2 bar map sensor Options

[jesterwr217]

yea it doesnt sound very safe lol but i desperately need to kno how to get these injectors in lol

[presure2]

yea it doesnt sound very safe lol but i desperately need to kno how to get these injectors in lol

i took a quick look at tinas 7a when she was up for her auto/manual swap, it looked to me like you'll have to remove the upper intake manifold cover, and possibly throttle body.
there are a few allen head bolts on the intake cover, and 4 12 or 14mm bolts on the throttle body

[NuclearHappineS]

How come you guys NEVER understand this ... it's so simple..

Ghetto setup
This setup is only good for 5psi.

Stock FPR, 8:1 to 12:1 FMU, stock injectors, HIGH PRESSURE fuel pump (walbro 255HP) , stock map sensor + Checkvalves or instead of a check valve use a turboXS boost cut defender (FCD) or a greddy Boost Cut Controller (BCC) or an HKS FCD


Proper setup

Stock FPR, NO FMU, DOUBLE your injector size, regular low pressure fuel pump (walbro 190LP or 255LP), 2 bar map sensor, NO check valves, NO BCC, NO FCD

This setup is good for 12 to 14psi (depending on your exact SAFC settings and how close your injectors are to the ideal sized injector your fuel cut will vary in that range from 13 to 15psi)

Insane Ghetto setup (like for a 350-400hp setup on a stock ECU)
2.0 bar map sensor
FCD or BCC (BUT NO CHECK VALVES)
3:1 FMU
Double your injector size
Walbro 255HP or even a dual walbro 255HP setup

with a setup like this if you start with 400cc/min at idle, the FMU will make them act like 700cc/min injectors at 20psi

This setup is geared good for 450 crank hp @ 20psi of boost

Insane non ghetto setup (and possibly horrible idle setup)
2.5 bar map sensor
2.5 times your stock injector size
no FCD
no BCC
no Checkvalves
no FMU
Single Walbro 255LP (low pressure)

This setup is typically good for 350-380hp @ 18psi of boost (which is where you find your fuel cut)

OK so the summary.

If you are going for more than 5psi, don't use an 8:1 FMU.
If you are not going to make 450hp don't mix an FMU with bigger injectors
If you use bigger injectors don't ever use a check valve
If you use bigger injectors always use a 2.0 bar map sensor
Don't EVER use the SAFC IN/OUT settings to trim your fuel, use a 2Bar map sensor and the right sized injectors instead.

Idle at 17:1 to 15:1 AFR is OK
Part throttle at 15:1 to 14:1 AFR is ok
In boost your target should be 12:1 to 11:1 AFR

This post has been edited by NuclearHappineS: Aug 7, 2007 - 1:47 PM

[jesterwr217]

How come you guys NEVER understand this ... it's so simple..

Ghetto setup
This setup is only good for 5psi.

Stock FPR, 8:1 to 12:1 FMU, stock injectors, HIGH PRESSURE fuel pump (walbro 255HP) , stock map sensor + Checkvalves or instead of a check valve use a turboXS boost cut defender (FCD) or a greddy Boost Cut Controller (BCC) or an HKS FCD


Proper setup

Stock FPR, NO FMU, DOUBLE your injector size, regular low pressure fuel pump (walbro 190LP or 255LP), 2 bar map sensor, NO check valves, NO BCC, NO FCD

This setup is good for 12 to 14psi (depending on your exact SAFC settings and how close your injectors are to the ideal sized injector your fuel cut will vary in that range from 13 to 15psi)

Insane Ghetto setup (like for a 350-400hp setup on a stock ECU)
2.0 bar map sensor
FCD or BCC (BUT NO CHECK VALVES)
3:1 FMU
Double your injector size
Walbro 255HP or even a dual walbro 255HP setup

with a setup like this if you start with 400cc/min at idle, the FMU will make them act like 700cc/min injectors at 20psi

This setup is geared good for 450 crank hp @ 20psi of boost

Insane non ghetto setup (and possibly horrible idle setup)
2.5 bar map sensor
2.5 times your stock injector size
no FCD
no BCC
no Checkvalves
no FMU
Single Walbro 255LP (low pressure)

This setup is typically good for 350-380hp @ 18psi of boost (which is where you find your fuel cut)

OK so the summary.

If you are going for more than 5psi, don't use an 8:1 FMU.
If you are not going to make 450hp don't mix an FMU with bigger injectors
If you use bigger injectors don't ever use a check valve
If you use bigger injectors always use a 2.0 bar map sensor
Don't EVER use the SAFC IN/OUT settings to trim your fuel, use a 2Bar map sensor and the right sized injectors instead.

Idle at 17:1 to 15:1 AFR is OK
Part throttle at 15:1 to 14:1 AFR is ok
In boost your target should be 12:1 to 11:1 AFR

i have that exact setup the first one anyway and im only running 8 lbs and dont plan on running more so im good then?

[NuclearHappineS]

a 12:1 FMU at 8 psi is a fuel rail pressure of 136psi

you are NOT ok

The walbro you have (the TT version) is a LOW PRESSURE pump. That means if you run it for extended periods of time at those pressures it will fail, or at least fail to deliver the desired fuel and cause you to lean out ...

Furthermore, anything abouve 80-90 psi of rail pressure and you start risking cracking your injectors or having them stick open, unable to close under the pressure, which can wash out a piston from its oil coating and kill that cylinder ...

To be very clear... if you use an FMU, 5psi is your max and you must either use a high pressure walbro or use a regular low pressure in tank pump with a supporting inline pump ...

>> i have that exact setup the first one

you don't, be careful

my suggestion is find some injectors that are double your stock size, take out the fmu, put in the 2 bar and those injectors and you should be good to go at a more reasonable and safe 40psi fuel rail pressure with a matching fuel pump

[Shocker]

Ive got it.... On you SAFC put your imput a 4 and your out put at 8..it should run more smoothly..if that doesnt work trry it the other way around. My car is running great now.

hmmm sound safe to you manny?

lol, i unno, you ST guys are nuts...lmao
with that setup your telling the SAFC that you have 4 airflow signals coming in, and 8 going out?!?!

Im having a guy tuning my car and im almost positive that is what he showed me,, id have more info but we are still making my celica uber fast for an st.

This post has been edited by Shocker: Aug 8, 2007 - 9:47 AM

[jesterwr217]

a 12:1 FMU at 8 psi is a fuel rail pressure of 136psi

you are NOT ok

The walbro you have (the TT version) is a LOW PRESSURE pump. That means if you run it for extended periods of time at those pressures it will fail, or at least fail to deliver the desired fuel and cause you to lean out ...

Furthermore, anything abouve 80-90 psi of rail pressure and you start risking cracking your injectors or having them stick open, unable to close under the pressure, which can wash out a piston from its oil coating and kill that cylinder ...

To be very clear... if you use an FMU, 5psi is your max and you must either use a high pressure walbro or use a regular low pressure in tank pump with a supporting inline pump ...

>> i have that exact setup the first one

you don't, be careful

my suggestion is find some injectors that are double your stock size, take out the fmu, put in the 2 bar and those injectors and you should be good to go at a more reasonable and safe 40psi fuel rail pressure with a matching fuel pump

if it were to lean out due to the fuel pump wouldnt i see it on my wideband??
and which exact parts are u suggesting like injectors? i have the lime green top supra ones

This post has been edited by jesterwr217: Aug 8, 2007 - 2:41 AM

[NuclearHappineS]

>>with that setup your telling the SAFC that you have 4 airflow signals coming in, and 8 going out?!?!

This is called hte SAFC hack, it's a horrible way to tune a car.

What it does is tell the SAFC that you have 1 bar hooked up, and to lie to teh ecu and tell it that you have 2 bar hooked dup

so if your 1bar is reading 5 volts, and your corrections are 0% then the SAFC will report half that voltage (2.5volts) to the ecu... this does allow you to idle doulbe the size injectors, but it has a major shortcoming which is...

once you go above 0psi ... the map sensor no longer knows anything... it will read 5 volts weather you run 0 psi or 20psi. The SAFC will see this 5 votls and report it to the ECU as 2.5 volts, you will never hit fuel cut this way, but this way you will get the same amount of fuel being dumped in for 0psi as you do for 10psi.

So what you are forced to do with this setup is take your car to a dyno and dyno it and tune it at 10psi.

What happens when you are running 3psi ?
well you are running very rich because you have 10psi worth of fuel (so your boost transition and throttle response will suck

What happens when you run 12psi on a cold night where boost bumps up just a bit?
well you will run lean because you are missing 2psi worth of fuel and can possibly blow the motor.

This setup is cheap, and it may work, but in the end it is a hack, and it leaves your ECU totally blind

A 2 bar map sensor will give you the same result, except the ECU will see boost, you will get boost dependant fueling, and if anythign fails with your boost controller you will still have a fuel cut somewhere around 12psi to save your motor...

[Shocker]

Im using that in conjunction with the 2 bar. Im going there today im hoping so i will find out for sure.

[Shocker]

This is What Brad sent me today.Should clear up anything i posted wrong.


Re: Hey Brad its Jack
Saw your message on 6gc. What I did was set it so its an 8 in 3 out. The 2bar map sensor sends out what would be considered an "8" signal in terms of an SAFC. Your car's stock map sensor and ecu use a "3". What I did was set it up so that the SAFC interpolates the "8" and makes it a usable signal to go into a "3" ecu. Its much better that way than just setting it up for 8 in 8 out or 3 in 3 out. With either of those you have to richen or lean the car all over the place to get it to even run. It looks to me like the celica guys dont understand what swapping to a 2bar sensor actually does. The ecu CANT SEE BOOST under any circumstance or else it will flip out. Using the stock 1bar sensor, somewhere around -700mm/hg is 0.0v and -10mm/hg to absolute pressure is 4.5 volts. In its normal NA setup WOT will give it somewhere around 4.5v and fuel and timing settings are used accordingly.

When you put in the 2bar sensor and dont set the SAFC up the way I did you run into several problems... First off, it ranges from around -700mm/hg at 0.0v to ~14.7psi at 5v. By putting that in the car it wont let it hit boost cut as soon as it sees boost because the car doesnt look for "boost" to hit it's boost cut, it looks for 5v. You'd have to get close to 14psi before you got to boost cut because thats where it would send a 5v signal. That being on there means that your car's fuel setting for driving around in vacuum would be in the bottom half of their normal scale.... basically using from 0.0v to 2.5v for vacuum. By that, when you're normally driving part throttle you're telling the car that its pulling FAR more vacuum than it is. For instance, driving the car stock you're going from full vacuum to near absolute constantly and over the whole 0-5v scale. Now with the 2bar sensor you're doing that with a 0-2.5v scale. The car isnt tuned from the factory to drive like that so it'll run like shat.

The second big problem is the way it times the motor. In NA trim when you get closer to absolute pressure your car pulls out timing. During vacuum it has more timing. With the 2bar sensor at say 5psi the car is thinking its still a good bit into vacuum and therefor giving it ALOT of timing. That is BAD!

Oh and one more bad thing about just having the 2bar sensor in there and richening/leaning the car as it needs to be... The car's ecu will learn what it wants and correct accordingly making any settings you dial in there obsolete.

With my settings in there:
1)The car starts and runs fine with all of the fuel settings ZERO'd
2)Wont hit boost cut as soon as it see's boost
3)Drives like its stock when its in vacuum
4)Still gives you 100% ability to set the SAFC however it needs to be under WOT
5)Hell, the damn check engine light TURNED OFF!!!!
6)Oh and it'll still hit boost cut if you get to ~14psi

The main thing these guys dont understand is that fuel pressure is what will allow your car to run correctly under boost, PERIOD. Thats the main thing that controls the fueling of EVERY car under boost. Now, your car may run fine on the stock FPR and it may not. It may need a simple 1:1 rate aftermarket FPR, it may need a 12:1 FMU. I'm not 100% sure yet. What I do know is that the car runs and drives like stock out of boost with a turbo on it and a 2bar map sensor. The fueling under boost is something that is still yet to be determined, but thats NOT what an SAFC is for.

[NuclearHappineS]

Here's where he's right

the voltage vs vacuum/boost scales he posts are correct, that's why we chose to switch to a 2 bar.

If setting 8 is truly a 2 bar
and setting 3 is truly a 1 bar

then at 5psi , the map sensor should output 3.3333 volts
The safc using 8 IN should read 3.333 volts as 5psi because it knows it's a 2 bar (From the setting #8)
The it applies your correction, for simplicity let's say it's 0%
Then it wants to translate 5psi into what a 1 bar would see at 5psi (because of setting #3)
So it will go to a lookup table and lookup 5psi on a 1 bar it should go ahead and output 5 volts
You should hit fuel cut

So his logic is incorrect... it just doesn't work like that...

As far as the FPR comment that's wrong too.... flat out wrong

There are 3 things that control fueling

1 is duty cycle
2 is the actual size of the injector
3 is the fuel pressure
4 (is the voltage at the injector but we can ignore this for now)

Duty cycle is how long the injector says open as a percent of maximum, this is a function mostly of your map sensor, and your rpm

1- example: 6000 rpm, 14psi is 90% and 3000rpm, 14psi is 45% these are figures programmed into the ecu.
2- the size of the injector for example stock is 200cc/min and upgraded is 400cc/min
3- the fuel pressure stock is 40psi differencial, with FMU is 100psi differencial
4- ignore

so at WOT with a 1 bar with 400cc injectors with no fmu @ 5psi
@ 3000 rpm you will get 45% * 400 * 1.0 = 180cc/min of fuel or 123 hp of fuel
@ 6000 rpm you will get 90% * 400 * 1.0 = 360cc/min of fuel or 246 hp of fuel

with a 2 bar, 400cc injectors, no fmu @ 5psi
@ 3000 rpm you will get 30% * 400 * 1.0 = 120cc/min of fuel or 82 hp of fuel
@ 6000 rpm you will get 60% * 400 * 1.0 = 240cc/min of fuel or 164 hp of fuel

with 1 bar + fmu + 400cc @ 5psi
@ 3000 rpm you will get 45% * 400 * 1.58 = 284cc/min of fuel or 195 hp of fuel
@ 6000 rpm you will get 90% * 400 * 1.58 = 568cc/min of fuel or 390 hp of fuel

with a 2 bar + FMU , @ 5psi , 400cc injectors
@ 3000 rpm you will get 30% * 400 * 1.58 = 189cc/min of fuel or 129 hp of fuel
@ 6000 rpm you will get 60% * 400 * 1.58 = 378cc/min of fuel or 259 hp of fuel

Let me redo the numbers for 14psi so you can get teh whole picture...

1bar , 400s, no fmu , 14psi
@ 3000 rpm you will get 45% * 400 * 1.0 = 180cc/min of fuel or 123 hp of fuel (same as 5psi)
@ 6000 rpm you will get 90% * 400 * 1.0 = 360cc/min of fuel or 246 hp of fuel (same as 5psi)

with a 2 bar, 400cc injectors, no fmu @ 14psi
@ 3000 rpm you will get 45% * 400 * 1.0 = 120cc/min of fuel or 123 hp of fuel
@ 6000 rpm you will get 90% * 400 * 1.0 = 240cc/min of fuel or 246 hp of fuel

with 1 bar + fmu + 400cc @ 5psi
@ 3000 rpm you will get 45% * 400 * 1.58 = 284cc/min of fuel or 195 hp of fuel
@ 6000 rpm you will get 90% * 400 * 1.58 = 568cc/min of fuel or 390 hp of fuel

with a 2 bar + FMU , @ 14psi , 400cc injectors
@ 3000 rpm you will get 45% * 400 * 1.58 = 284cc/min of fuel or 183 hp of fuel
@ 6000 rpm you will get 90% * 400 * 1.58 = 568cc/min of fuel or 368 hp of fuel << this is why i say not to use an FMU With 400s, no one on here is making that kind of power...

the problem with a 1 bar or simulating a 1 bar is that you have no boost based fueling ... you get the same fuel at 3psi as you do at 14psi...

that's what i'm objecting to...

if you redo all these numbers with 200cc/min (stock injectors) then divide all the hp figures by 2 and you will see why you need an FMU with stock injectors

for example 2 bar + fmu + 200cc injectors @ 14psi = 184hp @ 14psi which is sorta close to what you'd see from a car that has around 100hp stock... ...

This post has been edited by NuclearHappineS: Aug 10, 2007 - 3:54 PM

[Shocker]

thats better than the simple im sorry hes wrong.