Advancement of fuel delivery?

[Alky V6]

Note to myself: writeup on the need for launch rev control with a tight T/C.

Another glitch with the TEC unit is the rev control. Depending on how I manipulate the rev control parameters, then program and change the rev control and re-program the TEC unit, I can sometimes get the launch rev control to work. Basically, it's unreliable. When it does work, it works well. I pretty much gave up on using it since each time I make a small change to something and program the unit I lose launch rev control and then have to go through the ritual all over again. Even then, sometimes that doesn't work to get the launch rev control back.

What I've found was that I'm able to go WOT as soon as I final stage and the rpm may rise 100 to 150 rpm above the initial stall at 0 boost (2440 rpm) the whole time I'm waiting for the ambers to come down. The low stall of my torque converter naturally gives me a sort of launch rev control without having to actually use a launch rev control system. Kinda neat, isn't it. You can see it in the datalog I posted. Look at where I went WOT in the TPS screen and then see how much the rpm rose after that and before the nitrous comes on. You can tell the moment the nitrous turns on by the sharp up turn in rpm increase. The nitrous turns on a programmed amount of delay time after I've released the transbrake button on the first sign of the first amber. The transbrake then releases a programmed amount of delay time after the nitrous has turned on.

 

[Alky V6]

If you look at the top bar of the screen for the datalog you'll see the full file name of the program that's loaded into the WinTEC software on the laptop at the moment. That would be the calibration program I'm working with, whether it be reviewing or making changes to. Alky 3.1.5 10g.bin is the name of the latest program I have programmed into the TEC unit on the car. Each time I make a change or test something new on the program I increment the letter that identifies the program up one. That way, I save the last version and can go back to it if I don't like the change I made. For instance, the very first program for engine version 3.1.5 was Alky 3.1.5 a.bin. So where did the 10 come from in the Alky 3.1.5 10g.bin? Everytime I reach the end of the alphabet I start over with a number in front of it showing how many times I went through the alphabet.

Yeah. By the time you've gone through the alphabet that many times, you'd better have your fueling within 1 percent. :tongue:

 

[Alky V6]

No No No..... My correction. I'm talking "upper" VE/boost (35-40psi) That turbo will laugh at 24psi:biggrin:
Scott Wile

I don't know. The T76 wasn't able to give me that much boost, so I don't have anything to compare to what the new turbo might do. Even the sims can't help me. In the sim, the T76 won't give me boost past what I'm getting in the real world. And when I plug the FI91X into the sim, I can't get any real boost without throwing nitrous at it. The thing is I can't simulate how I'm going to be using the nitrous in the real world. The sim won't let me just inject enough nitrous to get up on the turbo and then shut the nitrous down. I have to use the nitrous for the whole calculation which messes the readings up for me in terms of how I plan to use the nitrous, real world. The only thing that may be accurate with the sim is it showing me about where in the rpm band I can expect the turbo to reach full boost with the help of the nitrous.

 

[Alky V6]

The GPO1 screen on the datalog post is the general purpose output number 1 of 4. It is used to arm the nitrous system as far as the ECM is concerned. I have 3 other switches in the nitrous system that must also be closed before the nitrous will flow. When I get a chance I'll post some of the other screens of the datalog that aren't showing in the first posting of the datalog, such as coolant temp, intake air temp, volts, etc.

 

[Alky V6]

Here's the other screens of the datalog. I included the rpm and map screens for easier reference. The detail line is at the start of nitrous injection in the first picture and is at the end of the run in the 2nd picture.

 

[Alky V6]

The IAT sensor is in the up pipe around 12" before the throttle body. All temps are in celsius.

 

[Alky V6]

I just did some math with the time stamps of the datalog examples that I posted and it's not as far off as I thought it would be. When I take the time of the pic that shows where the nitrous turns off and then the time of the pic that shows the end of the run, it's pretty close to what the ET slip showed. I'll be keeping a close eye on that in the future.

According to the timestamps, the nitrous is on for .8 to .868 of a second.

 

[Alky V6]

The latest drag sim calculation using the new turbo and a peak hp level of 1,198.

Other changes other than just the turbo:
Tires: 29.5x10.5-15W.
Rear axle ratio: 3.73:1.
Launch rpm: 3700 rpm.
Shift points: 7700 rpm.
Traction factor: 100% ???

60 foot: 1.141
330 mark: 3.306 @ 106.55
660 mark: 5.180 @ 132.01
1000 mark: 6.822 @ 149.61
1320 mark: 8.218 @ 162.28

This seems very optimistic to me. Especially with M&A heads with original size valves.

 

[Alky V6]

Same calc, but with a more realistic traction factor of 95%.

60 foot: 1.162
330 foot: 3.337 @ 106.26
660 foot: 5.214 @ 131.82
1000 foot: 6.858 @ 149.50
1320 foot: 8.255 @ 162.23

 

[Chevota]

I think the MOST optimistic part of that calc is the 60ft. Add at least a 1/10 to that 60ft and I think the numbers will be more realistic. But what do I know?

scott wile

 

[Alky V6]

I think the MOST optimistic part of that calc is the 60ft. Add at least a 1/10 to that 60ft and I think the numbers will be more realistic. But what do I know?

scott wile

I agree with you, Scott.

 

[Alky V6]

You'll notice at the upper right hand corner of the fuel map, the pulse width flattens and dips down. This is where the electronic injectors have reached maximum duty cycle. I've been slowly cranking the volt booster up to the new fuel pump. If I don't get any responce so I can decrease the injector pulse width in the upper range, I'll have to increase the mechanical nozzle size, which will mean having to re-map the fuel from the start of the wall on upward.

 

[Alky V6]

There's some brothers that run a big block Ford, 106mm single turbo, race red colored Mustang up at the track I race at. They've been fighting a problem with getting the turbo spooled up enough at the line to get a decent launch. They finally broke down and hired a 10.5" tire record holder fella to help them with the tune. Another Mustang guy, of course. The tuner did end up helping them with the spooling problem. Just yesterday, I had the chance to ask one of the brothers what change in the tune ended up helping with the spooling problem. He said it was really pretty simple. The tuner leaned out the mixture at the WOT, no/low boost point and that helped a lot. The leanout only lasts a very short time, but that's enough to get it on the turbo. The owner said the leanout was really lean. He didn't sound positive, but from what I gathered it was in the mid to high 13s to one. He also stated that he thought the engine, at that particular rpm and load, was being put on the edge of detonation.

When I take what he told me and look at my own tune, I find an interesting resemblance. When my nitrous first hits, I get a very short lean spike that typically ends up giving me a high 13 to one a/f reading. As I've stated before, this is the fueling stradegy that I have found from trial and error to give me the smoothest map and rpm rise from my engine. Some food for thought for you guys not using nitrous.

 

[six shooter]

There's some brothers that run a big block Ford, 106mm single turbo, race red colored Mustang up at the track I race at. .

Gasoline fueled i assume?

 

[Alky V6]

Gasoline fueled i assume?

Yes.

Sorry. You have to keep in mind that my datalogging is setup to give me a/f numbers for gasoline. I'm just used to using those numbers when I reference my own a/f conditions. After you've got used to learning what number gives you what performance, why convert or do the math to figure out what the real lambda or air/methanol ratio is?

 

[Alky V6]

Some may wonder why I bothered to take the time to tune my fuel map to within 1% of target. I realize that there are a lot of people that would rather just get the darn thing to where it's safe and runs, play with their a/f target table and let the O2 correction take it from there. And I can't blame them. It takes an extraordinary amount of time to get the fuel map to the level that you can just turn off the O2 correction and have a perfect fuel delivery throughout the run. For those that have never had their tune to within 1 percent, you're not missing a whole bunch. I will say this though. The engine is much more stable and especially smooth through the launch, which if you're on the edge of traction, as I am with my small tires, it makes the launch much more of a fun experience rather than a potential nightmare. It's not fun at all when you stage your car and wonder, "What's the car going to surprise me with this time." I used to even get comments from a lot of the regular spectators that show up at the track complimenting me on the entertainment value of my car. They would say, "Your car is so much fun to watch. You never know what it's going to do." Good grief. :frown: I was glad people were getting a kick out of watching the car, but man, at times, it wasn't fun for me at all.

If you take the time to get within 1% correction, and work for that smooth rpm and map rise, you will learn some very interesting things about fueling techniques. That I guarantee. Even more so if you have as challenging a fuel delivery arrangement as I do. Sometimes smooth lines in your tables just don't get the job done.

 

[Dusty Bradford]

There's some brothers that run a big block Ford, 106mm single turbo, race red colored Mustang up at the track I race at. They've been fighting a problem with getting the turbo spooled up enough at the line to get a decent launch. They finally broke down and hired a 10.5" tire record holder fella to help them with the tune. Another Mustang guy, of course. The tuner did end up helping them with the spooling problem. Just yesterday, I had the chance to ask one of the brothers what change in the tune ended up helping with the spooling problem. He said it was really pretty simple. The tuner leaned out the mixture at the WOT, no/low boost point and that helped a lot. The leanout only lasts a very short time, but that's enough to get it on the turbo. The owner said the leanout was really lean. He didn't sound positive, but from what I gathered it was in the mid to high 13s to one. He also stated that he thought the engine, at that particular rpm and load, was being put on the edge of detonation.

When I take what he told me and look at my own tune, I find an interesting resemblance. When my nitrous first hits, I get a very short lean spike that typically ends up giving me a high 13 to one a/f reading. As I've stated before, this is the fueling stradegy that I have found from trial and error to give me the smoothest map and rpm rise from my engine. Some food for thought for you guys not using nitrous.

This is very common in the heads-up world where spool-up for pro-tree racing is important and n20 is not allowed. Racers spend a lot of time trying to balance a/r size, cam specs, converter, staging technique etc.

I usually will disable the 2 step, turn off the correction and bring the car up as if I'd be staging and log a/f as boost is climbing. Most cars work well between 13.0-13.5 with 36-40 degrees of timing. I have one car that needs closer to 12.5 to spool quickly. Tune the VE table to get the best results and turn the 2 step back on. The correction must always be disabled when on the 2 step or it will start dumping fuel to compensate for lean a/f reading. The sensor will read lean due to the 2 step dropping a cylinder.

 

[Alky V6]

Real good stuff Dusty. Thanks for including the timing. Timing is another area of my tuneup that I haven't spent a lot of time on yet. I can say this, when I was setting the nitrous ignition retard to a lesser value, things were more violent at the launch. In fact, where I have the nitrous retard now is where I had to put it to tame down the launch. Still more areas of the tuneup to explore.

Thanks for contributing, Dusty. I know some people can be funny about passing on tuning experiences. And I can't blame them. A lot of time goes into discovering the setups that work.

 

[Pablo]

Without running lean pre-boost my car is a dog spooling the turbo.

I always considered the engine to essentially be N/A before the spool up and tuned it accordingly. This made a huge difference in spoolup for my car in particular. The one non N/A factor is that the leaner mix increases egt which thus improves spool

 

[Dusty Bradford]

Real good stuff Dusty. Thanks for including the timing. Timing is another area of my tuneup that I haven't spent a lot of time on yet. I can say this, when I was setting the nitrous ignition retard to a lesser value, things were more violent at the launch. In fact, where I have the nitrous retard now is where I had to put it to tame down the launch. Still more areas of the tuneup to explore.

Thanks for contributing, Dusty. I know some people can be funny about passing on tuning experiences. And I can't blame them. A lot of time goes into discovering the setups that work.

These cars with big n2o hits will leave the line with as little as 4* of timing to tame them down.

The tuning goes hand in hand with converter set-up. I can spec a converter for a car but I often get into helping with tune-up as well. I have seen cars instantly go to 24* of timing as soon as boost hits and they will not spool. The tune plays a very large role in a cars spool-up. When this kind of info is passed on it's much less headaches for everyone wanting to improve their car.