turning up my boost

[gstsilverrocket]

I have a 96 gst and here are the list of mods done to it.

k&n air filter
1g bov
two stage boost controller
air ruel gauge and oil temp gauge
new rebuilt 7 bolt from overbore.com in NY with this done to it
-pistons .020 over stock
-new oil pump
-new upgraded rings
-full quality gasket set and viton seals
-new pins
-new water pump
-new rod bearings
-new stainless valves
-new main bearings
-new 3g lifters
-new thrust bearings
-new vaulve guides
-new timing belt and tensioner

its also has a set of after market cams that is suppose to be one step up from the stock cams. The counter balance shaft has been removed, at the speed shop, the holes plugged, and then the engine was balanced. It has 3" down pipe with no cat. and 3" all the way back.
I replaced the stock inner cooler with a front mount. It has a ported 16g turbo, also ported the exhaust manifold to fit the new turbo's ported inlet flange.
Has a apex neo programable air/fuel controller.
Has a wabro 255 lph fuelpump.



ok with all this said I just bout a B&M adjustable fuel pressure regulator and was wanting to know how much boost i can run on the car before having to go to bigger injectors. The car is tuned at 15psi right now.

 

[boostedjay32]

leave it there... i didnt see you put what your tuning it with?
get something to tune it with first

 

[CJTurbo]

The first thing I can tell you is you need to get yourself a datalogger. With that you can monitor your injector duty cycle and determine if you are maxxing out the current injectors. I wouldn't do anything until you get the datalogger and see where you currently stand. You will most likely need to upgrade the injectors and in my experience I would buy a step above what you need. I.E. if you need 550's got with at least 660's, you have the Neo so you can adjust accordingly and it will leave room for future upgrades, bigger turbo, etc.
Good luck

 

[fastmitsu18]

You should be able to run 10psi safely.

I see that you have an apexi and a walbro, but that alone won't do the trick for much boost. 450cc should be maxed out that this point, so injectors should be upgraded before you start turning up the boost. You should also install a fuel pressure regulator to make sure the walbro hasn't increased the pressure to high.

I also suggest you buy "how to build max performance 4g63t engines". Its a great book and that I picked up. It have a section about how to figure out what injector size, fuel pump and fuel pressure you should be running for your setup.

David.

 

[gstsilverrocket]

i was reading some posts and saw that someone was running 20psi on stock injectors? since i got an adjustable fuel pressure regulator what should i set it at? and were do i install a fuel pressure gauge so i know how much it is running?

 

[abaum565]

at 20psi on that 16g with 450s you can probably say goodbye to that motor, especially on pump gas. Usually the fuel pressure gauge gets put on the adjustable fpr. you need to set your fpr at 43.5psi with the vacuum line unhooked.

You WILL need larger injectors
a afpr

...in order to run more boost.

 

[fastmitsu18]

33psi with the vaccum hose connected, or 42-45psi with the hose disconnected.

You can either buy a gauge kit at your local auto store to check it and set it, or you can buy a pressure gauge kit that stays on the filter, or one that sits in your interior. Lots of options there.

 

[abaum565]

^^more like 37psi with the hose connected

 

[gstsilverrocket]

The afpr that i bout you have to cut the stock one and attach the one i have to it like shown on this link

How To: Install a B&M fuel pressure regulator. (pics)

is there any other place's you can put a fuel pressure gauge? I know on my civic i had one attached to the fuel filter i did not know if you can do the same with a gst?

 

[abaum565]

There are fittings out there that allow you to connect the gauge right after the fuel filter.

 

[fastmitsu18]

^^more like 37psi with the hose connected

Haynes Manual says 33psi.

 

[d_hidayat2000]

you should use the data logger and AFR meter
try to put more boost step by step,then check the AFR, don't go too lean, and with the dataloger check the injector duty cycle.
the safe point if You see "injector duty cycle" between 85-90 %
and don't forget water injection & race gas will allow You to put more boost safely.
I think no body can give You the exact PSI of Safe Boost without AFR and datalogger

 

[abaum565]

Haynes Manual says 33psi.

http://www.dsmtuners.com/forums/articles-engine-fuel/338084-aeromotive-afpr-install-install-kit.html

Not that I want to argue about base fuel pressure but 33 is low for both 1 and 2g. Also I wouldn't trust the Haynes manual for anything. just my 2cents.

 

[fastmitsu18]

http://www.dsmtuners.com/forums/tun...onfused-about-base-fuel-pressure-setting.html

Not that I want to argue about base fuel pressure but 33 is low for both 1 and 2g. Also I wouldn't trust the Haynes manual for anything. just my 2cents.

yeah, i though 33 did sound a bit low.

so just to confirm 37 with hose, 43.5 without hose.

 

[abaum565]

yeah, i though 33 did sound a bit low.

so just to confirm 37 with hose, 43.5 without hose.

Correct.

 

[gstsilverrocket]

I have an air fuel gauge.....what is data logger and how do i get it? so just to confirm 37 with hose, 43.5 without hose. with out hose what do you mean?

 

[abaum565]

I have an air fuel gauge.....what is data logger and how do i get it? so just to confirm 37 with hose, 43.5 without hose. with out hose what do you mean?

Your A/F gauge is probably a narrow band gauge, which really doesn't do anything but take up space, it's useless. You need to get yourself a Wideband 02 gauge to monitor your actual a/f ratios. There are many dataloggers out there, just run a quick search, such as some of the pocket loggers. You will need a datalogger to monitor what your engine is doing, it can tell your airflow, estimated values, tempatures, etc. It's crucial if you want to turn your boost up, you will need to know what your engine is doing.

There is a vacuum hose connected to the fpr (check the stock one, you will see it) this is the hose you need to remove to set your base fuel pressure.

 

[zhjiln]

to the OP .. please look up Evoscan datalogger.. you will need it..

 

[gstsilverrocket]

Ijust ordered a data logger from there and should be here soon.

 

[gstsilverrocket]

ok i got my ajustable fuel pressure regulator on and now how much boost can i run on stock fuel injectors??

 

[rocafellafw]

ok i got my ajustable fuel pressure regulator on and now how much boost can i run on stock fuel injectors??

I would not go ANY higher until you get injectors, do some logs and see how high your IDC's get, I like to keep mine below 88%.

 

[fastmitsu18]

the fuel pressure just makes sure that your injectors get enough fuel to work property (not to much, and not too little). But that doesn't mean that your combustion chamber will get more fuel. You would need to upgrade the injectors.

bigger injectors + high flow fuel pump + proper pressure = more fuel.
More Fuel + AFC/Controller = right air to fuel ratios for more boost.

Right now if you are still running the stock injectors, they will be your weekest link since they are only 450cc, and are just barely enough to handle stock boosts.

 

[chanley talon]

I know this is a month old but. I ran 20 psi on pump gas 450 injectors with a 255 and small 16g rewired and front mount never ever had an issue. The cams are the only thing i think may make you max the injectors quicker, but on race fuel don't worry about it. 15 psi is about all i would push it though until you get some 550cc or 650cc. A logger will help you track knock. If your not knocking than your fine to go higher.

 

[tscook3]

You can probably turn it up a couple pounds but I wouldn't do it. You will need bigger injectors in the future, just be careful and aware. Not worth messing something up.