3 bar, tstat guys-- How's your driveability?

Jtrain · February 12, 2015, 11:00:59 AM

Just want to get some feed back on everyone's thoughts of their tune / set up's drive-ability

Especially in the: High-load, mid RPM, High Boost section (Coming out of a corner and giving it 1/2 - 3/4 pedal)

SHOnUup · February 12, 2015, 12:07:06 PM

If in "lugging" situation the car does not like it, like most vehicles. Will see it pull timing during this. My most common point I get caught in a lugging situation is merging onto the freeway behind slower cars. Little more pedal and it is no issue.

Rich

Jtrain · February 12, 2015, 12:46:41 PM

Lugging, like the boost fluctuates?

SHOnUup · February 12, 2015, 12:59:25 PM

Light throttle getting you to 6th gear at 45 mph, then medium throttle getting slightly into the boost but not enough for a downshift.

Rich

SHOnUup · February 12, 2015, 01:00:59 PM

I know Livernois has a grade assist tune, and I bet Torrie could accommodate this no problem as well.

Rich

Jtrain · February 12, 2015, 01:15:45 PM

Yeah we've gone back and forth quite a few times. Just trying to figure out if this is something other's experience and I should jump back on massive data logging / back and forth-- or just kind of accept it.

The power and stuff is solid, but long drives / daily driving kinda stuff is... well-- exactly what we've been talking about.

I don't want to waste Torrie's time (or my own) over something that is common or accepted.

ZSHO · February 12, 2015, 01:40:14 PM

I am really happy with the current tune in every aspect,the only thing i would change in perspective is the Reische 170stat to the LME 160stat which i believe is better for performance and provides better longevity twards the fans.

Brucelinc · February 12, 2015, 03:23:02 PM

Under the conditions mentioned by the OP, (High-load, mid RPM, High Boost section (Coming out of a corner and giving it 1/2 - 3/4 pedal) I would say the drivability of my car is perfect - just like it was with no tune except a helluva lot faster and stronger.

I wouldn't call the above scenario lugging. To me, lugging would be 45-50 MPH in 6th gear and applying all the throttle it will take without a downshift - exactly what Rich described. Under that condition, my car pulls some timing and it will show as Knock Retard on the gauge, but I really don't feel it at all.

SHOnUup · February 12, 2015, 03:40:26 PM

Like Bruce said, I probably wouldn't notice it if I didn't have a KR gauge staring me in the face. Damn KR gauge is shortening my life expectancy...lol

Rich

Jtrain · February 12, 2015, 04:12:18 PM

Sounds like it's time for me to get back on the data logging train.

Brucelinc · February 12, 2015, 04:32:22 PM

Quote from: SHOnUup on February 12, 2015, 03:40:26 PM
Like Bruce said, I probably wouldn't notice it if I didn't have a KR gauge staring me in the face. Damn KR gauge is shortening my life expectancy...lol

Rich

LOL...yeah, that is why I quit monitoring KR. I was only getting positive numbers of 4 or more under rare lugging conditions, anyway. I could reduce or eliminate it with a shot of E85 but it is easier to just avoid conditions where I know it exists.

BiGMaC · February 12, 2015, 11:36:02 PM

In regards to the 3BAR... The car is smoother in performance, and Dan Millen confirmed this in a conversation with him. He explained that it allows more incremental tuning of response due to data sent to the ECU. I noticed the difference immediately compared to the LME 2BAR version of the v8 tune. No matter what you do the 3.5 GDI in the SHO doesn't like to lug... It will pull timing unless you can be brisk on the throttle or get a downshift.... IMHO it's a great mod for $50-$60 bucks... Regardless of whether you use more boost.

AJP turbo · February 13, 2015, 12:47:19 AM

Quote from: BiGMaC on February 12, 2015, 11:36:02 PM
In regards to the 3BAR... The car is smoother in performance, and Dan Millen confirmed this in a conversation with him. He explained that it allows more incremental tuning of response due to data sent to the ECU. I noticed the difference immediately compared to the LME 2BAR version of the v8 tune. No matter what you do the 3.5 GDI in the SHO doesn't like to lug... It will pull timing unless you can be brisk on the throttle or get a downshift.... IMHO it's a great mod for $50-$60 bucks... Regardless of whether you use more boost.

Not really true at all, bad information. YOU LOSE RESOLUTION with a 3 bar sensor installed where the 2 bar sensor was. The stock 2 bar sensor is 0-5 volt. Meaning that 0 Bar is 0 volts and 2 Bar is 5 volts. When you run the 3 bar, then 0 Bar is 0 volts and if you are at 3 Bar then the sensor is putting out 5 volts.

When resolution goes down then you have LESS INCREMENTS per volt. THink of it like this. A speedo gauge that goes to 200mph and another that goes to 100mph and both gauges are the same size. The spaces in between the 200mph speedo will be smaller and harder to read than the 100mph gauge. If the 200mph speedo gauge was larger then the resolution could be the same. But since the voltage scale is still only 0-5 volts with both map sensors the 3 bar has a wider range and still has to be represented by 5 volts. But it won't cause poor drivabilty and the perceived better drivability is probably due to the overall tune being better than stock. If the 3 bar map sensor operated on a 0-7.5 volt output then resolution and incremental change would be identical for both sensors. Not sure how else to explain it. If you've ever had to setup an analog equation to enter in for a datalogger for anything from a wideband or any other analog gauge this would be easy to understand.

And although lugging an engine is not good it doesn't automatically cause timing to be pulled. Your spark tables need adjusted if you are pulling timing when lugging. If you spend time tuning your spark tables your knock sensor should be fairly flat when logging. I have my spark tables on the conservative side so my car actually adds timing when the knock sensors see fit when I lug.

When the borderline spark tables are over advanced then you will see the knock sensors pulling timing. It's common for timing to be wrong in that area as timing really needs to be more retarded due to slow piston speed and not usually operated in that area of the tables. Sometimes timing will even be displayed as a negative number, meaning it sparks after top dead center. That's why you normally see more timing advance as RPM increases with load being the same.

SHOnUup · February 13, 2015, 03:39:44 AM

If my car was adding timing in a lugging situation, wouldn't that be bad, or a sign of a real conservative tune? If it pulls a slight amount of timing there, but barely any going WOT, would make me think I'm sitting right in the sweet spot for my timing. Hmmm?

Rich

AJP turbo · February 13, 2015, 05:10:18 AM

Quote from: SHOnUup on February 13, 2015, 03:39:44 AM
If my car was adding timing in a lugging situation, wouldn't that be bad, or a sign of a real conservative tune? If it pulls a slight amount of timing there, but barely any going WOT, would make me think I'm sitting right in the sweet spot for my timing. Hmmm?

Rich

Not really...depends what ur final timing is after compensations ...if my commanded spark was 4 degrees lower than yours at a certain load and rpm and the knock sensors add 2 degrees then I'm still 2 degrees lower overall