Login    Forum    Search    FAQ

Board index » Racing Forum » Electrical and Electronics




Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3
Author Message
 Post subject:
 Post Posted: Thu Nov 27, 2008 9:02 pm 
Offline

Joined: Sun Nov 11, 2007 10:33 am
Posts: 1293
Location: Montgomery, Alabama
haha  =;

You must have an alternator because it's impossible to have 13.5 without one. :-$


Top 
 Profile  
 
 Post subject:
 Post Posted: Thu Nov 27, 2008 9:08 pm 
Offline
Site Admin
User avatar

Joined: Tue Apr 18, 2006 6:38 am
Posts: 11804
Location: Coming At Ya!
Slowpoke wrote:
11 is what I was told by MSD


What is your system voltage when the engine is cranking?

_________________
Big Boyz Toyz!

Image

Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.

William Pitt, British Prime-Minister (1759-1806)


Top 
 Profile  
 
 Post subject:
 Post Posted: Thu Nov 27, 2008 9:19 pm 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
Scott Smith wrote:
haha  =;

You must have an alternator because it's impossible to have 13.5 without one. :-$



Yep and won't run another bracket car without one... Ever put an amp meter on your car with everything  on including the transbrake???? You may be surprised to see what the AMP draw is O:) ..

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post subject:
 Post Posted: Thu Nov 27, 2008 10:11 pm 
Offline
User avatar

Joined: Wed Oct 24, 2007 6:36 pm
Posts: 718
Location: Blanco, Texas
Ken0069 wrote:
Slowpoke wrote:
11 is what I was told by MSD


What is your system voltage when the engine is cranking?


Around 10.5,  they didn't say it wouldn't work below 11 volts, like in a no load situation at idle.  As the load goes up, I would think having the proper voltage would become more important.

Good luck tomorrow,

Donee


Top 
 Profile  
 
 Post subject:
 Post Posted: Thu Nov 27, 2008 11:28 pm 
Offline
Site Admin
User avatar

Joined: Tue Apr 18, 2006 6:38 am
Posts: 11804
Location: Coming At Ya!
Tried to call you back tonight but you wouldn't answer!  Image  See how you do me! ;-)  We're testing tomorrow so I won't be home until late.

As engine RPM goes up, AMP draw on a MSD system goes up.  Volts can be anything  and you could still have an increased amp draw.  What I mean is that you could have say a 15 amp draw at 6 volts and you could also have the same amp draw at 12 volts.  Old point systems had a balast resistor in the 12 v circuit that reduced that voltage to somewhere between 6 to 9 volts at the points depending on what car you were working on.

I will call them next week to find out exactly how they control voltage within that system, and to see exactly how low it can go and still function correctly.  I know a lot of guys that don't run alternators and I'm sure a bunch of those have had battery voltage a good bit lower than 11 volts at times.  I'll post what they (MSD) tell me.

_________________
Big Boyz Toyz!

Image

Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.

William Pitt, British Prime-Minister (1759-1806)


Top 
 Profile  
 
 Post subject:
 Post Posted: Fri Nov 28, 2008 8:56 am 
Offline

Joined: Sun Nov 11, 2007 10:33 am
Posts: 1293
Location: Montgomery, Alabama
Quote:
Yep and won't run another bracket car without one... Ever put an amp meter on your car with everything  on including the transbrake???? You may be surprised to see what the AMP draw is d'oh! ..


How much horse power do you think that alternator uses? And how is it possible it uses it consistently?

I'm walking out the door to the Turkey Trots. See ya later! Image


Top 
 Profile  
 
 Post subject:
 Post Posted: Fri Nov 28, 2008 10:29 am 
Offline
User avatar

Joined: Wed Dec 06, 2006 9:24 pm
Posts: 5071
Location: Elizabethtown, KY
One time in the spring after we changed to a MSD 6al box. we tried starting it on a low battery. it was around 9 volts cranking. It would pop then die. put the charger on it then it fired right up.

_________________
Steve

6.7772 @ 101.51 1/8th 10.747 @ 122.24 1/4

Image


Top 
 Profile  
 
 Post subject:
 Post Posted: Fri Nov 28, 2008 4:50 pm 
Offline
Site Admin
User avatar

Joined: Tue Apr 18, 2006 6:38 am
Posts: 11804
Location: Coming At Ya!
My battery voltage drops to 9.3 while the starter is engaged.  Checked it several times today and it was about the same each time.

_________________
Big Boyz Toyz!

Image

Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.

William Pitt, British Prime-Minister (1759-1806)


Top 
 Profile  
 
 Post subject:
 Post Posted: Fri Nov 28, 2008 8:39 pm 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
Scott Smith wrote:
Quote:
Yep and won't run another bracket car without one... Ever put an amp meter on your car with everything  on including the transbrake???? You may be surprised to see what the AMP draw is d'oh! ..


How much horse power do you think that alternator uses? And how is it possible it uses it consistently?

I'm walking out the door to the Turkey Trots. See ya later! Image




Here are the tickets from the last time out trying to get the shocks set up right and get rid of the tire spin/screech and some more down force down track. Looks constant to me even with the alternator on all the time and with the suspension not right, messed up 3 circuit carb and a cold track........So what do you think Scott????


Image

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post subject:
 Post Posted: Sat Nov 29, 2008 12:05 am 
Offline
User avatar

Joined: Tue Sep 05, 2006 10:41 pm
Posts: 407
Location: Bronson,MI
Scott Smith wrote:
Quote:
Yep and won't run another bracket car without one... Ever put an amp meter on your car with everything  on including the transbrake???? You may be surprised to see what the AMP draw is d'oh! ..


How much horse power do you think that alternator uses? And how is it possible it uses it consistently?

I'm walking out the door to the Turkey Trots. See ya later! Image


I've taking the belt of alt and put it back on and seen no difference other then voltage gauge.  I would think the alt would be more consistent then not having one, constant voltage to ign,delay box,transbrake would make things more consistent right ?

_________________
David Lanning
IHRA NHRA 387B

http://www.nyesautomotive.net
http://www.diamondracecars.com
Fleenor Racing Glides
"get one before one gets you"


Top 
 Profile  
 
 Post subject:
 Post Posted: Sat Nov 29, 2008 7:47 am 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
Hammertime wrote:
I've taking the belt of alt and put it back on and seen no difference other then voltage gauge.  I would think the alt would be more consistent then not having one, constant voltage to ign,delay box,transbrake would make things more consistent right ?




My thoughts also...

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post subject:
 Post Posted: Sat Nov 29, 2008 7:17 pm 
Offline
User avatar

Joined: Wed Dec 06, 2006 9:24 pm
Posts: 5071
Location: Elizabethtown, KY
I put a switch on the field wire so Jake could turn off the Alt if he needed a couple of .01's when he ran index class. That way it could charge until he staged then turn it back on on the return road.

_________________
Steve

6.7772 @ 101.51 1/8th 10.747 @ 122.24 1/4

Image


Top 
 Profile  
 
 Post subject:
 Post Posted: Sat Nov 29, 2008 8:52 pm 
Offline
Site Admin
User avatar

Joined: Tue Apr 18, 2006 6:38 am
Posts: 11804
Location: Coming At Ya!
WR169 wrote:
I put a switch on the field wire so Jake could turn off the Alt if he needed a couple of .01's when he ran index class. That way it could charge until he staged then turn it back on on the return road.


Steve I'm not sure this works on all alternators?  The switch that is!!  It doesn't work with mine and I have a 3 wire alternator also.  Once it starts charging, disconnecting the fields doesn't stop it as evidenced by my data logger.  No way to get 14.23 volts with the fields supposidly disconnected to make it NOT charge.   ;-)

_________________
Big Boyz Toyz!

Image

Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.

William Pitt, British Prime-Minister (1759-1806)


Top 
 Profile  
 
 Post subject:
 Post Posted: Sat Nov 29, 2008 10:49 pm 
Offline
User avatar

Joined: Wed Dec 06, 2006 9:24 pm
Posts: 5071
Location: Elizabethtown, KY
That could be Ken. I just run 2 wires. one from the battery and then the field wire I run from the kill switch to the switch panel then to the Alt. I don't run the 3rd wire for the idiot light.

_________________
Steve

6.7772 @ 101.51 1/8th 10.747 @ 122.24 1/4

Image


Top 
 Profile  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3

Board index » Racing Forum » Electrical and Electronics


Who is online

Users browsing this forum: No registered users and 3 guests

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron