Rb20 3071 Upgrade

[muvro]

Hi all,

I'm hoping someone can help me out.

I'm doing some upgrades on a mates R32. It's an Rb20 and have done some mods to it.

Basic Mod list;

- GT3071, .63 rear housing external gate.

- Tial 32mm gate

- Turbosmart FPR800 fuel reg

- Turbosmart Dual port BOV

I made the following stuff for it;

- Custom exhaust manifold, top mount. Using 32mm steam pipe.

- Custom 3.5" dump with 2" screamer into 3" system with metal cat.

- 3L surge tank with an 044 pump.

- Also made some intercooler piping for the bay to accommodate the top mount manifold.

My question is, what size injectors do you guys recommend?

I was thinking about some Seimens 600cc, Or should I step it up to 800cc. As soon as this motor pops, an RB25 is going in, with a fabricated inlet manifold. I was planning on getting some fuel rail extruding and making a fuel rail for it as well.

Also, is the RB25 injector spacing the same as the RB20? ie, can I use an RB25 fuel rail, or is the spacinf different?

Thanks in advance.

Tark

[R31Nismoid]

GTR injectors/440cc would be enough.

[ARTZ]

they would be enough, but could it be more beneficial to get bigger ones to have some headroom for future upgrades or E85 fuels etc..I mean its better to have under worked rather than overworked injector isnt it ?. Plus I beleive the siemens have been getting a good rap and are fairly well priced to.

[R31Nismoid]

Ye true, depends if he is going to change turbo or not really.

600cc would be more than enough for a 3071 on E85 - loads of room!

But 440's will be enough for a 3071 on PULP either way.

Depends on budget. GTR injectors - $150 for a set is a darn sight more affordable than 600's

Just comes down to what you want to do. You can always sell the GTR ones off later and buy 600's if you need.

[ARTZ]

I see they are cheap..

When i was looking for injectors i was told to get the 480 s15 ones but i couldnt find any for less than 400 a set so when i found 650s for the same price figured may as well go bigger. stupid sidefeeds

But yeah if you can get them for 150 you have nothing to lose and plenty to save

[eightsixboy]

It depends on what fuel your running and power goals for the planned 25.

Either way if you get gtr injectors and need bigger later you can always sell them as there are always people wanting them. Just make sure you get them cleaned first .

I would go for some 600cc injectors if there not to expensive compared to GTR injectors, they should be big enough even on E85.

[muvro]

Thanks for the replies guys, much appreciated!

We don't have a specific hp goal. It's more just put the right components together with the right tune (I forgot to add, I'm putting a Vipec ECU into it.) and be happy with what it's got sort of thing. Having said that, I'd be expecting around 330-350rwhp, on around 18psi.

I think I'll grab the 600cc injectors. Would rather get new injectors and know they are right.

Is the injector spacing different between the RB20 and the Rb25? (In reference to the Fuel rail.)

Just wondering if I can mod the mounting of an RB25 aftermarket rail, or I'll just make my own.

Cheers