max boost?

[04scooby]

can someone please tell me how mush boost I can safely run on the stock fuel injectors while running a evo3 big 16g? I plan on turning the boost down until I can upgrade everything else on my stock 92 GSX.

thanks.

 

[GSTBlack95]

Its hard to say for sure as each car is differnt. You really need a logger to tell how much to run or not.

 

[04scooby]

maybe a good conservative number then until I can get the money for the rest on my toys.

 

[rowlex]

safe? run 12lbs.

 

[92GSXBaltimore]

when i got my b16g, i had a stock fuel system and i couldnt turn the boost past 11psi before i would knock.
with a walboro255 and a afpr i can squeeze a bar without any knock......cant wait for my denso 660's

 

[04scooby]

well I was only panning on boost at a max of 10 PSI so I guess I need to listen for knock and if I have it, turn it down slightly. Cool deal. Thanks.

 

[crazyman633]

I've found you can go up to around 14lbs of boost before you get into fuel cut. To be safe, stay around 12. The turbo stock will hit between 9-11. I have the same turbo, and thats what she did until she got the boost controller.

 

[PieEyedPiper]

well I was only panning on boost at a max of 10 PSI so I guess I need to listen for knock and if I have it, turn it down slightly. Cool deal. Thanks.

listen? I hope you're being symbolic or something with that response. you'll need a logger.

 

[rowlex]

ive never ever audibly "heard" knock. And I have had a lot of it. At best you can feel it pulling timing and the loss of power.

 

[92GSXBaltimore]

I've found you can go up to around 14lbs of boost before you get into fuel cut. To be safe, stay around 12. The turbo stock will hit between 9-11. I have the same turbo, and thats what she did until she got the boost controller.

fuel cut is not what he has to worry about, he doesnt want to hole his pistons

 

[92GSXBaltimore]

and your more likely to "feel" knock with engine hesitation then actually hear it. I've gotten phantom knock from loud ass lifters at low engine speeds that will register like 40 counts and i can hear it inside the car, but when I would floor it the noise of the engine drowds out the loud lifters so I couldnt hear them in the car but I'll still get the phantom knock of like 60+ counts.

p.s. No, i dont still don't get knock like that.

 

[Kapok6]

ive never ever audibly "heard" knock. And I have had a lot of it. At best you can feel it pulling timing and the loss of power.

Yeah, you can definitely feel the car pull timing. It's a sick feeling.

 

[alain]

shit... i have been boosting 19-21 psi....

 

[~laser_craver~]

with stock fuel setup? WTF

id say to stay safe no more then 15 unttill you have some fuel mods and something to log with because you can totally f**k your motor with knock and its not a knock you can hearlike rod knock this is fuel burning before it is suppose to and sennding a charge down on the pistons before they are suppose to go down which can result in a piston with a hol in it

 

[alain]

I have delphi 680cc injector with t3/t4 turbo controlled with s-afc II. I had the boost controller set to 20, the gauge has marked up to 22. The shop told me up to 25psi is ok... is 20psi too much for that setup>... the motor is a '91 cyclone, new or less than 20k miles.