A friend of mine owns a 98 Cobra that runs 12.30's on the motor, gained 7 hp on a chassis dyno by putting in an altenator cut-out switch. All you have to do is wire up a toggle switch to the small wire that comes off the back of the 3 wire altenator plug. I think it is white w/black stripe, but will double check with him today and let everyone know. This mod will probably only be used by those of us that like to stomp shovies, because you have to remember to turn it back on, or you'll drain your battery. Every little bit helps..........

 

Yep, those alternators do indeed take some horsepower to turn, and I'm not surprised that he picked up 7 hp at the rear wheels by using a cut-off switch. This is why the aftermarket underdrive pullies are so popular, they reduce parasitic losses to drive accessories. I'd be really curious to hear how your friend got his 98 Cobra running 12.30's on the motor. (Stock they run 14.0-14.2) That motor certainly has the potential, but I haven't known anyone who has seriously modified one yet, other than installing superchargers. Last year saw the first CNC ported DOHC cylinder heads, and they'll set you back $5,000, for an advertised gain of 80 hp. And I have seen larger throttle bodies, etc. Anything you can share with us would be greatly appreciated!!

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Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com

 

A friend of my brother had a couple of cut-out switches on the dash of his old Mustang. One cut-out was for the alternator, the other bypassed the ignition ballast resistor. I think the best way to implement this idea would be to have a switch that opens when the throttle is past, say, 3/4 throttle. The way you would get max power near WOT, but it would automatically return to normal when you were done playing.

Danny

 

He hasn't called me back yet, he's a lawyer need I say more.
Mike: Some of the mods to the 98 cobra are: 4.30 gears, pullies, svo headers, off-road pipe, Pro-m mass air meter, some type of secondary throttle blades removed from the intake, south-side bars. That's all I can remember for now. He said th biggest gain was from exhaust.
Pullies: Steeda Motor Sport here in S. florida has pullies in stock for the 4.6 trucks. SVO Headers: Also in stock for around $305. (stainless!)

 

Bluedefens,
I installed an alternator cut-out switch on my Mustang GT and it definitly works. Best way to perform this mod is to use a momentary push button switch and a fabricated bracket bracket mounted on the throttle body. Mount the switch to "open" at WOT throttle position to break the field circuit on the alternator.

Mike Faulkner

 

The wire is green/w red stripe located at the three wire plug on the top of your altenator. Also ordered my Motorsport SVO headers today for $280.

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98 Nastruck, air box mod, tps set, k&n filter, superchip, shaved throttle blade shaft,silencer removed, hellwig rear sway bar, flowmaster, lowered 4", undercover strobe kit, 5" autometer silver face tach......

 

Thanks (for the wire color)! I thought I had read that our alternator has an internal regulator. Does the field wire loop out and back in?

After doing this mod, I would expect to see the "Alternator", (or whatever) light come on. That's not a problem, I just hope the computer doesn't notice it and store an error code and then light the "Check Engine" light. Anybody know?

Danny

 

Bludefens
What are the SVO headers for?

 

S.Cammpbell,
Sorry the headers are for the truck.
gaudenti,
yes the field wire loops back in, that is the white wire/w black stripe. As far as I know the altenator light shouldn't come on, but you will see a drop on your volt gauge on the dash.

 

Thanks, I found the wire. The Electrical Manual also lists it as white with black stripe. There is a orange/light blue wire that goes to 12V through a fuse and a light green/red wire to the indicator on the instrument panel.

Danny

 

Bluedefens

What year model of truck do you have and what size motor. I have been looking for some headers for my 99 SC 4.6????

 

Medic12,
I've got the 98 Nastruck, 4.6l

 

HI!... Hey guys I am also interested in doing this ( alternator mod ) but I am a little confused on exactly witch wire to splice into. Is it the green/w red stripe or the white/w black stripe?

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NEAL [ the horsepower freak ] NEWMAN
'99' F-150 XLT SPORT, oxford white, reg cab shortbox stepside,5.4, auto, 3.55L.S, air silencer mod, TPS mod

 

HI!... BLUEDEFENS how did you exactly shave your throttle blade shaft? Was there any problems with your truck afterwards?

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NEAL [ the horsepower freak ] NEWMAN
'99' F-150 XLT SPORT, oxford white, reg cab shortbox stepside,5.4, auto, 3.55L.S, air silencer mod, TPS mod

 

NEAL,
The wire to splice into is the green/w red stripe. As for the throttle blade shaft, I removed it and placed it in my vise and very carefully ground down the shaft to about half its original size on both sides. (when looked at from the open position)This includes grinding down the protruding screw ends that secure the throttle blade. I also put loctite on the screws for added insurance. I learned this from a friend of mine who used to build carbs for short track cars. As for power increase????To small to notice. No problems with idle quality either.
SAVE MONEY: If anyone is planning on putting a supercharger on in the near future, DO NOT buy pullies or a K&N or Airaid intake because they get replaced with the supecharger kit. At least on the Powerdyne and Vortech. Hope this helps

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98 Nastruck, air box mod, tps set, k&n filter, superchip, shaved throttle blade shaft,silencer removed, hellwig rear sway bar, flowmaster, lowered 4", undercover strobe kit, 5" autometer silver face tach, motorsport headers, alt. cut-out switch.....




[This message has been edited by Bluedefens (edited 04-21-99).]