Removing the Secondary Plates (Butterflies)

[Jamie]

Hi,

Mine were removed by the dealer. Back then, I did not even bother to figure out how he did it.
A buddy of mine, apparently a capable wrench, now would like to do it all by himself. Any "how to" step-by-step advice (or ref to an OLD post) I could share with him?.

Thanks. Jamie

 

[hombre]

Expose the throttle bodies by removing filters or plastic plenum if still used.

Open secondaries fully by pushing on them with finger... they will rotate.

COMPLETELY SEAL CLOSED MAIN THROTTLE PLATES UNDER SECONDARY PLATES WITH MASKING TAPE!!! This will save you from major disaster of tiny screw falling into intake runner!

Using small screwdriver, remove the 2 tiny screws from each secondary throttle plate, one plate at a time. I found it helped to have needle nose pliers in left hand to "grab" parts as they came loose (screws and plates).

After removing all 3 secondary plates... remove masking tape (obviously).

 

[dragline708]

Closing bottom TB plates & taping is good idea ,
an added precaution , to make job easier if drop one
of the 6 little screw , or possible little brass shaving
that may come loose from braded screws.
push a kleenex in eachTB hole .
Shaving would be hard to get @ even with needle nose pliers.
Tissue great for sweating job too !

Wayne

 

[BigWillie]

This may be a strange question, but what will it effect if these are removed?

 

[REGULATOR]

removing the secondaries increases the grin factor


it also removews the factory restrictions in the first 3 gears

 

[Lester532]

Do you need to change the tune when the secondaries are removed ? And is there a down side to removing them ?

 

[BigWillie]

That was going to be my question and I also wonder what restrictions. I have heard about it but don't know about them. I need to talk to you guys more.

 

[Pig9r]

Only downside is you'll get more power in the lower gears. No real need to retune, a 12 minute tune would be good enough.

On the standard Rocket map, this is the position of the secondaries. 0% is completely closed, and 100% is completely open.



This is the Triumph tune for off road and aftermarket pipes:



So you can see that they close quite a bit. Even more so for the "performance" pipe tunes.

 

[hombre]

The real reason to completely remove the secondaries, is that even with them set to 100% open in all fields via TuneBoy, they remain partially closed at idle... and open WAAAY too slowly for this hot rod cowboy on WOT. Don't believe me? Pull off your filters and watch for yourselves.

'Tis because of the way the secondaries use MAP to control idle. Or is it the other way round?

 

[Sidecar Flip]

.02

Would it not be more advantageous to not only remove the plates but also the shaft and linkage? If I was going that route I'd machine aluminum plugs for the shaft holes and remove the whole assembly. Cleaner, straighter shot without any turbulence.