Anyone want to look at my tune? Cam surge...

[SSpdDmon]

Well, I tried SSpdDmon's map and it helped a bit, the surging still isn't gone, but its a lot better than it was. I didn't do a RAFIG again yet, just took it around the block. It is a 00 tune sent over to a 02 OS. It looks like you put the spark tables back to stock(or close to it) any main reason for that?

I'll play with it a bit more tonight once the roads are more clear, it at least feels like I'm heading in the right direction now, thanks a bunch!

No problem. I started you out at 27* because that's a general safe point for that cam. I actually found running more than 27* @ WOT cost me power when I was on the dyno. Until you can get on one, it's probably a good place to be. Try my tune afer you have updated the Desired Airflow table using the RAFIG process PLUS a couple of driving cycles. That should give it a chance to learn itself some.

Also, looking at your desired idle airflow....I like to smooth out the results a little. It should look like a hockey stick....not the tough side of a saw blade. If you log the IACDES_B pid, it'll help you see what the values need to be (assuming there's no other IAC influences). I usually take the average for a given ECT (i.e. 154*F) and add in about 0.5 grams/sec as a buffer. It smooths out pretty good if you use the average of just 154*F or 176*F or whatever cell you're working on. All the temps inbetween will just skew the data. The easiest way to see one temp (176*F for example) is to filter ECT less than 175*F and greater than 177*F. Then, adjust your data, change your filter, and move to the next cell. Make sense?

[rosey]

Yup, makes sense. 27* sounds good under load, I was just wondering why you pulled so much out down low at lower loads(mainly where the surging is happening) I was under the impression that more timing would tend to make the motor less susceptible to surging.

Thanks again for the help, I own you one.

[SSpdDmon]

Yup, makes sense. 27* sounds good under load, I was just wondering why you pulled so much out down low at lower loads(mainly where the surging is happening) I was under the impression that more timing would tend to make the motor less susceptible to surging.

Thanks again for the help, I own you one.

You should read the idle tuning writeup in the tutorial section (again). I used to think the same thing.

I guess you could call it a result of the butt dyno. I tried to get in a position where I could really 'feel' what the car was doing. I noticed when the surging started, the first motion was always forward. Then, it would rock back and forth until you did something different. With the throttle cracker completely zero'd out during the surging and AFR in line, the only culprit left was timing. Since more timing makes the RPM want to run more, I started pulling timing....and it got better. People are so quick to jump on the 'more timing is better' train. I pulled a little timing and it ran just as good (even better in some spots). Everyone would always say, run MBT (the least timing making the best power). So, through trial and error I put that theory to work. Then, I did a little reading on distributors and realized they advanced timing at part throttle based on where WOT is at plus a certain amount as vacuum increases. That's why the timing is more linear than stock going from left to right. Could you really dial it in better? Sure. But I don't have the time, money or equipment to do that.

[rosey]

Well, playing with the throttle follower has helped, its still the worst decelerating(off the throttle) so after trying 10 different things I ended up back on the throttle cracker table and its been liking it when I add air in the 1000 and 1600 rpm rows. Then I came back and read the idle tuning tutorial again and laughed when I read this line...

"For light load, low RPM bucking, you can increase the multiplier to bump up the throttle follower airflow that is added. Remember, this is for surging while your foot is on the gas. If you have problems with surging off the throttle and believe it's airflow related, that's addressed in the throttle cracker tables"

Looks like the answer was right in front of me the whole time...guess it just didn't stick the first 3 times I read it :lol:

[SSpdDmon]

Well, playing with the throttle follower has helped, its still the worst decelerating(off the throttle) so after trying 10 different things I ended up back on the throttle cracker table and its been liking it when I add air in the 1000 and 1600 rpm rows. Then I came back and read the idle tuning tutorial again and laughed when I read this line...

"For light load, low RPM bucking, you can increase the multiplier to bump up the throttle follower airflow that is added. Remember, this is for surging while your foot is on the gas. If you have problems with surging off the throttle and believe it's airflow related, that's addressed in the throttle cracker tables"

Looks like the answer was right in front of me the whole time...guess it just didn't stick the first 3 times I read it :lol:

Well....check the 'edit' date at the bottom of the post. I recently updated that section. So, you don't have to feel entirely bad.

[rosey]

Sweet, maybe I'm not completely losing my mind after all.

I'm fairly confident that I have found my problem. As I understand it the throttle cracker will be active whenever above the activate speed(b4311), until it gets delay/decayed out at the deactivate speed(b4312), correct?

I'd been bumping up my throttle cracker more, and more because it seemed to help when I added a little in the 1000 and 1600rpm rows. Not much was changing, so I finally said screw it and bumped all the values way up, so most were in the 5-7g/s range. While watching my logs I noticed whenever I let off the throttle, the throttle cracker and follower(both set very high, adding 5+g/s each) dropped to 0 almost immediately, and then it started bucking as usual. Looking back on some old logs I noticed this as well, they never decay, they just cut out instantly and my IAC desired airflow pid goes to ~6g/s(which is about what my RAFIG table is set to).

My start speed for throttle cracker is set to 3kmph and deactivate is 2kmph...All my decay/delay tables look normal, and I've tried several different things...it seemed to help most when I added 2g/s to my RAFIG, but the idle hung way up obviously.

I don't see any other table that could be affecting this, I'm completely puzzled , heres a log...

[TuneMaster]

From what I can see in the log it looks like spark is being pulled out from your spark IAT table? Also here in Australia our Holden's don't run EGR so check your EGR spark tables. If someones knows are these values being added or subtracted from your Timing values. You need to log the run spark pid to see what ur actual timing is and go from there.

[rosey]

From what I can see in the log it looks like spark is being pulled out from your spark IAT table? Also here in Australia our Holden's don't run EGR so check your EGR spark tables. If someones knows are these values being added or subtracted from your Timing values. You need to log the run spark pid to see what ur actual timing is and go from there.

Good call, I'd noticed that as well and I've 0'ed all the cells up to 140* since that log had been taken. I don't have an EGR valve either, and my b1301 is set to disable, so it shouldn't matter, but I just went and 0'ed the table anyway for the heck of it.

I'm convinced all this bucking is down the the throttle cracker not cracking, and the follower not following. It seems like the follower works as it should, but the instant I move out of a cell that its being used, it drops to 0. The cracker just seems to pop up every once in awhile, but then goes right back to 0 even when I'm still moving and in cell that should be using it.

I've made "custom" dash to help me watch whats going in with the TF TC and IAC...see how the tps just became 0 and the TC and TF are both 0? This is where it starts bucking

[TuneMaster]

In your throttle cracker table for 2000 RPM there is zero values. Try putting some numbers from 1600 RPM upwards and see what happens.

[rosey]

In your throttle cracker table for 2000 RPM there is zero values. Try putting some numbers from 1600 RPM upwards and see what happens.

You mean something like this?

All that changes is it spikes up higher...still drops back off to 0 right away...delay and decay rates were set to stock.