I know the best WOT tuning is accomplished on a Dyno. However, those of us who do not wish to use a dyno either for cost reasons or for our own enjoyment of tinkering as we go, is there a viable alternative?
For instance. What if you were to make consistent 3rd gear WOT pulls from 2500 - redline and adjust your timing, fuel, etc until you see the quickest time between various rpm ranges. Takes a bit of time and would have to be on same stretch of road each time etc. Why would this not be a realistic alternative to a dyno session? I mean unless you are after the almighty dyno number for bragging rights, would this method not be just as effective?

Your Thoughts??

 

ideally besides a dyno is logging your scans and going to the nearby/local track and doing your tuning there. that's why most tracks have a Test and Tune session during the season. you record/log your scan, make a pull down the strip and see what your ET and MPH is and go back and read through your scans and repeat til you're satisfied.

 

This. Keep in mind when tuning for power it's the Trap speed you are trying to improve. Consistency is the name of the game, and if you get wheel spin that log is no good. You want to get solid consistent runs, no wheel spin, and advance until you stop seeing the trap speed increase. Alternatively, you could get a race logger and find a lonely stretch of back road somewhere and do this too.

There's some other ways to do it in the scanner to see improvements, but this is the best way if you don't have a dyno.

 

Yes this is a good way as well that I can see. However when not at the track, how do you guys feel about timing your runs between set rpms in say third or fourth gear depending on the amount of road available to you. I'm just trying to make it as easy as possible and not wait till track days and only getting a few runs in even then at best(at least in my area).

 

I've done this, although it's frowned upon due to safety and legal reasons. Needs to be a long, level, straight road, and minimize differences to weather, weight, etc. I'd get the fueling correct, then pre-build ten calibrations each with a different commanded AFR (such as 12.0 to 13.0 by .1), then compare the elapsed times per RPM range to find out which AFR gave me the best acceleration in that RPM range. Then I'd populate the PE Ratio table with the combination of AFR's that gave the best ET. I had intended to do the same for WOT timing but never got around to it. After the ideal timing was found, I was going to re-log AFR again.

 

Trying to time them isnt consistent nor is it a measure of power gained. That is why mph was mentioned earlier.

If you want to tune for power off a dyno set up a custom config that will map calculated horsepower.. then look at your map kpa during runs as well as airflow and wideband. You definitely wont be as consistent or safe though. Try launching a driveshaft at 130 on the street. Having a blowout. Or hitting an animal etc. Its not safe. There are always options for getting a safe controlled place to tune. It may take a drive and some money, but a car and a life are well worth it imo.

 

Yes I totally get the safety aspect. I live in the country with long quiet roads which an animal may be my only obstacle(but very very rare). I would never condone this type of tuning on the city streets. This and also the reason I would use third gear pulls to keep the speed down.
I also agree that using MPH at the track is the best measure of power changes. However using the HP tuners scanner and tracking time between say 3000 and 6000 rpm during WOT would also indicate a change in power, assuming no traction loss and using the same stretch of road each time, weather, temp etc. With the laptop in the car you can make at least 6 runs in an hour, tuning along the way and conditions stay the same. This way as well you can track where in the RPM did the change you made make the difference(much like the dyno). Using total MPH will tell you you have a change of power but not exactly where.
I will be trying this out in a few weeks and will let you know how it works. Hey its all about learning and enjoying our cars right!

 

Tuning without a dyno can give just as good or better results if you have an infinite amount of time, are impervious to accidental death, and have an endless variety of weather conditions to choose from. This is assuming no cops or bystanders are around. Otherwise, you do the best you can in whatever manner you feel is "safe enough".

 

Timing a run wont give you an idea of power gained unless its substantial.
Tires blow out and parts break often and when that happens, it doesn't matter how good the road is.
Being close to civilization matters alot. Especially when you either break down or have some odd issue come up with a flash or computer issue, battery issue or anything else like that.
To be clear i am 100% speaking from experience on all of that.
Plus 3rd gear will give you much less useable data. Youre bandaiding a very important process.

 

Alright.... I know what you want to do, and I cannot condone it, but at the same time cannot say I am not guilty of the same thing, as most of us are. So I'm going to give you a useful tool in determining your gains. This can be used at any speed, and so forth, so I trust you'll use it responsibly. I am not responsible if you crash and burn or what not tuning off the track or dyno. But at least this will let you know if you have made gains, and since it can be used at any rpm and speed, I hope it helps you dial it in without getting too unsafe.

First, go to "User Maths" in the scanner...

If you use MPH under Generic Sensors, then it should look something like this:

([50020.114.avg(-1000)]) - ([50020.114.avg(1000)])

50020.114 = Generic MPH PID on mine, individual results may vary.

1. Select "new variable" and then either the generic MPH PID or your specific vehicle one.
2. Under the "Edit PID", select "Average" and under "period" write in -1000 (it will only let you type -100, but you can add another "0" after you have it on the formula area.
3. Add a " - " symbol
4. Repeat step 1 to add in second reference frame (same MPH PID again)
5. Select "Average" for second PID and under "period" write in 1000
6. Use 3 decimal places
7. Select MPH as units.
8. Name it something awesome like "Scare factor" or something.

* note, for all PID's and units make sure you are using MPH. The PID's will normally populate with m/s which is meters/second

Should be good to go after that.

That will create a math for acceleration rate. After you're done, create a chart and you can log it and see if you're gaining anything with changes. Again, like always, consistency is the name of the game.

 

Thank you very much. I will definitely try this out. I'm a 50 year old man and am in charge of my actions. I know when and where to push the limits of cars like ours. Being responsible is key even when stretching the imposed limits if you get me.
Again thank you

 

Making an hp config is much easier and will get you quite a bit of info also

 

This too.

I am also working on a way to do it using injector pulse width and duty cycle. So far, mixed results on that. Couple that with the fact I can't do any testing or tuning since I'm deployed at the moment. It works in theory, since the optimal spark will cause optimal burn if you have the fueling spot on. If in SD it will show up as richer numbers since spark being correct will need less fuel. In other fringe areas of the tune, End of Injection Timing (EOIT) can affect this too, again showing richer numbers when it's on the money.

There are very long threads and discussions on this stuff over on HPT forums if you want to really get crazy deep into the physics of it lol.

 

I started tuning my turbo combo on the street (freeway) at low boost. Living in a big city makes it difficult. The roads are never clear.
After blowing by cars at 125 plus I quickly realized this is dumb and finished the tuning at the drag strip.

To this day I’ve never been on the dyno. Even though I’m a dyno operator.......

Just be safe. If you have clear roads piece of cake.

 

With a naturally aspirated LS1 / LS6, and pump gas, and a reasonable AFR, what happens first as you advance the ignition timing - best torque, or knock? I

f the answer is knock, then it seems like it should be pretty straight forward to get a reasonably good tune (good enough for a daily driver) without even trying to measure power. That worked well enough for my Subaru so I've been wondering if it will work for my Corvette as well.

Of course if you want to really maximize power, you need to measure power, but I don't race. So I'm fine with the idea of picking a typical AFR curve and then tuning timing - but only if I'm going to find knock before I find MBT.