FPR psi setting???, need help! Options

[nate95]

ok, so does anybody know what PSI setting i should have my FPR set too? also, do i have to do any adjusting to the FMU or does it do its own thing? cause on top of it theres a little thing that tiwsts..

[NuclearHappineS]

it's a FPR or an FMU ?

if it's an FMU it will increase FPR with reference to boost...

so if you start out at 45psi, it may go to 90psi @ 7psi of boost (for example)
that's a rate of about 7:1 for your FMU. so it adds 7psi of fuel for 1 psi of boost (that's what a '7 to 1' FMU means).

So if you have 200cc injectors at 45psi at idle. At 7psi they will look like 282cc injectors (45% larger).

So in this case , if you have a cartech Super FMU or a vortech SFMU. You set the base fuel pressure to 45 psi, and you set the rate to 7:1
So you can now support 45% more hp at 7psi.
example:
So if you had 140hp stock and you expect to make 203hp @ 7psi
==> 7:1 will do.
if for example you expect 250hp @ 7psi, the a 7:1 rate will not be enough... so you'd have to adjust your rate up to around 14:1...

If you have for example a 2.5 litre stroker, instead of a stock 2.2... then you will expect to make 13% more hp at all rpms/boost levels... because of the displacement... in this case your 45psi base is not enough... you'll want it to be higher ...and the math works out to around 58psi.

So with the base pressure you're adjusting your idle fueling and your shifting the overall fuel curve up or down. With the 'rate' setting you are controlling how much fuel is added only when you are under boost.

Again, what kind of car is this (ST, GT?) what size turbo ? (T25,T4)? and what kind of FMU is it (Begi, cartech, vortech)? (FPR/FMU/SFMU)?

I can't be more specific till you are more specific.

If all you have is a FPR and you set it to 45psi at idle you will lean out under boost.

If all you have is a FPR and not an FMU...then that can work...but you'll need an SAFC/Emanage to reduce fuel at idle ...

so let me know the details and i can help you out more

from your info:
Garrett T3 Turbo
Fuel Management Unit
Fuel pressure regulator

what PSI ?
what FMU ?