LLY: Low rpm tuning efi live

[Jakej03]

My truck is a zf6 manual and has tunes by Idaho rob, I don't have much power or torque below 1300-1400 rpm, for everyday unloaded driving its fine but when you add a trailer to the equation just after releasing the clutch I'm at around 900 rpm, I can put the pedal to the floor and the truck pretty much does nothing more than it would if I was at 5% throttle until it gets up to about 1300 rpm, then it starts to build boost. My question is what tables control the torque limit that can help this if it can even be fixed. (I'm assuming it's the injection timing or amount limits based on throttle or rpm per mm3)
I don't think there is a problem with the tuning because it did the same thing when it was stock, I think because the autos will just slip the trans to keep the engine above 1400 rpm no one really pays attention to power below that, and if someone is gonna tell me to slip the clutch, that doesn't work, the truck hops like a jack rabbit if you even look at the go pedal when taking off haha.

Thanks in advance,
Jake

 

[quinton]

Have you emailed rob yet?

 

[Jakej03]

I emailed him a while back, sent him my tune and he said nothing was wrong with it, I thought that it may have been my maf table that I had adjusted myself (I switched it to lbz table after putting on a new intake) but he said it was fine. I originally thought I needed to add more fueling at low rpm so I did and it changed nothing, now I'm leaning more towards timing. I like doing things myself so I figured if come on here and ask if anyone had any advice on making more power below what the turbo can spool.

 

[quinton]

Ya for some reason I've had the same experience with rob. I would tell him something is wrong and he would look at it and say nothing is wrong with tuning, if go in and play with it and fix it in the tuning. That's why Ido my own tuning. His tunes where great and all but just wasn't happy with customer service.

 

[Bobo]

Check your B0727 table to see if that is restricting the throttle from commanding the fuel amount you want. If that is not it, then update your B0751 and B0752 MAF limit tables to allow a higher fuel rate at the RPM you would like it at. What is happening is your throttle is not getting the correct mm3 value corresponding to what you want the truck to do. You just need to figure out what table is limiting the mm3 output. Have you data logged it to see what the mm3 value is while your not getting the response you desire? That will get you closer to understanding and fixing your issue.

You can also check you B0742,B0743,B0744 TQ tables to see if there is a tq limit set in the rpm area in question. The Base TQ tables B1103,B1104,B1105 can also cause limits as you describe. B1106 can also limit TQ.

If all that don't help, then the structure of your pulse width table and fuel psi table could cause you to have poor low RPM performance. Since those tables work hand in hand, its hard to explain what to change there to fix the issue. You could either add more low psi pulse to the tune or add more low rpm rail psi to it.

 

[McRat]

You should have ~60HP at 900rpm and 100HP at 1200rpm according to GM.

Make sure the vanes aren't choking the engine by datalogging vane position. A common programming error can have the vanes try to make more boost than compressor is capable of at low RPM. So it keeps tightening up the vanes to the point at which it loses power.

 

[Bobo]

You should have ~60HP at 900rpm and 100HP at 1200rpm according to GM.

Make sure the vanes aren't choking the engine by datalogging vane position. A common programming error can have the vanes try to make more boost than compressor is capable of at low RPM. So it keeps tightening up the vanes to the point at which it loses power.

Its not stock so those values are not going to mean much and he says it does not build boost under 1300 rpm so I doubt the vanes are tightening up too much. :hug:

 

[Jakej03]

These are the kind of responses I'm looking for, thanks guys.
I just checked the B0727 table and it doesnt look altered. At the first break point its 200 the goes up by 200 every point.
I'm 600 feet above sea level at 60 degrees F so shouldn't that mean im dealing only with TQ table B0742? I have played with this one a little bit so I don't think its the table that's limiting me.

I have also messed with my base torque on my tune number 2 to no avail. although i did just find something weird. There is altered versions of table b0742 (BARO A) in all dsp my tunes, but the modified base torque tables in the dsp tunes uses versions of B1105 (BARO C). Could this mean my base torque is limited to the the stock BARO A in my tunes? If so wouldn't that mean I'd only see the increased torque when I drive to places where the truck uses BARO C ??

Ill data log tomorrow and see what my mm3 is at.

 

[Jakej03]

Also b1106 is unaltered,
Thanks again

 

[Muff]

Check your B0727 table to see if that is restricting the throttle from commanding the fuel amount you want. If that is not it, then update your B0751 and B0752 MAF limit tables to allow a higher fuel rate at the RPM you would like it at. What is happening is your throttle is not getting the correct mm3 value corresponding to what you want the truck to do. You just need to figure out what table is limiting the mm3 output. Have you data logged it to see what the mm3 value is while your not getting the response you desire? That will get you closer to understanding and fixing your issue.

You can also check you B0742,B0743,B0744 TQ tables to see if there is a tq limit set in the rpm area in question. The Base TQ tables B1103,B1104,B1105 can also cause limits as you describe. B1106 can also limit TQ.

If all that don't help, then the structure of your pulse width table and fuel psi table could cause you to have poor low RPM performance. Since those tables work hand in hand, its hard to explain what to change there to fix the issue. You could either add more low psi pulse to the tune or add more low rpm rail psi to it.

My buddy sent you an email or 3 trying to get you to rework the tunes you wrote for him, why dont you fix his tune before you leasurely stroll the forum and help fix peoples trucks that havent paid you? Its about 5 minutes worth of changes. We're tired of playin peek a bobo with you. Your customer service could use some help to say the least.

 

[xtremebikr04]

My buddy sent you an email or 3 trying to get you to rework the tunes you wrote for him, why dont you fix his tune before you leasurely stroll the forum and help fix peoples trucks that havent paid you? Its about 5 minutes worth of changes. We're tired of playin peek a bobo with you. Your customer service could use some help to say the least.

You too?!? Buddy of mine has the same problem. Sent numerous logs and his response is haven't had time to look at them yet. This was almost a year ago. He loves the tunes except for a couple items that need to be addressed. Waste of $900... Sorry for the off topic rant.

 

[THEFERMANATOR]

I emailed him a while back, sent him my tune and he said nothing was wrong with it, I thought that it may have been my maf table that I had adjusted myself (I switched it to lbz table after putting on a new intake) but he said it was fine. I originally thought I needed to add more fueling at low rpm so I did and it changed nothing, now I'm leaning more towards timing. I like doing things myself so I figured if come on here and ask if anyone had any advice on making more power below what the turbo can spool.

Are you running an LBZ airbox or just an LBZ mouthpiece? If just a mouthpiece then you don't need to change the MAF table to the LBZ scaling. If you change to the LBZ scaling with an LLY airbox, it will definately cause it to not fuel as early.

 

[Jakej03]

It's a homemade 4" intake and custom scoop box, the maf sensor is in the location. I would be looking there but it did the same thing with the lly intake and maf table.

 

[CaptPhil]

if you are running a 4" intake you need to rescale the maf sensor.

 

[xtremebikr04]

if you are running a 4" intake you need to rescale the maf sensor.

Why when the op says it did the same thing with the lly intake? Now I thought lly intakes were 4"? 4" is 4" to the maf sensor. Long as the placement is not in a bend or elbow so it gets an inaccurate reading.

 

[CaptPhil]

Why when the op says it did the same thing with the lly intake? Now I thought lly intakes were 4"? 4" is 4" to the maf sensor. Long as the placement is not in a bend or elbow so it gets an inaccurate reading.

the lly intake is 4", but the location of the MAF is only 3.5". With a stock turbo truck you may not see much of a difference, but with my 366 for example the truck would not spool on the line more than 5lbs, even with my foot to the floor, without a rescale. After rescale it is perfect.

Another option is to max out the maf scaling table and essentially take the maf out of the equation and see if that works. I ran that way for awhile and it was nice to have full control of fuel with the throttle.

 

[Jakej03]

It's a Donaldson filter clamped onto a 6" long piece of 4" aluminum pipe connected to a 4" silicone 90 then a 12" piece of tubing with the maf about 5" away from the first elbow rotated 10 degrees clockwise off center, (yes it's facing the correct way) and then another 4" silicone 90 into the lbz mouthpiece, is that specific enough? Haha

 

[Bobo]

My buddy sent you an email or 3 trying to get you to rework the tunes you wrote for him, why dont you fix his tune before you leasurely stroll the forum and help fix peoples trucks that havent paid you? Its about 5 minutes worth of changes. We're tired of playin peek a bobo with you. Your customer service could use some help to say the least.

You too?!? Buddy of mine has the same problem. Sent numerous logs and his response is haven't had time to look at them yet. This was almost a year ago. He loves the tunes except for a couple items that need to be addressed. Waste of $900... Sorry for the off topic rant.

I guess I need to know who "my buddy" is before I can help them. That would probably be a good starting point.

 

[Muff]

I guess I need to know who "my buddy" is before I can help them. That would probably be a good starting point.

Hard to believe the attitude you have to people that have payed you there hard earned money. Will (sixsixkid) and I have not disrespected you or gave you any reason to ignore his emails for tuning changes. Your not better than anybody, yes your shit stinks, lose that attitude I believe your a grown man not a teenager. I understand your very successful and me bitching on a public forum will not affect your business and you'll still make lots of money doing what you do. Have some respect for the people that give you their money and expect good service in return. I will have him email you AGAIN.

 

[xtremebikr04]

I guess I need to know who "my buddy" is before I can help them. That would probably be a good starting point.

Pm sent