NB Miata Fuel Line Cleanup / Simplification
 

Hi All - I'm failing to find the right search terms for what I'd like to do. My nb2 miata has this weird spider web of fuel lines on the inner passenger side of the engine bay. They are held together by a brass colored bracket. Its ugly af and I'd like to remove/clean it up as best I can. The real best reason I have is the corner of one of the brackets presses into the FM reroute hose I have and right now I basically have a system of zip ties pulling against the bracket to hold it out of the way. Its hideous. If anyone can poitn me in the right direction so I stop getting search

results on how to replace and or simply disconnect the lines, thanks!


https://cimg9.ibsrv.net/gimg/www.mia...cf095dcd3a.png

That is the fuel pulsation damper, you want to keep it. Some aftermarket fuel rails, (the Radium ones anyway) have provisions for mounting one on the rail itself which would let you ditch the factory one on the fender apron. But it’s something you’ll want to keep in the system either way.

As for the hose rubbing the bracket, I’d get a short spare bit of radiator hose and slit it down its length, wrap it around the reroute hose and then zip tie the whole thing to the bracket if needed. The second layer of hose will prevent the actual coolant hose from chafing.

There is a factory pulse damper on the fuel rail too. For some reason Mazda built the NB with two. I'm a big fan of not fucking with something unless absolutely necessary, and you could probably easily make it clear with the above mentioned protection sleeve, but if you must, I'm fairly certain I've unclipped the line from the rail, and clipped it directly to the line from the tank.

Ahh interesting. I knew NAs had one on the rail, didn’t realize the NB had a redundant setup.

Someone did clean those lines up this summer I think. I can't remember exactly who's build thread it was in but I want to say it was @OptionXIII or @redursidae

I’ve redone mine as part of going to ITBs and the damper at the rail is critical on NBs. The damper in the engine bay does help eliminate some fuel pressure spikes when closing the throttle abruptly, but without it the pressure was acceptable and the car ran fine on a standalone ECU. I run both dampers with the ITBs, but if you give me a couple of weeks, I will be testing replacing the auxiliary damper with an ethanol sensor and watching the fuel pressure once more for more recent data.

Im in the camp that if Mazda put it there, they had a reason. The thing isn’t cheap and they would have liked to cut costs. Maybe relocate it to a neater place and make new hoses, but I would keep it

Now that I know it was called a fuel damper, I was able to find an old miata.net post where many people said they have removed the one in the engine bay (not the rail) without any issues.

• https://forum.miata.net/vb/showthread.php?t=402066
• https://www.miataturbo.net/general-m...-damper-83991/
• https://forum.miata.net/vb/showthread.php?t=673707

Most people are saying they removed them and noticed no ill effects. I haven't found anyone that has actually scientifically tested for differences.

EDIT: Found this YT video from high performance academy: - his summary is that they are good. You probably won't notice if you remove it, but you might and what you'll notice is fluctuations of lean/rich times that wouldn't have been there when the damper would have been there.

https://cimg6.ibsrv.net/gimg/www.mia...65ff05d98.jpeg
This is how I did mine. Rail damper is towards the firewall.

I cleaned up the mess and made some AN lines. I posted a parts list and you can find some pictures as well:
https://www.miataturbo.net/build-thr...1/#post1655663

I've cleaned up my fuel lines too, for the mods and coolant re-route saga with lots of pics, see thread starting here: https://mx5cartalk.com/forum/viewtop...6716&start=347

Long story short,here's the final solution, cut-down OEM fuel damper bracket with NO 90* fuel line bends:
https://cimg9.ibsrv.net/gimg/www.mia...8809303365.jpg

<rant>
The video posted above includes one of my automotive "pet peeves", the guy keeps calling it a "dampener" when he MEANS "damper", it's clearly written as "damper" on the product and the video's title even says "damper"!
It may be petty, but it demeans his credibility.
</rant>