im rebuilding my motor and going single turbo. i have almost everything now. i plan to run around 400 whp with as low boost as possible. (very good rotary tuner in my area) im doing this with no porting. would 850cc primary and 1000cc secondary be to much? im just gonna use the stock 850cc secondarys and make them the primarys. would i need more? i wouldnt think so. also, i have a walbro 255lph fuel pump. anyone think a fuel pressure reg. is needed? any tips would help. thanks

If you have an access to a "very good rotary tuner", I would ask him as he might have a preference as which injectors and such.... Otherwise, there are going to be several people saying different things..

id run 850/1300 cause then you get to keep the stock rails and such.

And if you are leary about boring out 850's to 1300 you can run 850x4 and should have enough fuel to get close to your goal.

well, i whent with the 850/1000. seems like i good idea. i hope...

Is somebody drilling out a set of secondaries to get 1000? In thatcase why not just go with 1200 or 1300?

what do you mean?



"Is somebody drilling out a set of secondaries to get 1000?"

I may be wrong but i think he ment, That if he was sending them out to be bored out to a larger than 850cc, why just do 1000cc why not go to 1200cc while you are there so you will have more room for improvement later on without hurting the injectors life.? at least thats how i took it i may be wrong tho...

Seems like you don't know much about FD injectors...



Like I said.. Go talk to your "very good rotary tuner" and get his advice..

Ultimately, he'll be tuning your car and he might recommend a set up that he likes to tune more than something you put together.. example, he might prefer you get upgraded rail to fit top fed 1600s with aftermarket fuel pressure regulator vs bored 1300s on stock rail.. Or he might recommend not shoot for 400RWHP?? Who knows.. but if you say your tuner is VERY GOOD! you need to ask him vs. US!

Im no expert in these the rotarys yet but im trying and I think Herb is totally correct, you prob should be talking to him and see what will be best for him and you for your goals. Ive built other cars before just this is my first rx-7 and i know my local tuner is picky on things he likes to use so im sure most other tuners are the same way.

by my understanding.. bored out injectors aren't as stable and accurate as manufactured injectors.. Especially when its 50% or bigger bore.



Maybe someone could enlighten us and tell me what RC bores out?



Here are some diagrams of top fed inj.. which the principle is the same..

http://static.howstuffworks.com/gif/...on-diagram.gif

http://www.pprep.com/fuel_i11.jpg

FYI:... Before someone ask or when you are looking for upgraded top fed..



1. All 550 and 850 cc FD injectors are Side Fed, HIGH IMPEDANCE injectors..

2. NO you can't use Top fed injectors with stock rail

3. No you can use low impedance injectors with PFC without modification

4. Make sure to change the setting when using different size injectors with PFC..



Thats all I can think of right now..

Thats why I run 4x850. I dont know how big of a deal it is but I have heard htat bored out injector spray pattern isnt as accurate. Even if you get the flow rate correct I would think the spray pattern is just as important. Personally I would go with top feed 1600 injectors and upgraded rail before boring out a set of 850's.

im not boring out injectors. i just planned on buying two injectors. i dont wanna go to big...like 1600cc. im just wondering if 1000cc would be enough?

Tom,



I'm not sure about spray pattern. I know the diffuser in the engine helps out some with diffusing the fuel.. I'll be running 1200s on my engine with 850s.. Just to try it.. then I have 1600s and a rail after that.

I modified my secondaries through RC to 1300, and just cleaned and flowed the primaries at 550.Went with Supra Turbo fuel pump,and adjustable ECU. Added a set of BNR stage 2 turbos and too much other stuff to talk about.That set up worked great for me. Docile around town but when you spooled it up it was an animal.Raced my cars all kinds of ways and lost only once to a Porshe Turbo 911.Even beat more than 6 Vipers to many to count Corvettes and finally just got tired Mustangs.As I'm sure most of you know, fuel, and lots of it, keeps your engine together. High boost and lean conditions are sure seal death.By the way, I've got lots of parts for sale.

One of my 1300 secondary injectors packed up at high revs (it happened to a few UK FD's) and resulted in an engine rebuild. Car was only running 300rwhp at the time.



By tuner suggested that I kept the stock primary injectors and went for 1600 secondary injectors.



Chris

do bosch 1600cc ionjectors fit witout any mods to the secondary rail?

Just curious.. Are you even reading this thread??



Go read post #9 that I've posted... And once again, if you state that you have a very good tuner, ask him.



Also, do some research about the injectors here and rx7club.. Its very clear just by reading this thread that 1600 will not work!!!! I've stated this already!



Geez!