Notices
ECUs and Tuning Discuss Engine Management, Tuning, & Programming

V increase from powering fuel pump from battery w/ relay

Thread Tools
 
Search this Thread
 
Old Apr 15, 2010 | 04:19 PM
  #1  
orion4096's Avatar
Thread Starter
Senior Member
iTrader: (22)
 
Joined: Oct 2007
Posts: 550
Total Cats: 19
From: bay area, ca
Default V increase from powering fuel pump from battery w/ relay

I remember seeing a link here for a site where someone wired the battery up to the fuel pump with a relay. I can't find the link anymore and was wondering what V increase that guy saw which I remember being listed at the site. If someone has the link please post it up.
Old Apr 16, 2010 | 07:09 AM
  #2  
richyvrlimited's Avatar
Elite Member
iTrader: (1)
 
Joined: Jun 2006
Posts: 2,642
Total Cats: 42
From: Warrington/Birmingham
Default

SLOWMX5

A full volt improvement at the FP
Old Apr 16, 2010 | 08:51 AM
  #3  
olderguy's Avatar
AFM Crusader
iTrader: (19)
 
Joined: Oct 2004
Posts: 4,716
Total Cats: 364
From: Wayne, NJ
Default

Link doesn't work, but it is a good idea.
Old Apr 18, 2010 | 05:57 AM
  #4  
richyvrlimited's Avatar
Elite Member
iTrader: (1)
 
Joined: Jun 2006
Posts: 2,642
Total Cats: 42
From: Warrington/Birmingham
Default

Worked fine when I posted it,looks like the sites gone down :(

I gained about 5% DC when I did the mod on a mates car
Old Apr 18, 2010 | 08:34 AM
  #5  
inferno94's Avatar
Senior Member
iTrader: (2)
 
Joined: Sep 2008
Posts: 521
Total Cats: 2
From: ON
Default

This is a thread that comes up on every car forum once in a while. Answer is yes, 99% of the time it works.
Old Apr 18, 2010 | 10:12 AM
  #6  
orion4096's Avatar
Thread Starter
Senior Member
iTrader: (22)
 
Joined: Oct 2007
Posts: 550
Total Cats: 19
From: bay area, ca
Default

Thanks. Here's the link that works for me: http://www.slowmx5.com/ECU.htm#Fuelpump

I just remembered my car came with an aftermarket alarm which has a fuel cutoff. That might also explain my higher duty cycles if they rewired the pump. I'm between 210-220 whp (no dyno time yet) and seeing 83%+ duty cycles on a walbro 190 and rx-7 460s at 11.3:1.
Old Jan 23, 2014 | 04:08 PM
  #7  
Ian's Avatar
Ian
Junior Member
iTrader: (2)
 
Joined: Jan 2012
Posts: 167
Total Cats: 4
Default

Bringing this one back up.

On the only miata rewire documentation I could find, I am not able to view pictures through web.archive.org and the slowmx5.com site is down.

ECU and Electronics

Would anyone be kind enough to post pictures of their rewire for those of us who are primarily visual and not the most electrically inclined?
Old Jan 23, 2014 | 04:29 PM
  #8  
FAHREN's Avatar
Newb
 
Joined: Dec 2012
Posts: 42
Total Cats: -7
From: Garden Grove, California, United States
Default

Here let me google that for you


This circuit is a high side switch and switched power circuit, slightly different from your linked article circuit but it will serve your purpose.

Personally I prefer to run a low side switch, with high side switched power. this way you can jump your switch positive voltage from your fused fuel pump source voltage and the whole circuit is fused.
Attached Thumbnails V increase from powering fuel pump from battery w/ relay-fuel%2520pump%2520relay.gif  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
lsc224
Miata parts for sale/trade
2
Oct 1, 2015 09:17 AM
viriiguy
General Miata Chat
5
Sep 28, 2015 07:39 PM
ReallyRottenTurbo
MEGAsquirt
4
Sep 22, 2015 12:49 PM
Mikel
MEGAsquirt
29
Sep 14, 2015 09:11 AM
thumpetto007
General Miata Chat
8
Sep 4, 2015 05:25 PM




All times are GMT -4. The time now is 09:31 PM.