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.

SLOWMX5

A full volt improvement at the FP

Link doesn't work, but it is a good idea.

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

This is a thread that comes up on every car forum once in a while. Answer is yes, 99% of the time it works.

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.

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?

Here let me google that for you
https://www.miataturbo.net/attachmen...ine=1390512580

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.