DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Sorta botched diy duel feed rail. What now???

Old 02-28-2010, 10:34 AM
  #1  
Elite Member
Thread Starter
iTrader: (11)
 
miatauser884's Avatar
 
Join Date: Feb 2009
Posts: 2,959
Total Cats: 11
Default Sorta botched diy duel feed rail. What now???

I have a 99 fuel rail (some of you can probably see where this is headed)

With my lack of understanding about where the fuel entered the rail I assumed it entered through the fpr. I drilled my hole and was happy. I then read that the fuel leaves through the fpr. Son of a bitch! I now how two fuel feeds on the same end of the rail.

Options:

1. continue tapping 99 rail, plug the hole, then tap the top of the rail on the other end and use a 90 degree fitting.

2. modify the fpr so it can be used in line and not attached to the fuel rail. I can probably thread the little nub on the fpr (where the o-ring is) and then attach a female hose barb. Then, I can tap both ends of the rail for supply and use the original supply line as the return with the fpr attached via fuel injection hose.

3. modify a 1.8 rail by doing the usual diy duel feed steps, and cut the in and out hard lines so it will fit on 99 intake.

4. buy a pre-made duel feed

Which seems like the best option at this point?

PLEASE add a note in the diy fuel rail "useful saved post" that the instructiosn are NOT for a 99 rail.

Last edited by miatauser884; 02-28-2010 at 12:30 PM.
miatauser884 is offline  
Old 02-28-2010, 12:18 PM
  #2  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,172
Total Cats: 1,128
Default

Can we get a pic for those of us that have never seen a '99 rail? I wouldn't suggest #2 though. Tapping and plugging your hole would work, did that with my dual feed hold and it's held fine.
curly is offline  
Old 02-28-2010, 12:25 PM
  #3  
Elite Member
Thread Starter
iTrader: (11)
 
miatauser884's Avatar
 
Join Date: Feb 2009
Posts: 2,959
Total Cats: 11
Default

I think I am going with option #1




The 90 degree fitting will be between the fpr and the #1 injector feed. If for some reason this location doesn't work. What would be the next best solution?

miatauser884 is offline  
Old 02-28-2010, 12:26 PM
  #4  
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,537
Total Cats: 42
Default

Originally Posted by djp0623
With my lack of understanding about where the fuel entered the rail I assumed it entered through the fpr.
Wow dude. Well, at least you're brave enough to admit what you did around here.

I'd either get another '99 rail and start over or buy an aftermarket dual-feed. Maybe do #3 if doing so isn't jury-rigging it. You want to be especially careful with the fuel system.
kotomile is offline  
Old 02-28-2010, 01:00 PM
  #5  
Elite Member
iTrader: (4)
 
Pen2_the_penguin's Avatar
 
Join Date: Dec 2009
Location: Reno, NV
Posts: 3,686
Total Cats: 95
Default

if its an aftermarket FPR, then #2 is an option if not, dont waste your time with modifying the stock FPR. The FPR is designed the keep the pressure built up in the fuel rail by basically backing up the fuel line like a dam to the fuel tank, so I doesnt matter if its an aftermarket if you go with number 2, just as long as it keeps the fuel rail pressurized. Here is an example of my aftermarket FPR.

Name:  10-16-09_1830-1.jpg
Views: 747
Size:  57.6 KB
Pen2_the_penguin is offline  
Old 02-28-2010, 01:10 PM
  #6  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,172
Total Cats: 1,128
Default

So if I understand that fuel rail correctly, it's feed via the hard line that goes along the entire length of the fuel rail, and then the pressure is regulated, but no fuel is returned? You'd need to braze a fitting on to the side for it to work, otherwise I'd be worried that any fitting threaded in directly next to the FPR would block flow to the FPR and hinder its performance. That's why drilling and tapping on the end is the popular choice for the return systems, you're drilling out the entire end plate for a tap, and I believe threading some of the square tubing of the fuel rail, so you'd definitely block the FPR. Man, I can't for the life of me make a coherent post this morning, I need coffee.
curly is offline  
Old 02-28-2010, 01:48 PM
  #7  
Elite Member
Thread Starter
iTrader: (11)
 
miatauser884's Avatar
 
Join Date: Feb 2009
Posts: 2,959
Total Cats: 11
Default

Correct, the 99 does not return. the 99 fpr has no outlet line.

I went back out and looked at the location of the fpr relative to the centerline of the rail. I noticed while looking into the rail through the hole that I already drilled that the entrance into the fpr is offset from the rail centerline. The side I plan to tap and the entrance to the fpr appear to be on opposite sides. I feel pretty confident that I will not get obstruction of the fpr. You brought up another concern, and this is a concern of mine now as well. Is the side wall of the fuel rail thick enough to tap and thread?





Sorry about the less than spectacular image quality.
miatauser884 is offline  
Old 02-28-2010, 01:57 PM
  #8  
Elite Member
iTrader: (4)
 
Pen2_the_penguin's Avatar
 
Join Date: Dec 2009
Location: Reno, NV
Posts: 3,686
Total Cats: 95
Default

wow... 99' fuel rails confuse my NA mind... no return lines? wtf voodoo **** is this?! lol
none the less, the rail needs to stay pressurized.
Pen2_the_penguin is offline  
Old 02-28-2010, 02:43 PM
  #9  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,172
Total Cats: 1,128
Default

In layman's terms, its pressurized and the fuel stays there until it's used. Instead of the NA systems, which grabs whatever fuel it needs on it's way back to the fuel tank.

No, I don't think the fuel rail is thick enough to create a good thread for sealing, especially at 100psi or whatever it runs at. We worry about our thin oil pans, which are 2-3 times thicker, and those drains supposedly have 0psi going through them.
curly is offline  
Old 02-28-2010, 02:45 PM
  #10  
Guest
iTrader: (6)
 
M-Tuned's Avatar
 
Join Date: Sep 2007
Location: Vaughan, On, Canada
Posts: 1,085
Total Cats: 1
Default

M-Tuned Miata 94-05 Fuel Rail M-Tuned

M-Tuned is offline  
Old 02-28-2010, 03:06 PM
  #11  
Elite Member
Thread Starter
iTrader: (11)
 
miatauser884's Avatar
 
Join Date: Feb 2009
Posts: 2,959
Total Cats: 11
Default

Originally Posted by Marc@M-Tuned.com
Sell it to me for $100 shipped. Call it at dumbass discount.
miatauser884 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
04-12-2021 04:21 PM
emilio700
Wheels and Tires
151
06-02-2017 02:36 PM
Girz0r
Gaming
12
03-28-2016 03:15 PM
JesseTheNoob
DIY Turbo Discussion
15
09-30-2015 02:44 PM


Thread Tools
Search this Thread
Quick Reply: Sorta botched diy duel feed rail. What now???



All times are GMT -4. The time now is 04:42 AM.