Hello all.
I have a series 5 NA engine I am installing into a GSL-SE.
I am using the Gsl-se injectors, wiring, and intake.
I am wondering if it would be better to use the series 3 (Gsl-se) defusers, or the series 5 defusers?

 

Rob.
If I recall correctly.,those GSL-SE injectors are the 680's?.Tan tops?
they are pretty well the same as a set of s4/s5 injectors,.(have the s4 connector though)
So I'd leave the diffusers alone.

 

So you think it would be ok to leave the s5 defusers in using the Gsl-se injectors?

 

you'd think the S5 diffusers would be better than the -SE ones

 

The injectors are basically spraying on to a plastic Sive...THAT part is the diffuser.
It just atomizes the fuel.(debatable)
The diffuser is part of the "spacer" that is placed into the engine(or manifold) and held securely with the rubber o-rings that surround it.
Many guys have cut that little "pizza table" off as they get brittle over age and can Break.
The newer Type injectors such as ID or whatever have a better spray pattern so really that plastic diffuser is not needed.

Now,the injectors whether it be s4 or s5 sit in the engine pretty well the same way,and it uses the TOP of that "diffuser apparatus" as a seat.
So really it is up to you whether you want to get rid of the BOTTOM of the Part..The top will still accept any other injector as it is meant to sit there and be a Seat to the injector. The injector will have it's Rubber seat grommet to sit on that said "inserted Diffuser".

You got my # Rob?..call me,I can explain it better..lol!