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-   -   Afc & Boost Gauge conflicting (https://www.homemadeturbo.com/engine-management-10/afc-boost-gauge-conflicting-23618/)

MikeJ-2009 07-18-2004 09:46 PM

Afc & Boost Gauge conflicting
 
Ok, so the gauge goes to 11psi and then stabalizes at 10. The afc call back on the max manifold pressure is 0.62 (9.1 lbs.)
Last night at the track I cranked this bitch up and the gauge goes to 15, and the afc says 0.62. WTF? There was definately a difference in the performance. The afc does seem to read up to .62 but it won't go past that.

Afc hooked to ecu harness

Expensive Autometer E-Boost Gauge hooked direct to manifold.

I was kind of sketching at first as to which guage I should be trusting (11psi vs. 9psi) but I think it's obvious as to which is more accurate. What might be the problem, and could any of you see any adverse effects on the setup? Thanks in advance.

(Once I get TE running, I'm gonna shoot my afc) ;)

RENR 07-18-2004 10:02 PM

Re:Afc & Boost Gauge conflicting
 
even your boost is stealth, the afc doest see it ;)

Carnesd 07-19-2004 12:04 AM

Re:Afc & Boost Gauge conflicting
 
If the afc is reading off the map sensor, it will only read up to 11.7 psi. Don't know why it's only reading 9psi? Did you convert it correctly?

The only bad thing is that if you go above 11.7psi, your ecu will only use the last fuel column that it has which is 11.7psi, and if your not tuned for higher than that you will run lean. Don't know about the afc but this is how it works on turboedit.

TurboEF9 07-19-2004 12:36 AM

Re:Afc & Boost Gauge conflicting
 
OBD0 only reads to about 10psi.. so that's right.


MikeJ-2009 07-19-2004 01:00 AM

Re:Afc & Boost Gauge conflicting
 

Originally Posted by TurboEF9
OBD0 only reads to about 10psi.. so that's right.


So no cel even if I'm at the end of the map sensor? I was running the car at 15psi for a couple test pulls and everything seemed to be working as normal. Sometimes it goes to .63, but most of the time it's .62 :-\

TurboEF9 07-19-2004 12:20 PM

Re:Afc & Boost Gauge conflicting
 
Depends on what code you're using.

If you're using a version of TurboEDIT with your AFC, then no, you won't get a CEL because it's been disabled (per say).

Chris Harris 07-19-2004 01:59 PM

Re:Afc & Boost Gauge conflicting
 

Originally Posted by TurboEF9
OBD0 only reads to about 10psi.. so that's right.

Looks like his MAP only reads to ~9.1psi...

I have seen all sorts of ranges for OBD0 - OBD1 MAPs...and I believe OBD0 ends right about 9.1-9.5...

MAX raw voltage from my MAP I have ever logged is like 4.38 which I think if you do the calculation is right about ~9 psi.

You'd need a REALLY accurate mechanical guage to verify all of this of course.

scttydb411 07-19-2004 10:19 PM

Re:Afc & Boost Gauge conflicting
 
the map will only output it's max voltage...once you get beyond it it'll still only output the same voltage. if your afc has it corrected enough you could boost way past that. you would be limited to the injector sizes and last fuel tables.

i ran 12psi daily on my safc/dsm hack.

Carnesd 07-19-2004 10:45 PM

Re:Afc & Boost Gauge conflicting
 
If the stock obdo map can only read 9psi, then there might be a problem with people using the new ng2* bins and running high boost. The map values in this version go to like 10.3psi correct?

When people want to run more boost than the TE map will allow, we fatten up the last fuel column. If the map sensor is only reading to 9 psi, then the last fuel column in the TEtry11 will be void cause it's at 10.3psi.
The ecu would only give fuel for 9psi therefore you wouldn't be giving any extra fuel for the high boost your running.

Just a thought that popped into my head when I was reading. Wouldn't want anyone to blow up their engine. Mabye a feature that when the stock map sensor is being used, the vac/boost values should only go up to 9psi.

MikeJ-2009 07-19-2004 10:59 PM

Re:Afc & Boost Gauge conflicting
 
No, I'm only running the hack. The turboedit tune didn't seem to want to run, so I'm slowly getting back into that stuff. I hope to be running TE soon, I just didn't have any luck the first time and just stayed with the hack. No knocking or cel with 15psi, 100 octane, 1 step cold plugs, and a fluidyne. :-\
The motor is built, so I figured I could push it a little harder than I normally would. Seems fine, I just wasn't sure what was going on with the afc.


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