SPA Turbo FMU

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RobFour1Four

New Member
I have this fmu. im a bit confused on how to adjust it. Heres a link to a diagram what the fmu looks internally and externally. how would i adjust it to give more gas when in boost? i tried looking at the pictures too see how i would do so, but im still a bit slow :p
 
yeah i have a wideband. i just need to know if i loosen or tighten the bolt for more fuel at boost, and what the little bolt is on the top-side of the fmu. when i loosen that smaller bolt, at a point, it will leak air from a hole where the bolt screws into. its meant to be there, i just dont know what its for
 
FMU?? Wow they still sell them things? Good luck not blowing the engine.

Pay for a tune, you will gain WAY more HP and TQ than off of that bullshit FMU.
 
FMU?? Wow they still sell them things? Good luck not blowing the engine.

Pay for a tune, you will gain WAY more HP and TQ than off of that bullshit FMU.

i have a tune aswell, and thanks for the good luck. im getting my retune in a few weeks because i have different internals. I rebuilt my bottom end. the fmu is a safety for more fuel in boost.. thanks for the help though
 
oh no I meant the nut thats on top. turn it one way then just look at your wideband, if it goes leaner then you know to turn in the other way or vice versa
 
I always thought that FMU's were set to a certain ratio to increase fuel pressure at boost, and all you could adjust was base pressure. I never really looked at em tho, theyre not the best method of fuel control.
 
yeah they are preset. im looking to tune it at idle cuz its being dumb. when i get it retuned, im taking the fmu off. i have no idea what the boost ratio is so im kinda of in a nut shell ha
 
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