So @cleatus12r , does that mean an overboost regulator is actually a good idea? I was always under the impression that if it didn’t defuel then there was no need. Are the times I’m over MAP capability going to cause issues with the tuner trying to control fueling?

 

Great question.

I have not had tunes that require a regulator for years. I do notice the MAP signal does different things above 24psi on different trucks and tunes - so I figured there are different ways to manage ‘defueling’ and SES light.

The 6.0 MAP sensor was popular for a minute, because tuners were using the higher range. But, that trend didn’t seem to last long.

 

I have a boost regulator/boost fooler on my truck. Not sure if it's necessary, but I guess I can leave it there until it's a problem.

Speaking of problems, I guess the Injectors didn't cure my PMS.... Just ordered a stage 2 KC300x from Clay. My credit card is really not going to like me this month.

 

 

Not to speak out of turn here, but it is my understanding that the "defuel" activation time can be adjusted to mitigate or eliminate the "defuel" result.

For example, a driver hits 30 PSI boost/MGP and the PCM defuels to bring the boost back down.

A tuner can adjust that "defuel" parameter to say 45 seconds or whatever and then when that driver hits 30 PSI boost/MGP the PCM will delay the "defuel" for 45 seconds. I don't know what the time length limit is of the adjustment, but this is my understanding based on my research.

So, not that a boost fooler is useless, it may just be more useless to some versus others that have access to tuning or tuners that suits their driving style. I have a Riffraff OCR and feel it was the right call for my use of the truck. Even though I don't normally go higher than 25 PSI, I do at times and I don't know what PHP (tuner of my choice) has written, changed or adjusted in regards to the defuel parameter.

 

PHP tunes don’t defuel or set SES light.


My current (and past) GH tunes don’t either.

In fact, I question the quality of tunes that do defuel. I have a few boost foolers I’ve removed sitting on the shelf... Not needed.

 

Compound turbos will help!

 

So does NOS!!! Go baby go!!!

 

There's no reason that a regulator isn't fine to use although there are a few ways around having one. Plainly put, it's not hurting anything. I haven't seen many calibrations that alter the manifold absolute pressure sensor "reference points" in the mapping although I have seen many that alter the way the PCM interprets the input from the sensor. The thing to keep in mind is that factory mapping stops making fuel adjustments based on boost pressure once the 12-13 PSI threshold is crossed. I guess Ford calibration engineers figured that with stock injectors on stock mapping, there was no reason to worry about fuel adjustments between 12 and 18 or so PSI (and I don't blame them as there's no reason to worry about it). What I'm getting at is that tuning for a lot of aftermarket injectors, from a lot of different places, doesn't care about any fuel adjustments based on boost once 13 PSI is exceeded.

Boost fooling 101:
Either -
1. Change the mapping that cuts injector pulse width over certain boost pressures.
a. This allows full fuel but will still cause an overboost code.
2. Change the mapping AND change the high limit for boost.
a. If you have a problem, you'll never know it.
3. Change the way the PCM interprets the voltage.
a. This keeps the PCM from seeing the actual boost pressure so no corrections to the mapping or code-setting parameters is needed BUT also changes your OBD readings on a scanner so if you're using the datastream for your boost readings you will be disappointed that you're making lower-than-expected boost pressures.

If you're wondering, I keep the overboost stuff intact although I keep the PCM from cutting pulse width in my calibrations as I like accurate data and don't want to mess with the diagnostic ability of the PCM. I own and maintain over a dozen 7.3Ls (and repair them on the side AFTER work and on weekends) with functioning and yet somehow NON-LEAKING exhaust backpressure valves, up to 13 years and hundreds of thousands of collective miles on exhaust manifold gaskets on all of them that STILL don't leak, and I like to hit the injector hold-down bolts with a torque wrench for a second time after the engine's been warm for good measure. Maybe I am just lucky...or stupid. Probably the latter.

 

Thanks for the explanation. Sounds like there’s really no reason for me to install a fooler. PHP tunes do not even light the SES so I see no benefit in an OCR based on your information. Unless something flew completely over my head. I was mainly concerned that the fueling would be confused once the MAP reading went above limit.

I too have had good luck (on 1 truck) with manifold gaskets. I did retorque them after warmup for good measure.