Safe Boost Levels?

[wasabigrinch]

Last week, I let Flowmaster's research branch borrow my truck for a few days to do some airflow testing for a CAI they are building. In exchange for letting them borrow my truck, they put offered to put on a catback exhaust system and a new (not yet released) delta boost module.

First of all, I love the improvement to the truck. The delta boost module is a piggyback setup on the stock airflow sensor (more info here), and it adds noticeable pull. Turbo lag is lower, and my truck now chirps tires when it shifts into 2nd with traction control on. I'm also really happy with the exhaust they chose. It's quite mild, but produces a bit more aggressive sound around 3 - 6000rpm, and has minimal drone compared to other Flowmaster setups I've heard.

Here's my concern: The delta boost module claims that it can add up to 4PSI of boost. If I floor the truck in Sport mode and module in MAX mode, I'm seeing 28 - 29 peak boost while running 91 octane. I'm seeing this from the calibrated boost gauge in the module's app... the boost gauge in the truck appears maxed pretty early in the acceleration process.

The Flowmaster guy said that I shouldn't be concerned, stating that 'these motors can handle a lot more boost'. If something did go wrong, apparently the mod is completely untraceable. That said, I'd rather not pop my motor.

Any insight on what is 'safe' to run on these motors? Any idea what the peak boost from other tunes typically is?

Thanks in advance!

 

[combatninja]

Stock Raptor runs 18psi of boost so either the boost measurement you are seeing is off or they added waaaaay more than 4psi. Your stock turbos should be good to spike around 21-22psi and then taper to redline. I don't know what is going on with your exact setup but I do know that there is no way you can run stock turbos at 29psi for long. Do you have a way to log intake air temps (IAT)? That would shed some light as the IATs are going to spike really fast at those boost levels on an otherwise stock truck.

 

[shelteredraptor]

Something is off. First, these turbos can't make and sustain that kind of boost. Second, the BOV won't let that happen. Something is amiss. These engines are said to be able to survive upwards of 30psi.

 

[MKomertz]

I've hit 22 psi boost a couple times running 89/91 octane, stock. Love when the turbos spool in sport mode.


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[Guy]

First

The gauge is wrong. It's not posssible on many levels.

Furthermore, The stock boost isn't/wasn't 18 on my truck. 93 octane with multiple air temps with a real data logger put my boost peak around 16. 15.8-16.2 roughly. Tuned im logging about 20. 19.8 to 20.3.

Even at that boost the ECM fires 4-5 degrees of Knock retard at times.

Your delta boost is quite possobly safe. Your data logging needs some help!

 

[TheProcessoperator]

First

The gauge is wrong. It's not posssible on many levels.

Furthermore, The stock boost isn't/wasn't 18 on my truck. 93 octane with multiple air temps with a real data logger put my boost peak around 16. 15.8-16.2 roughly. Tuned im logging about 20. 19.8 to 20.3.

Even at that boost the ECM fires 4-5 degrees of Knock retard at times.

Your delta boost is quite possobly safe. Your data logging needs some help!

From your experience of data logging, would you say that the stock boost gauge is accurate or not? My truck is stock and pegs out the boost when I'm on it (I've always ran 93 Octane).

 

[wasabigrinch]

Thanks for the quick responses, all! Just to recap and make sure I understand correctly:

1. It's not physically possible for the stock turbos to be making 28+ PSI of boost. There almost certainly has to be something wrong with the datalogging.

2. Even IF these numbers were actually happening somehow, they should still be within the 'safe' range for the motor, correct?

Any other insight? At this point, I just want to make sure I'm not doing anything damaging.

Thanks again for the quick responses!

 

[Guy]

Good question.

The stock boost gauge would also peg all the way over on mine in stock trim too.

On the data logger on a good day it was 16ish while the graphic looked like it was at 20.

And with it tuned and the logger reading 20.... the stock gauge doesn't shoot up any higher.

The ultimate truth is that the original poster isn't running 28psi of boost. Not gonna happen. Those turbos can't even do it within the scope of the engine.

So I wouldn't worry that you're going to implode. My guess is your box is similar to an AFE scorcher or a boostmax and those do work.

 

[jes.jr]

What is the Ford GT's max boost?

 

[Mcnawsty]

21psi