Im going to be getting my car dyno tuned soon and i want to up the boost a little. My mods are in my sig, what else will i need for my car to handle more boost? Does the apexi power fc have a boost controller on it? Or do you have to buy something separate to change the boost? Thx- Eric

 

How much is "a little" boost? As far as boost control, you can buy the add-on for the power fc (though I've heard they're not that great) or you can buy an electronic boost controller such as a greddy profec or any other sort of controller. You might want to consider a higher flowing fuel pump like a walbro or supra pump. If you want to go past 14lbs., you'll need bigger injectors, the pump for sure, and a 3 bar map sensor as any higher and the stock one can't "see" anymore. I know I'm forgetting something, but I can't think of what at just this second.

 

You'll need the boost solenoid for the PFC. Also, please don't go past 15 psi unless you have AI or race gas (legit or ghetto toulene). Look at this poor guy's seals at 18 psi. Might have been bad tuning, but could very well be poor knock resistance of regular gas.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/post-mortem-665092/

 

I was thinking around 12psi.. i wanna be around 300whp hopefully i can achieve that around 12-14psi.. I was thinking about the greddy profec B spec 2.. and i have a walbro fuel pump.. should i get a complete fuel system upgrade or just bigger injectors?

 

Im glad you posted this since this topic has never been covered before.

 

don't mention it... seriously..

 

Ok so im purchasing an Apexi AVCR Boost Controller tomorrow. Ive done some searching and didnt find really what i was looking for. What size injectors should i get and will that all i need to up the boost safely? No more then 14psi.

 

Just get some 1300cc injectors. You won't need to buy a new fuel rail and it will be more than enough for just 14psi.

 

I believe you are gonna need upgraded injectors past 12psi.....

 

the power fc can control boost for you. although people say ebc's offer quicker boost response than the control the pfc offers. if you get the add on boost control kit, its basically the avc-r without the display.

 

the popular mod to do for the powerfc to regulate boost efficiently is to get the avcr boost solenoid and use it with the Powerfc. look it up. I think some of the powerfc guys on the forum are doing this, if I'm not mistaken.

 

1300cc injectors are pretty expensive.. would i be ok with any other size injectors and do i need primaries and secondaries? I searched a good amount but didnt find exactly what i was looking for.. I know absolutely nothing about injectors :-\ im a noob. sorry.

 

If you are getting tuned soon and you only want 12-13 psi, I say leave the fuel system alone. And you need to work on searching...."fuel upgrade" should turn up a LOT of hits....

 

I can tell you my previous FD was tuned for 12 psi, and injector duty cycle was just over 90% at WOT at redline. I think I recall seeing 94% or that area. That was with and intake and downpipe, no other flow mods. I'd say you need bigger injectors for anything higher than 12psi.

 

So would you say that 1000cc or 1600cc injectors would get the job done?

 

I tried searching that but didn't really get what i was looking for. Me being a noob when it comes to cars i can search but it either doesn't make sense to me or its not what i need. Bottom line i just need some1 who knows what there talking about to tell me what size injectors i need that i can get for the best price that will go well with my setup.

 

efranklin,

Read the conversation in the following thread:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/what-situation-do-you-have-259912/

 

Thx.. ill read over it while im at work hopefully it will help me.

 

Fuel pressure under these conditions? Had you rewired the pump?

 

I suggested 1300cc injectors because they'd be a direct drop-in and would more than cover you incase you wanted to go up to 14-15psi which is the absolute max on stock twins. Any injectors higher than that, like 1600's, and you have to buy a new secondary fuel rail. I don't suggest upgrading the primaries only, but for 12-13psi you could go with just 850's all around and be fine, however it seems to cause problems with your idle when you do, so stick with 550's there.

 

Hrmmm.. what i got out of that is that i really dont need to upgrade my injectors.. even if my inj duty is bad.. aslong as i keep an eye on my a/f.. didnt really tell me what kind i should get if i were to upgrade.. but honestly how much HP difference will there be between 12psi or 14psi? (assuming that i can run 12psi safer then 14psi.)

 

If the 1300ccs weren't so expensive (330 a piece) i would definitely go with that. So your saying 850s all the way around will cause idle problems.. but are 550s stock? Or did u mean get 2 850's and 2 550's...?

 

^^ i take back the 330 a piece comment.. on rx7store they are 330 a pair..

 

Stock,550cc are primary and 850cc are secondary..They are saying that you can upgrade the primaries to 850cc as well and run 4 850cc's,but that it will cause idle problems as opposed to just upgrading your secondaries to 1300cc..

 

You have to pay to play...whining about it isn't going to do any good!

The only other option is to run 1600cc injectors, which will also require an aftermarket fuel rail and fuel pressure regulator. And most likely a FP gauge.