3 Bar and Stuff

[BiGMaC]

The 3BAR (with tuning for it) will allow the ECM to adjust for and use boost levels above 14.7 psi, since the 2BAR MAP can't even detect them.  These levels are primarily spikes and the stock Garret SHO turbos, per the manufacturer site, are only capable of maybe 17 psi or so max. In at least one dyno tuned SHO at LME more WHP was actually attained with less boost than the canned LME tune. Engines do differ, even in the same model.

My experience has been a much smoother performance overall, but especially in brisk acceleration, due to a more incremental sensing and transmission of boost data to the ECM... I confirmed this in a phone conversation with Dan Millen at LME after I added my 3BAR a year ago.  I am much more pleased with my car since the 3BAR was added and have had no problems over about 13K miles.  It is actually an F150 EB part... they have larger turbos on their 3.5TT GDI than the SHO.  Will this affect your shift issue... dunno.  Consider that any increased performance (tuning), if the power is actually used, increases stress/wear of the engine and drivetrain ultimately shortening lifespan.  ...And like you I love "pole position" at a stoplight! So i have a bit of a leadoff too, LOL, and on the freeway I cruise at 80-90 mph with throttle response remaining very good.

Hope this helps... I would not be without a tune and I love the 3BAR overall performance.  It is a relatively inexpensive, quick, and easy thing to try... If you don't like it, just revert.

Bigmac you gotta let go of that 3 bar being able to read boost in smaller increments...This really goes against the logic for using longer range map sensors for any tuning software...Your perceived smoother car is the result of better overall tuning, and I do believe you are feeling a smoother car, just not for the reason you think...And I believe someone would pitch that as a benefit and perk to running a 3 bar.

And I've never seen a car have less power when running the same car with more boost....Perhaps the canned tune was less aggressive with timing and running richer...You should see the dyno charts and the article on kenne bells website and the results of 1 degree timing changes...More boost can become less efficient but still make more power all things being equal.

You are asking for more interpolation by the ECU between data points with the 3 bar plain and simple. But I love my 3 bar tune also. The increased interpolation that I speak of though is not enough to diminish drivability so it's really a non issue...So meet me halfway...It doesn't hurt but it won't help drivability either lol

I see the point on the sensor data ... The interpolation of the data from the 3BAR causing increased frequency of of adjustments by the ECM... and the drivability is not decreased because the polling and communication of data are not enough to slow the car's computers.  Does it make the car perform better... I guess that depends on definition:  quicker: don't know, smoother performance: my butt dyno tells me yes, but why...I didn't write the tune, but it makes sense that interpolation of data point as you mention could be responsible by making more frequent adjustments.

 

[SHOnUup]

It's almost 100% across the board on better times after adding the 3bar isn't it?

Rich

 

[ajpturbo]

It's almost 100% across the board on better times after adding the 3bar isn't it?

Rich

Do you mean good times? Or faster times lol?....I say yes to both!....Btw I don't have in my sig that I have a 3 bar sensor..I never really saw the need because it's common in other platforms when you go forced induction that you sometimes have to change the map sensor.....I actually have a 4 Bar in my Honda that is good to read 4 bar or 40 psi...I don't need that much headway but it's the map sensor that the tuning company recommends. BUt it seems to be the lingo here as a popular way to describe the mod and level of tune you have. Seems like in other cars people don't really mention it they just say how much boost they run.


Perhaps I'll add it to my sig...I like just saying how much boost you are actually running rather than what you are capable of possibly running because you have the MAP sensor to support it

 

[SHOnUup]

Just a question, figured one of the guys who've been around for awhile would be able to chime in on it.



Rich

 

[SHOdded]

If the 3bar gives an actual reading for an over boost scenario instead of some random # the 2 bar can't pickup...wouldn't the ecu have a better chance of adjusting for it?

MAP sensors (any sensor) work over a given voltage range (the specific range may differ by vehicle manufacturer).  A 2 bar sensor will divide that range into x number of steps.  A 3 bar sensor will divide that range into double the number of steps, because the range has to stay the same.  So, given a range of 0-5V, a 2 bar sensor will read 1.5 bar at 2.5V.  A 3 bar sensor will read 1.5 bar at 1.25V.  That's why you don't run a 2 bar tune with a 3 bar MAP or vice versa.

As far as "overboost", that is determined by the PCM, which knows what the stock turbo & wastegate setup is.  IDK if this is a fixed parameter, or whether a tuner can alter it.