The tuners are working around the problem. There are a bunch of trucks running 20+ psi now.

 

Which tuners? Could they maybe step in and provide some guidance on the issue?

 

Who?

 

I think that this might be part of the reason that my truck only ran a 13.0 @ 102 last weekend. I had an excellent launch 1.7 60' pulled like a **** to the 1/8 mile then just kind of lolly gaged around to the 1/4. I ran a 12.8@ 107 with the following mods

6# lower
chip
airkit
slicks

the 13.0@102 was done with the following add ons

custom exhaust -cats
2400 stall
traction bars
ported plenum
new chip/burn
2# upper

Granted my a/f was way rich.. 10.5 and lower through the mid to high rpm's when I was on the dyno. It only put down 370hp and 485tq

last time I was dynoing it was at 397/497

 

I have chips from JL and JDM. I have run over 20psi boost with both of them. Give one or both a call.

 

I have a 6lb lower, oval TB, ported plenum, and intake and I can hit 4.9V every time. I would think this is dangerously close to running out of headroom with the MAF. My 6lb is about the same as a 3lb on a lightning so if you have a 6lb, I'd love to know what you are hitting on your MAF voltage.

Sal told me that he can adjust the "default mode" settings in the event that the maf is pegging, so I think it is curable to some degree on a stock MAF, but not pegging it in the first place would be a nice option...

 

Flying **** I use the Pro M 95mm. It barely outflows the Ford 90mm. Ive used both on the dyno back to back. They both hit 5V at about 4700 on my truck. It is possible to tune around this.

 

So is the problem the size of the hole or the computer?

Wouldn’t “tuning around” this really be a band-aid?

 

Both. The computer only reads a maximum of 5 volts and doesn't know how to deal with any higher value, and or the hole is too small.

 

Here's a different way to aprroach it that may work.

As I understand it, the MAF voltage comes from the number of volts needed to heat the filament (wire) in the MAF.

Couldn't you use a more conductive or smaller gauge wire that requires less voltage to heat? That way you would have a lower voltage reading for the amount of heat required, ie, lower voltage reading at lower RPMs, which would allow more headroom for the MAF readings?

Please correct me if any of this seem's wrong.

You would have to recalibrate the MAF settings with the chip, but that shouldn't be too difficult?

Also, talk to Mark @ BOP, and ask him if the PCM can be reprogrammed to allow readings higher than 5 volts.

 

Seems like the proportional band across the range would work as long as the A/f ratio was compensated in the x y axis. With a chip reprogram of the reference look up tables to compensate for the upper range why couldn't the voltage reference work from 1.0 to 4.5 volts ? Numerous TPS sensors I have used on Merkurs worked well below 1 volt. If the range is 1.0 to 4.5 then the PB should work.....Or install a resistor or variable capacitor to fudge the current as needed.

Ok..tell me if I'm phucked up....

 

It's probably just me but that just went "whoosh" straight over my head. Just go really slow and sound out the words for me

If you could explain that in "layman's terms" I really would like to learn more about this.

 

Hahahahahaha

 

Uh.....let's see.....


Lie to the PCM......

In a control loop you have variables....

Setpoint

Reset

Proportional Band

Reset Delay so it does not jack off....or oscillate wildly..a stabilizing factor..incremental adjustments..

Fine tuning is a matter of Control.

Control will be the output voltage in this case...

Reference Voltage will be the sensor actuator , the TPS in this case.

An infinite loop with tweaks to maintain preferred Setpoint with applicable reference signals taken into accout.

The Brain..PCM....trys to feed proper Voltage +- :>5 volts DC.
The sensor supplies the reference voltage for any given position or temperature.. MAF sensor is a potentiometer of sorts....a bi metallic strip of sorts that allows current to flow from the referrence suppy..being 5 volts or less in this case.

Just my opinion...I could be wrong.

 

Without giving away to much info at this point, I plan to dump the stock engine management computer altogether, so removing the stock computer’s limitations, what size hole will be able to take advantage of 25-30lbs of boost?

Or am I even on the right track?