Modifing S4 Fuel Rails

[vex]

Originally Posted by WE3RX7

Do you need larger fuel line for what you're running or are you just getting into this for kicks? Just curious...

How much boost are you planning to run and what size injectors are you putting into the rails?

Just for kicks, I think a majority of the problem I was having came from the surface finish on the inside of the secondary. It gave a place for the fuel deposits (rust, dirt, crap) to collect before coming loose and getting lodged and disabling the fuel injectors. I drilled out the interior of the fuel rail purely because it was so dirty. The actual increase in diameter was null, I may have increased it by 1/64" if anything at all.

I'm planning on going to -6 AN and running a parallel fuel setup. This will feed 680/720 Injectors. Granted not very large injectors but enough to run 5-7psi (maybe more when I have enough to rebuild/port my engine). I'm also doing this for easier connections and disconnects when I pull the UIM. If I really desired to I could run -8, but there's really no reason to at the moment.

If I had a proper feeler gauge I may port the fuel rails to even larger, but honestly for the power gains I'm looking for it shouldn't be that big of a deal. Only looking to make 200-300HP (a good 33-110% increase in power from what I'm making now).