Injector Related Questions + External Gate

[Streetglow]

hi, im planing on throwing a bolt on setup onto my standard Rb2det

Set up is a hypergear SS2 (top mount), external gate, adaptronics ECU (mafless tune), forward facing greddy plenum FPR and injectors etc....

Im unsure of the injectors. I will only run the car on pump fuel for now and i want to push over 300 atw... something around the 320 mark i hope looking at the 300kw thread.

Ok here are the questions:

*Can i use side feed injectors on a forward facing plenum? (will probably go top feed anyway)

*what size injector can i run without maxing out the duty cycle? ( i was going to go ID1000 so i can go flex fuel later but still unsure)

*If i go with the ID1000's will it still idle well?

*size external gate i should run? (hoping to be tuned on 18-20 psi. Had a read on flow calculations to determin the correct size but i am still unsure)

Appreciate the help

[GTSBoy]

Just use ID1000s. Everyone here swears by them and they idle at least as well as factory injectors.

Sidefeed vs top feed depends more on the fuel rail than the plenum. As you didn't indicate exactly which engine (you called it an RB2DET...no telling if it was 20, 25 or 25Neo) it's a bit hard to say whether the plenum you plan to use is suited to either sort. All that's really important is that you have to be able to bolt the rail down to the manifold.

Are you aware that FFPs don't offer any benefit except clearing your topmount?

[Streetglow]

series 2 RB25 from a R33 sorry.

Yep, the FFP was to reduce the cooler piping, neaten the bay and let me go top feed with no clearance issues. Doesent help flow at all?

Also are aftermarket RB26 injectors compatable with the Rb25 or little modification?

Edited April 16, 2013 by Streetglow

[Reese69]

i am running nismo 740 side feed injectors in standard fuel rail on a greedy FFP - tuner said that set up with my turbo will give 300kw on pump and E85 (another member here hit 304) but i will be upgrading to id1000 and top feed which my tuner recommended so might as well go the good ones up front -

[Streetglow]

ah cheers for the reply... yeah i was going to go 740DW then upgrade later but i think ill just go the ID1000.

[AngryRB]

ah cheers for the reply... yeah i was going to go 740DW then upgrade later but i think ill just go the ID1000.

so you'll need an aftermarket rail for the ID's, theres a write up in the DIY section, there not easy to setup but doable.

Edited April 16, 2013 by AngryRBGTX

[Streetglow]

anyone know how to calculate how big of an external gate to run?

[ARTZ]

44-45mm is usually perfect

[hypergear]

I'm using power enterprise 850 injectors. They cost abit more but they are very good and direct drop in. They started to go lean at 430rwkws, but that is above the maximum efficiency of the SS2 turbocharger.

Those injectors where bought from CJmotors

I'm running a 50mm gate made by my self, So I can make you one if you are not in a hurry or use a turbosmart 50mm gate.

[Streetglow]

44-45mm is usually perfect

I'm using power enterprise 850 injectors. They cost abit more but they are very good and direct drop in. They started to go lean at 430rwkws, but that is above the maximum efficiency of the SS2 turbocharger.

Those injectors where bought from CJmotors

I'm running a 50mm gate made by my self, So I can make you one if you are not in a hurry or use a turbosmart 50mm gate.

so what actually determines the size of the gate? boost? size of turbo? power?

how much would a vband gate be if you made one?

Edited April 17, 2013 by Streetglow

[hypergear]

the gate size is determined by the diameter of the actual wastegate port that sets against the manifold. The 50mm gate is $350. fully machined from stainless steel casting.

[s213b]

so what actually determines the size of the gate? boost? size of turbo? power?

the gate size is determined by the diameter of the actual wastegate port that sets against the manifold.

That doesn't really answer the question?

I remember reading something like:

Big turbo low boost - big gate

Big turbo big boost - med/ big gate

Small turbo low boost - small gate

Small turbo big boost - small/med gate

Because the bigger the turbo the more flow, the lower the boost the longer the gate is open etc.

I could be wrong this is just my understanding, anyone elaborate?

[Dose Pipe Sutututu]

you're correct..

as you run more boost, you flow more exhaust gasses into the turbine to generate pressure, i.e. less exhaust gasses are diverted to the gate.

If you're running less boost, it's more ideal to run a slightly larger gate to prevent boost creep.

[s213b]

you're correct..

as you run more boost, you flow more exhaust gasses into the turbine to generate pressure, i.e. less exhaust gasses are diverted to the gate.

If you're running less boost, it's more ideal to run a slightly larger gate to prevent boost creep.

Is there ever a gate-too-big situation?

I'm planning a gtx3076 on 20-24psi rb25det. Would a 38/40mm gate be to small?

Not really sure how gate sizing goes with a mid framed turbo on med/high boost...

[scotty nm35]

If your gate flows too well (or is too big) the controller may have issues holding flat pressure, somewhere around 45mm would work well in your situation. It is all related to the pressure in the exhaust manifold and the angle the wastegate is mounted more so than the size.

[kitto]

Dont forget, manifold design plays a part in waste gate selection. As does waste gate position.