Maybe, If you could count on the person taking the video to do a good enough job to catch the whole run with good detail. But then, how does a person with a video camera help you out if a car were to get away from you?
Come on now. I'm not that naive.In my experience it has not been a maybe.
The driver removes foot from pedal. Now I havent compared driver reaction to traction control reaction but I wouldnt sell the human body short.
Human Benchmark - Reaction Time Test
Come on now. I'm not that naive.
How long does it take for a driveshaft to rotate one quarter turn at 7500 rpm in high gear? That is how fast some TC units take before starting to correct for tire slip.
If human reaction time was enough, then why the huge moves to come out with all the forms of stability control?
How often do you see the tires getting blown away at the track? Is that just a lot of people needing practice on their super human reaction time?
EDIT: What is the reaction time to a stimulus when the person is concentrating on other things? Steering, gear changing, the person in the other lane, tachometer, other gauges, pulling the chute, talking on the cell phone.
I take it you're comparing this system to a TC system you have tried. Which TC system were you using that gave less than satisfactory results? EDIT: Never mind. I went back and saw.
I take it you're comparing this system to a TC system you have tried. Which TC system were you using that gave less than satisfactory results? EDIT: Never mind. I went back and saw.
The slew system is an open loop situation then. No feedback control. You either get the change in the pits right, or you're done. So there is a learning curve involved to come up with these particular tunes. It's not something that will adjust for changing conditions when actually making the run. Similar to the AMS1000 not being a feedback system. After the run, not during the run, changes are made according to changes that may have occurred during the past run.
I am pretty sure Dusty was only using the Heuristic (or slew control). He can correct me if I'm wrong. Here's some "propaganda" from the XFI manual, take it at face value:
"There are two modes of Intelligent Traction Control that can be used in an XFI. One is called Heuristic Mode, and the other is called PA Mode. Each mode can be used separately or together to reduce or eliminate a loss of traction which can occur due to any number of reasons such as limited tire size, suspension issues, or track conditions. Both modes utilize a speed sensor to monitor driveshaft RPM and are easily set-up using a simple 2D graph. The fact that both modes rely on driveshaft speed instead of other methods that utilize engine speed (RPM) to base their traction control on makes this much easier. The reason for that is you no longer have to ‘chase’ plots on a graph that are constantly affected by other factors such as gear changes, torque converter or clutch slippage, or anything else that can affect engine RPM and the rate at which it changes. Those variances don’t occur with driveshaft speed."
I find the Heuristic (slew rate) mode will work if the car is barely spinning (or low hp) and the PA Mode (connect the dots) works better if traction is worse (or high hp). I have also been testing using an output on the XFI to lower boost in the AMS when traction control is "active".
That's a good point. I was thinking of ignition retard followed by boost lowering in a one after the other routine. The ignition retard would come first and if that wasn't enough then the boost would be lowered.I am pretty sure Dusty was only using the Heuristic (or slew control). He can correct me if I'm wrong. Here's some "propaganda" from the XFI manual, take it at face value:
"There are two modes of Intelligent Traction Control that can be used in an XFI. One is called Heuristic Mode, and the other is called PA Mode. Each mode can be used separately or together to reduce or eliminate a loss of traction which can occur due to any number of reasons such as limited tire size, suspension issues, or track conditions. Both modes utilize a speed sensor to monitor driveshaft RPM and are easily set-up using a simple 2D graph. The fact that both modes rely on driveshaft speed instead of other methods that utilize engine speed (RPM) to base their traction control on makes this much easier. The reason for that is you no longer have to ‘chase’ plots on a graph that are constantly affected by other factors such as gear changes, torque converter or clutch slippage, or anything else that can affect engine RPM and the rate at which it changes. Those variances don’t occur with driveshaft speed."
I find the Heuristic (slew rate) mode will work if the car is barely spinning (or low hp) and the PA Mode (connect the dots) works better if traction is worse (or high hp). I have also been testing using an output on the XFI to lower boost in the AMS when traction control is "active".
I used the XFI traction control and was happy with it. But these system's don't work like some people think they do. You can't just throw everything at it and expect the car to go faster. My experience was exactly like Lazaris is describing. It will save a pass where the car would have blown the tires off and could be used as a tuning tool as you described earlier. I can see the safety aspect of it but I can hear the rpm difference and feel the acceleration suddenly stop from tire spin. You just know what tire spin feels like after so many passes in the car. The guys smoking the tires for 100 feet before lifting are simply being boneheads.
So I wouldn't call any traction control un-satisfactory. They do what they are intended to do, save a pass. But they do not make a car faster.
I couldn't agree more. I think Donny needs to put traction control on his car and then tell us if it works like he expected it to. It's pretty apparent that those of us who are currently using it have diferent expectations/experiences with the systems we are using. Hopefully he goes with the Davis unit. So far, I have heard great things about it and I would like to hear more feedback from someone like Donny who isn't trying to sell me one.
I agree. The safety part of it is what I'm mainly looking for. If I get carried away and throw too much at it, I can feel a little bit more secure that it won't launch for the wall.I used the XFI traction control and was happy with it. But these system's don't work like some people think they do. You can't just throw everything at it and expect the car to go faster. My experience was exactly like Lazaris is describing. It will save a pass where the car would have blown the tires off and could be used as a tuning tool as you described earlier. I can see the safety aspect of it but I can hear the rpm difference and feel the acceleration suddenly stop from tire spin. You just know what tire spin feels like after so many passes in the car. The guys smoking the tires for 100 feet before lifting are simply being boneheads.
So I wouldn't call any traction control un-satisfactory. They do what they are intended to do, save a pass. But they do not make a car faster.
That might be awhile waiting for feedback from me. I think I'm going to start working on my own system. I'm waiting for the money to upgrade the fuel system, and while I wait for that to materialize I'm going to be awfully bored, so I'm studying up on my electronics to see if I might be able to make something for myself.I couldn't agree more. I think Donny needs to put traction control on his car and then tell us if it works like he expected it to. It's pretty apparent that those of us who are currently using it have diferent expectations/experiences with the systems we are using. Hopefully he goes with the Davis unit. So far, I have heard great things about it and I would like to hear more feedback from someone like Donny who isn't trying to sell me one.
Some things are in the works. Might be able to test a Davis box by the end of Feb on another car.
I was thinking of ignition retard followed by boost lowering in a one after the other routine. The ignition retard would come first and if that wasn't enough then the boost would be lowered.
That was my thinking too. Controlling the boost has to be the slowest way of controlling engine torque.Please keep me posted on your findings.
The boost lowering routine is very slow reacting. I use it as a last ditch effort to save a run after timing retard and dropping cylinders. Do you have a blowoff valve?