Alternator

s351

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Hey guys, I have an 03 turbo cobra with a 01 cobra alternator, just curious on a couple things. I'm running I believe a 6.75 balancer, with a 2.2 pulley on the alternator at a max engine rpm of 7000, and that's spinning the absolute crap out of it like 21000 rpms. I would need a 3.0" pulley to get the speed down to just under 16000 rpms.

Just curious on what everyone's doing to solve this issue, and also which would you guys run a ford reman or a new pa performance alternator?

Thanks
 

s351

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Thanks for the replies, I've never heard of kmj before I'll have to check them out.
 

s351

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I also found a 76mm/2.95", ford 4g pulley well that's at least what it says, and that will get me in the rpm area I need to be. But I'm not getting my hope's up on that pulley till its actually in my hands and I can confirm it's the correct pulley.

And bad cobra, have you ever had a cooling issue running the 5.5 March pulley on hot days?
 

s351

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Also forgot to ask is going to a 200amp over the 130amp worth it? The guy at kmj said the alternator would run cooler.
 

DSG2003Mach1

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I run a 5.5" March underdrive pulley balancer, never an issue with alternator speed that I am aware of and rev 8k.

For alternator, run a KMJ. ALTERNATORSONLINE.COM -KMJ Alternators-

hmmm... i need to replace my current HO unit, will look at them too. Current one starts falling off @ idle when heat soaked and ac going.
 

s351

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Well, still a little lost on this alternator issue, I ordered a kmj unit and now I've just been waiting for it as he got pretty sick a week ago.

I've been messing around with reman alternators and have killed 4 of them. 3 I tried back to back to back they didnt survive a day.

So I rewired everything, new power wire, all new grounds, bat to block, block to chassis, bat to chassis, and I even removed the factory fusible link like the j2fab video on YouTube so that couldn't be and issue. Plus bought a new battery, and put a new pigtail on to connect to the alternator.

So I put the 4th reman alternator on and drove the car for about an hour, everything was good no issues. So I decided to make a hit on the way home, found a nice safe straight stretch on a back road, go wot in 2nd gear and pull probably 3/4 through 3rd, and bam battery light on cars not charging any more killed another one.

I got another reman on there today and put a bigger pulley on to slow down the shaft speed, while waiting for my kmj alternator. Is there anything else I can check to see what's wrong? or is this simply shitty reman alternators that can't keep up. This problem came out of nowhere.

Thanks
 

DSG2003Mach1

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Well, still a little lost on this alternator issue, I ordered a kmj unit and now I've just been waiting for it as he got pretty sick a week ago.

I've been messing around with reman alternators and have killed 4 of them. 3 I tried back to back to back they didnt survive a day.

So I rewired everything, new power wire, all new grounds, bat to block, block to chassis, bat to chassis, and I even removed the factory fusible link like the j2fab video on YouTube so that couldn't be and issue. Plus bought a new battery, and put a new pigtail on to connect to the alternator.

So I put the 4th reman alternator on and drove the car for about an hour, everything was good no issues. So I decided to make a hit on the way home, found a nice safe straight stretch on a back road, go wot in 2nd gear and pull probably 3/4 through 3rd, and bam battery light on cars not charging any more killed another one.

I got another reman on there today and put a bigger pulley on to slow down the shaft speed, while waiting for my kmj alternator. Is there anything else I can check to see what's wrong? or is this simply shitty reman alternators that can't keep up. This problem came out of nowhere.

Thanks

a 6.75 crank and 2.2 alternator is almost 21.5 rpms @ 7k engine rpm. The design limit of that alternator is 16k rpm. With my 10% OD crank pulley I have a 3.2" alternator pulley on the way which will put me a hair under 16k @ 7k rpm.
 

robvas

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Well, still a little lost on this alternator issue, I ordered a kmj unit and now I've just been waiting for it as he got pretty sick a week ago.

I've been messing around with reman alternators and have killed 4 of them. 3 I tried back to back to back they didnt survive a day.

So I rewired everything, new power wire, all new grounds, bat to block, block to chassis, bat to chassis, and I even removed the factory fusible link like the j2fab video on YouTube so that couldn't be and issue. Plus bought a new battery, and put a new pigtail on to connect to the alternator.

So I put the 4th reman alternator on and drove the car for about an hour, everything was good no issues. So I decided to make a hit on the way home, found a nice safe straight stretch on a back road, go wot in 2nd gear and pull probably 3/4 through 3rd, and bam battery light on cars not charging any more killed another one.

I got another reman on there today and put a bigger pulley on to slow down the shaft speed, while waiting for my kmj alternator. Is there anything else I can check to see what's wrong? or is this simply shitty reman alternators that can't keep up. This problem came out of nowhere.

Thanks
You can try getting one from a different store...but you ordered one so just keep it under 4,000rpm until then :)
 

s351

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Thanks for the replies, I just put a 2.95 pulley on the latest reman, should put me right around 16000 rpm, just blows my mind that my old alternator took abuse for 5 years never had an issue even with the small pulley, and these new ones cant even do it 1 time.
 

robvas

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OEM was built better. I actually ran my OEM one for a couple weeks with only 2 bolts on (the third bolt snapped off in the alternator housing and I couldn't get it out, which is why I got a new one) and it ran just fine...
 

s351

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Ya hopefully the better quality fixes the issue, just been pissing me off, going over the car over and over looking for something wrong trying to enjoy the car. The 2.95 pulley puts me at 16,016 shaft speed.
 

s351

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Forgot to ask, is it normal for my x4 when I'm using the live data to be .5 - .7 volts different to when I use a multimeter at the battery? So for example at the battery it reads 14.4 but in the car through the sct x4 13.7
 

olympic

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Forgot to ask, is it normal for my x4 when I'm using the live data to be .5 - .7 volts different to when I use a multimeter at the battery? So for example at the battery it reads 14.4 but in the car through the sct x4 13.7

It's normal. Mine does it and I've heard the same from many others.
 

9397SVTs

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This is what I have been using for over 10 years....


I have a PA 200 amp alternator. I damaged the bearings in one due to excessive rpm's, but haven't had a single problem since running the larger pulley. No charging issues either.
 

s351

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Ya I just put a larger pulley on, and no issues so far just driving around but no full hits yet, the next sunny day will let me know if the larger pulley fixed the issue as I'll make a full hit to 7k on the car.
 

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