.woh.rr.com/slurp812/gb5.jpg


I was also wondering how much my fans were commoing on. I cant hear them very well unless I have the windows down all the way, and I am going really slow. So, I did this:

https://home.woh.rr.com/slurp812/fan_on_1.jpg

https://home.woh.rr.com/slurp812/fan_on_2.jpg

https://home.woh.rr.com/slurp812/fan_on_3.jpg

https://home.woh.rr.com/slurp812/fan_on_4.jpg

The LED lights up when the fans are on...

Nice! I was thinking of doing the same thing, and I'm glad to see that I'm not the only person who taps relays like that! :)

cool can you explain more about the witing ?

sure.

I made up an LED tester with an LED, and resistor. Before I wired it up, I tested the socket of the relay to see which one of the contacts was powered. The relay turns the fans on. One side is always hot. At least on my car. Other cars may need the key on? I hooked the positive side thru the resistor to the relay (the switched side) as shown. The negative side I just hooked to the nearest screw with a crimp on terminal. and soldered the little red wire to the other side. I should have put a small fuse inline near the existing fuse box. If you are not really comfortable with electronics, I don't recommend doing this yourself, bad things could happen. Anyway, on my car, the fans are turned on as soon as you turn the AC, so its a quick way of testing the LED...


Heres a pic of the LED tester. I make these all the time...

https://home.woh.rr.com/slurp812/fan_on_5.jpg

The black side is hooked to ground, and the resistor side is hooked to whatever it is you want to test/indicate. In this case, its the fan relay. Notice the Negative side is the bigger of the 2 pieces of metal inside the LED. Also the metal thing above it is a holder like I used in the car. Just makes it look neat.

I hope this doesn't sound too confusing.....

cool ,,what resistor is that :thumbup:

I too would like to know the value of that resistor. It appears to be gold-red-black-brown (1k) but could be gold-red-green-brown (1m).

If you have a supply of these available, a common 12v phone charger or other 12v adapter with an LED could save some time, depending on where/how you want to mount it. I've got an abundance of these and intend to use them for such things as a fan indicator. Just crack it open, hack wires on to it, and maybe extend the LED away from it.

It is a 1000 ohm resistor. So yea its a 1k. Most LED's are usually 20 milliamps max, and the 1k should make it a bit less than that, close enough. :D

Slurp, while we're meandering... I have an 04 Si. Have you considered cutting some of the back bumper up higher while also smoothing out underneath? Talk about a big air brake area! I was thinking of cutting out along the indented lower area. I'm sure we could get 2-3 mpg on smoothing out the whole bottom and raising the rear, etc., etc. I also think removing the rear "wing" would help, might look funny, though.

thanks :thumbup:

removing the lower part of the rear bumper will definitely help, but i am not so sure of the duckbill "wing" on the hatch. it may have properties of a vortex generator.

For the indicator I used for my TCC indicator I got a green 12V led from radio shack. It was only a couple bucks but you don't have to worry about soldering in a resistor or anything and it's not so bright that it will ever bother you during driving. The only downside to it is if you mount it in a place that isn't shaded from the sun you can't see it come on in the day.

FYI:
If you don't want to mess with connecting your own resisters into a circuit, for just a little more money (than the cost of buying bulk resisters and LEDs and connecting them yourself) you can get a LED module already setup for 12v car systems. For example https://www.superbrightleds.com (a place I buy most of my car LED modules from, due to the quality and price of many of their LED modules) sells a 12v LED module (in your choice of colors) for $1.99-$2.99/each (depending upon color of LED). And their shipping (via US post) is only $5/order, as long as your order is under $100 (and for larger orders, shipping seems to start at only $10/order).

https://www.superbrightleds.com/store.../led_wired.jpg

https://www.superbrightleds.com/specs/wiredLED.htm


BTW:
I've personally been thinking of using that exact module mentioned (I've already bought a few in different colors) as indicator lights on my dash (I just haven't gotten around to wiring them in yet).

My personal thoughts were to wire up a green, a yellow, and a red LED (in a "traffic light" pattern?) on the (side of the) dash. I could then hook up the green to the FI (so I can get a rough idea of fuel use, including a clear sign of DFCO), hook the yellow up to the radiator fan circuit (so I can see when the fan is on, just like the OP is doing), and hook the red up to the brake light circuit (so I can get a clear idea when I've pressed the pedal enough to turn on the brake lights). Oh yeah, I was thinking of wiring the common ground (for all these LED modules) up to a small switch (and likely also a small fuse), before hooking them up to ground, so that I could easily turn on/off these indicator lights when I wanted to (so I'm not forced to see these lights at all times if/when I don't want to). Of course, that's the idea, and I haven't yet gotten around to actually wiring things up that way (i.e. it's on my "to do eventually" list)...

I don't want to start cutting the body panels just yet. :eek: I want to be able to put the car back like it was. I was thinking about something with the wing area in the back, not sure what tho. Oh and Draco you have some good ideas. As always, if I do anything it will be posted here first!

:thumbup: Good information and ideas, DracoFelis.

I still think the car charger is the easy/cheap/fast way to get a prefab 12v indicator LED. You can often get them at dollar stores, especially if you're not picky about what it's made to charge; or you may be able to get them for free from someone getting rid of a phone.

If you're going to the effort of intstalling LEDs and mounting a switch, why not just skip the brake light LED and mount another switch instead? Then there will be no question and no chance of braking when you don't want to.

DracoFelis,

Good idea to monitor brake, ignition-dfco and fan.

If you only monitor 2, I guess you can get a LED with 3 legs. If you monitor 3, then you could get a LED with 4 legs (RGB colors!). However hurry up to Radio Shack. These guys will be going under I bet, they are too expensive, and don't have a decent business model.

Computing LED resistor

BTW, if you want to compute your resistor for your LED, here's how you do it I think:

- Get the reverse voltage of the LED (specifications), usually 1.7V
- Get the reverse current needed to light it, usually 15mA
- Assume the max battery voltage is 14.5V
(Vbat - Vled) = R Iled

=> R= (Vbat - Vled)/Iled

For a small basic LED:
R = (14.5-1.7)/15 * 1000 = 800 ohms

A smaller resistance will make it brighter, till it burns (when it burns, the light will dim irreversibly as it gets destroyed, and then will go black)

Some specs from LED101:

small: 15mA, 1.7V
medium: 25mA, 2V

Specialty. high brightness LEDs will come with their own specs, that may be much higher, like 5V or 1000mA (1amp!).

Nice info!

I don't think Radio Shack's business model is broken, nor will they go under. They have a great business model: Have no competition for a large portion of your inventory, be positioned as the place to go when you need help with the rest (by being a small store with people that will take a couple minutes to fail to help with your cell phone or R/C car), and charge too much for everything. It's worked for them for decades...the only difference now is that you can buy LEDs and transistors online -- which doesn't help when my project needs it right now.

Every time I go there, there's noone, or almost. Their biggest business is cell phones, with mondo competition. They ditched their core business for that. Electronic gear parts is overpriced because not a big sell anymore. It's even hard to find parts at RS now. Their competition is the web and complexity of electronic gears.
RC cars are sold by toy stores.
They don't really sell/make their own electronic gear any more (like stereos).
I bought at Radio Shack a ref book on the intel 80386 way back. not today!

BTW I'm not happy about it, but they're on their way out IMHO.

Note: I live in silicon valley, and there's not a single decent electronic store around. Go figure.
(end of off topic)

I took the block off today. My fan comes on at least a few times per trip when I drive. Normally its never on, I try not to idle much. It will go back on when the temps drop. I will see how this effects my overall...

Rats. I'm blocking vicariously through you and live in Tuscon. What about increasing the opening some more? Are you going to mess with the upper grill?

Monitor your Fan with a Scanguage
 

For those of you who want to monitor the fans, Don't forget that if you already have a Scangauge 2 that supports the Xgauge (I think any one purchased in the last year) on many vehicles you can program it to monitor if your fan is on or off... no parts or cost if you already are running a Scangauge.

I left my top grill open and blocked under the bumper on my car. I thought everything was good, but have since realized that the fan was turning on at highway speeds. I couldn't tell by the gauges and listening, but with the Scanguage I could watch the temp and it woudl go up to 215, then the fan would kick in and it woudl drop down to about 200 (thermostat is 195). Digital gauges rock. :-)

In my case, I have black duct tape as my grill block (because I have a Bra, which has screen over the openings). I have just been slowly removing duct tape until it stays cool enough not to turn the fan on at speed on a warm day.

-Mr_C

DOH! Thanks for that info. I could use the LED for other things aw well. I am going to lookinto the upper grille block, and cutting some off of the bottom, so it blocks less. I will post here!

There's an idea -- add a bra, and now you can do lots of grille blocking underneath it and not have it attract attention...well, any more than you'd get with a bra nowadays.

It isn't the prettiest thing in the world... but it doesn't attract much attention either. The nice thing is the bra on my car already has a screen over most of the coverings, so there is a little flow restriction right there. Plus, I pulled off the upper part of the bra that goes over the hood. that wasn't doing me any good anyway. Right now the bottom is just covered with black duct tape, Once I know its how I want it I will sew on some black vinyl to make it match nicer and last longer.

https://www.fuelly.com/attachments/fo...be019542fd.jpg


-Mr_C