I read somewhere that you need to mod the primary fuel rails to fit 850cc secondary injectors in? I just got a set out and they appear to drop straight in other than the tip sits slightly further up inside the body?
Can someone confirm if need to make a mod I haven\'t spotted or if what I read was a load of rubbish!? or I mis-read it of course!
Thank you
Lee
you will hear conflicting stories, the mod is to machine 2-3 mm (definitely no more than 3) off the top of the holder so the injectors sit lower, if you do too much the injector wont seal inside. Its easy to do but i know of people who just put them in without the mod and say they work fine, i did the mod and they ran just like stock ones. If you imagine the injector spray pattern, if it sprays higher up inside the holder the fuel will hit the inside of the holder and not be in a nice mist when it goes into the engine.
HTH
So it was what noticed about the injector sitting further up inside the body! I don\'t know what the mist pattern is like so how much the housing would actually mess up the spray I don\'t know? Surely machining the top down to make the injector drop lower means you might start to obscure the fuel coming in or blow it up past the top seal instead of throguh the injector? would want to measure up very carefully before doing anything like that.. If it works fine without then there seems no sense in messing about with them. plus if I ever want to swap back at a later date and just wap in some huge secondaries I don\'t need to hunt around for a new injecor holder!
Is it not possible to take 2mm off the other end that goes into the engine or maybe taper the opening further inside?
Some more views would be nice. but thank you for yours..
Cheers
Lee
I\'ve looked into this myself as its somthing i want to do shortly, (Dont have the milling tools sadly :( ) The yanks bless em have mentioned that they put an extra O ring onto the injector if they dont modify the rail as there have been instances of it not sealing and spreying fuel out into the engine bay!
Mine\'s just away at Super 7 having this done as we speak. I know Jason said he had to make some modification to the fuel rail to make it work, he was going to make one up before I dropped the car off and then just swap them over to save time. Not sure exactly what the modification was though, soz. Not being much help am I? I was going to visit the car today if I get time, I\'ll ask him
Strange. I turned a bush and swapped the o-ring over to a different size and they have been fine. Although the Fuel rail is my own design too :Giggle
Shaun
i have heard that there is a chance they will leak without the rail being thinned, and you don\'t want any change really, however small!
Well, that didn\'t work out so well! Went to visit the car, but she was away on the dyno, so didn\'t get a chance to ask about the technique J used on mine :Hammer! Early results from the dyno cell indicate that it bloody works, though, whatever it is! :eek:
hi we have a couple of injector bodys machined and ready to fit 850\'s if your keen give kayleigh a call she will sort you out
thanks dwayne
Quote from: Silverstone Autosport;611586hi we have a couple of injector bodys machined and ready to fit 850\'s if your keen give kayleigh a call she will sort you out
thanks dwayne
can you get a good safe map on 4 x 850\'s with a single ?
Are you guys talking about bored out side feeds or siemen top feeds with a custom rail ??
Shaun
stock 850 side feeds iirc
Stock 850\'s is correct..
I spoke to reworx and that\'s all they said I need for my requirements.
Dwayne - I have a spare rail and access to a mill so was planning to DIY the job.. unless you want to do a dirt cheap exchange on your machined rail i\'ll do that once I confirm what I need to do!
can you say if it is just 2mm machined off the top face? What\'s your number in case I change my mind anyway!
Cheers
Lee
what tubby size are you going for lee ?
what if you remove the black spacer between the iron and the prim fuel rail piece?
or replace the spacer with a thinner one?
Speedworks. I am not sure what you mean on that. I\'ll look at the injector rail later but I think if it needs doing it has to be a machine job..
Slingo - it\'s a surprise! Not your normal choice of turbo. put it that way!
I\'ll post up some pics just as soon as I get a little further on.
Lee
hollset it is then ?
Pip told me not to do this as it really messes up the idle and is hard to map properley
Not to do what Robbie?
Slingo I am not saying! Have you been reading some of my old posts by any chance!?
Not to fit 850\'s in the primary slot
Quote from: leeroy_25;611903Not to do what Robbie?
Slingo I am not saying! Have you been reading some of my old posts by any chance!?
ha ha na dude its just where im going next :) im trying to find a link on rx7club about using 850 pri\'s ! bear with :(
Post away Slingo..
If you have read my old posts. search holset rx7 or Holset RB30 and you will find some good reading.. I can possibly offer a bit of assistance size wise and where to pick one up cheap! I expect you\'ll have read a lot anyway if you are on rx7club too!
Robbie.. I am jut going by what I was advised would be fine?! I was thinking of plumbing in another secondary fuel rail but was told no need!
I have 4x 850 injectors with no idle issues etc.
My thread form a while ago on RX7club.com
http://www.rx7club.com/showthread.php?t=806494&highlight=850
Should tell you everything you need
I have 850\'s all round in my car. What I was told it that they are hard to get a smooth idle with unless you run them fairly rich. Stands to reason that a larger capacity injector will have issues when trying to run at very low flow/duty requirements. Suffice to say, they are fine when higher flow rates are needed and the only real issue I have is my emissions at idle are rather high.