Camaro9969

iTrader: (12)

So i have been dealing with this since last year tried everything from new 160amp alternator to using larger gauge alt wire Car has a relocated battery to the trunk
Volts when cold are amazing 14.5 but after a few passes at the track i am seeing 13ish idle and when running down the track 12.5ish car def has a lot of draw
twin 255 pumps one off hobbs gauges all over the car just installed the Alky Control kit which i tried a pass without it and they were a little better but only about .5 so still some concern. I am thinking a couple things. One is heat under the hood with the turbo is just killing the alt, maybe i'll change the wiring from the back of the alt for power on the 2 pumps to straight to the battery. Any help would be great i gotta figure this out.

Empatho

iTrader: (16)

Try insulating the wires from heat or routing them away from heat, the conductivities of most metals decrease as the temperature increases.

Camaro9969

iTrader: (12)

Did that with wrap and re routed them away from everything along with Welding wire. I'm hearing truck alt is better but i think the heat is killing it.

Empatho

iTrader: (16)

Yeah the truck alternator is better then the stock one, I picked one up at the junk yard from an escalade for around $60 and its been running strong for a couple years now. Im sure that turbo you have is creating a lot of heat, have you tried a turbo blanket?

LilJayV10

iTrader: (39)

Have you upgrade your ground cables also?

Camaro9969

iTrader: (12)

Yes. 5 grounds from the block to the chassis including one ground from the battery ground to the block.

Camaro9969

iTrader: (12)

This isnt the stock one but a 160amp alt doesnt have the same pulley as the truck one so may try that one for now. I do have a turbo blanket here is what it looks like under the hood

BigDB

What battery are you running? I'm having the exact same issue and I'm running a red top. When its low on volts I cut my headlights on and it will pick up a volt with the extra load. I don't think the charging system senses the same load as a lead acid battery, at least that's my theory.

N2Ojunky

What gauge wire are you using throughout your charging system? Search "Big 3 Upgrade" which will consists of 0 gauge stereo power wire. I had problems with my charging system so I put a 145amp truck alt. on and did this upgrade. Everything is great now!

Camaro9969

iTrader: (12)

Its just a duralast gold i was thinking of going to a red top but now after you saying it didnt help i might not........The voltage is great up until i make a few passes in the 90 degree weather then i just think it gets heat soaked.


I have a 0 gauge to the starter 0 ground 2 to the alt all welding cable 2 to the fuse i am thinking about going to the truck alt that has the fins to remove heat out of the alt...its ugly but could help right?

jimmyblue

iTrader: (11)

When new my car would really sag voltage in the summer
with A/C on and RPMs low. To me it seemed like a thermal
foldback kind of protection in the alternator field regulator.
But that's just my theory. At any rate, lowering underhood
temperatures (by running full time fans) and raising idle RPM
(so as not to require so much field current) helped it out a
lot. I'm talking just going from 600RPM to 700RPM.

Underdrive pulleys will aggravate this kind of action. An alt
overdrive ought to even things back up, if you've got a UDP.

Empatho

iTrader: (16)

Your alternator looks like its pretty far from heat sources, plus you have everything wrapped. From what I have seen, some high output alternators give less power at idle than stock. If you can get your hands on a truck alternator for cheap it might be worth a try. From the picture it looks like you are still using the stock radiator, does the car overheat as well when you are having voltage issues?

Those are some good ideas also.

Camaro9969

iTrader: (12)

I'll have to try the truck alt first unless I can find a larger pulley for my alt. Thing is when I start it cold I have 14.5 steady volts even after a drive it's great it's up until temps get really hot where I have issues. And as for coolant temps they are amazing I never see above 195 even after a full pass. Normal cruising is around 175*

Camaro9969

iTrader: (12)

I do have an slp 25% udp and thought of trying an od pulley for the alt just not sure where to get one

N2Ojunky

The truck alt. Could work and so could the O.D. or a stock pulley vs the U.D.P., but your having problems when everything get hot. So to help I would have 0 ga. going from the battery up front (like you do), 1-2 0 ga. Grounds in the back off the battery, 0 ga. From the alt. to the starter, 0 ga. To the fuse, and 2 O ga. Grounds up front. Call it over kill but I would want the charging systems wiring to be as conductive as possible. Just my 2¢

JimMueller

iTrader: (9)

Any chance you're simply overcharging the alternator at high RPMs?

https://ls1tech.com/forums/generatio...-solution.html

Camaro9969

iTrader: (12)

Only thing is my volts do not drop during wot. It's a heat thing they charge perfectly until I'm driving for over 20 mins or a full hard pass

Camaro9969

iTrader: (12)

So wire from switch to alternator and off alternator to the starter?? I am up for trying anything at this point

Camaro9969

iTrader: (12)

Where would i get an OD alt pulley?

Empatho

iTrader: (16)

Your cooling system is up to par for sure, so the engine is not overheating but your alternator is. Try out an oem truck alternator, a lot of the after market alternators are junk and over heat easily or give less out put at idle.

If you have an under drive pulley you should get an over drive pulley for the alternator.