NatAsRex7

iTrader: (5)

I recently got my injectors cleaned from RC. Im about to put the injectors back in but I saw those plastic things that hook up to the injectors. The diffusers slightly restrict the fuel flow from going into the manifolds. I wonder if its safe to remove them. Did anyone remove them and did you feel a significant difference?

drifting in drifting

iTrader: (11)

keep them they help atomize the fuel better

K-Tune

iTrader: (26)

They aren't "necessary" but they help with fuel efficiency.

NatAsRex7

iTrader: (5)

do you think it would effect the throttle response?

farberio

iTrader: (7)

And by doing so they promote atomization of the fuel....which is what you want.

gxl90rx7

iTrader: (1)

leave them in

bumpstart

i take them out,, they are old and cost engines when they break
my engines are late close ported and run aftermarket ECUs with no diffuser but are still capable of a decent idle

also i more oftent than not upgrade my engines for 2 x 1000 secondarys or 4 x 1000 cc packages

these injectors ( disk type ) have there own inbuilt spray difuser

so the mazda stuff is nothing but risk,, and a restriction to higher airflows and fuel flow from bigger injectors
( ask Howard Coleman CPR, a part of one of those difusers cost him a rebuild recently )

if fitting the rochy type ( marren ) 1000 cc injectors then you replace the secondary diffuser with an extra rubber base grommet
if fitting these injectors to the primary you can use two more rubbers or a single rubber on top of the top section of the two part difuser installed up side down

i have done this many times and i am yet to see any issue

RotaryRocket88

iTrader: (7)

The injectors also won't seat properly if you take them out. Leave them alone.

NatAsRex7

iTrader: (5)

good point there bumpstart but i dont think the oem 460cc denso injectors have built in diffusers. im pretty sure you can replace the diffusers with o-rings to fill in that gap but i think im just going to leave them in. i wouldnt want my engine to burn non-atomized fuel. time to remove the intake manifolds from my bucket of vinegar and baking soda and start scrubbing that carbon off!

thanks!

bumpstart

speaking only for turbo setups
i have put normal turbo injectors in the same situ,, regained the mounting position same with extra base rubbers
i also have coolant crossovers blocked ( ambient is 5- 42 C here coldest/hottest )

and in the turbo cars it does not cause any noticeable differences,, no added injector pulse width for idle,, no puddles,, no stains
-- manifold is more than hot enough despite no coolant crossover in these conditions

the only time i would think there is an issue without the cups or coolant crossovers would be in very cold ambient conditions or when there is emissions idle checks

K-Tune

iTrader: (26)

The s4 primary diffusors are actually quite robust and don't protrude very far into the air stream, I don't recommend messing with them...the secondaries however are a bit thin. My method of removing them is I simply break their legs off leaving the upper plastic seat, this way no additional o-rings or spacers are required.

JustJeff

iTrader: (13)

I'm considering replacing my diffusers. One broke while removing it to have the S5 turbo LIM powder coated. What I have read about people doing is once they loose the diffuser part on the end they cut the remainder and use the o-ring part so that the injector seats correctly.

Sgtbaker

iTrader: (2)

So are the secondary diffusers necessary or not? I have the top part still intact but the bottom part with the legs broke so I wont have any seating issues.

arghx

iTrader: (3)

Now that's for the primary injectors. I doubt it matters as much on the secondaries because they don't come on at low speeds. The biggest reason for the diffusers are HC emissions and to a lesser extent fuel economy.