^byah!
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^byah!
Very good writeup
I gotta say, I disagree with some of this. Do NOT set your Max Airload Torque table to 90+ everywhere. That is what causes the twitchiness that you experience, and then you turn to the max torque vs gear tables to eliminate. The Max Airload Torque table and the desired airload work in concert, one table modifies the other.
The GM stage 1 tune has a lot of hints to be found in it if you examine it closely. I'm looking at mine right now and comparing it to the tune I did following these instructions. The driving experience (and boost) was IDENTICAL, however the GM tune was much less twitchy. They obviously modified a lot of tables we don't have access to, however I have learned a lot from what they did to the ones we can access.
GM, for their Max Airload Torque table, adds 2 at 1650, ramping it up to adding 13 at 4k rpm, and finally back down to adding 3.75 at 6500. If I were you guys, I would modify my max airload torque like that, and work the DAL table to achieve what I want from there. I found it makes for a much smoother driving, better performing car.
To clarify my point, the Max Airload Torque table is described in this guide as "Across the top is the RPM obviously and the value below each RPM is the Max Airload in % the VCM will be looking for." However, HPTuners describes the table as "Torque used to calculate the maximum allowed airload." Granted, HPtuners description makes ZERO sense, because torque is a function of airflow not the other way around, HOWEVER if you think that Max Airload Torque is simply a table that modifies your DAL table it is simpler to understand. But until someone proves me wrong, I refuse to believe the description included in this guide. The Max Airload Torque table is not a torque limiting table, it is simply a torque-that-exists-for-the-purposes-of-our-calculations table.
If anyone disagrees with that, I'd love to hear your reasons why so I can learn from them. :cheers:
There are a few things that cause twichyness (however you spell it) from my experience. The biggest offender in my opinion is grossly jacking up the DAL's. You can "out DAL" all of your gear based max's and such.
Go to the drag strip or whatever some time and jack your 80+ DAL to like 400 and set your gear based to like 20 1/2 and my car totally ignores that and goes max effort.
Also everyone likes to drive their car differently, so adjust to your feel.
Shrug
I'll play :usa:
The only places you should be setting the MAL to 100 is past 2700, IMO. Since you're using the GMS1 as an example, GM also starts to ramp up the MAL at 2700 but only to levels they needed to achieve the airload/power they were after (as well as modifying the WG duty cycle). We're after more, obviously.Quote:
Originally Posted by IFRYRCE
Max torque vs gear table will only limit the ETC. It has nothing to do with the MAL or DAL.
The "twitchyness" is easily taken care of by reducing the DAL from 400RPM down to 2500 (more if you prefer) and all the way across to 60 or 70 ETC%. This way, instead of allowing the MAL to be the nanny torque management, you use the DAL. Best of both worlds. Also helps to keep 1st gear from being annoying.Quote:
Originally Posted by IFRYRCE
GM made small enough changes to the MAL, DAL and modified the WG duty to allow for more boost and to achieve a specific airload/hp limit. They also wanted to protect the turbo from being "overspun", which is why a GMS1 car will fall off to near stock HP levels past 5-5500 RPM. HPT cars do not, thanks to the MAL table being maxed. You may have a "smoother" driving car (This is only relative to the person behind the wheel as we all enjoy different driving styles and the ETC is slow as balls, which causes a lot of people to try to over compensate and give it more pedal. By the time things have "caught up" the car is "twitchy" etc.) but it definitely will not be better performing.Quote:
Originally Posted by IFRYRCE
The MAL table is one of, if not the main torque management table...Quote:
Originally Posted by IFRYRCE
Read this thread as it will help you to better understand how this Bosch ECU works. It will also illustrate as to why you want to use the DAL as the "limiter" instead of the MAL table as MAL is calculated via the DAL and the ETC position (and more I'd assume): http://www.hptuners.com/forum/showth...ight=LNF+bosch
Don't drive my car, you would die. That 'twitchyness' is called RESPONSE in my book. I have my DAL's jacked from 60% up. 25 psi of boost at 50% tps, yes plz.
:crazy:Quote:
Originally Posted by mkriebs
I have tried this on my car as well but I have since smoothed it out because doing unintended rolling burnouts gets old after a while. Still hits hard when I want it to and has great drivability.Quote:
Originally Posted by mkriebs
Mine doesn't really do an unintended burnout. I have my tq management dialed down in the lower gears, I just want it to hit super hard when i come out of the curves. Its not really a DD map, its more of a tearing the curves map.Quote:
Originally Posted by Terminator2
It's all personal preference. I ramp my DAL's up hard 80% and higher so I don't burnout rolling around people in traffic. :D No torque management except first gear and MAL table at 100% by 2500rpm, steeper than stock or GMPP.
Man I like you guys quick responses...
Twitchiness in my book is defined as response beyond what is expected... Such as having the car lunge forward when I move the throttle less than 1/8 an inch. I hate ETC, I can't wait until HPtuners releases whatever table Vince is getting 1:1 throttle control from. I just don't want to be trying to pull away slowly from a stoplight and start doing a burnout, or have my girlfriend slamming my head in the headrest accidentally while she drives my car. While we're on the ETC subject, I also hate how I can leave it at 25% and the car accelerates to 100 mph if I just hold it there... I am supposed to have to open the throttle more, the car isn't supposed to do it for me. Stupid smart cars.
After studying the GDI guide I see what you guys are talking about, I was totally incorrect & got no problem admitting it. Anyone have an idea what the max torque table does (the one next to MAL)? I have mine doubled in all the cells that weren't 100%, but I am hesitant to set it all to 100%. I've also changed my MAL tables back to 100% from 4k up.
Finally, does anybody know how I stop this stupid computer from closing the throttle when I shift? I don't care if you call it no lift shifting or powershifting (NLS is a cop out in my book, I've been powershifting cars that didn't have fancy electronic nannies since before I got my license) but the throttle is NOT supposed to close at all when you do it, and I can both feel it closing and see it closing in the logs, especially on the 1-2 shift.
No way to stop the nanny from closing the throttle until you can turn her off completely. If I get wheelspin in third with ESC off she still shuts me down.
1:1 throttle like while the key is on, engine not running (try it while logging sometime) would be very nice but might cost a transmission or two.
I don't care, as soon as this F35 trans blows up I'm going to the F40. Six speeds ought to fix the shit gas mileage this car gets. My LS1/T56 RX7 averages 20, I only get 18.5 in the cobalt. Although, that is comparing the DIC mileage to the calculated mileage.Quote:
Originally Posted by Iam Broke
Your getting HORRIBLE mileage in your cobalt. I beat the hell out of my HHR thats been tuned for over 30k now and am just getting my worst mileage, 20mpg at worst running 1:1 e85 to 93 and a/c on all the time. Also, the f40 isnt easily swapped in and doesnt have a double overdrive like the t56. Your t56 should be getting better than 20mpg on the highway...
Wow, tune your MAF tables. I get 28 in mine, when I am ripping it.
25 mpg on 50% ethanol beating on it.
I did the ratio comparison of the F40 not too long ago, and it would IMO be a really awful choice of transmission for this car. Also I doubt the F40 is much stronger than the F35 from the specifications I've seen.
http://www.ecimulti.org/scratch/gear_comparison.jpg
My T56 gets way better than 20 mpg on the highway, I am not talking highway MPG, I am talking average per tank. The T56 in the RX7 gets 34 mpg on the highway with the cruise control at 70.
If you guys are talking average per tank mpg, I am way behind... I'll get on tuning those MAF tables since it makes such a difference and then I'll get back to you guys. I mean I picked up the car off the lot last friday I haven't had it long either.
Gimp, I don't see what about those ratios is bad-- Closer 1-4, farther 5-6. Better acceleration and MPG. Trans is plenty strong V8 guys use them in Fieros, and I am looking into the new parts available with the 2011 Regals that come with F40s and LNF-variant motors to see if I can acquire some of the parts for the swap. Gimp, you also got a PM about that E85.
We have the torque to pull the longer gears, I'm just thinking all the extra shifting in the end is going to be a wash. Kinda like all the turbo K series cars I've ridden in, they end up shifting all the time and get almost always seem to get pulled.
Hey, the stock T5 in my old SBF RX7 held up well too hooking 1.5-1.6's... but I also had about 1200lbs less than a Mustang :) all a matter of perspective. Try that in a Mustang and usually you'll have a bucket full of T5 parts.
Not trying to be a jerk or anything man, I love to be proven wrong.... just don't think its a good transmission for the Cobalt.
Ask the MS3 guys if they enjoy shifting as much as they do...
Updated the guide with some new info :)
Curious as to why you adjusted the MAL table the way you did? Are you trying to keep the throttle from being too "touchy" with the DAL's you're commanding?Quote:
Originally Posted by BackyardTurbo_FTW
I gave it a shot just to see how I'd like it with the GMPP setup and I lost 2lbs of boost and 20ish % load (220, down from 240+).
Could it be the weather? I know around here it got a WHOLE lot cooler, and I lost about the same.Quote:
Originally Posted by T-Man
it's 100+ here (102 on my way home). Boost was 23-24 this morning, around 90-91 degrees.Quote:
Originally Posted by mkriebs
When I had the MAL set at 100% from 27 or 3K up the car would spike hard, then dip down, then pick back up. It never held 22psi for me, it would be a 23-24 spike, then the dip then hold 20.5-21 for a little bit.
Switching to the MAL table I posted now the boost comes on smooth, holds more, and is flatter holding more boost longer. I also tried making the DAL table 270 down to 3K then ramp them up to 350 by 6k.
Quote:
Originally Posted by BackyardTurbo_FTW
Even with the modified WG Duty cycle?
I'm just wondering if mine has to do with the fact that my DAL's are extremely conservative and I've never really needed to exceed 260 in order to achieve the boost I was after.
I'll give this MAL table some 60-100 runs and see how it performs.
Thanks again BYT.
I can tell you why that happened with the stage 1 tune. One time I wanted to do an experiment. I set the MALT to 75% straight across but I cranked the DALs in the 100% column to 400% or so. When I used to do this with the normal GM tune and 2.5 bar sensors the car would spike 25psi then hold 22 psi or so like normal. When I did this with the GMPP file the car was boosting only 16-17 psi.:bigshock: I thought I had something broken on my car LOL. It appears that on the GMPP tune the MALT controls the boost level to a much greater degree than the DALs. I find with the GMPP tunes it is always best to leave the MALT at 100% all the way across as it gives better boost response in the midrange but that is my own personal preference. With the normal non GMPP tunes I normally ramp it up smoothly starting from 75% on the first cell and up to 100% by 3K.Quote:
Originally Posted by T-Man
Thanks for the heads up Term. I had a hunch that the MAL table was much more of a factor with the S1 but I had no evidence to back that up.Quote:
Originally Posted by Terminator2
I'm going to do 3 60-100 runs on both tunes and report back later on, when it's cooled off a bit... ONLY 110 degrees right now, nothing serious :shrug:
No, Im talking about a HP Tuned car only. The combo tune is very different.Quote:
Originally Posted by T-Man
Makes sense now between what you and Term have said.Quote:
Originally Posted by BackyardTurbo_FTW
Thanks Guys!
Thanks for this again.
I just wrapped up an 09 Cobalt SS today but unfortunately I just saw this thread tonight! Here are some random thoughts...
This was the first of the platform that I have tuned. I enjoyed it so much that I spent a lot of time working with the car. I have an update session with the owner on my dime just because I want to spend a little more time on a few smaller points with it.
I spent some time playing with cam timing... more than I should have and all roads led back to OEM. This car had a Hahn (sp?) intercooler and cold side, an aftermarket downpipe and a replacement turbo that looked the same as the OEM unit to my eye (?). The cam timing will be more important later with a larger turbo and the need for more camshaft.
At WOT from about .87 all the way down to 0.75, the car made the same tq except up top. North of about 5500 there was a small (2-4 ft/lb) drop being that rich. I was somewhat surprised to see zero impact on tq in this area. It just didn't mind being fat. Also, the car didn't do as much with timing as expected. I ended up with the car being up to 14 deg up top. You guys can lean on your own cars and have more time to push on things; I'm not game for testing the limits on something that I don't own. :) Also as I said, I hope to have an update session with the car in a week or so.
The correction moves fast... with LTFT-ing disabled correction can move more than 10% in a half second even applying no learned value. As nice as this is, this is going to get people into trouble for relying on it! Having an on-board wideband, short term trimming literally becomes an expression of AFR error when filtered down. Once you get things like IAT normalized on a short cruise, 2-3 passes through the MAF table get's it within a percent. I actually set timing lower than stock and went over the MAF first thing after the base setup before doing any other tuning. The correction is nice but it should not be used as a crutch. If the underlying MAF is off, correction may work fast, but all of your transitional fueling will be off in the direction the MAF curve is off in that particular spot. It's good to get the underlying airflow model done BEFORE fine tuning spark at all. Any lean spots covered up by correction in the MAF curve have the potential to create tip in or transitional knock. It's important to realize the root of the issue rather than hacking up a sprak table right off. It's also comfort to know that you will hit target AFR at WOT regardless of correction so that you have the confidence needed to begin to manipulate timing at WOT.
Unlike mentioned by some in this thread, this car really had little-to-no false knock anywhere. A side note... you guys should expand the resolution of your timing tables. The screen shots on the front page show whole numbers. The factory carries it out a good bit farther. You can click the error with the 0's in the table's tool bar to get at least one decimal place on your timing values. The extra res is nice for fine tuning. The same is true for the MAF correction table; you might go 3 decimals on it if you take that approach.
Best of luck guys; I have to get back into my email.
This is a basic guide to show examples of how to work with the software on our cars. It is not intended to be an in depth hand holding guide. If you are tuning the car, you should have a general idea of how a motor works and what effects fueling, boost and timing have on it. Reading some guide quickly on HPT isn't going to teach anyone that stuff lol
I didn't read this to learn how to tune a car (or maybe you didn't fully read my post); I read it after tuning one and was just sharing some thoughts and what I observed. I don't normally do it and I can certainly take the post down if you are having a hard time with it..
Your post is fine, Im just explaining that there's a LOT still not covered and this is just a very basic how to for the software.
What kind of power did you end up making?Quote:
Originally Posted by Frost
Why are you running that poor car so rich? 0.75 lambda is way too rich for this car. I am shocked you did not loose a ton of power up top running it so rich. When I dyno tuned my last LNF (I normally street tune) going from 0.84-0.88 PE lambda made a 26 whp difference in the car.Quote:
Originally Posted by Frost
I didn't say I LEFT it there, just that running that range had no impact and that I was surprised (as you were as well). It was the first one that I had for tuning (typically all F-bodies and Vettes, trucks, etc) so I spent some extra time playing with everything to make sure that the owner was getting a good return on his dollar. I ran the range of AFR testing timing along the way. Also worth noting, you would expect running that rich would allow for at least SOME gain in timing vs. the leaner setting but that didn't pan out either.Quote:
Originally Posted by Terminator2
Last weekend went to dyno and played with lambda on the 5500-6500rpm range.
Initially I had 0.78 on that range, based on my reading especially around here I thought I loose power because of that.
I have bumped it little by little up to 0.86 on that range, no difference in the power.
The only thing which made me to gain something on that rpm range was Advance changes, initially had 11-12 degrees and bumped to 14 degrees (13.5 read) made to gain 2-4 KW ( 2 - 6 whp)
Used a mustang dyno.
I am a big time street tuning fan, but this underscores the importance of having BOTH sides of the coin. Why would you leave a car at .86 to .88 if it made no power leaning it out past .78 right? I left the car I tuned at .8. Going to .86 or .88 would just mean higher cyl temps and less resistance to knock. .88 is for N/A cars :)