Beer

Planning on using a Power FC.

What psi figure equals 4.3-4.5 ish volts on stock map???

thanks,

sgT

the stock map sensor will break at 11-12psi.
Its a 2 bar map sensor, and at 0 vacuum it should be 2.8-2.9
so given a logical estimate, i would say about 12-14psi.

Speed PHreak

yeah, I boosted mine to like 10.5 yesterday and it threw a code 3 at me, so I had to back the boost down...Now it runs kinda funny, thankfully i've got another MAP sensor....wish I hadn't a burnt out the 3 Bar I had.....

*mental note* don't be fucktard on your GM 3 bar MAP wiring

The_Head

Do they break at 11-12 psi, or is it that they just won't read any boost past that point? ..like theyre maxed out or something.

CovertFI

either way they dont work! past 11-12

5 Liter Eater

People say that the physical limit of the MAP sensor is ~12 PSI but I have never heard of anyone actually breaking the diaphram on one. I think it's a 1 BAR sensor which would make it good up to 14.5 PSI which should be 5V.

sgT

1 bar sensor only reads up to 0 vacuum.
2 bar up to ~14.7
and 3 bar up to ~29.4

You are forgetting about vacuum.
I have seen my share of broken map sensors, and know plenty others
who have had the same results.

b18cTurbo

im still using the blue box from greddy whit 310 cc injector !!im boosting 16 psi dayli on stock map sensor even it saw 18 psi sometime,the car pull hard has hell never had chek engine light!!! beeing boostin for about 3 mounth no prob

sgT

I think its safe to say that
A. you are pressing your luck
B. you are probably running lean

b18cTurbo

no sgt im running full rich (a/f meter)my egt stay cool 1500f to 1550f
my setup:18g greddy gsr turbo kit
all internal are done
3``downpipe whit externe dump pipe
3``exaust no cat
msd6a whit coil whit retard units
ported exaust manifold
fuel setup is a secret but work perfectly cost me 150 can
dayli 16 psi and fast has hell(spinning in 3rd gear)205 50 15
i will dyno soon and hopping at least 300 whp
so yes its possible to run 18 psi on stock map sensor i did it

ExospeedAMcrx

really? 11-12 lbs? i've seen them run on 15-17lbs of boost on a drag 3 setup, on 3 different cars.
must have been luck?

Wil

dustin

hehe.

Just because your car still runs doesn't mean it's actually reading 18psi.

b18cTurbo

ok what so funny dustin?

[B16]HiGhCaM

Are you using anything for timing? or do you have any other mods past the greddy turbo kit?

Ran greddy kit last year @ .5 bar Building internals now looking for 1.0 ~ 1.2 bar. B16 greddy kit.

Gmedalion

I ran 12-14 psi on my greddy GSR kit and never had a problem with the stock map.

dustin

hehe the thing is.. that it isn't going to deliver any more fuel at 14psi than it is at 12psi.

MAP sensor is a 3 wire sensor. It takes ground, +5v, and sends output back to the ecu. This means it can /never/ send more than 5v out. And 11psi of boost makes the sensor read 5v. You follow the logic.....

brian b

the stock map sensor reads .95bar which is 13.78psi on my car without a problem every day

turbod97ex

Some of you are running over 11-12psi with your stock MAP sensor. Great. The MAP sensor is doing nothing for your fuel management over 11-12 psi though. The MAP sensor will tell the ECU to add more fuel as it sees that the pressure is rising. Like Dustin has already pointed out, above 11-12psi, the MAP sensor isn't telling the ECU to deliver any more fuel because it is not designed to read any more than that.

Because some of you are running over 12 psi and getting enough fuel doesn't mean that it is the MAP sensor that is telling the ECU to deliver more fuel. Instead, my guess is you must be getting the fuel using a rising rate FMU or some other method.

And by they way mikvtec, what are you saying when you say your fuel management is some "secret"? You are the first person I have seen on here to say that your setup is a secret. As we are on a discussion board that talks about Forced Induction, and that a good percentage of the posts deal WHIT air/fuel management, I think it's funny that your fuel setup is "secret".


[Modified by turbod97ex, 2:35 AM 6/20/2002]

ion_four

I'd think that if it was a 1bar that it would top out at 14.7psi...ie. put out 5v at that point...maybe someone should hook it up to a bike pump with a pressure gauge and see when it puts out 5v? I'd do it, but I don't have a bike pump