Wastegate Duty Cycle / DAL's / MALT

[MikeM173]

Smoothness is always key in my book. I did not add any 3D pics for this write-up, but you can see by the look of the tables that everything is extremely smooth. I had to wipe my computer clean, so these are from random tunes, and thrown together, and keep in mind, these were not for a stock k04.



DAL Table

Don't mind the idle section, as this was an adjustment for a completely separate reason. You will see how everything is linear and smooth. This IS NOT the only way to tune this table. Higher numbers in sections can mean more for performance, and lower numbers can mean more for gas mileage. This is of course coupled with different tables to get the overall effect that you want. Also keep in mind, if you want to go with gas mileage, I would log your car with your normal day to day drives, and see what your rpm's and load percent are, and then adjust your DAL's accordingly lower in those areas. In fact, it would most likely dip towards the center of the table (well sort of center), in the 2500-3000rpm, and 50-70% load range. Of course this is truly pendent on your driving style, and what your day to day driving is like. Keep in mind that having numbers too far off can cause responsive issues, or other issues. Because most people want tunes with power, and most are picky on getting the most gas mileage out of the vehicle, I don't have a full set of DAL tables for gas mileage anymore (since I had to wipe the hard drive). Performance could be done up similar to the way I show in the picture, but gas mileage you would want a lot different, including gas mileage with performance being a lot different as well. I almost forgot... The DAL table I used was for a larger then k04 turbo, which is why you see 240 in the last column. I do not run that with the stock turbo.



MALT Table

This table is used to determine what air load it will use. In all honesty, even with the k04, but definitely with larger, later spooling turbo's, I would not really be concerned with this table. I have used 100% in the whole table, and I have used stock, along with other variables in it. If you can manipulate the other tables well enough, then I would not even be concerned with this one. I'm sure some will disagree with this, and if you are one of them, post your reasons up, and we can gladly discuss it, just keep it nice.


Wastegate Duty Cycle

I posted a couple of different setups I have used. As you can see, one of the tables has 0 in the first column, which is similar to stock, and one does not, which is described in my idle thread. You can also see how smooth it is. What will probably throw you off is the 100's in the low rpm high load area, and then where you see it drift off. This is not needed, but because every car, and every setup is different, this was just an easier way to make sure that when you are WOT, you can have boost come in full and as quick as possible, without any delay. You can lower this without any concern, and still achieve the same results, but the issue is you can end up lowering it too much in the wrong spots and not be as responsive as you could be.


Driving Style

One of the biggest factors in tuning is, how a person drives. Do they floor it everywhere? Do they granny drive? Do they shift at 2500rpm, or do they shift at 4000rpm? One persons tune being nice and smooth, may not be a super smooth tune for someone else. Anyone can make a tune drive smooth, but to make a tune perfect in every way, and make it meet exactly how a person wants it to be is a completely different story. Most people are ok without going into that much detail, and that is ok. If you want to be picky on your car though, I would highly recommend switching things up a little bit in spots.


Pressure RPM Factor

Almost forgot this table. You will notice I raised this up to 6 in every cell. This is because this table can limit boost. You multiply the number by the barometric pressure, and that is what boost is limited to. If baro was 100kpa, and a cell said 2, then boost would be limited to 200kpa. If you put 6 in the cell, and baro was 100kpa, then the boost would be limited to 600kpa. Now we are not shooting for 600kpa, but at least we know we will not be limited by this table. Of course if you don't want boost to every go over a certain amount, then you can see how this table would come in handy.




I did this write-up quick, so please ask questions on this, or please mention if I missed anything (tables or descriptions), and definitely let me know if I gave out any misinformation because I definitely did not proof read this. It should be 100% though.


Wastegate and DALs.jpg

[PSYKOSTEVO]

MALT Table

This table is used to determine what air load it will use. In all honesty, even with the k04, but definitely with larger, later spooling turbo's, I would not really be concerned with this table. I have used 100% in the whole table, and I have used stock, along with other variables in it. If you can manipulate the other tables well enough, then I would not even be concerned with this one. I'm sure some will disagree with this, and if you are one of them, post your reasons up, and we can gladly discuss it, just keep it nice.

Wastegate and DALs.jpg

You are correct. You can pretty much set this table to whatever you want (if you are reasonable, and know what you are doing). I have one tune running 25psi with the MALT set at 91% and another tune running 22psi with the MALT set at 100% across the board. But boost is obviously not the final solution when it comes to power output.

[PSYKOSTEVO]

Pressure RPM factor can be useful when wanting to limit overboosting without limiting the Torque Output by Gear/RPM table. I will see that some of my customers have a tendency to NOT downshift properly when wanting to pass someone at freeway speeds, and without proper mitigation the ECU will calculate a lower than expected torque output by load/rpm and call for a higher boost output. To limit the maximum turbo pressure to safe levels for those drivers that are not load/stress conscious you could use that table to keep boost under control at low RPM high load.

[T-Man]

You are correct. You can pretty much set this table to whatever you want (if you are reasonable, and know what you are doing). I have one tune running 25psi with the MALT set at 91% and another tune running 22psi with the MALT set at 100% across the board. But boost is obviously not the final solution when it comes to power output.

I disagree with you both on this but only because of my understanding(possible even lack of, if we're being honest here). I always interpreted the MALT as a look up table, pulling data from the DAL table, using both interpolation and extrapolation between the different columns to find the final desired driver demand torque. It makes sense for me this way because any time I've tried to use 100% throughout, it made the car VERY erratic and on/off like. But again, as you both already stated, it's dependent upon ones overall calibration

http://www.hptuners.com/forum/showth...ad-Information

Pressure RPM factor can be useful when wanting to limit overboosting without limiting the Torque Output by Gear/RPM table. I will see that some of my customers have a tendency to NOT downshift properly when wanting to pass someone at freeway speeds, and without proper mitigation the ECU will calculate a lower than expected torque output by load/rpm and call for a higher boost output. To limit the maximum turbo pressure to safe levels for those drivers that are not load/stress conscious you could use that table to keep boost under control at low RPM high load.

I find that the torque by gear/RPM is the BEST and most intrusive table to use for a torque reduction/smooth power delivery type of strategy. I prefer to max out the pressure RPM table

[MikeM173]

T-man, you're correct on how the MALT Table works. It's a Max Air Load Torque Table, but if you understand how all of the other tables fully work then this table is not necessarily needed. Depending on driving style and tuning style is what determines whether the table matters.

[Area47]

I personally use the crap out of the pressure rpm factor table myself for various KO4 and zfr cars with great success. Lower MALT numbers in the lower range of the rpm spectrum seem to make the car less "jittery" and less like a puppy trying to pull you on a leash IMHO.

Then again, everyone has a different strategy.

[MikeM173]

Pressure RPM is a great table to use, and can be used for various reasons. In fact I use other tables not discussed on the forums for various reasons as well.

As for the MALT Table, like I said, that is pendent on the person who is driving and how the tune is being set up on how I would use it. I've done various tuning methods, and it always matters what is done to the car, what the customer wants the car to do, and how they drive the car.

[powermizer]

I used to use the MALT table a lot before I figured out how to adjust the OS table and the DAL's. It was a great tool when I hadn't figured out how to get the boost I wanted and my DAL's were way too high in the high load range. I think high DAL's come from when there was no duty cycle table and others. I get all the boost I need with not very much over stock DAL's and throttle is smooth. OS table and pressure rpm has a lot to do with it. 100% MALT is all I use now.

[metroplex]

Are these particular guidelines fairly proven at this point? I know I've seen numerous variations posted by Iambroke, Terminator2, and a few other guys over the years from 2009 - only to find out those recommendations were wrong or not quite accurate due to the lack of tables available in HPTuners.

How much boost were you seeing with these tables on a non-stock K04? Do you have tables available for a stock K04?

[T-Man]

Are these particular guidelines fairly proven at this point? I know I've seen numerous variations posted by Iambroke, Terminator2, and a few other guys over the years from 2009 - only to find out those recommendations were wrong or not quite accurate due to the lack of tables available in HPTuners.

How much boost were you seeing with these tables on a non-stock K04? Do you have tables available for a stock K04?

Take the info, play around with it and figure out what works best for you/your car/your conditions etc. This was posted as a guide, not a copy and paste.

It's not that Tom or David were wrong, it's that they were working with what we had at the time to try and achieve what we can seamlessly achieve now with more access. Same with BYT's guide, it's got some decent info but it's not necessarily "up to date"

[MikeM173]

How much boost depended on how much I commanded. I ran anywhere from 22 - 28psi. I ran more but it wasn't common or needed in most cases so I didn't do it. It really just depends on what your setup is and what you want out of it and what is ultimately safe while still pushing the limits.

[metroplex]

What are you using to command boost? Is it a single table or the combination of the tables in your original post? Setup would be stock K04, 3-bar MAPs, K&N SRI, and application is mainly street with some drag racing, autocrossing, and road racing (smaller rinky dink tracks, nothing close to Road America or the larger courses) running on 93 octane pump gas.

[califcarm]

What are you using to command boost? Is it a single table or the combination of the tables in your original post? Setup would be stock K04, 3-bar MAPs, K&N SRI, and application is mainly street with some drag racing, autocrossing, and road racing (smaller rinky dink tracks, nothing close to Road America or the larger courses) running on 93 octane pump gas.

I can't speak for these guys who have WAY more experience than I have, but I ended up with 4 things affecting/controlling my boost. I ended up with DAL's in the high end of the table set to more or less 255 across the board (and then left that constant). Then I used the WG duty cycle to adjust the boost curve so it was pretty flat and where I wanted it (around 23-23.5psi in 3rd gear). That was resulting in higher than desired boost in 4th and 5th gear (higher load gears, so that makes sense). So I used torque X rpm to bring boost in 4th back to be equal to 3rd gear, and 5th to be even a little lower than 3/4 as time is that gear would be long and intake temps can rise more so I limited it bit more for that reason (to 22 psi).

After adjusting ignition timing, I was making more power in the lower rpm's and experience some clutch slip down low (stock clutch), so I was working on torque X rpm in 3/4/5 gears to limit ramp up. I found that gave me some weird results and sometime limited boost more than other times (16psi down low one time at WOT, and then part throttle that allowed 22-23psi the next). My guess is that maybe the torque X rpm limiter works on pedal position and not throttle position (? but who knows). But in any case, since that didn't work well for me to limit ramp up, I ended up using the more universal MALT table to slow ramp up for all gears which did work well (even though I did not need to limit ramp up in 2nd, I just accepted that affect to get 3/4/5 ramp up soft enough).

All that to show that all these tables mentioned can and will affect boost. You must choose which ones to set 1st, 2nd, 3rd, or 4th (or set so that they don't interfere if you don't want on the limiter tables). I chose to set DAL constant and play with WG duty cycle to tune the boost (but you could do the reverse and get good results too I am sure), and use the limiters to change boost by gear and how it ramps in (to save the clutch and keep higher gears in check).

BTW - I am completely stock with a K&N drop in.

[street253]

I see that your duty cycle table is lower at lower rpm compared to gm. Can someone explain what gm had in mind with the values for the stock duty cycle? Performance? Gas mileage?



I have never mess with the duty cycle until now. I have watched cssob video for lnf boost control and it was very informative. I just want a better understanding on what gm mind set was.

Thanks in advance