chrome

*edited





[Edited by chrome - 7/22/2003 7:12:41 PM]

Pavlo

After finding used injectors for sensible money, they have all run out (ie I bought them all).

So now the prices are so high that new injectors are not much more if you know where to look and what to look for.

First of all lets start with some details of what's available. All the injectors referred to here are high impedance and side feed, that is common to all the phase 1 and 2 injectors up to 2000 cars. Bugeye cars have high impedance top feed injectors, 440cc on the WRX and 565cc on the Sti.

So some pictures of what I supplied.

This first one is a 550cc/min injector. This is the same as sold by Blitz, AVO and Power Enterprise, and it doesn't fit into Subaru fuel rails without assistance. I'll refer to this as the Blitz 550 from now on.


Next is a Sard badged 550 injector, it's from the same family as the above injector, but has a different, aluminium pintle cap.


Next is an 850 injector, again from the same family, but slightly shorter in overal length, body diameter the same though. This is sold by Blitz, AVO and numerous others.


Next is a genuine JECS injector, these come in various colours, I think the SR20 Nissan ones are red like this and 400cc or so, Yellow subaru ones are yellow and 440cc, plus there are 550 and 740s also, one red, one yellow I can't remember which way round.
This is the format of the standard Phase 2 injector, the uprated ones are sold with Nismo and Tomei brand names.


Next up is the Blitz injector fitted with the adaptors I had made to fit it to a Phase 1 subaru fuel rail. The diameter of the upper portion of the rail is the same as phase 2, but the bottom is larger, hence an additional adaptor.



The 850cc injector can be adapted in a similar way, with the exception that the top Alumnium collar is not as high due to the reduced body length of the injector.

Next is the same injector fitted to a phase 2 rail, the normal Subaru injector is on the left.


Now the buyers guide.

You can buy Nismo/Tomei 550 and 740 injectors from Phase2Motortrend, weblink: http://www.phase2motortrend.com/fuelsystem.html

The Blitz page has part number of injectors and fitting kits. Phase 2 rails are same as SR20DET. Weblink: http://www.blitz-na.com/Blitz_Injectors.htm

Tomei 550/740 from J-spec in the US, weblink: http://www.jspec.com/tomei740cc.html

Blitz/Greddy 550 and 850 from Digital Racer, weblink: http://www.digitalracer.com/catalog/...ist.asp?cid=80


If you want 850s but don't see a kit for the SR20 rails available, let me know and I can sort you out. Likewise I can supply the collars and o-rings for the 550s and 850s to fit phase 1 rails.

Hope this helps

paul


fixed pics

[Edited by Pavlo - 2/25/2003 10:53:51 PM]

Claudius

Very helpful indeed

I think you mentioned O-rings being very inexpensive; where can you buy those?

Phase 1 and phase 2 rails, from when to when (MYs) are they used in EJ20s?

john banks

http://www.phase2motortrend.com/tom74sr20det.html

Thanks Paul. So the above 740s would fit straight into my Phase II fuel rails, or do I need their or your O-ring kit?

Pavlo

More info to come.

Phase 1 was 93 to 98, phase 2 is 99 to 00, bug eye is also phase 2, but with further changes, not covered above except at the start.

You can also get injectors from AVO in australia direct weblink: http://210.15.220.239/flash/subaru/wrx_pi.html

The price given to me for 850 injectors was $1600 austrlian dollars.

I'll do a summary of o-rings to when I have gathered the info.

Edited to add: The SR20DET fitment is exactly the same as subaru phase 2. So the Tomei/nismo injectors will fit straight in, no o-rings or adaptors necessary. Anyone buying 550s from someone that I supplied can get some of the extra things for phase 1 rails from me, cost £30 delivered to the UK.

Paul

[Edited by Pavlo - 2/25/2003 11:19:11 PM]

Claudius

What do I need to do to fit 740s in a phase one rail then?

Pavlo

Something very similar to what I used with the blitz style injector. Infact I think you might get away with using the very part with a different o-ring on the injector. Otherwise I will look at getting some made if there is enough interest. Alternatively publish a drawing so anyone with access to a lathe or friendly machine shop can get their own done.

looks like this picture, it goes over the o-ring on the small end of the injector, and fits into the fuel rail with an o-ring on the outside just below the shoulder.


Paul

BoxerFlat4

Paul -

You say the AVO injectors don't fit without "assistance" : could you describe what assistance is required, for a Phase 1 & 2 engine please.

Many thanks.

BoxerFlat4

I assume, having re-read your post, that the adaptor collar is required : correct ? I ask, because AVO claim the injector fits as is, and I was after some clarification.

Tone Loc

iTrader: (1)

Brilliant info Paul .

Tony.

Pavlo

Paul,

The AVO injectors come with all the parts required to fit them, it's just that they are of the same format as the Blitz and so on.

There are some caveats with phase 1 fitment and the retainers, AVO suply new machined retainers. Also the plug polarisation lugs are the wrong way round, I cut them off, and have had no problems (ie not a production line environment).

Paul

jameswrx

iTrader: (4)

Paul, wheres a good place to sorce info on injector sizing?

Been reading about them by accident when trying to learn more about map sensors. And got a bit interested.

What I am trying to work out is sizing for power wanted, just trying to learn a bit, but how does this sound...bare with me...

440cc injectors are good for 271 hp @ 77% duty cycle 352 hp @100% duty cycle??? I say 77% though because isn't this maximum real efficiency of injector?

I read a basic rule of thumb

injector flow rate per min divided by 5 multiplied by number of injectors to be used in the engine

as above: 440 / 5 = 88 x 4 = 352 (100% flow i presume?), and working on what i've heard people mention on here about 77% duty cycle, 352 / 100 x 77 = 271.04 hp

basically cc's per min didn't mean anything but am I a million miles away with presuming a four 440cc injectors are happy to flow for 271hp unstrained?

working on this theory 740cc injectors circa 450hp?

James

john banks

I am happy to go to 85% on IDC, a lot go higher without issues. Apparently they can stick mid position with obvious consequences. People seem less scared to have a quick peak into the 90s at high revs.

Raising fuel pressure from the std 3 bar differential to 4 bar results in about 15% extra flow. (sqrt 4/3)

FPRs are available in 1:1 to do this.

Alternatively 1.7:1 adjustable rising rate could give at 1.5 bar with a base pressure of 3.5 bar a 6.05 bar absolute so a differential pressure of 4.55 bar, which would give a (sqrt 4.55/3) 23% increase in flow over standard, so 550s could behave like 677cc. This is my initial plan for my 450 BHP 2.33 litre engine. Should do what I need at 91% IDC. You could get about 360 BHP out of 440s with a similar method at 91% IDC I reckon. Hope I've not got any sums wrong LOL.

If I need 1.7 bar for my 450 BHP, then I would run a lower base pressure. Don't really want absolute fuel pressure over 6 bar

Sensible base pressure will keep the idle good on the JECS.

Wonder if the Walbro will support this? Think it should...

[Edited by john banks - 2/26/2003 10:25:28 PM]

jameswrx

iTrader: (4)

lol..my sums need some work i'm getting circa 330hp based on 440's with your 23% increase in flow and 91% duty cycle using my sum.

...swims back to the shallow end

john banks

440 * 4 / 5.5 * 0.91 * 1.23 = 358 BHP

Tone Loc

iTrader: (1)

John.... have i read it correctly that your going for a rising rate FPR? I thought these were difficult to map with?

Tony.

john banks

I don't think it will be a problem. Just use a wideband, flat boost profile would make it even easier.

Pavlo

I'm not a fan with the jecs because you can get to a portion of the map with 2 different circumstances, each with different boost levels altering the effective fuel pressure.

But if you're mainly intersted in WOT and high boost performance, then I think it would be a huge problem. Especially if the rate rise wasn't massively high. Andy's 1.3:1 measured rising rate isn't a problem for instance.

paul

Danson

HELP!!!!!!!

I have a question
i am look for injectors 550cc for a MY98

where can a buy than

sorry my engels is not verry good


-Danny

john banks

Paul I have been thinking through the two circumstances to hit the same zone thought. I think this will happen on transients primarily since on constant throttle (even part throttle) there will be a correlation between MAF and TPS and the intermediate zones can be mapped to suit by wideband logging. In practice I wonder whether there will not really be an issue... the acceleration enrichment (non adjustable on 99/00 JECS) being beefier because of the bigger injectors will counteract the relatively lower fuel pressure in this zone than when on constant part throttle. Agreed not by design, but as a compromise seems preferable to making a lean base fuel map to stop it going too rich with a heavy handed cold start enrichment from 740+ injectors? People have done a lot worse, and it will be interesting to see what we can get out of the earlier factory ECU. Would be nice to be able to double the factory output and keep it. Will need some work of course.

john banks

Ordered the 740s. Will use a lower limit on the coolant temperature signal to cope.

EMS

John,

I have 660cc in my car and at low injector opening times they don´t give that much more fuel than the std. 440cc. Cold start is absolutely no issue! I corrected the fueling over changing the MAF scaling and decreasing the load scaling of the fuel and ignition maps. (and of course changing of the fuel map itself) One advantage is that I only reach about 35 as load value (at 1.4 bar boost) so no maxing out of the JECS load!

Idling is a little more jerky, because of the closed loop lambda correction. The small changes in injector opening time while in closed loop, give a bit more change in fueling so the car idles a little more rough. It´s not to bad in my opinion! (I don´t know for 750 cc injectors though) I don´t know what power you are after, but it has to be massive to need more than 660cc injectors! (660cc should be enough for + 500 BHP)

Mark.

Pavlo

Nice work John, I hope the links were useful.

Rescaling the MAF calibration seems like a good idea to me, combined with either a larger maf tube or bypass.

Paul

john banks

Based on 5.5cc/BHP 740s at 3 bar differential should be good for 538 BHP, at 85% IDC 457 BHP, 450 is my present target but I want to be future proof. Presently running 550s to 100% at standard fuel pressure, the idle has already suffered (until I got rid of the lambda sensor ) However, the cold start is snappy. Bob said 740s were a bit of a nightmare on 2.0 for cold starting because there was far too much enrichment. But it will be a 2.33. I'll only do the coolant temp sensor trick if I have to. If 660s are OK on 2.0, 740s should be on 2.33.

Pavlo

hmmmm, 850s.

Paul

David_Wallis

trouts runs fine and idles fine on 740's..

David

john banks

Trout doesn't use JECS. The only issue is non-adjustable coolant temperature compensation - it chokes with fuel at cold start up apparently.

David_Wallis

ahh.. I see what you meant now..

David

Wallace_Performance

Paul,

From what I can gather in your post, you can fit the up-rated Tomei (JECS) injectors to a phase 1 rail with your adaptors. Is this correct?

If so, how much for the adaptors?.

I'd appreciate a prompt reply as I'm getting desperate for some!

Why aren't these as easy as vauxhall LET's!

Gavin

Michael Robinson

I have a 1995 WRX, what injectors are in my car currently ? and is it worth upgrading them and too what ?