13b mazda rx7 injectors.

[czy18e]

I've been told that these injectors are rated at 550cc and will fit an rb25det.

Is this true?

Cos i can get them real cheap.(but i dont want them if you guys reckon there crap)

What sort of power will 550cc injectors max out at with a good fuel rail and regulator?

If not what sort of injectors are the go.I'm after about 250kw to 265kw at the wheels out of my rb25det.

[Roy]

You will struggle to fit RX7 injectors into an RB25, unless you were very good in kindergarden at fitting square blocks into circle cutouts.

I dont think there is a cheap option for injector upgrades on RB25s other then change the fuel rail, or get some 550cc aftermarket one...for an R33 or R34?

[Skyrine-Dave]

for rb25 you just need a top feed fuel rail, top feed injectors and suitable collars to fit into the head. Mate has done it on an SR20 and is in the process of doing it for my RB25 head.

I would be interested in hearing what sort of power figure 550cc's will max out at. Is 500rwhp out of the question ?

[ylwgtr2]

i remember testing some of these(i assume your talking about turbo ones?)the ones i tested were red in colour...they pumped out 800cc of fuel per minute on 38 psi of fuel pressure

[Skyrine-Dave]

ylwgtr2: They sound like they were 12A injectors.

RX7 13B injectors came in Low impedence (red tops) and high impedence (purple tops) both @ 550cc

[raist60]

You can use an RB20 rail with a couple of slight (5 minute) modifications and two new bolts.

The injectors are probably good for about 340 at the wheels depending on rail pressure.

[MicK51]

The problem with rx7 injectors is there spray pattern (or lack of it). The rotors use a squirt like fuel delivery as opposed to piston cars which require an atomised mist to mix with the O2 properally. We all know how important air/fuel mixture is in a turbo motor and thats why a few tuners up here in brissy will refuse to a tune a piston car with rotor injectors.

[Skyrine-Dave]

hmm being nippon denson, pintle head cap design and identical to a stock rb20 fuel injector how does the spray pattern vary? would it be the duration that they are held open etc. Thats the only thing i can think of for a fuel injector to spray differently if they have the same design.

[MicK51]

well thats what i was told, i'm not sure if it applies to all rotor injectors though. The duration that there open for is controlled by the computer so that shouldn't make any difference.

[raist60]

Spray pattern on the 550's seems pretty good at a decent pressure... (40psi +)

Also depends entirely upon how quick your cycling them. It looks like they atomise like shit on an injector flow tester when cycling slowly. If you up the rate they seem to atomise quite well...

[MonstaS4]

Unsure about R32's, but an R33 uses side feeds. Therefore 13B-REW (series 6 primaries and 20B's) will fit - apperantly. I've tracked down a couple for my RB30DET, just haven't taken delivery yet so i can't confirm. Here is a page with relevent info. Pretty sure S15 SR20's use the same style injector as an R33. http://www.nissansilvia.co.nz/tech/howtous...0Binjectors.htm

[czy18e]

I'm using a sub-zero fuel rail ....

will the 13b injectors do the job for 280kw at the wheels??????

[RBVS]

I'm using a sub-zero fuel rail ....

will the 13b injectors do the job for 280kw at the wheels??????

Is that in a rb25det with stock pistons? just that many people upgraded fuel regs with rb25dets got nice ar ratios but alot of them blew the stock pistons, and theres talk of spray pattern being the cause?

[ylwgtr2]

ylwgtr2: They sound like they were 12A injectors.

RX7 13B injectors came in Low impedence (red tops) and high impedence (purple tops) both @ 550cc

They were RED and they were from a 13BT....original fitment