Inlet manifold for fuel injection system.

jenand40 · Post by **jenand40** » Sat Jan 04, 2014 11:28 am

Does anyone know if you can use the flapper EFI system inlet manifold with the Hotwire EFI system?
Will the Hotwire injectors fit in the Flapper injector holes?
Andy.

ChrisJC · Post by **ChrisJC** » Sat Jan 04, 2014 4:01 pm

I believe not, but I am sure somebody else will confirm.

Chris.

Quagmire · Post by **Quagmire** » Sat Jan 04, 2014 7:38 pm

You cant interchange flapper injectors with hotwire ones.

The flapper injectors are clamped down differently, they have a specific metal clamp that hold them down in pairs. The hotwire manifold has them clamped by the fuel rail.

The flapper injectors have a barb at the top for a small section of fuel hose to clamp to that connects the injector to the rail. The hotwire style injectors are more modern and have an o-ring at the top that seals into the seat of the fuel rail that the injector pushes into and is clamped down by.

I would go with a hotwire manifold if there was a choice as you have a larger selection of injectors to choose from. I went from flapper to hotwire top end for this very reason and I have vauxhall injectors in mine.

*Edit

Almost forgot! Flapper injectors are low impedance and need a resistor box, hotwire style ones are high impedance and don't therefore need the resistor box.

jenand40 · Post by **jenand40** » Sat Jan 04, 2014 8:56 pm

Thanks for your replies chaps, but I did not explain myself very well.
I have the Flapper system at the moment and I am changing over to the Hotwire system. To save me removing the Flapper inlet manifold, can I use the Hotwire injectors with the Flapper inlet manifold?

ChrisJC · Post by **ChrisJC** » Sat Jan 04, 2014 10:07 pm

No. I thought Quagmire was pretty clear on the reasons why not.

Chris.

DaveEFI · Post by **DaveEFI** » Sun Jan 05, 2014 9:28 am

Are you missing the hotwire manifold? Once you stripped off the flapper bits, it's hardly any more work to change it. Perhaps an hour or less.

daxtojeiro · Post by **daxtojeiro** » Sun Jan 05, 2014 9:49 am

Ive done what you want to do years ago.
It needs the inlet maniflod injector holes drilling out to 14mm, which means you have to take it off anyway.
I wanted to keep the Cold Air Valve from the flapper whilst we were developing MS1 (no stepper or idle control back then).
Im fairly certain fitting the injector rail from the hotwire wasnt an issue, although it was a long while ago, so I cant recall exactly.
thanks,
Phil