What's up 7 ups? Need your opinion on what I should go with for my secondaries. I've got the whole apexi set up. fmic, intake, dp, mp, dual n1, pfc, cosmo fp. All I need now is to work on the rest of my fuel system. Oh, I'm still running stock twins on sequential.

Just to let you know I love getting BOOSTED. Anyways let me know what your experiences are on either one. I noticed there's was big price difference on both. Why is the 1600cc less than the 1300cc? thanks...

see ya,

car 53

 

The 1300cc injectors should be more then enough for your stock twins, they are enough for a small single turbo. If you get the 1600cc injector then you will also have to change your fuel rail. I suggest the 1300cc.

 

Also keep in mind that the Power FC does not natively have support for greater then 1300cc. People have gotten around this by wiring in a resistor, check the Power FC forum here and search combination of 'resistor', 'secondaries' or anything else you might think of tobring it up.

Don't quote me on this, but I think I read somewhere that one of the Apexi Power Excel shops can go deeper into the programming and let you put in 1600cc secondaries. Again, please search '1600cc', etc.

This is just speculation on my part, but it's also a large jump from the 550cc primaries (should you keep them this size) to the 1600cc secondaries, and may affect drivability to a small degree. If you truly have extreme hp needs like Ari and Steve Kan, upgrading both pri and sec is a good idea, if not mandatory.

www.maxcooper.com has a nifty thing where you can calculate the sizes you need for a given hp range. I've got 1300cc secs (550cc pri) and is enough to support my Apexi single turbo.

 

the resistor is to match the impedence( stock or mod 1300cc -high impedence 1600cc- low impedence with resistor) be carefull or you will screw your ECU . 1300 cc are easy to install .Use math to find what you must have to run power level wonted

 

1300cc's it will be, but I was wondering about 850cc's in the primary's? I know that I will get a rough idle, but what about 850cc's all around?


see ya,

car 53

 

That whole 850cc primary idling rough is a bunch of crap. It' s all about tuning them right. I have seen T-67's and T-04E's use them in the primary's with no idling problems whatsoever. I myself have 850cc X 4 and my idle hasn't changed since I put them in. They work just fine for the stock twins. I have about 79% to 85% injector duty running appx 1.0 kilos boost.

 

Go with the 1300cc for your secondariness. As for 850cc for your primary injectors, it's definitely an overkill.

 

...now two more things and that should be it. Would guys recommend modding the 850's to 1300's or just buy brand new 1300's? Who would you refer me to?


see ya,

car 53

 

I am going to test out the 850's all around and I'll let you know how it feels. By the way what set up do you have and what's the power band like? thanks.


see ya,

car 53

 

I think "Brand New" 1300s are still just bored out 850s. I don't think anyone makes brand new13s.

 

Srmotorsports say that they have some in stock!!??


see ya,

car 53

 

I did a ton of research on this subject cause I just did this. I found out basically exactly what you said. Plus the PFC will only support the 1300cc. I would say go with those.

 

Ok, yea, I checked that out & saw it. Never heard of brand new factory Mazda 1300 injectors tho. Has anyone?

 

I say 1600 cc injectors all the way. They are cheaper and for the cost of less than a dollar in resistors you can hook it up to your stand alone EMS. All you have to do is tune appropriately.

Only downside is that you would need a new fuel rail or have to mdify your current one. Which is really not a big deal.

But if you are going to replace your injectors might as well get the big ones now incase you decide to upgrade later.

 

I would really like to know about this question. Makes me wonder what I'm being sold or told about remans and new items.


see ya,

car 53

 

My lord, you asked me what my setup is...okay here we go...

Non-sequential turbo's, Intake, full exhaust(fp, mp, catback), HKS twinpower and NGK 9's, Power FC w/commander and datalogit, 850cc X 4, ND fuel pump, Feed FMIC, and any other remaining things that can possibly go on.

I think it would have been easier if I said I DON'T have a diff, because everything else I have

My car pulls and pulls and pulls...I shift at about 9000 rpm's in 1st gear, and then after I shift at redline.


With the 850cc primary's, do a search for the proper settings. I'll have to look again to see what they are. Also, you can't just put them in and expect to run. You'll have to shave appx. 2 mm off of the top of the injector seat to have them seal properly.

either way, bigger is better...if you don't go bigger...well, you've got the fuel to go bigger JUST IN CASE!!!

 

1300 cc injectors are 850cc injectors bored out to flow 1300cc's...don't come as 850cc initially

 

I appreciate the info. I'll keep you posted on how things go.


see ya,

car 53

 

LOL... just re-read my post and thought it was funny that no one found my mistake...

the post is supposed to read, "1300 cc injectors are 850cc injectors bored out to flow 1300cc's...1300's come as 850cc initially

 

1300
------
1300s are enlarged 850s. You can use them in the stock fuel rail and you don't need any resistors to change the impedence. You can set the injector size up to 1500 cc/min with the PowerFC Commander, so you will be fine there.

1600
------
"1600"s are Bosch 160 lbs/hr top-feed low-impedence injectors. Chrysler and Ford also has part numbers for them, but I think they are all made by Bosch. 160 lbs/hr actually converts to about 1680 cc/min, but it would be a good idea to get them flow tested before installing to really be sure about the flow rate. You need to know the exact ratio of primary to secondary to get the transition right, so it would be good to measure the flow rate to be sure. You'll also need the FC-datalogit or a PowerExcel (PowerXL? I don't remember how to spell the name) to setup the PowerFC correctly. I think you can also play some tricks on the PowerFC to get the ratio right (search for my posts with the keyword "1600" for my guess as to how and why this might be possible -- but remember it is just a guess). Its better just to set it properly, though.

You'll also need a different fuel rail (and possibly a fuel pressure regulator unless the new rail accepts the stock FPR). The fuel rail will not be compatible with the Air Control Valve, so you'll have to remove that and use a block-off plate.

You'll also need some resistors to increase the impedence so you don't burn out the injector driver in the PowerFC. Low impedence injectors are usually mated to an ECU with a "peak-hold" injector driver section that gives a current spike to open the injector and then drops the current while it holds the injector open. If the PowerFC is like the stock ECU, it has a "saturated" injector driver that uses a lower current, constant injector pulse signal. Using a low impedence injector with a "saturated" driver might burn out the injector driver or the injector itself. That is, unless you add a resistor in series to raise the impedence of the injector.


But, if you need "1600"s, it should all be worth it (but you don't need them with stock turbos). You can use fuel pressure to change the flow rate, too. My fuel calcs page may help you determine what you need:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

-Max

 

already looking at your site for advice and direction.


see ya,

car 53