R34 Injector Upgrade

[vlv00m]

I have just brought myself a GT35R turbo and now wanting big hp.

The problem is that I'm running the stock injectors and want to upgrade them.

Does anyone know what a cheaper injector upgrade would be for a RB25DET NEO.

Looking at about 550 cc Top Feed injectors.

Would the Rx7 injectors fit ?

Would Bosch 363 injectors fit ?

Any other good injectors ?

Thanks

[meggala]

the only injectors that fit are nismo 530cc's from what I have heard

[MonstaS4]

If it uses the same rail as the R33, Series 6 RX7 or 20B cosmo injectors will fit. You need to buy/make some collars to hold them in securely.

[666DAN]

I'm sure Blitz do some 720cc ones for the R34

[vlv00m]

I'm sure the fuel rail is different to the R33.

Do you think that a R33 fuel rail would bolt up to the R34 inlet manifold ?

Does anyone know how much it would cost for a custom fuel rail ?

[666DAN]

R33 Fuel rail will only bolt up if you change your inlet runners...R33 are side feed, R34 are top feed...and vastly different.

[ed]

Would GTR injectors fit? You'd need the resistor pack too though.

[R34GTT]

I'm using 750cc Sieman injectors on my neo rb25. If i remember correctly, the set cost $1100.

[Sydneykid]

R33 Fuel rail will only bolt up if you change your inlet runners...R33 are side feed, R34 are top feed...and vastly different.

Stick with the top feed, half the rpice and heaps more choices. But R34 GTT's have small holes in the inlet manifold to suite those skinny injectors. There are a few more brands making injectors for R34's now, shop around.

[IanH]

RB20DET injectors also fit and go upto 720cc you just need to change the plug (simple soldering job)

[Sydneykid]

RB20DET injectors also fit and go upto 720cc you just need to change the plug (simple soldering job)

Help me out here Ian, this is a picture of the three types of RB injectors. The one on the left is the R34 GTT injector style, the one in the middle is the R33 GTST injector style and the one on the right is the RB20/26 injector style.

Is there a fitting kit you can buy that let's you fit the RB20/26 style of injector into an RB25 Neo? If so what brand, how much and where do you get it?

[IanH]

I'll get you the info ASAP - There's at least 1 GTT I know running 550 RB20 injectors.

[ed]

anyword on this IanH?

[Weq]

I dont know if this helps, but i know u can use RB20/26/RX7 injectors in Honda's with a resister pack. SO if the theory holds tru, u can can run injectors made for our cars. Ppl in the US like RC Engineering / Rodchester / Lucas / Bosch make upto 1000cc++ injectors which cost half the price as ur jap counterparts. We use em all the time with great results.

http://www.camp1320.com/parts/new/fuel.html

Has some low impedance (u need resister pack) to fit, but just google and u'll get plenty of dealers. I got some 4x440cc's for $300AUD.

Just to add, apparently WRX injectors can be made to fit quite easily, and there is a mod to allow double the flow capcity (a factory installed restrictor is removed).

http://forums.nasioc.com/forums/showpost.p...9&postcount=100

I have also heard bad things about RX7 injectors and spray patterns.

just something to think about, maybe a bit outside the square.

[Sydneykid]

I dont know if this helps, but i know u can use RB20/26/RX7 injectors in Honda's with a resister pack. SO if the theory holds tru, u can can run injectors made for our cars. Ppl in the US like RC Engineering / Rodchester / Lucas / Bosch make upto 1000cc++ injectors which cost half the price as ur jap counterparts. We use em all the time with great results.  

http://www.camp1320.com/parts/new/fuel.html

Has some low impedance (u need resister pack) to fit, but just google and u'll get plenty of dealers. I got some 4x440cc's for $300AUD.

Just to add, apparently WRX injectors can be made to fit quite easily, and there is a mod to allow double the flow capcity (a factory installed restrictor is removed).

http://forums.nasioc.com/forums/showpost.p...9&postcount=100

I have also heard bad things about RX7 injectors and spray patterns.  

just something to think about, maybe a bit outside the square.

You are right weq, for RB20/26 there is no Problem with using Rockester, Bosch, Jecs, Nippon Denso etc The top feed standard is readily available. Hondas run the top feed standard so they are interchangeable. But I haven't been able to find any of the large OE injector manufacturers making the skinny R34 GTT (RB25DET NEO) style. So you have to buy the expensive Japanese brand names.

As for RX7 injector spray pattern, I heard that story years ago. So I tested them and they look pretty good to me, sure I have seen better (Bosch Motorsport for one), but I have seen plenty that are worse. Most of it comes from the fact the Series V turbo injectors are getting old now, and you have to buy 8 or 9 to get 6 good ones. But that's nothing unusual for used injectors.

Hope that clarifies

[vlv00m]

I found some prices on direct fit injectors for the RB25 NEO

SARD 540cc injectors = $275 ea

NISMO 540cc injectors = $287 ea

Which is a fair bit.

IanH can you find out about those RB20 injectors on the R34

Thanks