The Sub-Genius MOSFET mod

Mostly dealing with electronics and pcbs and modifying them, all the things that make electrical-engineers tick and the rest of us cringe in fear.
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bryan4691
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Long time reader first time poster.

Post by bryan4691 »

I just wanted to give a shot out to SuperFly for posting diagram of the Mosfet Mod. Just completed it today and damn!! this car is fast. It took me about 10 minutes but I have been soldering PCBs for about 7 years now. For anyone out there that is looking for the Inernational Rectifer #IRLML2502 a distributor in the US, Future Electronics, reps for them. www.futureelectronics.com if anyone is interested. This is now a must on all the cars that I have.
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hogjowlz
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Post by hogjowlz »

welcome to da hood bryan

we aim to please well sometimes at least.
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Post by CaboWabo »

welcome bryan - glad ya found something here that helped you.
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lefftoe
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Re: Long time reader first time poster.

Post by lefftoe »

bryan4691 wrote:I just wanted to give a shot out to SuperFly for posting diagram of the Mosfet Mod. Just completed it today and damn!! this car is fast. It took me about 10 minutes but I have been soldering PCBs for about 7 years now. For anyone out there that is looking for the Inernational Rectifer #IRLML2502 a distributor in the US, Future Electronics, reps for them. www.futureelectronics.com if anyone is interested. This is now a must on all the cars that I have.
i checked out future, but 3000 seems like alot of fets.....i gots lots of bits, but not that many....... :shock:

i agree with the fet mod to be a must on all my cars........so far i got every freq, including boosters, and zips, and a boosted zip fet'd........hands down the best mod for a bit!!!
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SuperFly
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Post by SuperFly »

I've been getting the mosfets from Digi-Key.com. If you want more than $25.00 worth, get them there. If you just want enough for a couple cars, PM me and I'll break you off some of ours.

Thanks for the shout, btw, but I've got to give credit to pht2, Crazy Dave and left toe (as well as MicroAmps and various german dudes) for sharing the info as well. And to hue35 for helping me stumble through it. I'm mostly coming at it from the angle that if I can do it, you can too!
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bryan4691
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Post by bryan4691 »

I've been getting the mosfets from Digi-Key.com. If you want more than $25.00 worth, get them there.
I deal with Digi-Key almost everyday because of my job. Anyway, you can order and $$$ amount. If you total is not $25.00 or more they will charge you $5.00 for not meeting their min. $$$. Just a little FYI for all the bit pimps in the hizous.
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hogjowlz
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Post by hogjowlz »

word to yo mutha. its always good to have another gearhead hangin round here.
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Post by ph2t »

So has anyone started FET-Stacking?

ph2t.
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Post by ph2t »

Couldn't wait fellas, :smile: .

Here's my attempt at the mod using the layout Crazy detailed earlier.

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I played with it for a day and then said stuff it, lets stack 'em.

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Here's another view.

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And when they have all been soldered on:

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I have never seen a 3.8 motor go so fast, dang!

The principal behind fet stacking (mini-Z's are big on this) is to half the resistance of the Fet. This gives you more juice and oompf (very technical terms here....) in the motor.....

ph2t.
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crazydave
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Post by crazydave »

That's cool to hear that FET stacking works, but now I'm thinking, everytime I mod a car I end up with a pile of transistors left over. Since I'm waiting for mosfets, maybe in the meantime I could stack the transistors in one of my cars, to see if that gives me a slight boost.

Yeah I know it wont be nothing like a mosfet mod, but my cars could use a little xtra oomph to get these 4.2s going, maybe that just might help.
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hue35
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Post by hue35 »

Thanks for the info, ph2t... another tiny soldering project to try.

Hey, Dave... I just smoke all the leftover transistors. The mosfets are a nicer smoke, but the leftovers are free. :cool:
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SuperFly
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Post by SuperFly »

Here's another picture of a non-boost Microsizer PCB with the above-board mosfet mod, for reference:

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Not the most perfect job, but a pretty clear illustration of what needs to be done.
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Nitrolio
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Post by Nitrolio »

will someone please sell me some MOSFETS please. please let me know. thanks
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Post by ph2t »

crazydave wrote:......, maybe in the meantime I could stack the transistors in one of my cars, to see if that gives me a slight boost.
Actually Crazy, this won't work man 'cause the transistor P-N junction is different to a Field Effect junction. I won't go into the theory 'cause it's boring and confusing at the best of times. Bottom line is that the P-N junction (ie: NPN and PNP transistors) causes a voltge drop for the current running through it. On the ausmicro board, an Italian user called Efarel attempted this with no actual gains shown.

Cheers,

ph2t.
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bdebde
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Post by bdebde »

ph2t,

Is there a big difference with the stacked fets, is it worth the extra hassle?

Nitrolio,

Welcome to da hood. Don't have any mosfets to sell, just enough for my cars.

For anyone interested, Another source for the mosfets is:

http://www.newark.com/

They have no minimum order.
Scotty, beam me up.
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