Upgrading Injectors

[T.D]

Hey, I'm looking to upgrade my injectors in my S2 R33 GTS-t in preparation for my ATR43G2 turbo upgrade.

At the moment, I'm still running stock injectors and want to know what injectors are best suited to my power goals?

I've looked at Nismo items but are abit pricey and I'm leaning towards the Bosch, Siemens and stock S15 injectors.

My power goal is roughly 260-270rwkw, though I do wish to have a little but of headroom with the injectors (that is, I don't want injectors which will be at 100% cycle duty @ 270rwkw).

I'm leaning towards S15 injectors as I read they are drop in items and can be had fairly cheaply

Current mods:

- 3" dump/front pipe

- high flow cat

- blitz sus pod

- blitz turnflow intercooler

- turbosmart e-boost

- 3.5" kakimoto catback

- E-Manage Blue

- 12psi

Current power figure: 195rwkw

Any advice/recommendations would be appreciated.

Cheers.

[paulr33]

if your going to spend the money, i would just do it properly

nismo 550cs and be done with it

you may find stuffing around with s15s a pain

as there are differernt for ADM/JDM manual and auto as well and you have to find 6 as well

go for it if u want

but you may find it simply easier and over all cheaper in the end by going nismo's

bosch and siemens are fine as long as you dont have to mangle plugs, change rails etc

and you can hook them up. afterall, the nismo ones would be made by jecs or bosch anyway

[krzysiu]

I'm running nismo 740cc injectors and on 281rwkw hitting 62% injector duty. 555cc are about 50$ cheaper. Not worth it so just get the bigger ones + leaves room for future mods

[T.D]

No worries at all mate, thanks for the reply. I guess I'll forget about the S15 injectors then.

What sort of cc injectors will I need? I found a general rule of thumb was 1cc per hp so my power figure requires 400cc as a minimum. Is that correct?

What size are standard purple top RB25det injectors?

Cheers.

[T.D]

Would I run into issues with using overly large injectors for my application? I don't plan on going over 290rwkw, and even if I did, it would be WAYYYY into the future lol

[krzysiu]

Nuh man. Been running the 740s for over a year now. No dramas at all.

[T.D]

Alright then, that's good to hear. The only thing now is seeing if my Emanage will support 740cc injectors, which is why I need to know the stock injector size. It's around 370cc is that correct?

Also, series 2 RB25det use side feed injectors yeah? Are top feed injectors able to be used?

[JonnoHR31]

stocker injectors are 370cc and .63ms latency

top feed needs new rail and front facing plenum, not worth the hassle for a mild upgrade. the nismos, whilst expensive, are by far the best option

[T.D]

Thanks for the info Johnny. Kind of slightly off-topic, but I have a Greddy Informeter that measures injector duty in "ms". Is that the latency you're talking about? The .63, is that the maximum value?

[JonnoHR31]

no. latency is the dead time, the time which an injector has power but isnt spraying any fuel. (the time it takes to open and then close again). different injectors have different latencys, so when changing injectors the tune needs to be adjusted not only for the bigger size but also the different latency, especially under light load around idle.

[T.D]

Ahhh I see, cheers for that