The aero mods begin (Now working on Diffuser) !!!

[ptjones]

fbov   the way I understand what you are doing is sealing the hood so no turbulance is created and improving aero. Are you also improving air presure to air intake? I would like to try it when I get a clear understanding what is going on.

Paul

[mtb9153]

Thinking about doing the acrylic covers to Maxus.  Was thinking of alternative ways to secure it without drilling and tapping holes like recumpence.  Thought of securing with long nylon cable ties through the wheel spokes and back through the cover with two small holes drilled in the covers.  I found a local plastics supplier which can custom laser cut four 17 inch circles to fit perfectly over the wheels.  I have a question for recumpence, are you covering all four wheels or just the fronts.

[ptjones]

Thinking about doing the acrylic covers to Maxus.  Was thinking of alternative ways to secure it without drilling and tapping holes like recumpence.  Thought of securing with long nylon cable ties through the wheel spokes and back through the cover with two small holes drilled in the covers.  I found a local plastics supplier which can custom laser cut four 17 inch circles to fit perfectly over the wheels.  I have a question for recumpence, are you covering all four wheels or just the fronts.

The wheel covers need to be at least 18" to 18-3/4" in diameter and would recommend polycarbonate. I've had my covers on over 2,000 miles and am having some rubbing issues on the spokes. It appears that the wheels are exactly the same because it is rubbing on the inside spokes on one wheel and the outside spokes on another wheel so I need to come up with another solution. I have my covers mounted with a 1/4" screw through the center and I made an aluminum cap to go on the back side of the wheel so I could screw into it. It only takes a few seconds to install or uninstall the covers. Also I put a nylon 1/4" x 1-1/2" long screw about 1-3/4" in to keep the covers from turning. 

Paul

[Recumpence]

I have all four wheels covered.

[ptjones]

Recompence  are you having any rubbing problems on the spokes? The wheels don't seem to be same with some rubbing on the inside and others on outside spokes.I'm getting dust on wheels too.

 

Paul

[fbov]

fbov   the way I understand what you are doing is sealing the hood so no turbulance is created and improving aero. Are you also improving air presure to air intake? I would like to try it when I get a clear understanding what is going on.

Paul

I looked at the intake system, and have, in effect, blocked its cold air inlet.

 

The plastic runner comes through the bulkhead, turns toward passenger side and ends in a perforated tube under the latch. Lots of open space into the engine compartment, far greater area than the intake plenum, so blocking off the slots in the grill should have little effect on intake air flow. Add in that lower drag always helps while we try to use the ICE as little as possible, and at low RPM at that, and it seems like a reasonable tradeoff.

 

I'm most of the way to a set of lower grill blocks, but had some "other fun" on tap today...

 

Have fun,

Frank

[Jus-A-CMax]

Frank, thanks for the pics...its on my to-do list when Maxine comes home. Nice!

[ptjones]

I looked at the intake system, and have, in effect, blocked its cold air inlet.

 

The plastic runner comes through the bulkhead, turns toward passenger side and ends in a perforated tube under the latch. Lots of open space into the engine compartment, far greater area than the intake plenum, so blocking off the slots in the grill should have little effect on intake air flow. Add in that lower drag always helps while we try to use the ICE as little as possible, and at low RPM at that, and it seems like a reasonable tradeoff.

 

I'm most of the way to a set of lower grill blocks, but had some "other fun" on tap today...

 

I do not recommend blocking off the top grill because the right half is for the engine intake and hopefully the air is somewhat pressurized and the left half opening cools the top of the engine compartment. Today I took some packing tape and taped up the hood.

Will see if this makes any difference on my trip back to Georgia from Flagstaff, AZ via I-40, US 78, I-20, GA 27.

[fbov]

Paul, take a closer look behind that grill (remove the 4 plugs) and you'll see that what looks like a nice ram-air intake is more of a water splash baffle. The engine air intake aims sideways.

 

I tried to be patient and test one thing at a time, but I'm now jonesin' for more improvement after my PCM update 5%. I finally bumped the tire pressures from stock to sidewall, and that already shows a 5% reduction in parasitic losses in a coasting test. And the snow's coming and snow tires will not be an improvement...

 

Take a look at the tuft test...

 

HAve fun,

Frank

Edited November 4, 2013 by fbov

[ptjones]

I'm actually cheating a bit; I finally bumped the tire pressures from stock to sidewall, and that already shows a 5% reduction in parasitic losses in a coasting test.

 

I tried to be patient and test one thing at a time, but I'm now jonesin' for more improvement after my PCM update 5%. And the snow's coming and snow tires will not be an improvement...

 

Take a look at the tuft test...

 

HAve fun,

Frank

fbov Thanks IMO the Grill Covers give the biggest improvement specially when it gets cold. I'm working on testing air filters to find the least restrictive.  Also improve ram air effect on intake system. :)

 

Paul

[fbov]

I have a set for the lourvred grills... baselining with the lourvres enabled first, in conjunction with the reductions higher on the front. Been gettin' frosty in the morning, but I'm hoping Winter will hold off until Thanksgiving!!!

 

You may want to review this link if you're interested in intake improvements. Part 2 is his tuft testing. I'll give away one punch line (no emphasis added):

"I have never seen a standard filter element cause any more than a tiny proportion of the total restriction in the intake of any standard car!"

 

HAve fun,

Frank

[Recumpence]

Recompence  are you having any rubbing problems on the spokes? The wheels don't seem to be same with some rubbing on the inside and others on outside spokes.I'm getting dust on wheels too.

 

Paul

My spokes have paint scuffs where the lexan vibrates against them. The silver paint has turned black there.

 

Here is my experience with the aero mods so far;

 

The center grille block made roughly 1.5mpg increase. The lower grille block has made no improvement (though I know why and will correct it soon). The wheel covers helped another 1.5 To 2 mpg.The Gaspods seem to be roughly .5 To 1mpg or so with my driving.

 

I can tell you today was 53 and rainy but I still averaged 57.2mpg for the day. That is far better than the 51 or 52mpg I would normally see last year without mods.

 

Matt

[Recumpence]

I have had my lexan wheel covers for about 20,000 miles so far and I have to tell you they are really taking a beating. They are scratched, nicked, and overall, in rough shape. I taken them off every few thousand miles to clean the wheels and the covers. It is a pain that they are always dirty on the inside and the wheels are much dirtier.

 

I plan on either painting these silver or black, or I may remake a new set from black G10 (epoxiglass).

 

Matt

[ptjones]

I have had my lexan wheel covers for about 20,000 miles so far and I have to tell you they are really taking a beating. They are scratched, nicked, and overall, in rough shape. I taken them off every few thousand miles to clean the wheels and the covers. It is a pain that they are always dirty on the inside and the wheels are much dirtier.

 

I plan on either painting these silver or black, or I may remake a new set from black G10 (epoxiglass).

 

Matt

I have 6k on mine, 42k total and have issues with rubbing on  spokes and same dirt problem. Fortunately mine come off in a minute or two so today I installed 3/16x3/8 high density foam tape (weatherstrip for windows) from LOWE'S on the inside outer edge of wheel cover.  At least now the cover isn't touching wheel spokes. We will see how that works.

 

Paul

[salsaguy]

wow. gorgeous car/SUV that Tesla X is.

 

Some day we won't have mirrors.

Tesla, Ferrari, Lamborghini, Toyota, etc are almost ready now

 

http://www.teslamotors.com/modelx

 

[ptjones]

wow. gorgeous car/SUV that Tesla X is.

 

That is one of the mods I'm looking at for CMAX.

 

I have had my lexan wheel covers for about 20,000 miles so far and I have to tell you they are really taking a beating. They are scratched, nicked, and overall, in rough shape. I taken them off every few thousand miles to clean the wheels and the covers. It is a pain that they are always dirty on the inside and the wheels are much dirtier.

 

I plan on either painting these silver or black, or I may remake a new set from black G10 (epoxiglass).

 

Matt

Last night I put a .04 thick LEXAN cover on with weather stripping and heard a bad noise from the wheel above 40mph and when I got home (2.4mi) saw the cover had broken the 1/4" plastic screw and loosened the center screw. Apparently air is going through the wheel above 35mph. this would explain why our wheels are getting dirty.

 

Paul

[Recumpence]

I know there is a lot of pressure on these covers because even with 5 stainless bolts per 1/4 inch thick cover, I see vibration marring on the wheel paint where it touches.

 

Oh, keep your eyes peeled here for grille block updates. I already have my lower and center grille block panels installed (have had them for many thousands of miles already). However, I am redesigning the lower grille and fabricating a new one, making inlet opening changes to the large center grille, and fabricating an upper grille to cover the upper most grille.

 

I have done some research and I believe I have made a couple somewhat critical design errors with my grille blocks that is reducing the gains that are possible.

 

Oh, also, I have some flexible carbon fiber that I plan on making fog light smoothing covers out of. I may relocate the fog lights to the lower grille, or I may leave them where they are and make carbon fiber covers for them that are slighly opened up where the lights bulge out. The direction I take on them is dependant on how it looks and how much labor I am willing to put into relocating the fog lights. Heck, I never use them anyway. But, I have a hard time completely eliminating something I paid for.........

 

Anyway, my guess is the redesigned lower grille, revised center grille openings, new upper grille, and covered fog lights should be good for 1 to 1.5 mpg, conservatively.

 

1 mpg may not seem like much. But, if you can gain 1 mpg on 4 or 5 different things, it adds up. Multiply that by the 40,000 miles per year I drive, the savings really stack up.

 

We shall see. I will keep you all posted.

 

Matt

Edited November 10, 2013 by Recumpence

[Recumpence]

I just came in from making some prototype fog light covers. They are extremely thing (maybe 1/2mm) carbon fiber. I found that the outer bezel comes off the outside of the car very easily. Removing the bezel provides enough clearance to use a flat cover over the opening.

 

I will post pics and results as I have them.

 

Matt

[fbov]

I know I've posted this graphic already, but I've no idea where...

 

This is from a Masters' thesis looking at brake rotor cooling.The hypothesis is that the larger open area on the wheel, the more cooling you get, and the data seems to support that trend, up to a point. The open alloy wheel has far better brake cooling than the others, and comes in second when blocked (spokes act as vanes?).

 

By way of calibration, I measured C-Max wheels and they have ~360 sq. cm of open area. The Ford steel wheels I'll use have about 100 sq cm open area.

 

I expect you'll see a much higher pressure behind an alloy wheel cover than if you were covering a steel wheel. By way of confirmation, can you tape over the alloy wheel spokes? That would eliminate air pressure from under the car; maybe something else is going on?

 

HAve fun,

Frank, who's now wondering if belt and suspenders will be sufficient...

[Recumpence]

I have some very interesting observations regarding the fog light covers. Here is what I did;

 

I covered the fog light openings and I reduced my lower grille block openeings from 4 openings to 2. Now, here is the interesting part;

 

I am seeing a 2mpg increase with these changes. That is almost ridiculous. This is only one day of driving. So, it is tough to make a judgement. However, up until noon today the weather has been consistant the last few days and my mileage was up 2.5mpg for the first half of the day. At noon the temperature dropped into the 20s with rain and blowing snow. Even with this horrible weather, I ended the day at 50.2mpg! Last year I would have netted 42 to 44mpg for this kind of weather.

 

I have a theory about what may be going on;

 

The lower grille, fog lights, and wheels are roughly at the same height. I believe on the stock car, air flows from around the grille, over the fog lights, and accross the wheels. All of these add turbulence. When I added my wheel covers, I did not see a huge mileage increase because the grille and fog lights were dumping turbulent air to the wheels. However, now I have a smooth grille, smooth fog light covers, and wheel discs. So, that entire section of the car is seeing decent laminar airflow with attachement throughout the length of the car.

 

This is the only thing I can think of as to why my mpg went up so high by merely making fog light covers and decreasing the grille openings.

 

I remember Ford stating that they gained 1/4 of a mpg by eliminating fog lights on the older focus. So, that is what I was expecting, not this HUGE increase........

 

Matt

Edited November 11, 2013 by Recumpence

[ptjones]

What were your change in coolant temps? On my grill covers air goes around the covers with a small amount going through the grill. Part of the purpose was to raise coolant temps.

 

Paul

[Jus-A-CMax]

Matt - any chance you can dump some picks of your lower grill and fog light work?

 

If this holds true...much to be gained by the lower grill cover and the covering of the fog lights. I am not convinced of the pizza wheel covers...+my wifey would have my head on them....shes already LHAO over the Gas Pods.

Edited November 11, 2013 by Jus-A-CMax

[ptjones]

I used Carpet Tape over fog lights and have about 7K mi on them. Didn't see much improvement.

 

Paul

[Jus-A-CMax]

Frank - as a followup, what gains have you seen since the hood sealing project? Was it worth the time and material? Paul - did you do something similar?

[fbov]

Yes, I need to write up what became tire pressures AND upper grill seals. Mileage improvement was modest, +1-2%, and temperature dependent; 1% at 60F, 2% at 40F. I expect most of the difference is tire pressure, especially the slope change, but the upper grill block is invisible and the hood seals are the right thing to do, so it all stays.

 

I'm curious to see a repeat of the grill cover testing, post 13B07 PCM update. I didn't treat the lower grills so I didn't interfere with stock cooling, knowing the PCM update included changes to louvre operation. I am curious is the large benefit initially seen with grill covers has dissappeared. That would get at the aero contribution vs. warm-up for front end treatment.

 

And my pizza pans have been the source of spousal entertainment as well... we'll see when they're on the car.

 

HAve fun,

Frank