Z_Ghost

What all do I need to look at to get a chip tuned at 76* to work right at say 102*.
I got most of my BLM’s around 128 (75 KPA and lower) and did some work on timing and went back and worked on the BLM some more. It’s been around 76* the last 2 weeks and from the looks of it the weather might be in the upper 80’s by next weekend.

Could some one give me some pointers on anything I can start working on when the weather gets hotter? I want 1 chip to us all year long. I tried searching but have not found anything yet.
Thanks

This is on a 92 Z using tune cat.

Grumpy

Depending on the Mask your working on, the gm correction factors should be close.
Thou some aren't real good at weather changes, code wise, ie the 747 has no IAT.
BLs should compensate prety well for things.

It's also not just about the weather, fuel mix changes 2x a year, and that can be a headache in it's self when you tune for the edge.

Z_Ghost

730 $8d
So the closer I get to being right on at one temp the more off it will be when the weather changes a lot. Sounds like I will have to have 3 chips 1 for winter 1 for spring and fall and 1 for summer, I guess I know what I will be doing for a long time, good thing I really like this.
Thanks Grumpy.

I can see some difference in the BLM for 4:30 (83*) pm to 9:00 (72*) pm they look a little richer.

I have been working on the knock attack and recovery rates today and have seen most of the lower rpms (600 - 1400) and KPA Blms change with the temp.

Grumpy

No the closer you are at one temp the closer you should be all around.
This is why you need to have the injector constant right (for those that try and shortcut the system).

You generally want slightly faster attack rates, and really fast decay rates.

Z_Ghost

I see you were talking about the gas changing, missed that.
Good then I will not worry about having to tune for different times of the year when I am done (never really going to be finnished).

That's what I was doing, getting some knock around 2200 to 4000 rpms (part throttle), not a lot, 8d is the most I have seen. After working on the attack and dacay rates I see were it looks like it's really happening (3 spots) and will lower the advance some at the rpms and KPA were the knock is showing.

Grumpy

I been thinking about the weather part of your post (too much actually).

Anyway, what hurts people is when they try to run too small of injector, and crank the duty cycle way up to get the car to run.

This all get back to the way I suggest sizing injectors. With an oem ecm you want 50% more HP then stock you need a 50% large injector, that way you keep the relative VE tables and BL corrections intact.

You need to take some timing out and/or add some fuel before the detonation starts. Once it starts you have to cool things back down to stop it, meaning more fuel and less timing then preventing it in the first place.

Z_Ghost

Sorry about that Grumpy.

The motor is stock from the intake on, I do have a lots of parts to put on the car, but I want to know as much as I can about programming the chip before I do that.

I have left the injector flow rate stock as I have stock injectors (one of the things I will change later), so all I have been doing is lowering the VE as most of the BLMS were under 128. The stock chip has the VE @ 92.6 @ 3600 rpms and 100 KPA. I know the VE only goes to 100, So I can see why this would be a problem with a moded motor. I have run it up close to that with out being in PE and it looks like I will not have to go any higher than that on the VE.
I did the math and from what I can tell I will be safe with the way the car is with regards to duty cycles. I do have the post saved were you talk about sizing injectors, that will help later.

Taking out timing right before it happens, now why did I not think of that, stands to reason... if you wait until you get a knock count it's to late... Thanks Grumpy

Need to go do some more thinking, ouch that hurt, need aspirin.

Z_Ghost

I really think I will put an oil temp gauge on next weekend if I can find one.
On the last run (4 PE runs close together) I did to night I am getting a lot of sp knock when I am in PE and around 3300 to 3900. Right before I got 10.2d sp knock the water temp went from 190.0 to 192.5, it does have that cheesy oil cooler on it (GM). I might be getting the oil temp's up to high.

LBSZ28BLOWN

Z_Ghost,
If you have a relocated MAT sensor, I found that tuning the MAT Tables will help out on real cold or hot days, 128/128 all conditions.
Do a search on this thread, this may be what your talking about.
(MAT recalibration tables......)

Grim Reaper

Here is a copy of my "Inverse MAT Lookup Delta Multiplier" Table that I use for my relocated MAT. It functions at "128/128" from 0*F to 100+F.

As Bruce alluded, it took a year of monitoring to develop and then test. Also, if you use this table, you must realize it works in conjunction with my Injector Constant and VE Tables. So you will most likely have to adjust your Injector Constant and/or VE Tables initially to get 128/128. I would start with the injector Constant if you are already getting 128/128 at a particular ambient air temp.

Have fun.

Z_Ghost

Thanks Louis and Glenn.
Yes I did relocate the mat, did that a long time ago before Glenn started his post about it.
Looks like I will need to monitor the temp and humidity and log that in my notes.

Grim Reaper

I am still not finished with the entire MAT tables. I've tried to "expand" the table to use a scaling factor to cause it to use the entire range of the table (0-256) rather than 0-128. I feel it will give a better resolution.

But the table I posted is a good starting point for anyone wanting to run a relocated MAT on SD cars - realizing my initial cavaet about the Injector Constant/VE Table probably needing adjusting.

Z_Ghost

Glenn
why does it say GM/SEC seeing as the mat is temp?

Grim Reaper

Because that is how it is defined in the $8D hack. Also, you'll notice the title has "Inverse" and "Delta" in it. Trust me, those words are there for a very specific reason - the table DOES NOT work how you'd think it should. The best I figured is that it works with the "difference between your CTS and MAT" and uses a "multiplier" for the "computed air/flow" that the $8D does. This routine is very inter-related to the whole calcuation of air/flow and subsequent fuel calcibration. I did a LOT of "playing" with it to figure out how to get it to provide proper MAT correction values.

As I said earlier, there is a LOT to this routine and when I initially thought I had it all figured out; and I even tried "rescaling" the table, I sadly learnt I had not. But, since I had an MAT correction table the gave me good values and I had other things to work on, I just haven't bothered going back to analyze and determine precisely how the routine works. Maybe later in the future when I have more time, but right now it just isn't important to me.

This is also why I have never done a Tech article on it. Besides, most people seem to be more interested in "the numbers that work" rather than how the ECM/Eprom actually processes the information. There is a "second" table, which relates "Temperature to BIN Count" but trust me, that doesn't work as you'd think it should either. The two tables are linked. But feel free on reading the hack and figuring out how the two relate to each other. But be prepared to work on the actual "correction values" for the next year....or you can just copy the values I've given, make the adjustment to the Injector Constant/VE Table to make the table I've given work , and move on to more important "tuning aspects".

Z_Ghost

Thanks Glenn
At least I can see some light from the bottom of the hole now. One day I may get into the hack and learn it, but for right now I will stick with using Tunercat. You did shed some light on it and how it works, I do like knowing how and why things work, makes it easier to under stand some of the other reasons why when you change this it affects that.

Grim Reaper

Note the differences between my modified table and the stock table. While it may not look too different, the changes do have a dramatic effect. Prior to the change, I was running far too rich in Winter and too lean in Summer with a relocated MAT.

BTW, increasing the value in the Table results in "leaning" and decreasing the value in the Table results in "richening". That's where the "Inverse" part of the Table's name comes in.

Z_Ghost

Thanks for that info. I hope the weather is not bad this weekend as what I am going to do is burn 2 chips, 1 stock and the other one stock with your # in it and see what happens.

I do know that after moving the mat and when I was driving on vacation that I lost some mileage. Before moving mat I could get 26.3 @ with an avg. of 63 mph and after moving the mat the best I could get was 24.9. I go to the same place every year and at the same time of year and while it may not be very scientific I do believe I lost the mileage because of the relocated mat.

Thanks again Glenn, it's nice to have people on here that are willing to share information

Grim Reaper

Also, if you are running a relocated MAT, you should lower the "EGR Enable Temp" counts to a very low number. The stock value will cause the EGR to cease functioning if the Air Temp falls under 40(ish) F. That greatly affects fuel economy and the fuel calibration overall.

Z_Ghost

I think I did that on the third chip (would have to look at notes to be sure), I did read most of your post about relocating the MAT and did not want the EGR to be dysfunctional.

I like what you did with the sticky post, I do spend a lot of time rereading old post late Sunday night and will copy links to the good one. If you need help looking for something special let me know and I will work on it.

Z_Ghost

Results for test part 1
What I did tonight.
Burned 2 chips, 1 stock, and 1 stock with Glenn’s adjusted Inverse MAT Lookup Delta Multiplier # for the relocated mat.

So far just running through the scans (have over 1 hour driving time) I have seen the BLM’s running about 2 points closer to 128 (most were 122 with Glenn’s # and 120 with stock # @ 70 mph) and see less spark knock when in PE (about 5* less).
I am going to graph MAT / MAP / RPM / CTS readings just to see how much change there is, but from what I have seen it did help.
So you know it’s about 76 * out tonight.

Later in the year when it's hotter out I will try to run this again and play with the table some.

Seems like a better starting point to start tuning the BLM’s.

LBSZ28BLOWN

Z_Ghost,
I found here in Texas it seems to be best to tune to 128/128 @ 80deg F and then work with the MAT tables on warmer and cooler temps as they happen.

Heres what my tables look Like:
Keep in mind that I relocated the MAT sensor and have ram air mod & I'm Supercharged
gm/sec_________Multiplier
0 ------------- 1.000
16 ------------- .680
32 ------------- .578
48 ------------- .500
64 ------------- .328
80 ------------- .109
96 ------------- .086
112 ------------ .086
128 ------------ .086
144 ------------ .086
160 ------------ .086
176 ------------ .086
192 ------------ .086
208 ------------ .086
224 ------------ .086
240 ------------ .086

Grim Reaper

Z, if ALL your numbers are "consistantly in the 120-122 range, just increase your Injector constant slightly to force it to 128. Then just monitor it. You may find that you might have to do a little more tweaking but if they are consistent right now, I'd expect them to remain at 128 once you get your Injector Constant/VE Tables to give you values in the 128 range.

Z_Ghost

Glenn that's what I am going to do, should work out really nice, I want to get the BLM's really tight so I can start working on HWY mode.


Louis
I was thinking about the temp that would be best to work at.


???

When you two worked on the tables do you adjust all the # or just some of them for the different temp's. I would like to know how to work on them if I ever need to adjust them. Need some advice on how to change them. I know Glenn said that the # are inverse and I under stand that, just wondering how many of them need to be changed at one time. I just want to have a guideline to add to my notes.

Thanks for the help.

LBSZ28BLOWN

Z_Ghost,
Do a search for this post:
(MAT recalibration tables...... )
I think this will explain it for you.

Z_Ghost

I did and found a post I missed.

https://www.thirdgen.org/techbb2/sho...bration+tables

Grim Reaper

Yeah, I remember that old thing. I should probably "merge" that post with this post.

HOWEVER, you will note in THIS post that I mentioned that I THOUGHT I had it ALL FIGURED OUT (which I did when I wrote that post).

WELL, as I said in this post there is STILL more to it than I thought. There is a lot more to the "interrelationship" between the two tables AND your Injector Constant AND VE Tables that I originally thought. I am STILL trying to figure it all out AND I wouldn't be holding my breath for a "Final Answer" in the near future.

I do think I am "in the right direction" between the "BIN Table" and "Inverse MAT Lookup Delta Multiplier" Table. Just not well enough to "predict" how much of a change a person should make to go from "X BLM value to 128 BLM Value at a certain Ambient Air Temp reading".

Also, I believe your Coolant Temp is a factor in all this (from what I am seeing). I have not tested it, but I believe that if a person were to change their T-stat, they may find that they have to "recalibrate" this table. You have to realize that GM designed the MAT to be INSIDE the plenum....not relocated. I do know that there is "code" within the 7730 that "tests" both the CTS and MAT and IF the ECM thinks "one is screwed" it will use the other "for a reading" and try to "limp you home". This is part of "Fail Safe". Definitely interesting to say the least.

Z_Ghost

Glenn
that got me to thinking that it might be a good idea to have the MAT at the same temp when adjusting the VE tables. I know that when stopped the temp goes up and can take some time to go back down.

The comment about it all tying into coolant temp might explain something I noticed tonight, I see my BLM at idle sometimes at 119 and some times at 122. So far it's just those 2 numbers, if I get off the HYW and the coolant temp is around 186* BLM is at 119 and when driving around town the coolant temp is 191 then the BLM is at 122.

Grim Reaper

Yes, but the nice thing is that generally EVEN with a Cold Air Intake, the temp of the relocated MAT also rises (though not as much as the stock "in plenum") so the difference is not all that great between "on highway" and "in city". Also, the range of the VE table you run in the city is genearlly in a different area.

I think altering the Injector Constant (probably about .5 or so) and a few minor tweaks to the VE Table and you will be running 128/128 consistantly.

Z_Ghost

I am going to raise the Injector Constant and tune from there; I have been adjusting the VE mostly to help me learn how to do it and to see what happens. I need to build a good base of notes for later when I start putting on all my hot rod parts.
One of the things I have learned is that the stock chip in the lower KPA and RPM's the BLM's run rich and as I bring them back up to 128 I get a little hesitation at slow speeds. Playing with the advance and pump shot fixes this and the car runs a lot better than with the stock chip.
I have gone back to the stock chip to start over about 4 time now just learning a little more each time. Now that I have a good handle on adjusting the VE's I am going to get 1 chip were they are as close to 128 as I can get and get the spark advance worked out better. By then hopefully the G-Tech will be here and I can do some part throttle testing and get good at that, then start on the HWY mode and full throttle (need to get the wide band O2 circuit board solder up)
I am starting to think I am getting addicted to this.

Thanks for all the good information and help.

Grim Reaper

Hey, I do that ALL the time. In fact, I will sometimes do that JUST to find out WHY a certain "driveability issue" is occurring. What I generally do is install my original eprom back - to verify whether or not the driveabiltiy issue existed even then.

If the problem DOES NOT EXIST, with the original eprom, I then add "each table" and "constant" that was changed "one by one" until I find the culprit. Since TunerCat allows you to "copy" and "paste" from multiple BINS, I just do that to "speed up" the process.

If there is a LOT of tables involved, I will copy all of the tables to an Excel File (that I will be playing with). Then I just "copy/paste" from that. That was a great modification TunerCat made in their new Version last summer ("cut/copy/paste").

Z_Ghost

I already used that feature a few times, made it worth the money for Tunercat.

Glenn how hard is it to get Excel set up for the way you are using it, need to see how much excel is, but it sounds like a good way to go. It can take me a few hours to go through the scans and copy all the BLM, RPM, MAP figures then convert the blm figures to an adjustment value for the ve. I think I spent 4 hours working on that the other night, had over 25 data points to do.

Chris Etemadi

sorry for kinda bringing this topic from the dead kinda, but I have looked in GMEMCEDIT and WINBIN and I cant find that table, Also I cant find the "pump shot" table either. Does Tuner cat have those tables? Is there a free way for me to change these values?
Thanks, Chris