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well I'm gonna post food for thought here

Discussion in 'General Discussion' started by SaberJ2X, Aug 29, 2010.

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    SaberJ2X Lurk MOAR

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    well I'm gonna post food for thought here

    in my quest of making my rolla more efficient

    I've bought light weight rims
    got rid of a bunch of junk in the trunk
    run max psi in the wheels (if it's rated for 42psi I ran it at 40psi)
    common sense maintenance and a de-cat and low resistance air filter

    my only sin is running cleaner running but more viscous diesel engine oil

    and I'm stuck @ 220 per 9 gallons of gas premium edit: *best case scenario in highway... city running is 180~190*

    which translates to some nice 24.5 mpg of running.

    but since this board is pretty slow lately I'll put some crazy ass shit so you guys can shoot me down
    and we all get a laugh...

    (even if secretly I wanna do it cause it would be cool)
    [IMG]

    Attached Files:

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    Hummer Well-Known Member

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    Congratulations, your car looks like a helmet.

    :)

    [IMG]

    JDM?
    MacktasticSlick likes this.
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    SaberJ2X Lurk MOAR

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    EUDM!

    JDM is so 2001
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    roachrolla Hipster

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    what a dumb looking helmet lol

    [IMG]
    get these rims. less air drag than the ones you have on?
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    Hummer Well-Known Member

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    Even the guy wearing the helmet cant hold back from laughing his ass off.
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    roachrolla Hipster

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    he may appear to be laughing but deep down inside hes just jealous that he cant have rims like that on his bike
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    fishexpo101 Get Some

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    Not sure you will gain that much from a boattail add-on, especially at lower speeds. Might consider a Kammback setup. Similar gains, but you won't distort the length of the car as much. Add to that a grille block and rear skirts - you could be shaving 10% or more in overall fuel consumption.
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    SaberJ2X Lurk MOAR

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    I see fishexpo at least haven't joined the ranks of the hurr durr me-too tribe :D

    kammback does much of a diferrence?
    and yea, the boat tail is much more efficient... but how the hell I'd store that in the trunk I wouldn't have a clue... I'd like to do the nose front too but again, storing it when not in highway driving.

    was also thinking of doing the underside with that coroplast panels except near the exhaust
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    Ares Active Member

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    Wouldnt adding the weight just cancel out the gains? I just thought about the CRX having kammback rear might actually be for a purpose. I wonder if this is the reason why CRX's can easily be made into dragsters (and maybe the fact that swaps can be done for cheap)
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    SaberJ2X Lurk MOAR

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    well it can be made of plexiglass, tape (to seal the gaps cheaply) and some hooking system (spoiler mount points)
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    fishexpo101 Get Some

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    Also have to factor in your speed of travel - added weight is never a good thing, but drag on the car grows by a factor of two of the speed. Comparing commutes at 30MPH (typical city) vs 60MPH (typical highway), just doubling the speed will increase drag four-fold.

    Yeah, nothing will beat the boat-tail for efficiency, but the Kammback's lower profile makes it less of a hassle to deal with. You won't see the full pressure recovery of a "pointy" tail design, but it will be pretty close. Don't have hard numbers on their efficiency, but to say they are 25-50% of an airfoil is not out of the question (i.e., if a full boat-tail gave you a 10% gain in fuel economy, a Kammback will yield 2.5 to 5% gain in fuel economy. That's not bad considering the short profile, instead of a tail that is 8-12 feet behind the back of the car to keep in around that "magical" number of no curves greater than 20-22 degrees.

    If you are serious about this - might consider a hybrid design - something that is part boat-tail and part Kammback. In a sense, they were used in many road racing cars of that day than forbade rear diffusers.

    http://www.mulsannescorner.com/lolab2k40-2.html
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    SaberJ2X Lurk MOAR

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    I want it to be something I clip on and put some tape of the top since I won't use it 80% of the time

    and collapsible OR build-able in some minutes.

    will take 2 pictures of the car and line something serious in flash.

    could I have to do something from the bumper? or I can end it all at the trunk lid?
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    SaberJ2X Lurk MOAR

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    well...?
    [IMG]
    [IMG]
    [IMG]

    Attached Files:

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    fishexpo101 Get Some

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    That's not too bad!

    I wouldn't worry too much about the bumper, if you want to later, you can incorporate some sort of diffuser under the rear bumper to help with flow separate issues from the high pressure air running under the car. The underbody panels you mentioned before should help out. Without an actual test facility, your only other options are CFD modeling and/or trial and error.

    But what you have is actually a great start. Stick with the axioms of aerodynamics (and art) - form follows function and if it doesn't "look" right, it probably won't "work" right - that will get your a good portion of the way there.

    The Kammback on the old CRX was intentional. Same way with the Toyota Prius and Honda Insight.

    Though in the drag racing aspect - that was all brute force coupled with the lightweight body. Stuff more power under the hood and it won't really matter how the body is shaped.

    The Kammback is an endearing design, classic and clean - either love it or hate it.
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    SaberJ2X Lurk MOAR

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    yea, I still need to do the underside, *sigh* the original engine covers went bye bye by the previous owner, and the last 2 pieces where so messed up they fell so... I got a lot of fabrication to do...

    and no car lift to work on lol

    also I'm doubtful of making a grill block cause I live in a hot as balls place...

    so I'll consider other stuff
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    SaberJ2X Lurk MOAR

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    "prototype" proof of concept front blocking (partial due to tropical weather)
    done...

    gonna run the tank empty and see if anything improved...

    too high to be real, need another tank of fuel to confirm...

    edit, 230 miles... in the first tank (9 till 1/4 tank, and I already had driven 60 miles with this tank), hopefully the second one will be better
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    GSE21tuner Formerly rollatuner110. Representing AZLexus.club

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    CRX/Prius rear end? :)
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    SaberJ2X Lurk MOAR

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    yea, the kammback end...

    here, you go guys
    [IMG]

    laugh away, I'll enjoy my 23~ % better overall mpg with my ugly front until I do a plexiglass mold
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    GSE21tuner Formerly rollatuner110. Representing AZLexus.club

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    What about airflow to the radiator?
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    SaberJ2X Lurk MOAR

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    ran 50 miles in puerto rican weather and thru city... temp never passes the half point

    maybe it's cause the fan is always running cause I NEED my AC...
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    1337Rolla oh my

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    that MPG sucks. seriously something has to be broken to get 25mpg on the freeway.

    I can do 70mph and still get 36mpg (where speed limit >= 70)

    could you go somewhere like autozone with an obdii scanner and do some scans on the thing? On mine I can watch every sensor and make sure they're responding like they should. What is your driving style like? and I like the hatch :p

    my style when cruising:
    engine/tranny braking down hill.
    shift points: 1st => 2000rpm, 2nd=>3000, 3rd=>2500, 4th => 2000, 5th => 2000
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    SaberJ2X Lurk MOAR

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    3 speed auto
    hills about 70% of my drive
    a 1200ft~ climb to my house in less than 2km
    average drive is about 15 minutes
    95f
    heavy rain... like daily
    daily

    I used to drive it fairly hard, by the time I get to the place the engine just barely warmed up.
    then I got tired of beating the poor horse, but I still pretty much got the same mileage

    now with the modded front I can do the hypermiling techniques and see some results! but people drive like shit here, and the roads are NJ like (rough n with holes)
    mostly the front although it looks really nice in my sig.

    it has big gaps (big gaps for me is 1/2 cm something like I barely able to squeeze my pinky without it getting crushed
    and they're, beneath the headlights, between the hood and the bumper
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    fishexpo101 Get Some

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    Damn ~ 23% better fuel economy for just the taped up front!

    Might give skirting the rear wheels a try and see how that turns out.

    Yeah, the 8th gen is a brick-like compared to the 9th gen Corolla. It doesn't look it, but the 9th gen is smoother to the air than the smaller cross section of the 8th gen. There are quite a bit of airflow management on the bottom of the car - might be able to take advantage of that design and apply it to your 8th gen.

    I was thinking of a similar approach - just use one big piece of vinyl for the front end - get a DIY "clear bra" and improve on the aero aspect it one shot. May try and do that this year, before it gets too cold.
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    SaberJ2X Lurk MOAR

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    yea, I', currently running another tank with the front as you see now,

    didn't took pictures of the old first one

    since it was a hack with a bunch of tape doubling on top of each other and looked nasty lol
    which the front I did the first test... and didn't have the lower grill block

    which I added for this one... (and installed the second panel in the lower bumper since I got the clear tape :p)
    we will see how much better it does now

    and, someone did a belly pan for our rollas, only got 1.5 more mpg...
    it's still some 18 miles more to the tank though
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    SaberJ2X Lurk MOAR

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    [IMG]

    more stealthy front
    and no need for clear tape under the lights, I pulled the bumper up and fixed quite a few ill fitment problems in it

    glossy tape on top of painted black cardboard, looked like if I had used duct tape...
    so I made a new "die" taped it up to mist proof it a bit more. and painted it over matte black

    it's not perfect, but people won't stare at it so much

    last tank was 216 miles... and it was raining all the time like a mofo
    but it was 32.6L

    instead of the usual 38~41L for 190~ I used to get
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    GSE21tuner Formerly rollatuner110. Representing AZLexus.club

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    That definitely is an improvement on mpg, but what about when you need to open the hood?
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    fishexpo101 Get Some

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    Huge improvement in MPG! Congrats - add in a fab'd Kammback and maybe some rear wheel skirts - who knows what you might see.
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    SaberJ2X Lurk MOAR

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    I pop the hood and lift the hood then I slide my hand, drop the hood a bit and press the lever
    Open

    that's what I fixed of the first version which was ghetto 100% lol...
    the second one was the first picture, but it looked too weird, and still needed tons of tape.

    for the third one I adjusted the whole front first, remove the bunch of tape I needed to seal the bumper and light gaps. then made it the most stealthiest and dullest black I could... while keeping it pretty must the same efficiency.
    also added a back pieces to keep the thing pressed foward,

    as you can see the v2 up there, while being just made, looks bent back lol

    I made before a thread about HHO...

    but it would have drained so much from the battery that I doubt I'd get mpgs back from it...
    even if I added an EIFE...
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    Hummer Well-Known Member

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    Wow, you would go so far as to defile your car and embarrass your self to save a couple quarters on gas?

    Props to ya.
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    SaberJ2X Lurk MOAR

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    if you'd been out of work for like a year applying everywhere decent and still not get a job... but still needed to go here and there and there to fix PCs on your own to scrape money together... then yes... yes I would

    Hummer...
    THIS is to defile a vehicle

    [IMG]

    [IMG]

    [IMG]
    PIZZA PAN HUBS! worse thing ever...

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