danec020

Hey guys I been doing a lot of research and been seeing that at 12psi you definitely need better secondaries. My question is what psi could I run safely without swaping out the injectors?

I currently have a full RB exhaust, ported wastegate, 3 inch TID, DD Blitz BOV and a Walbro Fuel pump. Right now it is boosting around 8lbs. I have Rtek 2.0 on the way so I can do timing correction and fuel adjustments and increase my injectors duty cycle. I was curious with the Rtek 2.0 if my stock injectors would handle 10psi without too much stress on them?

Anyone with a similar setup?

Thanks in advance.
Dane

13bpower

If they have been balanced and cleaned, yes no problem. Most 20 year old injectors on a T2 would not be up to that task otherwise..... well unless you like to live dangerously.

I am sure many people will say they have without problems, but I wouldn't and when I built my last T2 I didn't push past 8# until I had the Rtek 1.7, injectors, and fuelpump.

Digi7ech

iTrader: (1)

YA for CLEANED INJECTORS!

Yeah like said above. Don't trust 20 year old injectors. They will leak and they will flow less.

I ran 10psi daily on my stock S4 motor for 2 years no problem. I had the Rtek 1.5

It's never recommended to increase small injectors duty cycle to take care of the fuel needs.
It's recommened to get bigger injectors and reduce their duty cycle.

You can get 2 720 injectors off Ebay from TLF or TFL performance for $160 shipped.
Then you could run 12psi all the time and use the rtek 2.0 to smooth out your fuel map.

adrock3217

Why would you want to run the risk? :\

Grab some 720cc's..and get your 550cc primaries cleaned + rebuilt. If you spent $400 on the Rtek..why waste it? Use it to full potential, and grab some 720's. You'll thank yourself later, as whenever you swap to a bigger turbo (needing 720 primaries, and 1000 or 1600 secondaries), you can just swap the 720's into the primary spots.

1SxyRXy

i ran 12psi for almost a year on my S5 TII before i sold it, i didnt even get the AF anywhere near the lean side, so i think your ok on 10 psi maybe even twelve oh yeah i was running a FD fuel pump

bigdv519

iTrader: (3)

Now I don't trust 20 year old injectors either, but if injectors start leaking, how do they flow less. I have had mutiple injector failures over the years, and they always end up flowing more when they are leaking, according to my wideband. I have known a few guys who have had injectors lock on them...in the shut position...and thats a very sad story.

danec020

The injectors have been cleaned and flow charted. The reason I am asking has nothing dealing with cost, its just I don't really want to boost higher than 10 lbs. If I can boost 9 I will keep it at that, but I am pretty sure I will be hitting high 9/10lbs with my setup. I am happy with how it feels right now, and was wondering if it was safe on 10lbs because I didn't see much sense in spending the extra money now on injectors if I wasn't going to be using them to their potential.

If a lot of people agree I should up the injectors I will be doing so, becuase like you mentioned I don't want to risk it. I was reading Rtek and it said it increased the duty cycle by 5% and I was wondering if 10 was maxing them out.

If I did go aftermarket, who has some good S4 High imp injectors? (S4 is high imp right?)

Thanks
Dane

rx7legend

im running 11 psi on my stock injectors and i haven't had any problems at all bro. so i think that your gonna be ok at 10 psi.

Digi7ech

iTrader: (1)

I didn't mean they would leak and flow less. I meant that as two things they do.
I got 6 cleaned and 2 had leaks and a couple flowed less.

Either way. Your not giving thr engine the right amount of fuel.

I say 10psi as a safe limit because you leave yourself a buffer.
Now on my car I have hit 15psi briefly and my engine was ok. For how long it could have done it? I don't know.
Also during winter the naturally cold air made it so I woudl boost in the 11-12psi range even with a ported wastegate.

So running 10psi left me a safety zone. If tuned it to 12psi then it may have creeped to 13/14 and gone pop.

adrock3217

High imp injectors normally cost a crapload. GReddy 720cc's are like $120 each (rx7store.net), and all you need is a 10amp, 10watt resistor inline on the injector wire.

Digi7ech

iTrader: (1)

The TLF performance company has a set of 2 high impedance S4 style 720's up on ebay.
Same price as low impedance.

Not too shabby. I was going to get them but I'm lazy and didn't want to remove the resistor pack I have on my secondaries.

I just bought 2x720's today for $160 shipped to my door from them.
Actually here are the high impedance ones.
http://cgi.ebay.com/ebaymotors/2-Maz...spagenameZWD1V

I assume they are just boring out stocvk injectors. Still a great deal considering these are cleaned and tested as well.