aeromotife fpr, what psi i should set it to?

[bobpogoman]

ok guyes im trying to boost a little more with my car. i have a ct-26 60-1 upgrade,550cc injectors,lexus maf,walbro 255lph pump and some more mods.

ive put the boost @ 16 psi on my gauge (btw, my gauge looks wrong...when the car is off, it show me 2 psi, and when idling, 17.5 vacuum, but the only thing it can do is raise my boost reading.)

my fuel pressure regulator is at around 92psi of fuel, is it ok? where i should set it?

i have a safc neo for a/f tuning and a innovate motorsports wideband o2/gauge for monitoring.

the problem is when i hit like 16psi the car do the same thing as a fuel cut... whats wrong?

 

[TurboStreetCar]

92 psi?! i hope thats a typo, should be in the ballpark of 35-40psi....

16 psi may be all you can run on your car with a lex/550 combo.

if you wana run more youll need bigger injectors.

what does your correction look like with 92 psi of fuel pressure?

 

[bobpogoman]

ill lower it to 40psi, the correction are almost 0 but i saw at many place that the 550 i can do 19.., the 440s are ok for 12psi without correction,550 corrected they can surely do 19..

one of my friend do 22psi on a gt35 with 550s and walbro fuel pump...

 

[s383mmber1]

First thing i would do, is get a boost gauge that accuratly reads your car.

 

[bobpogoman]

dont worry i will after i test this one.. ima go to a garage and make them check with a pressure/vacuum pump, and ima lower the fuel psi asap.. stock is 33-40 psi im @ 95 lmao :O

 

[Supracentral]

First and foremost fix or replace your gauge.

A working (accurate) vacuum gauge can be a hell of a diagnostic tool:

http://www.supramania.com/forums/showpost.php?p=249145&postcount=6

my fuel pressure regulator is at around 92psi of fuel, is it ok?

NO.

where i should set it?

Honestly it's different from car to car, but base pressure between 35 - 40 psi with the vacuum line removed from the regulator seems to work for most cars. (When you put the hose back on, you should be seeing 32 psi +/- when your car is pulling full vacuum at idle..)

Remember that a properly functioning 1:1 AFPR has no function surrounding enrichment.

the problem is when i hit like 16psi the car do the same thing as a fuel cut... whats wrong?

Some of what I wrote here likely applies. There is NO way that you fuel pump can keep up if your base fuel pressure is 90+ psi:

http://www.supramania.com/forums/showpost.php?p=179880&postcount=7

First and foremost - drop the fuel pressure to a SANE value and retune the car on wideband before you do anything else.

 

[bobpogoman]

hmmm weird, i tried to lower the fuel p.s.i with the screw on the fpr, but as soon as i get under 80psi the idle start to go up and down and under 75 the engine stall...

the gauge on the fpr may be bad? it was already on the car when i bought it..the boost gauge too...

i think i should check the fuel psi with soething else then the fpr gauge

 

[bobpogoman]

ok theres an update:

my gauge was bad of 2 psi, i installer my friend one, and im boosting 14psi.

im hitting fuel cut..wtf? at around 12.5 psi the car cut, my a/f show 22.5 (normal when it cut) then after the cut, the psi can go to 13-13.5 on the gauge without cutting again (im at the end of 2nd gear.)

my gauge on the fpr is wrong, event with both fuel hose unplugged it show me around 60psi of fuel.

how can i know if i really got the lexus afm ? cuz i checked it and seems to be it. (passage inside the afm are really large)

if its the lexus one, how can i hit the fuel cut @ 12.5psi then go at 13.5 on the end of 2nd gear?

 

[TurboStreetCar]

boost is resistance to flow, not equal to flow. fuel cut is based on flow not boost pressure.

Either that turbo is maxing out the amount of flow you can put threw a lex afm before hitting fuel cut or you have boost leaks.

what are your air fuels before hitting fuel cut at wot and full boost. you might need to pull alot of fuel to get things working smoothly.

 

[Supracentral]

Stop fucking around with that car before you kill it and fix the problems before you do anymore tuning.

I'm not trying to bust your balls, I'm trying to save you a world of grief...

Think about it this way, for the most part, modifying a Supra is really nothing more than removing every single safety margin build into the design by the engineers.

As you remove those margins for error, your errors start breaking things.

Trust me on this.

You need perfectly working systems, instruments and tools before you start making more power -- "turning up the boost" is the worst thing you can do at the moment.

I'd back the boost off to stock and then:

#1 - locate the boost leaks.

#2 - get a working FPR gauge.

#3 - after you get a working FPR gauge, retune the entire car. Be sure you are tuning to vF, or you are wasting your time. Read:

http://www.supramania.com/forums/showpost.php?p=545583&postcount=7

Scroll down about 1/2 way (the big paragraph between the images) when I start talking about vF. The post was written about MAP-ECU tuning, but the principles apply to any pigggyback.

The basics here:

http://www.supramania.com/forums/showpost.php?p=1265349&postcount=373

And here:

http://www.supramania.com/forums/showpost.php?p=182731&postcount=23

may help a good bit too. You're repeating a recipe I've seen dozens of times. And you're going to wind up with a busted motor before long.

Fuel cut DOES NOT happen with a Lexus AFM at the boost levels you are describing unless there's a boost leak or you're running insanely rich. It's not uncommon to get cut midway through a gear but not at the top of it with a boost leak. Fuel cut is not simply a "boost level" it's a specific Karmann-Vortex reading at a specific rpm, throttle position and extrapolated load level.

It honestly sounds like you've got an F'ed up AFPR gauge and a stock AFM.

Measure the round end of your AFM. If it is a Lexus it should have an inside dimension 3.210" and an outside dimension of 3.385". If it is smaller, you have a stock AFM.

 

[bobpogoman]

ok ima read all your stuff before going anywhere else, but for the fuel cut, im getting a code 34 (turbo pressure abnormal) with my frien working gauge at 12.5psi-13psi.

i have the lexus afm (larger port near the honeycomb and the adjustement screw on it) i loosed aout 10 turns of the nut to check only if i had the boost cut and its at the same psi. ive always been looking at the a/f gauge (my friend) and it never been higher then 13.5.

i dont think i have a boose leak (all my t-bolt clamps are well tightened on my piping), my bov is not leaking.

im getting a new gauge for my fpr as soon as possible.

 

[TurboStreetCar]

13.5 is too high for wot on boost. wot on boost needs to be at least 11.5 or numerically lower to be safe.

 

[Supracentral]

ok ima read all your stuff before going anywhere else, but for the fuel cut, im getting a code 34 (turbo pressure abnormal) with my frien working gauge at 12.5psi-13psi.

If you have a factory (7M-GTE) AFM that's normal. If you have a Lexus AFM, it is not.

i have the lexus afm (larger port near the honeycomb and the adjustement screw on it) i loosed aout 10 turns of the nut to check only if i had the boost cut and its at the same psi.

Have you measured the round end of your AFM? The factory AFM looks identical to the Lexus, it's just 25% smaller. It has a bypass port.

The part #'s for Lexus AFM's are stamped into the aluminum housing. You can check for those as well:

22250-50010, 22250-50011, 22250-50030 or 22250-50031

ive always been looking at the a/f gauge (my friend) and it never been higher then 13.5.

13.5:1 is SUICIDE on factory hypereutectic pistons and a turbo motor. You should never street tune a turbo car to leaner than 12.0:1... And that's for a pro tuner with a built motor running very close to the ragged edge. You should be tuning for 11.5:1 or 11:1 ...

Listen, hypereutectic factory pistons are very strong, but they are also very brittle. They have a habit of shattering under detonation. At 13.5:1, I am AMAZED you haven't detonated badly enough to crack a piston. Consider yourself lucky.

Stop making full boost runs.

That car needs to be fattened up (more fuel) a LOT before you make any full throttle pulls.

Set your S-AFC Neo back to 0% correction across the board. If you do in fact have 550 cc/min injectors AND a Lexus AFM, the car should run on the stock map - pig rich but safe.

i dont think i have a boose leak (all my t-bolt clamps are well tightened on my piping), my bov is not leaking.

Check every single coupler, pipe and rubber hose for leaks. Anything between the AFM and the throttle body is suspect. You either have a boost leak or a factor AFM - one of the two. Measure that AFM.

When things don't add up, check your premises. In other words, some assumption you are making is incorrect. Either you have a boost leak or a 7M-GTE AFM.

im getting a new gauge for my fpr as soon as possible.

Do that, and don't make any runs leaner than 12.5:1 - if you see your A/F gauge saying 12.6:1 or higher, it's time to bail out of the throttle, make some adjustment and run again.

Remember my earlier post about margins of error. Your damned lucky you haven't broken something already.

 

[bobpogoman]

ok, thanks a lot, seriousl your helping me a lot, i thought that the ecu was trying to put the a/f at 14.7 (for the pollution) but look like its not, im getting a ssi-4 so i will be able to log everything on a lab-top and then make some tunings..

for the afm i can see the 22250 numbers on it, but for the last series i saw on a website it was pressed on it (22250 is lifted) but cant see 2nd series of numbers...

i will measure it tomorrow, but the afm is looking to be the lexus one since i have the big ''U'' passage of air under the honeycomb.. with a large screw to set it...

for the injectors they r 550s rc engeineering

engine is:

.020 topline pistons/rings
clevite.77 main and rod bearings
hks 2.0 mhg
stock rods
stock crank
nippon racing head (valves and anything)

mods are:

ct-26 60-1
lex afm
550cc rc engeineering injectors
spearco replica ic + 2.25 in. piping
3in. exhaust
innovate motorsports wb o2
safc neo
automotive fpr
walbro 255lph pump
k&n filter