Alternator question...

[STP]

Just noticed after looking at one of my datalogs from BG that my battery voltage according to the FAST drops to around 11.4 as I go thru the traps. Does the voltage regulator shut off at wide open throttle? Seems as if I remember reading this some time back, or maybe my mind is playing tricks on me. Either way it has to be fixed...Any help appreciated. Scott

 

[Nick Micale]

Something wrong somewhere? Maybe belt is slipping, battery or connection or alt. I see 14.9-15.1 volts through the traps with a volt booster.

 

[STP]

Nick, thanks for the response. The belt could be slipping, but kinda hard to tell unless on a dyno. I do not have a volt booster and was contemplating trying one. Does the alternator still charge at WOT? TIA Scott

 

[EightSecV6]

Originally posted by STP
Nick, thanks for the response. The belt could be slipping, but kinda hard to tell unless on a dyno. I do not have a volt booster and was contemplating trying one. Does the alternator still charge at WOT? TIA Scott

It still charges at WOT, we use GN alternators converted to one wire with an external adjustable regulator, set the voltage where you want it.

 

[STP]

Thx Bill...How do I go about doing this? I suppose any good alternator/starter shop could convert it, but where do I buy the adj. regulator? I've seen PTE has one, is this the one you use? Scott

 

[Lee Thompson]

piece of cake

We did Dwaynes years ago. Buy the kit from PTE and it is pretty simple.

 

[STP]

Hrm..I woulda called but I dont' remember you and Dwayne having charging issues. Thx Leo

 

[Louie L.]

Lat I checked PTE does no longer sell that adjustable regulator. Bill was the only one that I found that could do one in a reasonable time.

Another option is to run the Powermaster single wire HV alternator. I ended up with one as a gift and it works awesome. It has a built in adjustable regulator. Its not cheap tho.

 

[STP]

You are right Louie..PTE doesn't sell the kit anymore..Just found one in the parts for sale from a few weeks back. Thought I remembered seeing it for sale..

 

[Louie L.]

Yeah the guy was selling the whole alternator with the PTE regulator for 100.00. But he did say he was not happy.

I have my Power master alt running at 17.5v with a Turbostart 16v battery. Im very happy with it. Even with out the 16v battery you have ne running at a steady 14v and it would be fine without killing the 12v battery.

 

[BAGN]

Originally posted by EightSecV6
. . . we use GN alternators converted to one wire with an external adjustable regulator, set the voltage where you want it.

C.P.P. does the same thing. It works great. It took care of my voltage problem with the F.A.S.T. system.

 

[Lee Thompson]

try this

Fire up car and laptop--Take a reading @ the alt. and battery. See how it compares to the laptop. Mine does the same thing----11.5 @ the traps, but 1 to 1.5 higher @ the alt. I had an alt. built with an adj. reg. Set it at 14 V at the alt. but only showing 12.5 --12.8 on DC. You may not have a problem as I have come to realize.

 

[ijames]

Re: try this

You may not have a problem as I have come to realize.

Um, doesn't that mean that you have a different problem, instead of no problem ? The ecm is going to do voltage-based injector pulse width corrections so if it is reading the wrong voltage the corrections will also be wrong. I think you (and I, I see the same thing on my stock ecm'ed car, sigh) need to find out where the voltage drop is occurring between alternator and ecm and fix that. Otherwise the tune will drift if this voltage drop varies, maybe enough to affect a good bracket car.

 

[Lee Thompson]

Carl

Good point!!! I am not an electrical person, but I have asked on this board as to why my ecm sees less voltage than the battery without a valid answer. I asked if there was a desinated wire from the ecm to DS for the volt reading. Seems there is not. Other car show the correct volts nut mine does not. Thought maybe Scott had the same thing going on.

 

[EightSecV6]

Lee, we have found the same issue on some cars, have you tried adding a 6 gauge wire from the alternator directly to the battery? I have also found alot of draw coming from the injectors, you can determine if this is causing any grief by simply adding a 10 gauge wire directly from the alternator to the injector harness and disconnecting the factory supply, if it works, Racetronix has a pretty neat plug and play kit to fix this!

 

[Otto J]

One thing i found out after last week was that a rear mount battery doesnt charge well when racing,My voltage kept dropping until i started charging it between rounds

 

[Nick Micale]

try 2

Originally posted by KLHAMMETT
One thing i found out after last week was that a rear mount battery doesnt charge well when racing,My voltage kept dropping until i started charging it between rounds

I had that issue too Otto until I added another battery with the one already in the trunk.

 

[Dwayne]

Hey Scott.....

I never see less than 14v going down the track or just puttin' down the road.......

 

[STP]

Can't seem to get the guy with the PTE setup for sale to respond.

Louie, would you happen to have a part number on that PowerMaster? I take it the case is the same as a stocker as far as mounting points? Thx Scott

 

[EightSecV6]

Scott, if you cant get what you need, I can put a nice one together for you this week, one wire, external adjustable regulator.