My boost is so close to where I want it, but I am about .3 pounds over. I am trying to set it at .6 bar which is about 8.7 psi. It is spiking to to .62-.63 bar which is around 9 psi. I have an FD fuel pump, Rtek 1.5, mild street port, stock injectors all around and a full intake/full exhaust with the stock turbo. Can the stock 550's keep up? At what boost level did your 550's max out? Thanks!

 

Did you port your wastgate, if not try porting it, that what i had to do to mine and now its stays at what ever psi i put it at. IMO i would not go any higher then 8-9 psi with stock injector. Just my thoughts.

 

stock injectors can easily provide enough fuel for about 14psi! i had on my s5 a full intake and exhaust plus FMIC and did 295hp a the flywheel at 14psi, no running lean or detonation! stock fuel system is better than many people think! a fuel pump upgrade doesn't make any sense as long as you run stock injectors, 'cause fuel pressure can easily be kept at level with the flow rate of the stockers!

regs

 

i wouldnt run over 9 on stock system you are looking at the great possibility of leaks....

 

http://rx7.com/cgi-local/2ndgencalc.cgi

At 93% duty cycle, which isn't good to do....you can pull off close to 300 flywheel HP, but it's extremely dangerous...one thing goes wrong, boom.

I'd stay under 10 psi on 550's....but with your streetport, man, I'd throw an rtek 1.7 and some 720's in the secondaries....then you'd have a pretty decent setup.

 

I ran 10psi with a pump, full intake and exhaust, and the stock top mount on the street and strip every day with no problem. 10 is the highest I'd go though.
The rTEK and 720s as suggested is an excellent basic setup and definatly lessens the risk of detonating.


Leaks over 9 on a stock system? What the hell are you taking about? Boost shouldnt leak period! Its the extra boost with no extra fuel thats the problem.

 

I was trying to avoid pulling the upper intake manifold off again because I just had all of the stock 550's cleaned and installed. I think I will suck it up and buy some 720's and upgrade my 1.5 to a 1.7. Even though there will be some extra cost and down time I think it will be worth it. Thanks for your input!

 

I have the rtek 2.0, hybrid T04, Walboro, and 550's. I am seeing good AFR's up to 9.5-10psi. Then I am going a bit lean, but does not appear to unsafe. However, I did use the RTEK to add 4% fuel at 9-10psi above 4500rpm. That lowerd the AFR's to around 12.5, but I feel I am at the limit of the stock injectors.

 

im running 11 psi on stock 550's, running damn well without problems and its been like like that for a little more than a year and it runs like a champ.

 

many people think that the stock injectors are good till 10 psi but i don't think so, i think they can go a little higher, my friend on hi 88TII was ruunning 14 psi on sotck 550's and he used the car everyday, he run like that for a long time and nothing happened, he eventually change the injectors when he did street port, bigger turbo etc.

 

im not talking about boost im talking about fuel...most of our cars are getting up there in the years and some of these fuel lines cant take all of that pressure...like
jkimbro said one thing goes wrong and you now have a serious problem

 

Well...I see what your saying but my theory is if your gonna upgrade the first thing you should upgrade is everything already there. What I mean by that is all the vaccuum lines, fuel lines, oil injecter lines, etc should be gone through before you start trying to add more boost and all these other performance parts on the market. Because you are right, these cars are old now, especially by today's standards.