Yea I didn't touch the boost cut. I was wondering the same thing. I am sure once it gets cold again I might hit boost cut but for now I'm not. The car also runs a little lower HZ on the street.

 

You learn more every day. I just know that if I exceed 1,330 Hz. at 4,000 rpm, I hit boost cut. Edit.....I own an 03 that has a lower boost cut value to begin with.

I also realize that altering the MAF signal by reducing the frequency will extend this value. I have been using that principal with ECU+ and 680 cc/min injectors for awhile, but Bryan had all of his tables zeroed when using ECUFlash......so I would have thought he would have hit boost cut...


........wait, I just realized that Bryan has a 05 model, which had a higher boost cut from the factory. This probably explains why he did not hit it

Well, I believe that I answered most of my own questions, but thank you EFIxMR for shedding clarity on the situation.

HiVolt

 

I was hitting 1169hz at 4,000 rpm

RPM MAS Hz
3010 639
3029 656
3060 689
3085 704
3117 724
3145 770
3176 791
3202 837
3229 847
3277 878
3308 915
3334 942
3370 964
3403 1038
3456 1008
3485 1006
3515 1073
3550 1034
3594 1014
3638 1014
3668 1014
3698 1111
3721 1066
3770 1062
3830 1077
3864 1127
3889 1154
3926 1123
3972 1125
4013 1169
4046 1152
4074 1148
4128 1194
4158 1161
4206 1224
4222 1210
4268 1178
4322 1229
4343 1215
4382 1226
4416 1243
4463 1256
4506 1243
4545 1279
4574 1289
4615 1306
4645 1295
4687 1306
4707 1331
4750 1351
4813 1354
4844 1354
4879 1399
4909 1421
4948 1415
4990 1454
5030 1451
5060 1434
5104 1471
5125 1441
5171 1451
5204 1489
5254 1492
5278 1478
5314 1461
5339 1510
5387 1521
5437 1503
5457 1514
5484 1544
5527 1547
5546 1563
5599 1591
5629 1583
5655 1591
5684 1567
5727 1611
5763 1624
5796 1619
5838 1624
5860 1645
5884 1649
5921 1658
5953 1671
5993 1685
6020 1698
6049 1689
6086 1694
6122 1694
6154 1698
6191 1689
6228 1703
6261 1717
6280 1698
6314 1712
6337 1703
6393 1722
6428 1712
6439 1741
6468 1741
6509 1775
6538 1751
6582 1780
6598 1765
6619 1765
6673 1796
6683 1765
6731 1796
6750 1796
6787 1780
6809 1791
6844 1775
6861 1806
6907 1796
6919 1816
6942 1791
6984 1791
7007 1811
7026 1801
7065 1806
7076 1791
7111 1816
7143 1854
7173 1816
7190 1849
7201 1816
7237 1832
7276 1838
7311 1843
7319 1832
7354 1827
7359 1849
7380 1832
7412 1832
7432 1838
7456 1827
7474 1843
7510 1832
7528 1838
7558 1871

 

Thats what I'd expect to see.. I hit over 1300hz at 4000rpm (with only 20psi of boost), but like I said, my blowthrough sensor is currently configured to intentionally be 35% higher than normal until I get my new injectors and other parts done..

Because of that, I'm not getting misfire, my injectors at that level are only 55-65% duty, but my timing is anywhere from +1 to -1 degree, and that is what I'm feeling.. When I go into the ECUFlash map, I can tell that my MAF reading at 3000-5000rpm would likely be in the 230-260% range (makes sense since the entire maf curve is 35% higher than stock)

Now I can drop my MAF curve back to 30hz at idle, and globally add a point to the fuel table, which should put my car back into happy fuel trims, and I should end up in a normal range for my cams, I can then complete full pulls and do some real tuning again.

 

I actually raised my boost cut value a small amount over stock..

I'll be using 1000cc injectors, I haven't determined the voltage latency value that is best for it yet, but I probably will set its size in the ECU for 900 or 925 (using the guideline from the stock ECU, 550's set at 513 are about 10% lower than the actual size) and use the fuel maps from there..

 

Malibu/Razor,

Have you guys sucessfully scaled larger injectors using ECUFlash? I assume that Razor did from his original post. I was wondering if you could give some advice to the rest of us that are trying to make this happen.

I must admit that I have only had 15-20 minutes with it thus far, but was unsuccessful. I did not really expect to be successful in that short of time.

My methodology is to change the scaling value to roughly 90-93% of the real injector flow rate and then globally adjust the voltage latency values to get appropriate short term fuel trims. Incidentally, my injectors are Precision 680 cc injectors.

Once I do this, I need to log and slowly increase load to make sure that I do not get too fat or too lean.

Is this methodology correct or is there anything else that should be added.

HiVolt

 

yes your methodolgy will work.. In general thats how I do it, only the bigger the injector the higher the latency, so I generally fiddle with the larger ones to get them right more than the smaller ones..

I have successfully scaled several different size injectors, the smaller ones didn't need the voltage latency value altered much.. the bigger ones did because its hard to get the trims "In check" without it at idle..

 

The best and most accurate way is to send the injectors to get flow tested and requesting dead times for each voltage.

Easy to do if you haven't installed them yet. Little harder if you have.

 

Some of that is already documented for commonly available injectors from some manufacturers... I completely forgot about that when I recalled that my older injectors came with a slip that had the flow data...

 

looking good razorlab.

 

So I got my hands back on a WinXP laptop today to make some tweaks to my maps.

I basically smoothed out the Fuel Map, richened it up a bit since I was running a bit too lean for me to be comfortable and I also smoothed out my Timing maps:

Before (my tune from the dyno on 06-03-06):



After (today 6-10-06):



Street dyno comparison (looks like the changes made a difference):

 

Hi RazorLab

can you tell me what you put in for the Injector battery voltage latency
and the injector scaling

I have also 720 cc injectors

 

I would love to, however, I actually cheated a little and got them from a local tuner. I wish to respect his work and not distribute it.

 

^^ booo lol. I'm trying to find some examples

 

I want to bring this thread back from the dead to reaffirm the above quote from bryan.

As most of you know, I run an Xede with a TBE on my car. I have been tyning to tune the car to run on 91 octane now that gas prices have gone up.

A couple of days ago I did some logs and on one pull the car would run knock free but on the other it would knock. This went on pull after pull. It drove me crazy.

So I finally decided to zero out the xede timing and ignition map and use it only for boost control.

Then I flashed my ECU with a 91 octane flash that I have been working on. I figured out how to patch the rom so I can log the 2 byte load (thanks Eric).

The runs were very very consistent with the flash as opposed to the Xede and the car put as much power as it did with the Xede. There is almost no knock in the logs

I have already done a second version of the flash and today I will test my third. I am gradually making the tune more aggressive until knock becomes a consistent problem.

I will keep my xede as a boost controller for now. I will remove it when I figure out how to get the ECU to control boost.