FMU on boost designs kit

[sunnys14]

i was thinking to run a FMU on my boost designs kit. should i run a 8:1 or 12:1 fmu at 8psi and stock maf with a t04e turbo? i sold my top feed fuel rail and 50lb injectors and am in the process of getting 370s and SAFC and z32 maf. i just wanna boost for now to see how its gonna feel. also, at 8 psi i hear you shouldnt need to retard your timing at all, can anyone confirm this? i am hearing alot of different answers.

[DammitBobby]

I think you are confused. You do not change your injectors or MAF to run a FMU. For fuel pressure the only thing you need is the FMU and Walbro fuel pump. I am currently running the FMU, Walbro fuel pump at 10psi.

[:: orion ::]

8:1 FMU + Walbro 255HP

- OR -

370s + S-AFC (no need for a bigger MAF)

...

And you should retard you base timing a couple degrees...the stock ECU gives about ~5 degrees too much advance for a turbo'd car @ 8psi...so retarding it a litle will save you a rebuild.

...and either of the above options SHOULD NOT be used with more than ~8psi from a T3/T4 - That'll make about ~240-250rwhp...limit of the 370s, limit of the stock MAF, and...if you choose the FMU route...fuel pressure will be dangerously high (consider 100psi the safe limit).

- Brian

[sunnys14]

thanks orion, youre always helpful. how much should i retard timing by? and yes i forgot to say that i was running a walbro pump too. so i guess 8:1 fmu would be fine on stock injectors then. my friend gave me a 12:1 fmu but i guess i cant use that.

[DammitBobby]

This is a common misconception that you can`t use a 12:1 FMU. You are far better off with a 12:1 disc then a 4:1 disc. There is not much you can do if it is running lean other then replacing the disc. If you are running to rich you can install a cheap valve and bleed some of the pressure off. Use the free FMU and buy a cheap valve.

[sunnys14]

do you know where i can get a valve to bleed the pressure and what does it look like so i can go ahead and start getting one. thanks

[DammitBobby]

Local aquarium shop have the valves if you want to go cheap or any MBC will work.

[sunnys14]

rseabrooke... what kind of BOV are you running? are u using the turboXS RFL? do you studder when you shift gears? any problems?

[DammitBobby]

Open Atmosphere and I am going to change it to one that recirulates. If you are running a MAF system and do not have a stand alone ECU then you need to recirculate the BOV. It is the one that comes with the kit. I am just tired of the car stalling out. No I don`t have any studder problems.