Porsche 1984 16v M28/22
Finally I can see the light at the end of the tunnel on this engine rebuild. I opted to fit different injectors, dampner and fuel regulator and have had Andre test the LH ECU and I purchased a rebuilt MAF from him. (Great Service).
I have made my own rails and fitted an adjustable fuel regulator and fitted a dampner onto the fuel rail itself, but is runs very rich when set at 2 bar.I have dropped the pressure but am concerned about making it too lean, I plan to get the garage to test the exhaust when she runs appropriately. The injectors I fitted have the same cc rated as the ones removed (250cc) @ 2 bar and are 16 ohms. (Bosch 0280150947)
Can I ask what injectors others have retrofitted to a new rail?
Has anyone fitted the later 85-86 (928 606 120 00 ) (Bosch 0280150706) to an 84 16v and had any issues?
Thanks again guys
Glen

 

The later injectors are the same flow rate but need adapter hats that are very popular in the VW crowd in order to allow an injector that expects to use and O-ring to seal against a fuel rail to connect to the stock short piece of fuel hose.

Personally, I would by a set of design III injectors with 4-6 holes with a 24lb flow rate and fit them.

They are brand new, quieter, and provide better atomization. The later helps idle tremendously, at least it did on a 944 I fitted them to along with an 89 928.

If the rails you made connect directly to the injector I would still opt for design III Bosch injectors.

 

Thank you for your advice, yes the rail I have made connects directly to the top of the injectors. I was hoping I could adjust the fuel regulator to make it run correctly but would anyone know how to calculate the flow rate from 2 bar to say 1 bar if the injectors are calculated at 250cc @ 2 bar. ?
Thanks

 

Pressure drop is proportional to the square of the flow so to double the flow you need 4 times the pressure drop- if you halve the flow the pressure drop will be one quarter- it is a square function relationship for flow streams subject to turbulent flow [i.e. Reynolds number greater than about 4000]. Low viscosity liquids [i.e. less than about 50 CSt] will exhibit turbulent flow unless the lines are ridiculously oversized.