Some basic tuning questions, and first log (sort of)

[xhaust50]

MODS: (Pasted from another thread) Mods are in profile, but important ones are 550 Injectors, 2g MAF, 255lph and Big 16g. I bought the car with all of the work done already, and it runs very strong and gets 24mpg mostly city so I know it is tuned pretty well. Anyway, the SAFC on low throttle is all up 11%, and on hi-throttle starts at +4% and gradually increases to +12% by 6000 rpms. The car seems to run very well, and I bought it from a moderator on a DSM forum.

The car is set to 20psi (from the original driver). I didn't want to lower it because I thought it would effect the tune and I didn't have a logger. I just got one for X-Mas though. Also, I drive extremely conservatively, and the car has only seen 20psi maybe 5 times in the last 9 months.

LOG: Using MMCD, I monitored RPM, Injector Duty Cycle, Knock, and Timing Advance. On a 15-minute trip around town I noticed an occasional 2-3 counts of knock at around 1500rpm, but only sometimes. Is this significant?

More importantly, I have 0 knock up to 5500rpms, then it climbs to 5 by 6000rpm's, where I let off the gas. Injector Duty Cycle here is 100%, so I know I couldn't get rid of know by adding fuel since the injectors are maxed out.

Questions:
1. How does temperature effect the tune? Would I be most likely leaner or richer in colder weather?
2. Is the occasional knock at low RPM's relevant?
3. How would water injection effect my injector duty cycle? Could I get away with 20psi with water injection on the 550cc injectors?
4. The car has a 255lph fuel pump, rewired, on stock FPR. This is a no-no on these boards, but if I remember correctly most say that the problem will be getting the car to idle because you are overrunning the stock regulator. The car idles perfectly though, way better than my stock TSI. I was just wondering if the larger fuel pump effects the Injector Duty Cycle at all?
5. Lastly (for now), on the SAFC is it better to set the TH setting to 30-70, or 69-70? I understand how the SAFC compensates, but I've seen people on here use both and I'm not sure what would be best.
6. How are EGT's relevant and what are they telling you? I thought that a really high EGT would let you know if you were too rich/lean, but if you tune for say 1 count of knock, wouldn't you know that you are just about on the money?


THANKS.

 

[ChvyKc]

MODS: (Pasted from another thread) Mods are in profile, but important ones are 550 Injectors, 2g MAF, 255lph and Big 16g. I bought the car with all of the work done already, and it runs very strong and gets 24mpg mostly city so I know it is tuned pretty well. Anyway, the SAFC on low throttle is all up 11%, and on hi-throttle starts at +4% and gradually increases to +12% by 6000 rpms. The car seems to run very well, and I bought it from a moderator on a DSM forum.

The car is set to 20psi (from the original driver). I didn't want to lower it because I thought it would effect the tune and I didn't have a logger. I just got one for X-Mas though. Also, I drive extremely conservatively, and the car has only seen 20psi maybe 5 times in the last 9 months.

LOG: Using MMCD, I monitored RPM, Injector Duty Cycle, Knock, and Timing Advance. On a 15-minute trip around town I noticed an occasional 2-3 counts of knock at around 1500rpm, but only sometimes. Is this significant?

More importantly, I have 0 knock up to 5500rpms, then it climbs to 5 by 6000rpm's, where I let off the gas. Injector Duty Cycle here is 100%, so I know I couldn't get rid of know by adding fuel since the injectors are maxed out.

Questions:
1. How does temperature effect the tune? Would I be most likely leaner or richer in colder weather?
2. Is the occasional knock at low RPM's relevant?
3. How would water injection effect my injector duty cycle? Could I get away with 20psi with water injection on the 550cc injectors?
4. The car has a 255lph fuel pump, rewired, on stock FPR. This is a no-no on these boards, but if I remember correctly most say that the problem will be getting the car to idle because you are overrunning the stock regulator. The car idles perfectly though, way better than my stock TSI. I was just wondering if the larger fuel pump effects the Injector Duty Cycle at all?
5. Lastly (for now), on the SAFC is it better to set the TH setting to 30-70, or 69-70? I understand how the SAFC compensates, but I've seen people on here use both and I'm not sure what would be best.

THANKS.

1) Most cars are going to be generally leaner during cold weather just because you are getting a colder charge due to the drop in outside temps.

2)I wouldn't worry about 2-3 counts of knock at 1500 rpms. I see phantom knock at odd rpms all the time in my car. It could just be some type of noise that the sensor is picking up.

3)Water Injection won't do a thing for your duty cycle. You still need just as much gas and maybe a little more. Water injection is going to do the same thing that an drop in outside temperature does. You are going to end up dropping your charge temp down by about 50 degrees (or at least that is what I saw)

4)The problem that you are going to run into with running the stock FPR is you are going to over run it when boost starts to rise. The fuel pressure is going to raise 1 psi for every pounds of boost you are running. You will have a fuel cut like problem (or at least I did) in the upper rpm range and you will get horrible gas mileage.

5)I would leave it at 30-70 depending on how the car acts. If you start to get some weird things going on between those two throttle positions then move them around or put them together like that to see if it fixes it. You just have to tune every car different.

 

[xhaust50]

I appreciate the response, and more responses are welcome. So is it possible that the current SAFC settings produce less/0 knock in the warmer temperatures? Do most people adjust the tune according to the weather? I think for now I am going to keep the stock FPR only because I don't see any problems with it, and also it idles fine with no strong gas smell like I read about. The car also gets really good gas mileage, just went on a trip this week and it got 30mpg on the tank. Lastly, I added a 6th question.

 

[Dream On]

For you question about EGT gauges, I think they're a nice warning meter, but not essential. I would tune for knock, like you're saying. And if the temp goes up too high, then it's running really lean, and probably knocking. It is a good heads up in case something goes wrong that your tune gets thrown off.

 

[xhaust50]

Two more questions: how are people logging their lbs/min, and will adjusting the boost alter the tune? Say I lowered mine to 18?

 

[ChvyKc]

Two more questions: how are people logging their lbs/min, and will adjusting the boost alter the tune? Say I lowered mine to 18?

I'm not for sure that you can log lbs/min with MMCD. The only software that I have seen people using to do that is DSMLink. If you lower the boost then the car will just run a little richer and you will probably get rid of the knock in the upper rpm range.

 

[xhaust50]

^^^ That makes sense with DSMlink, I just didn't think of it. I'll try lowering the boost to 18psi and see how the log is. Also, should I be maxing out 550 injectors at 6000rpm on a 16g?

 

[ChvyKc]

^^^ That makes sense with DSMlink, I just didn't think of it. I'll try lowering the boost to 18psi and see how the log is. Also, should I be maxing out 550 injectors at 6000rpm on a 16g?

No, you shouldn't be maxing out 550's with a 16G at 20 pounds. I was running 24 pounds with water injection on a supra sidemount with stock fuel pressure and I wasn't anywhere close to maxing out my 550's.

 

[xhaust50]

Would the stock fpr and the 255lph pump have anything to do with the injector duty cycles? It is possible the 5 counts of knock are from running too rich then? Also, wouldn't the water injection allow you to run slightly less fuel, since if you have knock instead of adding fuel you have the water injection coming in? (like having a higher octane). BTW I'm on 93 octane for reference. If it's not fuel pump related, and the car is indeed running lean and not rich, I guess it could be a boost leak or heat soak. Does the logger let you log intake temperatures?

 

[ChvyKc]

Would the stock fpr and the 255lph pump have anything to do with the injector duty cycles? It is possible the 5 counts of knock are from running too rich then? Also, wouldn't the water injection allow you to run slightly less fuel, since if you have knock instead of adding fuel you have the water injection coming in? (like having a higher octane). BTW I'm on 93 octane for reference. If it's not fuel pump related, and the car is indeed running lean and not rich, I guess it could be a boost leak or heat soak. Does the logger let you log intake temperatures?

Yes, you can have knock caused by to much fuel. I fought with that same problem when I was tuning my car.

As for the other questions, if you are running a meth/water mix then it will raise your octane level but I was running straight water. It was just cooling the charged air down and doing nothing for the octane level. If anything, I had to add a little fuel due to the drop in intake temps.

MMCD does not let you log intake temps and neither does PocketLogger since there is not an intake temp gauge from the factory on the car. I had a seperate gauge that I bought along with my water injection kit.

You should be able to tell if the car is running lean or not with the logger that you have. Generally, boost leaks do not cause knock but it is definately something that you need to check if you haven't done it already.

Heat soak would actually make the car pull timing as well. You would be able to see that on the logger. If you are heat soaking the intercooler then intake temps will start to rise along with knock and the ECU will pull timing to keep the motor from blowing.

If anyway possible it sounds like you need to make a log and post it on here so the other guys and me can look at it (preferable a third gear pull).

 

[xhaust50]

Thanks. This will be my last question before I do another pull and post the results. If I lower the boost to 18psi, theoretically I should either get slightly less knock or slightly more knock (because if I understood you correctly it will run slightly richer, which if I am on the rich side as it is this will create more knock, correct?)

And for the log:
RPM
IPW
Knock
Timing
TPS

Is that it?

 

[ChvyKc]

Thanks. This will be my last question before I do another pull and post the results. If I lower the boost to 18psi, theoretically I should either get slightly less knock or slightly more knock (because if I understood you correctly it will run slightly richer, which if I am on the rich side as it is this will create more knock, correct?)

And for the log:
RPM
IPW
Knock
Timing
TPS

Is that it?

Log O2 voltage as well. Since you don't have a wideband that will give me a better idea of just how the car is running. It's really best if you have a wideband but you can get a decent tune with the stock narrowband as long as it is in decent shape. Generally you can tune a 1G around .90 but you can go as low as .88 on 93 octane. 2G's are a little higher at around .93 with 93 octane. It's just a generally rule, every car is different but if you log those perameters then we should be able to get it straightened out.

 

[ChvyKc]

You may also want to read these tech guides. They have some really good information in them:

http://www.dsmtuners.com/forums/showthread.php?t=208824

http://www.dsmtuners.com/forums/showthread.php?t=105569

http://www.dsmtuners.com/forums/showthread.php?t=103469

 

[Dream On]

Generally, boost leaks do not cause knock but it is definately something that you need to check if you haven't done it already.

I seemed to get less knock when I fixed my boost leaks. Maybe coincidence, maybe not.

 

[ChvyKc]

I seemed to get less knock when I fixed my boost leaks. Maybe coincidence, maybe not.

Anything is possible when it comes to boost leaks. I've seen boost leaks cause some of the craziest symptoms. I've never personally had a boost leak cause knock in my car though. It has always either been a tuning issue or a bad sensor.

 

[xhaust50]

Alright, here's a log with the boost lowered to 17-18 PSI (for some reason Injector Duty Cycle doesn't come up on Excel):

RPM Timing Knock 02V TPS Airflow INJD
3063 25° 0 0.82V 63.9% 559.8Hz
3156 23° 0 0.86V 60.0% 673.0Hz
3250 19° 0 0.86V 57.3% 811.4Hz
3375 15° 0 0.86V 57.3% 912.1Hz
3500 15° 0 0.86V 57.3% 930.9Hz
3563 15° 0 0.86V 57.3% 949.8Hz
3719 16° 0 0.86V 57.3% 987.5Hz
3844 17° 0 0.86V 57.3% 1031.6Hz
3938 17° 1 0.86V 57.3% 1075.6Hz
4094 17° 1 0.86V 57.3% 1119.6Hz
4188 17° 0 0.86V 57.3% 1151.1Hz
4375 18° 0 0.86V 57.3% 1195.1Hz
4469 18° 6 0.86V 57.3% 1226.6Hz
4500 16° 5 0.86V 57.3% 1276.9Hz 68.7%
4656 16° 5 0.86V 57.3% 1314.6Hz
4688 16° 9 0.86V 65.1% 1402.7Hz
4813 16° 8 0.86V 70.6% 1478.2Hz
4938 16° 12 0.86V 76.9% 1528.5Hz
5031 15° 12 0.84V 91.4% 1591.4Hz 87.5%
5156 15° 11 0.84V 92.5% 1604.0Hz
5156 16° 11 0.84V 92.9% 1604.0Hz
5313 17° 11 0.84V 92.2% 1604.0Hz
5406 17° 10 0.84V 88.2% 1604.0Hz
5500 18° 11 0.84V 75.3% 1604.0Hz 96.8%
5594 18° 11 0.84V 68.6% 1604.0Hz
5594 19° 11 0.84V 54.1% 1604.0Hz
5719 21° 19 0.86V 60.8% 1497.0Hz 96.0%
5781 16° 19 0.84V 70.2% 1604.0Hz
5781 16° 19 0.84V 75.3% 1604.0Hz 100.0%
5906 16° 18 0.84V 75.7% 1604.0Hz 103.0%
5969 17° 18 0.84V 75.7% 1604.0Hz


I'm having trouble bringing up the 20psi log. Also, I have a ton of knock at low throttle boost, like 40 counts. If I'm not boosting its 0, and if at WOT it's 0 until the upper RPM's, but at around 2500rpm part throttle yet enough to boost there is a ton of knock.

 

[xhaust50]

For some reason my 20psi log is stuck in the "exporting data" screen, but it never finished no matter how many times I tried.

Here are my SAFC settings for reference:
TH - Low 16, High 72

Hi Throttle
1k +4
2k +5
3k +7
4k +9
5k +11
6k +14
7k +14
7.5k +14


Low Throttle
1k +8
2k-7.5k +15

 

[xhaust50]

Here's the knock at low RPM's, and the 20psi log:

RPM Timing Knock TPS 02V Airflow
1063 12° 0 12.9% 0.12V 44.0Hz
938 14° 0 17.6% 0.12V 56.6Hz
1031 12° 0 18.0% 0.04V 81.8Hz
1063 18° 5 18.4% 0.00V 94.4Hz
1250 17° 18 20.0% 0.00V 113.2Hz
1313 17° 26 20.0% 0.00V 119.5Hz
1438 17° 32 20.4% 0.00V 132.1Hz
1563 17° 32 20.4% 0.00V 138.4Hz
1688 17° 32 25.5% 0.00V 157.3Hz
1844 16° 31 27.8% 0.00V 207.6Hz
2000 16° 31 28.2% 0.00V 226.4Hz
2125 17° 31 28.2% 0.00V 239.0Hz
2344 17° 30 28.6% 0.00V 257.9Hz
2500 19° 30 29.0% 0.00V 276.8Hz
2688 20° 30 29.0% 0.04V 295.6Hz
2875 22° 29 29.0% 0.12V 314.5Hz
3094 23° 29 26.7% 0.14V 320.8Hz
3000 28° 10 10.2% 0.18V 113.2Hz
2688 37° 0 10.2% 0.18V 94.4Hz
2406 38° 0 10.2% 0.14V 88.1Hz
1875 37° 0 31.4% 0.16V 188.7Hz

RPM Timing Knock TPS 02V Airflow INJD
2500 23° 0 87.8% 0.84V 440.3Hz
2594 23° 0 92.5% 0.84V 471.8Hz
2688 21° 0 93.7% 0.82V 509.5Hz
2719 20° 0 94.1% 0.84V 559.8Hz
2813 18° 0 93.7% 0.84V 616.4Hz
2906 15° 0 92.9% 0.86V 704.5Hz
3000 15° 0 90.6% 0.86V 798.8Hz
3125 14° 3 87.1% 0.86V 905.8Hz
3250 13° 7 85.5% 0.86V 981.2Hz
3375 13° 6 81.6% 0.84V 993.8Hz
3500 13° 6 80.0% 0.84V 1031.6Hz
3656 13° 5 80.0% 0.84V 1075.6Hz
3750 14° 5 80.4% 0.84V 1119.6Hz
3844 15° 5 80.4% 0.84V 1157.4Hz
4000 16° 11 80.8% 0.84V 1232.8Hz
4125 14° 11 80.8% 0.84V 1276.9Hz
4250 14° 11 80.8% 0.84V 1320.9Hz
4375 14° 10 81.2% 0.84V 1377.5Hz
4469 13° 13 86.7% 0.84V 1465.6Hz
4594 13° 13 87.1% 0.84V 1484.4Hz 78.10%
4688 13° 12 90.2% 0.84V 1528.5Hz
4750 14° 12 96.1% 0.84V 1559.9Hz
4875 15° 12 97.3% 0.84V 1572.5Hz
4938 15° 12 97.3% 0.84V 1604.0Hz
5000 15° 11 96.5% 0.84V 1604.0Hz
5094 15° 11 94.5% 0.84V 1604.0Hz 87.50%
5188 16° 11 92.5% 0.84V 1604.0Hz
5313 16° 10 91.8% 0.84V 1604.0Hz
5438 17° 10 90.6% 0.84V 1604.0Hz
5531 17° 10 90.2% 0.84V 1604.0Hz
5656 18° 14 89.8% 0.82V 1604.0Hz
5688 17° 13 90.2% 0.82V 1604.0Hz
5719 18° 13 90.2% 0.82V 1604.0Hz
5781 18° 13 90.2% 0.82V 1604.0Hz 100.00%
5813 18° 13 89.8% 0.82V 1604.0Hz
5938 20° 12 89.8% 0.82V 1604.0Hz 103.00%
5969 20° 12 89.8% 0.82V 1604.0Hz 101.00%
5906 20° 8 11.0% 0.88V 748.5Hz
5813 44° 0 10.2% 0.78V 188.7Hz


Looks like I need to start over with the tune.

 

[xhaust50]

I'm Going To Move This Into A New Thread So It Is A Lot Neater. Please Reply To Other Thread If Interested.
http://www.dsmtuners.com/forums/showthread.php?t=249902