Advancement of fuel delivery?

[Alky V6]

Areas of the tune still to finalize and explore:

Optimize a/f ratio through the nitrous hit. This is a priority.

The amount of time to keep the spool valve closed. This can be extended out as long as necessary and the opening of the valve can be ramped at whatever level I choose. This can be played with while other tuning parameters are being adjusted.

The activation point for the nitrous system before transbrake release. Up to .5 sec more that can be tapped into. Play with this after nitrous system fueling and timing has been finalized.

Ignition timing on and off the nitrous system. At present, still very safe. This will be adjusted only after I have a good handle on the nitrous fueling.

The amount of boost that the 1-2 shift can handle. This will be a pretty important one. Traction will be the limiting factor. To be played with along with other tuning adjustments.

The amount of max boost by the end of the run that the present fuel delivery system and new chassis upgrade can support. This can be worked upwards while other tuning adjustments are being made.

The value of the nitrous system shot. There is still up to 80hp more that can be added to the present level. A decision on whether to increase the nitrous shot will be made only after all other tuning parameters have been exhausted.

Front wheel alignment. As time permits.

T/C stall. This will be explored only after all other tuning parameters have been exhausted.

 

[Alky V6]

Here's the latest fuel table showing the latest boost trail. This was with the spool valve used for only one second, pre through post launch. The next testing will have the spool valve on for 2.5 seconds, pre through post launch.

The red line is 91kPa. The horizontal line above that is 95kPa, and the line above that is 98kPa.

The blue line is on 3480 rpm. The vertical line to the right of that is 3800 rpm, and the next line to the right of that is 4000 rpm.

 

[six shooter]

Thanks for posting that map Donnie.

 

[Alky V6]

A big difference since the ECU upgrade, and basically starting over building up the fuel table.
http://www.turbobuick.com/forums/al...advancement-fuel-delivery-13.html#post2243955

I know some will say that I waste too much time dialing in the fuel map. That I should just do some rough adjustments to the table here and there and let the O2 make the fine corrections. Well, until you've actually felt the difference between the two methods, don't knock it. The smoothness and responsiveness of the engine is unparalleled when the time is taken to properly dial in the fuel table. And, I'm not just talking about simple street driveability. The difference can also be felt during a WOT pass. This is particularly more evident with large cams. When dealing with nitrous injection, the tune is also much safer. In a lot of cases, the O2 doesn't react quick enough or with the proper amount of correction to give you the same kind of tune as a table that is dialed in so carefully that the O2 correction can be turned off.
I wonder how many cars out there can be run with the O2 correction turned off.

In the latest fuel table you can see the crossover and reversion waves going on at the lower rpm before 3500 rpm. After 3500 rpm the combination settles down and concentrates on smoothly making hp. The stall of the torque converter is around 3750 on the present level of nitrous. If the stall were 4500 on the nitrous, this thing would be an absolute monster out of the hole.

 

[Alky V6]

One neat thing about having a fuel map that is carefully dialed in, it gives you a clear picture into the volumetric efficiency of the engine combination. About as good as a dyno sheet.
Using my fuel map as an example, you can see how the engine power delivery is very smooth from 4,000 rpm on up. Where as at the lower rpm values, you can see a lot of variation of engine VE due mostly to the large cam being used. Very cool.

 

[Alky V6]

I went ahead and filled in the fuel table. The engine will actually never see these regions, but I had nothing better to do.

[YOUTUBE]http://www.youtube.com/watch?v=fSe0s9q5EEw[/YOUTUBE]

 

[Alky V6]

Exhaust back pressure reading

Finally got it.

22-23 psi exhaust back pressure equals 26-27 psi intake manifold boost pressure.:biggrin:

That is an exhaust to intake pressure ratio of .85:1. I had to study the video 4 times before I would believe it.

 

[charlief1]

How'd she feel last night Donnie? One of these days I'll get lucky enough to see it run in person I hope.

 

[Alky V6]

The first couple runs felt very promising. So much so that some spectators in the audience who attend the events at the track regularly, noticed the difference in the car and came by the pits to congradulate me. "She's coming around." The nitrous bottle started going away after that so the next few runs were junk. New bottle for tonights testing.:biggrin:
Boost levels last night were kept to 26-27 psi.
6.4s with 1.65 60 foots. 116 mph. A 1.54 60 foot on one of the runs.
The boost ramped in a little late. Boost controller tuning still in early stages.
I've determined that nitrous bottle temp control is going to be very important with this current setup. I'll be looking for a good 110V heat blanket setup.

The launch on one run felt very seemless considering all the tuning junk I have going on at the launch. The a/f mix during the nitrous hit is extremely fat now, so I'm busy leaning that in. The top end is getting close. I'm at 10.3 to 10.5 on the top end now. The target is 10.7 to 10.8. She has always made real good power at that ratio.

The next pass will have the boost valve on for .5 second longer. 3.0 seconds total. Looking to have the valve open at 147 kPa. At 2.5 seconds duration boost reached 125 kPa by the opening point.

The car made a good 1-2 shift at 16 psi boost so far.
On one run, the nitrous stayed on until the 16 psi pressure switch cutoff and the boost got too high by the 1-2 shift. Boost controller was ineffective. The tires proceeded to smokith.

 

[charlief1]

Looks like all the hard work is finally paying off for you. If you get the 60' time down where you had it you're going to be fast for sure.

 

[Alky V6]

Now that the n/f ratio is way on the safe side, I'm going to start lessening the nitrous retard.

 

[lazaris]

The first couple runs felt very promising. So much so that some spectators in the audience who attend the events at the track regularly, noticed the difference in the car and came by the pits to congradulate me. "She's coming around." The nitrous bottle started going away after that so the next few runs were junk. New bottle for tonights testing.:biggrin:
Boost levels last night were kept to 26-27 psi.
6.4s with 1.65 60 foots. 116 mph. A 1.54 60 foot on one of the runs.
The boost ramped in a little late. Boost controller tuning still in early stages.
I've determined that nitrous bottle temp control is going to be very important with this current setup. I'll be looking for a good 110V heat blanket setup.

The launch on one run felt very seemless considering all the tuning junk I have going on at the launch. The a/f mix during the nitrous hit is extremely fat now, so I'm busy leaning that in. The top end is getting close. I'm at 10.3 to 10.5 on the top end now. The target is 10.7 to 10.8. She has always made real good power at that ratio.

The next pass will have the boost valve on for .5 second longer. 3.0 seconds total. Looking to have the valve open at 147 kPa. At 2.5 seconds duration boost reached 125 kPa by the opening point.

The car made a good 1-2 shift at 16 psi boost so far.
On one run, the nitrous stayed on until the 16 psi pressure switch cutoff and the boost got too high by the 1-2 shift. Boost controller was ineffective. The tires proceeded to smokith.

You may want to reconsider leaning it if your bottle was going away. I'd leave it with a new bottle and see where your at first.

 

[Alky V6]

You may want to reconsider leaning it if your bottle was going away. I'd leave it with a new bottle and see where your at first.

VERY GOOD ADVICE, lazaris! Everyone needs to remember this. Don't tune your car on a decaying nitrous bottle. Arrrg! It threw me off, and it took awhile to get back on track after the fresh bottle. Aren't you guys lucky you can learn all this bad stuff from me?

Saturday night was a tuning disaster. The tuneup right at the hit was all screwed up. The car would jerk and die. A few intake backfires.
I think it has soaked in that I need to take the bottle out and weigh it every so often instead of waiting like I did.
I weighed the bottle from Friday night. 2 lbs left in a 10 lbs bottle. I normally change the bottle out when it hits 5 lbs. This 91mm is eating up the nitrous much faster than the T76 did. Live and learn.

The first 3 passes were as described above. I'm lucky I got through them without hurting something. The last pass of the night, which was after 11:00pm , was the best so far with the 91mm. At least a very frustrating night ended on a very good note.
6.4x @ 120.x mph with a horrible 1.6x 60 foot. 280s to 290s kPa boost. Still inching the boost up during the top end surge. Previous best mph was 116.x.
Mixture on the top end was still a tad rich. Leaning in the top end one percent at a time.
Nitrous retard is back to 15 degrees.
Mixture was spotty (lean spots) from initial hit to 8 psi boost.
The feel of the launch was the best I've had yet. Very smooth consistent pull. And a good pull at that. I was amazed since I wasn't using any pre-spool time with the nitrous on that pass.
This was with the car setup for a .4 pro light start. No pre-spooling before transbrake release. At the driver's meeting it was announced that because of the busy night, test and tune might not get many runs in. So, I entered the Wicked Stangs bracket to get an extra run in. I knew I was a sitting duck, but at least I'd get a test run in. Well, the class I entered was using a .4 pro light. Good grief. What else could happen. I was getting kicked between the legs left and right tonight.
I hadn't done any tuning at all for a pro light. I went back to the car and quickly backed out all the delays. The pass ended up being one of the disaster runs I mentioned at the beginning. But,... I got some useful data and was able to discover another wrinkle in the fuel map. The lack of pre-spooling caused the engine rpm to run out further below the 100kPa threshold and another bump in the fuel map was discovered.

I'm going to stick with the present stradegy of leaving without any pre-spool until the fuel map is dialed in. Then, I'll slowly start adding the pre-spool time back in and working the fuel map until I've reached around .45 seconds of pre-spool time on the nitrous,... checking my bottle pressure regularly!

More tuning details after I've had a chance to study my one good datalog for the night.

 

[Alky V6]

Run 23d datalog

Timestamp (time into the run)

25.98 (0.000) - Start of the run. Nitrous is activated and the transbrake is released.

27.38 (1.400) - 100kPa is reached.

28.74 (2.76) - Nitrous shuts down at 200kPa (16 psi), 7,082rpm.
Time from 100kPa to 200kPa = 1.30 seconds.
Time from 109.5kPa to 200kPa = 1.0 second.
Time from 116kPa to 200kPa = .76 second.
Time from 125.5kPa to 200kPa = .6 second.

28.82 (2.84) - The 1-2 shift occurs at 221kPa @ 7298. One bounce off the rev limiter. Tire slippage noted until the 29.18 timestamp. The 1-2 shift should normally occur within .1 to .2 second.

For the future, the 1-2 shift needs to occur at 7100rpm @ 200-210 kPa.

29.02 (3.04) - The boost starts to level at 252.4kPa.
Time from 109.5kPa to 252kPa = 1.28 seconds.
I believe this is where the boost valve begins to open. If I remember right, it was programmed for 3.0 seconds. I need to time this opening with the 1-2 shift! Perfect! I also need to change the rate that it opens so that it creates a shorter boost leveling in the boost rise right at the 1-2 shift. This alone makes all the trouble I had last night worth it.

The fact that the boost valve was opening during the time duration that 1-2 shift tire slip was still occurring, is the only thing that kept the tires from just completely blowing away all together! This boost valve could turn out to be a very useful tool, in more than one way.

29.38 (3.4) - The level ends at 252 kPa and begins to rise.

30.34 (4.36) - The boost levels at 289.3kPa.

31.08 (5.1) - Shift into 3rd @ 7364rpm after bouncing off the rev limited twice. Shift occurred within .100 second.

31.68 (5.7) - The level ends at 288kPa and begins to ramp up.

32.08 (6.1) - The boost levels at 297kPa.

32.38 (6.4) - The run ends at 296.7kPa @ 6451rpm.

During the boost level between 30.34 and 31.68, 288-289kPa, the boost level varied a max of 22kPa. Half of that above and the other half below the average 288kPa. A 10kPa spike in pressure, above 288kPa, was due to the shift into 3rd.

I need to compare timestamps to the boost controller setup to see if changes need to be made. One change needs to be the control pressure amount I'm using to net a boost pressure of 16psi (200kPa). The boost rise rate with the boost valve and the nitrous caused an overshoot of the 16 psi target for the 1-2 shift. I'll first try to open the boost valve slightly sooner, just before the 1-2 shift.

 

[Alky V6]

Performance comparison to date

The average performace of the car with the T76 tuned in. Sportsman start (3 amber). .4 second of pre-spool with nitrous.

60 - 1.3-1.4sec
330 - 3.7-3.9sec
330 - 91-93mph
660 - 5.9-6.1sec
660 - 118-121mph

The best performance to date with the 91mm. Pro light start (.400). .001 second pre-spool with nitrous.
60 - 1.55-1.65sec
330 - 4.384
330 - 89.900
660 - 6.457
660 - 120.272

Delay box setup note: Launching with a pro light tune, no pre-spool, on a 3 amber tree netted a -.856 reaction.

 

[Chevota]

....getting closer to catching that "waskly wabbit".....

 

[Alky V6]

The aux channel of the boost controller was set to open the boost valve at 2.6 seconds from transbrake release. On a pro light that would be 2.6 seconds from the launch. I've moved it to 2.5 seconds to time the opening of the boost valve to the 1-2 shift. I also put in some ramping for the opening of the valve, set at 100 psi/sec to try and have it reach 0 pressure by 2.7 seconds. The best it would give me was 0 psi by 2.84 sec. It's a start.

The wastegate channel was set as follows:
All control pressures.

5 psi at launch
13 @ .41 sec
13 @ 2.86. This will be moved to 2.6 sec.
27 @ 3.36. The ramp to this level will be changed to max (0), and the pressure changed to 28.
27 @ 5.16. The pressure will be changed to 28 and the time shortened to 5.0.
28 @ 5.26. The pressure will be changed to 29 and the ramp set to 0.
28 @ 6.46. The pressure will be changed to 29.

Notes in red are changes to be made for the next test session.

 

[Alky V6]

New boost controller setup.
5psi @ launch
13 @ .01 sec
13 @ 2.6
28 @ 2.6
28 @ 5.0
29 @ 5.0
29 @ 6.46

Video of datalog run through coming soon.

 

[Alky V6]

Datalog 22x

This datalog showed the quickest boost rise for the weekend. It was substantially better than the rest.
147.7 kPa reached by 5429 rpm.
92.2 @ 3394
94.7 @ 3469 First sign of boost.
95.9 @ 3612
98.4 @ 3826
100.9 @ 3872
110.7 @ 4480
123.0 @ 4931
132.9 @ 5203
145.2 @ 5367

The boost ramp up speed was very steep starting at 4129 rpm @ 103.3 kPa, and carried on to 7315 @ 230.2. Time elapse: 1.54 sec.
200 kPa @ 6688 rpm.

Average mixture readout through the nitrous hit was 10.95:1.
Nitrous retard 14 degrees. Net timing through the nitrous hit was 20 at the start, ramping to 15 by the end of the hit.

THE TARGET READOUT ON THE NITROUS IS 10.95:1.

The target a/f ratio readout is 10.95:1 at the start of the nitrous hit, maintaining 10.95:1 to 165 kPa, then ramping to 10.6:1 at the present boost level of 299 kPa.

 

[charlief1]

Cool Donnie. Sounds like you're getting it worked out finally.