Can anyone tell me:

What is MBT (max power achievable) spark for our 5.4L's?

How are you guys measuring knock?

Thanks,

Greg

 

Anyone?

No one?

 

MBT is the maximum spark the engine will put out at a given load and rpm. It is the absolute best case scenerio, rarely met. Its useful for the track (copy it to the borderline knock table and run some good gas with octane booster as well) but for 99.9% of street driving, including performance/street, I don't recommend touching it. Basically, if the calculated amount of spark exceeds the MBT value, the PCM will use the MBT value instead. The borderline knock table is what you should look at instead of this table.

I don't understand what you mean by measuring knock. The knock sensor does that and you don't need to fool with it's settings under normal circumstances. What you need to be concerned with is advance rate and retard rate, degrees per second, etc.

If you purchased software for this and you don't know what you're doing then you really need to get trained. Its not something you're going to simply learn well from chatting on forums --- you may become a tooner, but never a tuner this way.

Get these books:

Engine Management: Advanced Tuning
By: Greg Banish

Read this before you touch your tuning software again. After reading it, read it again.

Then read the SCT Pro Racer Tuning Book ($75, available through many SCT dealers).

You will need to invest in a wideband O2 sensor and a laptop (if you don't have one) to datalog the vehicle. Without datalogging and the O2 sensor, you're guessing at best.

 

I know what MBT is what it is used for, I want to know where to stop adding, if that is even achievable, I understand it is best case scenario, but it is a point if you are there, no reason to go any further, you dig?

What I mean by measuring knock is how can you tell, other than the engine pulling timing that you have detonation? I am using the HP tuner software wh/ was currently released and there is no option at this time to illustrate when the engine is knocking, this would be nice to know when tuning, I think you would agree.

I have a wide band, and laptop and data log all my runs. I am not new to tuning, just new to tuning Ford F150's. I am also not 100% familiar with the HP tuning software. I am not tuning to become a professional tuner (tooner? is that tuner lingo for noob? LOL)

Obviously I am not God at tuning, otherwise I wouldn't be wasting my time talking to you "tooners" (it was a joke, take a breathe).

And the reason behind all my question is this. You need to know the limits (MBT is one of them). I am not trying to take anything away from anyone, I understand you probably have ill feelings towards me since I made the comment about technical help. It wasn't a bash, it was more a realization that the crowd isn't as big, so me finding the best crowd who not only knows what they are doing, have experience but is also willing to share it. I WILL figure out what I need to know, whether it is on the street data logging or on the forums. I don't expect anyone to become "tuner" by simply reading forums. I also have friends who tune, so they help when needed. More of a hobby, and learning is something everyone has done, including yourself Ken, you were a "tooner" once.

So, thank you for the explanation of the definition of MBT, but I still don't have a number. In the 4.6L 4V world, it was known the MBT was around 23 deg, most people tuned for this. Obviously, I am not going to be going ***** out with the F150 like I have in the past with my other cars, this is more for fun and learning. Is there danger in tuning my own stuff, hell yeah, but I have done most everything else on cars and now I am ready to move on to learning tuning. Again, my plan isn't to take over the world of tuning, but more to be able to check what effect different mods have on different parameters.

Thanks,
Greg

 

I have no ill feelings. I don't know where that came from and if I've come across that way my apologies, it was not my intention in the least. I just don't want to see anyone destroy an engine. I answered your question here as best I could based on your explaination (nor did I know your experience level so I have to assume the worst).

Okay... here goes...

MBT isn't a fixed number. Maybe you're referring to Maximum spark clip, which is a single value?

For instance, with the PCE1 F150 code, the MBT number can vary between 7 degrees and 50 degrees depending on load and RPM. Way more than you're going to need, even with 93 octane.

For the F150, don't look at MBT. Look at borderline knock. It should be much lower than MBT and you can increase the BKT for 93 (and higher) octane and still be well under MBT. Generally, if you're going from 87 to 93 you can add about 6 degrees to this table. Then increase the advance limit for the knock sensor (leave the advance rate alone). Keep the advance rate lower than the retard rate to prevent lots of knock. With a 6 degree increase in timing you have plenty of advance for high octane and more power, yet you're still under MBT.

I hate to run without going into great detail because there's a lot more to it that that, especially when it comes to the engine pulling timing but I have to be somewhere in an hour for my weekly night hanging out with the guys. (Every man has to have some quality friends time away from the wife!)

Use the drop down box under my user id and contact me with questions, and I'll give you a great deal of detail, including some recommended changes to get you started with a good base power tune. I'll need to know your truck's configuration, mods and mileage.

 

Oh...

In all seriousness, get those books!! You won't regret it.

 

Yes, thank you for the book recommendations, I meant to thank you at the end of my last response.

 

Thank you for taking the time to type all that out. I understand about weekly time with the guys, my night was also tonight. I will contact you with more questions.

Thanks again for you time and knowledge.