Fuel line/fittings & EFI

[millarg]

I'm in the final stage of consolidating parts for a CIS-EFI conversion (engine in car) using a 3.2 intake on my 78SC 3.0 (Bitz Racing kit using MS1)

Have most things in place, but need recommendations on spec and sources for fuel lines and fittings.

Am I correct in believing that I need 6AN fittings for both fuel filter and fuel rails.

With respect to the fuel line - I like the "bling" factor on the braided stainless lines with Aluminium fittings, besides the bling is the any other reason to use (or not use these) - The car will solely be for easy street use (island life)

I may also need a fuel pressure regulator and will need a fuel pressure guage, I am now aware that fpr with integral guages are available - can anyone suggest a suitable unit - I have the fpr from the 3.2 - is this capable of being adjusted to 2.5bar?

Also, I was planning on using a stock replacement fuel filter, is there something else I should consider?

I plan on removing the fuel accumulator (told its not necessary with the EFI) and relocating filter with the following flow

Fuel pump
Fuel Filter
Fuel pressure regulator/guage
1st Fuel rail
2nd Fuel rail
Fuel return

With reference to the fuel rails and return.

Is it better to run in a loop and should I use a "T" or "Y" into both rails at once (thinking that will help keep pressure constant?), then do the same for the return line.

One final thing, does anyone have a link to the fuel flow rate on the stock 3.2 injectors for a range of pressures - The Bitz kit recommends Accel Acc-150630 high impedance fuel injectors - I believe that the stock, which I hope to re-use are low impedance (?) meaning I will need to adjust the required fuel values in the MegaSquirt set-up.

Am I missing anything?

Any comments or advice appreciated,

Many thanks in advance, Glen (who is a little out of his depth!)

[mytoy]

Originally Posted by millarg

I'm in the final stage of consolidating parts for a CIS-EFI conversion (engine in car) using a 3.2 intake on my 78SC 3.0 (Bitz Racing kit using MS1)

Have most things in place, but need recommendations on spec and sources for fuel lines and fittings.

Am I correct in believing that I need 6AN fittings for both fuel filter and fuel rails.

( This is correct. As a note though you will need metric to AN adaptors in order to make this work. You will need M16 to 6 AN and M14 to 6An adaptors. As a special note the return line fitting on your stock lines will not accept a standard adaptor. I ended up removing the end that fit the line and used a hose clamp to attach the braided line to it.)

With respect to the fuel line - I like the "bling" factor on the braided stainless lines with Aluminium fittings, besides the bling is the any other reason to use (or not use these) - The car will solely be for easy street use (island life)

(These work quite well as well as the bling factor. The only thing that you have to take into consideration is that the SS braided lines are abrasive and therefore you have to carefully consider your routing so that the lines do not rub anything important.)

I may also need a fuel pressure regulator and will need a fuel pressure guage, I am now aware that fpr with integral guages are available - can anyone suggest a suitable unit - I have the fpr from the 3.2 - is this capable of being adjusted to 2.5bar?

(The 3.2 regulator is already set for 2.5 bar from the factory. Although this is a non adjustable unit and is not pressure compensated. I would suggest that you get an adjustable FPR with vacumn compensation to regulate the fuel pressure.)

Also, I was planning on using a stock replacement fuel filter, is there something else I should consider?

(This will be fine.)

I plan on removing the fuel accumulator (told its not necessary with the EFI) and relocating filter with the following flow

Fuel pump
Fuel Filter
Fuel pressure regulator/guage
1st Fuel rail
2nd Fuel rail
Fuel return

( I would seriously not reccomend this. Proper flow should be as follows:

Fuel pump
Fuel filter
1st Fuel rail
2nd Fuel rail
Return line from fuel rails to FPR
Return line to tank from FPR)

With reference to the fuel rails and return.

Is it better to run in a loop and should I use a "T" or "Y" into both rails at once (thinking that will help keep pressure constant?), then do the same for the return line.

(Either or is fine. I am running a loop and have not problems. You can certainly run the supply line to a T in the centre of the fuel rails and split equally to each side and do the same on the fuel rail returns to the FPR if you wish. Or you can enter on one side and exit the other side. Much easier and simplier.)

One final thing, does anyone have a link to the fuel flow rate on the stock 3.2 injectors for a range of pressures - The Bitz kit recommends Accel Acc-150630 high impedance fuel injectors - I believe that the stock, which I hope to re-use are low impedance (?) meaning I will need to adjust the required fuel values in the MegaSquirt set-up.

(The stock 3.2 injectors are indeed low z injectors and you will have problems trying to drive these with the MS unit without modifications to the unit. This is why Tony suggest the high Z injectors. Now the 3.2 injectors are stock 24 lb and I do not know why Tony suggests 30 lb injectors. Accel make 24 lb, 26lb, and 30lb injectors so you have a range to choose from. I know that the 24 lb injectors will handle 240 hp so why the suggested 30lb I do not know. Might want to ask that question on his site.)

Am I missing anything?

Any comments or advice appreciated,

Many thanks in advance, Glen (who is a little out of his depth!)

(Hope this helps you.)

[millarg]

Many thanks Gary, great help, flow makes sense of course (there would be no regulated pressure with my suggestion - duh! I likely maintain the standard loop arangement (gotta believe if a double loop was required - someone at Porsche might have suggested it).

I believe that Tony suggests the higher flow injectors to allow for future power improvements - he outlines it in the manual - I was simply trying to re-use the 3.2 stock ones to save a few pennies for my header fund. I don't mind playing with the MS programming - but will stay away from hardware changes.

Thanks again,

[bullethole]

are you using tony's rails.. he provides enough fuel like and the connectors needed to do this (not stainless braided though).