Custom Mustang hood scoop color?

[LBRC]

This is the Mustang

This is the hood scoop.

Should the scoop be the same color as the hood? Or flat black?

[GuiltyEnder]

if you can make it the color of the hood then go for it.. but if not then I would paint it flat black


edit: are those fets?
if so.. DAMN

[LBRC]

Yes 2x7 soon to be 2x8 to be visiable through the scoop. Not necessairly practical for performance mostly for looks, has 3 lithium-ions the third cell is removable for 2 cell opperation and is being outfited with the full spred GPM blue aluminum parts (minus the front deck and battery clips) and wide track bearings. The current motor is a Iwaver Pro Plasma Dash hybred.




Visit my photo gallery for pictures of the GPM parts.

[viperdout]

Do you really need all those FETs? How much current could you need? I had 5 li-ions and was only running a 3X2 setup, and it ran fine.

[LBRC]

No you don¡¦t need all the FET¡¦s as a matter of fact between 2x3 and 2x4 the efficiency of your stack starts to drop noticeably. I was trying for the Xmod equivalent to a 6-71 GMC blower not necessarily practical but necessary to the project.

The amount of current handling ability you need depends on the motor and gearing your using. Currently this car is using an Iwaver Pro/Plasma Dash hybrid with the blue gear set and would probably be ok with a 2x4. Eventually I will try to mount a Losi Micro Elite Modified motor with a custom gear set to make up for the loss of speed but added massive torque. Will it be enough to handle the Elite and larger pinion gear I don¡¦t know but it will be fun trying.

[LBRC]

Oh by the way the above blower is in a 65 Mustang.

To handle the power I beefed up the rear end a little.

[Jshwaa]

Yo, LBRC. Good to see another extreme mod'er out there. Good stuff. How's that 3 cell run? You got it regulated? Anyhow, I got a new and improved version of the H-bridge, using tabless power FET's(TO-262). I had to do up an xmod with it and a monster motor from mini-z workshop.



It flies. Draws so much current the cells get hot and after too many good hard take off's the heat makes the li-ions stop putting out current. Must go series/parallel or li-po. 28T is a current hog.

Anyway, just thought I'd give ya props and show off at the same time. Again, good stuff, LBRC. Is there a vid in the future?

[LBRC]

Looking good.

I¡¦m currently working on painting and attaching the hood scoop, funny but the modeling part seems to take me longer than the electronics. I¡¦m also rerouting the wires for a better look.

Yes I use a small SOT-223 package 1 amp low drop out 5 volt regulator located on the underside of the circuit board for the logic and steering circuits while powering the H-bridge at the battery voltage level. I¡¦ve tested it using 2 parallel l-ions (3.7V), 2 series l-ions (7.4V), 3 series l-ions (11.1V), and 4 l-ions (14.8V) theoretically I could go up to 20 volts, the limit being the regulator not the FETs but 4 cells seem to be a bit much, actually the 3.7 volt configuration showed some promise so some day I¡¦ll try it with a large pinion gear and high drain Kans as an experiment. The interchangeable 2 or 3 cell configuration is a nice compromise. It keeps the center of gravity low and still allows for an interesting drag race.

Note to Readers:
My stacked FET setup is not as efficient as those using larger FETs, the 2x8 stack on the Mustang is primarily for looks. The front deck circuit board was designed for 2x3 or 2x4 FET stacks, modified Mini-Z motors, and 4 to 6 fast drain NiMH cells or 2 lithium-ions. Stacking FETs is kind of like adding more wheels to a wheelbarrow 2, 3, or 4 can give you less resistance and a greater load capacity but after that they start getting in the way and you would be better off with a larger wheelbarrow or using different wheels, have you ever tried to push a 6 to 8 wheeled wheelbarrow.

I managed to match the paint exactly but decided I liked the look of the flat black scoop better, so I sanded it down and am redoing it.

I am trying to keep this car intact and uncrashed until it¡¦s completely finished. Then I plan to enlist help for a quality video and photo shoot.

[viperdout]

What color is it?

[LBRC]

To match the Mustang color I used Dupli-Color Avignon blue with a very small amount of light blue and then clear coat. The Avignon blue with a clear coat was a very close match buy itself when it dried, but with a little of the Dupli-Color light blue it was perfect. The scoop is now just plain old flat black which I like better for some reason.

[Jshwaa]

So, LBRC...I'm sure you understand that the FET stacking is an effort to increase current flow potential before the FET's dissipate too much power as heat and damage the FET, but do you have the cell composition to provide current at those levels(considering stacking would be the way to go in increasing the power of your H-bridge), and the motor that draws that current? If you have a 2x8 stack of 7A FET's(and let's suppose the increases are linear and disregard heat and such), wouldn't it be reasonable to think that you are preparing yourself to conduct (8 x 7A)=56A?

If you indeed do have this set up right, and are using a hot motor, then you've come to realize thatv AA sized li-ion cells do not put out enough current to necessitate the FET's. The motor will draw current at levels that make the cells heat up, and when the cells reach a certain temperature they will stop conducting current. The cells are the weak link, and so you have to be innovative in your power supply composition(with AA sized li-ions).

Li-ions have an internal resistance, just like the resistance that's inside FET's. Just like FET's, as you draw more current through the resistance, more voltage is dropped across the resistance, and thus more power is dissipated in the form of heat. As the heat goes up, so does resistance, and the heat and resistance will go up until the cell is a virtual open circuit, like an open switch...no current flow. So just like your FET's, you must "stack" your cells, meaning put some in parallel. Yes, do a series/parallel combination. You will then be able to double the current that your power supply will put out, not only in runtime, but in instantaneous current flow.......because you've lowered the resistance of your cells by putting them in parallel(stacking). it's the exact same thing. When you stack FET's, you are putting the FET's channels in parallel, thus sharing thier load and allowing more overall current.....same thing with cells. You have to lower the resistance of the whole loop, and make the motor the most resistive element in your circuit. The lower the resistance, the higher the current can be, and more torque you can get. More torque = more power.

So point being, back that circuit up with some more cell power. You either need series/parallel, C sized li-ions, or li-po's to really see the power. Stacking FET's alone will not do the trick.

Here's a link to a lil' more info at xmodrc.com, with cell wiring diagrams and a brief explanation of the pro's and con's of each.

[LBRC]

Jshwaa you must have missed what I said above this 2x8 stack is not for performance it¡¦s primarily to be seen under the hood scoop, as a matter of fact I¡¦ve written several articles on why 4 plus stacks are a waste. Maybe I just didn¡¦t say it very well even though I mentioned it in three different places. They are horribly inefficient it¡¦s not a lack of current handling ability although it¡¦s definitely not anywhere near 56 amps for a 2x8 (the 7 amp FET H-bridge myth seems to be caused by not reading the fine print on a data sheet), power loss is also not the problem either, it¡¦s just that the input capacitance becomes so great that they never fully open up acting something like a throttle limiter, a 2x4 stack will actually allow the motor to draw more current from the batteries than the 2x8, try it, and yes the batteries become the current limiting factor not the ESC.

Also you might have noticed that keeping a low center of gravity is a primary consideration for all of my Xmod creations. I don¡¦t like cars that just go fast in a strait line and then roll when you try to turn, which is why I don¡¦t like to stack batteries on top of each other the Xmod has a high enough center of gravity it doesn¡¦t need any more help. If you are wondering why my cells don¡¦t overheat like yours do it¡¦s simple; I balance the motor I¡¦m running and my gear ratio with the cells I¡¦m using and the type of driving I¡¦m planning on. Yes I could put a lower turn motor and/or lower gearing in the car and overheat the batteries but I¡¦m simply aware of my batteries limits and stay within them.

I¡¦m sorry but trying to tell me about lithium-ions and batteries in general seems a little insulting unless there is someone else using name of Jshwaa in the forums. I know you have seen me put four 10430 size lithium-ions in a MR02 using a parallel series combo pack without having to mod the car, I even mentioned parallel cells above so why the reference or were you just trying to get people to go and see your post at xmodrc. If I misunderstood your intent I apologize but I just don¡¦t see your point. Did you misunderstand the section where I said that it's the regulator that limits the amount of voltage the front deck circuit board can use?

[Jshwaa]

Sorry LBRC, don't take it like that. I didn't read all your posts before posting, no. I read a little about your FET stacking and saw pics of your cars with 3 li-ions in straight series and my ears perked.

As far as the center of gravity thing goes, flipping has to do with the surface you drive on and the tires you use too, and if you think the difference between an xmod handling like a Ferarri or a station-wagon has to do with adding 2 more cells on top of the conventional installation, ya right. I'll give ya that though, it does raise the center of gravity which would make the car flip before a regular 2 cell, but my 2 cell flips all the time anyway. The tennis courts have a sand-paper like surface by my house. You could flip a very lightly modified one if you don't slow down before turning. That happens in the street too. Hell, the only place it wouldn't happen is a dusty tile or wood floor, or painted cement. Because to say that your car doesn't flip at all, to some effect of some uber awesome chassis design and cell placement, you're saying that it isn't that fast and can't take turns that sharp. To put it into a real world perspective.....a Honda Civic CRX has one the lowest center of gravity ratings of alot of cars its size, and I survived flipping one after going into a turn at about 70. If the tires cut in, and the inertia is just enough.....up and over you go.

If you are wondering why my cells don¡¦t overheat like yours do it¡¦s simple; I balance the motor I¡¦m running and my gear ratio with the cells I¡¦m using and the type of driving I¡¦m planning on.

Let's not go there with the "mine don't overheat like yours do" crap. You obviously don't know squat about li-ions to be thinking that the cells not overheating has anything to do with having some virtual xmod slide-rule on power, motor, and drive train equations, built into your brain. Li-ions suck at current output, plain and simple. Case in point....why do think the pro's don't use them in their cars?? Answer, because Ni-Cad, Ni-MH and li-po's put out 10x's more power if not more. You can't say that you're going to get good power out of a motor that is running on cells that don't put out the current to drive them.

I just thought it was time for people to know that the fact that li-ions have made xmods fast is by luck at best. The cars are small enough to make their current-output/xmod-mass ratio favorable for a little acceleration and speed. Try putting a couple li-ions in a micro rs4 or any 1/10 and see what happens.

But at any rate, I didn't mean to get the thread all harsh, LBRC. You got some unrivaled innovations on your hand, that's for sure.

[newbitowner]

LBRC, where do you boy the GPM parts.

[LBRC]

Chin Ngai Hobby & Co. in other words GPM. My first order went fast and most of my second order has already been reserved. Not much help but they will be coming. I¡¦ll be placing a larger order that should be available by December.