Is it safe for me to push 12psi on 550cc inectors?

 

how many? 16 of them? if so, yes. 2 of them? no. how much fuel pressure? alcohol injection? oh, I know, how about you tell us some basic information about your car like if you have a stock turbo. OR, here's a novel idea, you could search, because I can't imagine anyone has ever wondered this same thing before....

but to humor you, IF you're running a stock TurboII you will need an aftermarket ECU to go above something around 9psi or use a fuel cut defender, and you'll need fuel management one way or another, and no I doubt you'll want to run 12psi on the stock injectors. for the love of Felix please search.

 

Bad idea.

 

Boom. Rebuild.

550cc primaries will max out before the secondaries can come online if you're running 10+ psi on the stock turbo.

A better fuel pump (FD, walbro, etc..), larger secondaries and some means of fuel control are essential.

 

psi aint psi without a temperature to calculate the mass airflow

12 psi on a stock turbo,, providing fuel pump is also OK with that , is fine with 550 x 4 injectors
12 psi on a large highflow , no
12 psi on a small highflow, yes, just



there is about 280 rwhp there on the stock injectors before you run short on duty and lean on AFR
however its prudent you go to at least 1000 secondaries if going highflow to be sure
( as good highflows start at 280 rwhp )
and 1000 secs will leave most standard pumps and wiring gasping if everything isnt up to scratch

hence the prudent move for those contemplating a highflow an in excess of 12 psi to go for the larger secondary injectors AND the walbro or similar pump upgrades ( with relay and support wiring )

overkill,,but no maybes ...the is no second guess

 

The stock TII fuel pump is the weakest link. Beyond ~50 psi/3.5 bar, flow takes a nose-dive: https://www.rx7club.com/showthread.p...ght=stock+pump. Increase boost pressure, increase fuel pressure.

 

Thanks khanArtis and Rocket88 thats all i needed was a simple answer. for the other guy FYI u acting like u know everything and tellin me to do research and **** instead of sheding ur knowledge does help me out at all and makes u seem like a *******. Now i have a bigger turbo den stock and a walbaro fuel pump. Ive done tons of research and found that i need 720cc secondarys and at least a rtek 1.7 and a wideband. I was just asking maybe some body just ran 12psi with the 550s and didnt blow there motor.

 

Hey bump start what you mean by highflow? N Rocket88 how much boost u pushing?

 

"highflow" is a hybrid turbocharger, or a stock turbocharger that has a larger compressor housing and wheel fitted to increase its flow.


Do not exceed 10psi of boost on the stock computer if you want your motor to last.

 

You would have to clarify what exactly this means. There are a million turbo compressor/turbine combinations larger than the stock turbo. Boost pressure means a lot less than the airflow your turbo is capable of. Airflow/HP potential determines what injectors/pump you need. Most everything mentioned so far is geared towards stock turbo setups, since you did not give much info at all to start.

 

Ill try to post a pic of the compressor sat.

 

I am an ******* and proud of it, and for God's sake if you want us 'sheding' our knowledge you ought to type legible posts. 'den' does not equal 'than', 'ur' does not equal "you're", and so forth. Giving information about your vehicle is critical, too, and it should be obvious that the answer could be different if you have a completely stock setup or not, which you've now said you don't. I guarantee people won't be as caustic toward you if you display some effort to this effect.

If you've done tons of research then you should already know the answer for a relatively simple question like this. You're not asking if the heat transfer rate of your front mount intercooler is sufficient to cool the intake charge from 180*F to 100*F with an ambient temp of 90*F, 75% humidity, with x air flow over the intercooler and 800cfm intake flow with 3" inlet and outlet... This is a relatively simple question.

 

The amount of threads lately which could be answered simply by using the search function are getting WAY out of hand. If you guys get to be idiots then we get to be ********.

 

What I don't understand is the fact that a lot of people on here act like elitist ****** when a simple response is all that is needed... Sure he could have used the search function also but cmon if it wasn't for the so called idiots that can't search we wouldn't really have a lot of new posts or topics... If it really bugs you that bad just avoid the post or hey here is an idea don't post at all... We are all here to learn about the cars we love not bash each other because we know something that others don't... flame me all you want I don't really care... It's just this stuff is getting out if hand

 

a simple response was all that was needed, but he didn't give enough details for us to give him the response he needed. to top it all off, he pretty much already knew the answer. I'm glad there is still new interest being generated in FC's, but that and following standards to make everyone's lives easier by providing efficient and correct communication are two separate issues. I can probably thumb through the first 5 pages in this section and find just as many new threads where the OP is essentially asking "what exhaust is best, should I go single or dual?" THAT is bullshit.

in short, I'm tired of being nice just because some new guy doesn't feel like following a standard that makes sense. before I even joined the forum I did hours and hours of searching and reading here. you know what I'd like to see? more people bumping old threads that are very relevant to their questions instead of starting new ones.

 

I agree with some of your points but you also know that they would get flammed for bumping an old thread. Don't get me wrong I do think that new people do not use the search function like they should

 

It looks like you're heading in the right direction, but to give you an exact answer, it would be nice to know what type of turbo you're using. Like said above, we sort of assumed you were running a stock turbo.

 

I disagree that our members are getting out of hand. Speed of Life was harsh but correct. The OP didn't provide nearly enough information for experienced members to help him/her. They still hasn't provided enough information to get reliable and safe advice. Some people have been kind but they are only able to give generalized advice.

The OP should read this new member's thread as a comparison.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/over-my-head-new-rx7-owner-943790/

This guy did his homework, provided ample information, was gracious in asking and came back with pics and dirty hands. Experienced members have been all over helping him.

 

Hey guys I have been running 12 psi on my stock turbo2 with a msd fuel pump, I know it is not safe but was not aware how bad it was on stock 550c injectors, I am also using a chipped ECU so no fuel cut for me

I will upgrade sec injectors to 720c and put a fmic for now on the stock turbo

 

I got you i should have put more info its not like you guys know my setup i also forgot to add I have a fmic installed im just tired of geting fuel cuts so i was planning on uping the boost a little bit while getting rid of the cut. Im gonna post pics of the compressor tomorrow is there any other pics i should post that will help you guys out?

 

Hey you never had to reply either if you wanna put it that way i thought guys on here would be cool with helping a fellow rotary driver out not tryin bash them or tell them they are stupid for asking questions my hole like all i known wa piston motors Rotary is a hole lot different and i love you can see by how many posts on here that im new to the game all i ask for is help if I wanns get bashed i talk to a V8 owner.

 

I didn't call you stupid, but I did indeed write in a way that could make you feel that way. I'm sure you could have been persuaded with fewer needles and I really let fly on you. Jeff is right, I was too harsh and for that I apologize.

About rotaries, they're not that different from piston engines in terms of what they need to operate. Fuel and spark in the correct amounts at the right times, sufficient lubrication and cooling. You ought to do some research on injector duty cycle if you haven't already.

 

What I have a problem is understanding why rotary need such big injectors for only 12psi alot of my friends have turbo cars none of them a rx7 tho. we get the talking bout future plans and i bring up needing 720's to run 12psi safe. They go on saying I don't need those injectors for that little bit of boost. They ask me to explain why they need so much fuel dumped for that and I can't explain the was the main reason for the question. I tell them hey its a rotary u can't compair it to your honda or nissan

 

I'd like to add also, do yourself a favor, and invest in a wideband kit. They can be expensive, but you have to pay to play. Don't go adding fuel mods and boost mods, and just hoping or even taking our word that it will/won't lean out.

Rotaries require a lot more fuel to run (safely) than standard piston engines. Haven't you ever wondered why your 1.3l RX gets worse gas mileage than their larger 4 cylinders?

 

Hell yea lol when i brought the car it was between the 7 and a turbo civic hatch me not knowing n e thing bout rotary was think hey its a 1.3L its gotta be great on gas boy was I wrong lol. Wouldn't take it for the world tho find myself growing more and more into a rotor head everyday. Also I plan on getting a wideband before I start messing with fuel or boost. I know running lean rotarys is asking for kabooms.