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[jdmhatchracer94]

anyone know the size or fuel line and return? just from the looks of it they appear to be the same size. Going to upgrade to 3/8" fuel line and not sure if the stock return it big enough. 


By the way got a da as new project.

[HiProfile]

The only time a 255HP pump is too much for the stock system is when you're using the stock FPR.

Worst case you have to retune some higher vac columns because the fuel backs up and raises fuel pressure. Just keep it in boost and you won't return any fuel.

[ratcityrex]

The only time a 255HP pump is too much for the stock system is when you're using the stock FPR.

Only time I've ever heard of that is when the small stock fpr is used.

[HiProfile]

Interestingly I found this at d-series.org (by someone we know):

You need a B-series FPR for a 255HP, the outlet is visibly larger so it's a no brainer if you have to pick one up out of a parts jumble. Without the B-series unit your fuel pressure at idle will drift, but it is fine during the operating range as pressure is bled off by the injectors.

I've taken a stock B-series FPR and fuel lines to 700 whp. In the 350 whp range the pressure from one side of the rail to the other varies ~4% which can be dealt with via individual cylinder trims, but don't trust it too high.

[92CXyD]

The only time a 255HP pump is too much for the stock system is when you're using the stock FPR.

Only time I've ever heard of that is when the small stock fpr is used.

Happened to me with large and small outlet stock FPR, even with modified one (drill a hole between passages).

I was using CDM 255lph HP pump and would max out past 200psi. 

[ratcityrex]

never had this problem because I have always had a large fpr. Even on my d series I had a large b series fpr.

[PhilStubbs]

i have never noticed it with a small fpr. i do have a big one now, but my idle with the small one was always solid

[jdmhatchracer94]

I run a f fpr the out let on it is larger than my ls fpr is.

[PhilStubbs]

Not all LS have the big one. Just some

[jdmhatchracer94]

I see. I had to use the f one cause the out let is angled and cleared the ge manifold.

[Foowee]

Yup, most accords in the yard have the large exit oem reg. 

Keep an eye on your crush washers for the pulsation damper.  I've seen the wrong ones used n cause high pressure before the rail, but not enough in the rail...

Does anyone know the size of internal threads of the fuel rail?  I think they're m14x1.5, but have been too lazy to measure...

[PhilStubbs]

No clue, but I have a z6 rail with the stud out. I'll try to remember to check it when I get home tonight.

[Foowee]

Just got off my ass, it's M12x1.25...