With all these new electronic aids we have available to us in the market these days, it's just a matter of time before we all start taking advantage of them. Sure, we can get by with tires, and suspension components to help getting the car to go straight but, ultimately we need some form of traction control. Don't think so? I saw Calvo motorsports Viper go 175mph in the half mile with NO TCS turned on....but with it TCS TURNED on, the car went 213mph(yes, SOME boost changes were made based on added traction but the point is sound). That to me, is enough to open my eyes to the capabilities of a race oriented TCS.

That said, we need a couple different inputs to work the TCS. A mechanical driveshaft sensor input to count rotations, and the inputs from the wheel speed sensors. The wheel speed will be received thru the ecm but the mechanical sensor needs to be added to the driveshaft, or in our case, the torque tube.

Here is what one looks like:

https://www.summitracing.com/parts/e...FZI1aQodiNkOgw

Just now, going through all this trouble of installing an aftermarket ecu in my car and a C6, with traction control as an option, we wanna use everything it has to help the car make some clean, fast passes. Who has installed one, and where in the torque tube did you install it? Any pic's? If I don't hear back from anyone(likely possible) than we'll just go about the install and figure it out ourselves. Just looking for some community based help from someone that may have already done it.

Thanks in advance.

 

I've been looking into driveshaft based traction control, and I've had some say you can use crankshaft speed for traction control. I think you could fit a tone ring to the driveshaft where the rubber joint is , then cut the torque tube and weld in a fitting for the sensor. Just my thought, I have not done this, but I'd love to know if someone has.

 

I would love to use a crank sensor, or perhaps utilizing a factory sensor input to register that crank/driveshaft speed. That would be awesome. I thought about if it was driveshaft mounted, to go into the area just in front of the transmission, in the torque tube REAR[bell type area] area, where the shifter rod goes thru. That, or cut a window in the tube, and mount it inside somehow. Very interested....but, people have had to have done this already.

 

If you have an ecu that works via wheel speed sensors, then there should be no need to go anywhere near the driveshaft.

In some cases you can tie into the ABS sensors, but it does depend on the type of sensor used.

And where does the OEM speed signal come from on a Vette ? Presumably it must be the rear diff area ? ie same speed as the driveshaft if that's what you need. This could be used, or do they not take any speed signal from this area ?

The Davis system seems to rely on rate of change of the driveshaft so only needs a single input, not sure how versatile this is in the real world..

But virtually every other system out there compares driven wheel speed to undriven wheelspeed and you then base any control on the slip between the two.

Neither are new though and have been around for many years. As to how much faster they can make a car in a straight line....harder to say, but there is no question it will make you safer and more consistent everywhere. That can always be a huge bonus.
Optimising traction control for actual acceleration can take some time, as traction levels will vary on different surfaces etc, and desired slip targets will also vary from tyre to tyre etc.

At a push, some ecu's would let you away with a driven wheel speed reference ( or diff/driveshaft ) and then use GPS as the undriven. Although as GPS relies on a good clean signal, this may not always be reliable.

 

[QUOTE

At a push, some ecu's would let you away with a driven wheel speed reference ( or diff/driveshaft ) and then use GPS as the undriven. Although as GPS relies on a good clean signal, this may not always be reliable.[/QUOTE]

I tried GPS. Its not nearly fast enough to function as a reference for traction control. I used a GPS sensor that had the highest resolution possible, and it still varied too much from actual measured wheel speed. I have used the wheel speed traction control strategy with Haltech, and it works pretty well. The guys from Haltech actually told me driveshaft based traction control wasn't worth the cost for a street car. At least with their system, they said it was much more beneficial for getting a car to leave with as much power put down as traction allows. I took that to mean its really designed for drag racing from a stop.

 

A Friend has a 7sec car that traps 170+ ( non vette ) and uses GPS as the undriven reference when racing on circuits etc ( and low traction airfields etc )

It can be fast enough. It would seem you just need either a better GPS system or better ecu. You can get 50Hz GPS systems ( pricey ) although even a 10-20Hz is capable, again depending on good clear signal which is key. Probably less of an issue for drag use, but for road/circuit type stuff especially if there are buildings or tree cover, it doesnt take much to interfere with the signal and make it unusable.

But wheel speed sensors will always be more reliable and would be the preferred option.

I would agree though that a system that uses only the driveshaft, will have limitations although Davis would probably argue that.

 

[QUOTE

It can be fast enough. It would seem you just need either a better GPS system or better ecu. You can get 50Hz GPS systems ( pricey ) although even a 10-20Hz is capable, again depending on good clear signal which is key. Probably less of an issue for drag use, but for road/circuit type stuff especially if there are buildings or tree cover, it doesnt take much to interfere with the signal and make it unusable.

But wheel speed sensors will always be more reliable and would be the preferred option.

I would agree though that a system that uses only the driveshaft, will have limitations although Davis would probably argue that.[/QUOTE]

I should clarify. It wasn't fast enough for me to consider it a good option, but it did work. I used a $200 VDO GPS sensor. I replaced it with a $50 hall effect sensor reading off the wheel studs. That was a much better solution for me. My ECU is a Haltech Elite 2500.

 

As said, a proper wheel speed reading will always be the better solution. But GPS can and does work with the right setup, even on very fast cars.

For 4wd cars as an example, using wheel speeds alone creates obvious difficulties...and GPS to a degree solves some of them, not that it would apply here of course.

 

Having the revolutions counted on the torque tube won't help without controller knowing the gear the transmission is in.

 

I don't know about other systems, but with the Haltech you can calibrate the rpm vs wheelspeed, and from that calibration the ECU knows what gear your in. There are some instances where you can confuse the ECU, but none of them would happen when under power.

Also, you don't need gear position to have functional traction control, but it does allow you to setup another axis to tune from. Boost by gear, ignition by gear, fuel by gear, amount of wheel slip differential by gear, AFR by gear, you name it and the Haltech will do it.

 

The way the two guys locally are doing it, on non corvette platforms, both cars go 8s at over 150 and do use the cars primarily on the street, use driveshaft sensors with wheel speed inputs. Is cost, that much to replicate? Wheel speed is already there, just needed(in their case) the D/S sensor. Sounds cheap to me. On a torque tube vehicle, I understand the drawback obviously.

I may call and talk to Davis Technologies and see what they say about their Holley capable box. I should also probably call and ask my tuner as well since he's been using the box on a few cars. Just haven't wanted to bother him. I may post this in the C6 section, as those guys seem to be ahead of the C5s in this regard.

 

Just another thought, I had a boost controller put on my F1X system and it launches at about 600 RWHP, then dials into the set progression. With well over 1000 RWHP (@ 25 lbs boost) my launches are 1.32-1.35 with RPM Level X 4l60e and it hooks. You can also adjust it to different track conditions by increasing boost at launch. At same time I had two step installed and set it at 2100 RPM.....nothing real high but easy on tranny while giving me very good reaction time on light without spinning. Just thought i would put this out to all who are trying to hook with high horsepower.....not trying to steal any threads or sell anything.

I also run primarily on street and can put down 5.7's in eighth mile. Have not run it yet in 1/4 but will soon.

 

What ecu are you actually using ?

Obviously you'd need something that is compatible with that.

The other well proven, albeit expensive option is Racelogic's system. It's standalone, splices into the injector wires and can retrieve ABS signals form most cars as far as I know.

Basically for any signal...hell, mag or otherwise. All you need is something where ferrous metal will pass over the sensor, then a gap, then metal..then a gap.

So this could be a toothed wheel, wheel studs, brake rotor bolts ( if using 2 piece rotors ), or even the UJ part of a driveshaft could suffice.

Although the more teeth per revolution the better...again up to whatever your ecu and tooth speed the actual sensor allows.

 

Holley Dominator.

http://www.moretraction.com/Instructions_EFI_TC.htm

 

from the yellow bullet:

Q-"I'm running Holley's Dominator EFI. Can this be used to retard boost?"


A-"Yes, the Power Reduction Setup Methods (selections) are:
Timing
N2O %
Boost
DBW"

http://www.yellowbullet.com/forum/sh...d.php?t=529384
_____

 

I don't know if your responses were geared toward me, but if you are measuring propshaft speed it is at engine RPM at all times. So without knowing gear you will not be able to back calculate driven wheel speed. So no direct comparison between driven and non driven will be able to be calculated giving a slip %.

Basically I was just trying to eliminate taking a measurement at the propshaft because it would be the same as knowing engine RPM.

 

The comments were not directed toward you. I was just giving general knowledge on how traction control works with a Haltech Elite series ECU. I assume other ECU's are similar, but have no first hand knowledge.

The driveshaft traction control method doesn't work by comparing wheel speed to driveshaft speed. It measures the acceleration rate of the driveshaft vs time, and if the shaft accelerates faster on the current revolution than it did the previous revolution then the ECU knows the wheels are spinning. Driven wheel vs non driven wheel is completely different. Neither require the ECU to know what gear your in to function, but it can be helpful in fine tuning traction control.

 

From PROefi(which we're currently installing in a C6)

"ProEFI’s state of the art traction control provides the flexibility to be used in any racing venue. The tuner can set up the traction control to be front and rear wheel slip differential, driveshaft/vehicle speed dependent, or based upon the engines rate of acceleration in each gear.

Wheel Speed Differential– The wheel speed differential traction control monitors driven vs. non-driven wheel speed and controls the maximum amount of slip from the driven wheels. The allowed slip percent can be adjusted based on a launch timer to allow maximum acceleration from a standing start, as well as dialing in a maximum slip percentage based upon any conditions. The tuner can select either a fuel cut, ignition cut, ignition retard, or a combination of the three. Using the ProEFI’s one of a kind fault management, the tuner can also tie other activities based upon the amount of wheel slip, things like turning on a warning light, disabling nitrous control, turning the boost pressure down, etc…

Engine rate of acceleration– This strategy is designed more for manual transmission cars. The engine rate of acceleration is broken down by each gear, limiting the engines rate of acceleration in rpm/sec. Unlike other engine management systems, you simply set this one up by entering your transmission gear ratio’s, tire diameter, and final drive ratio. Then the tuner simply dials in the allowed engines rate of acceleration in each gear! The tuner can select either a fuel cut, ignition cut, ignition retard, or a combination of the three. Using the ProEFI’s one of a kind fault management, the tuner can also tie other activities based upon the amount of wheel slip, things like turning on a warning light, disabling nitrous control, turning the boost pressure down, etc…

DriveShaft/Vehicle Speed – This strategy is designed more for automatic transmission cars. The tuner can select either the rate of engine acceleration allowed at a given vehicle speed, or the maximum driveshaft rpm allowed against a launch timer. The rate of engine acceleration by vehicle speed is a strategy a high horsepower, traction challenged automatic car would use for street driving conditions, while the driveshaft rpm control would be used in a drag racing situation. When an input is triggered, usually from a trans brake release or brake pedal release, the computer starts a timer and monitors the driveshafts rpm against that timer. If the driveshaft RPM exceeds the limit, then power reducing strategies are activated. The tuner can select either a fuel cut, ignition cut, ignition retard, or a combination of the three. Using the ProEFI’s one of a kind fault management, the tuner can also tie other activities based upon the amount of wheel slip, things like turning on a warning light, disabling nitrous control, turning the boost pressure down, etc…"

 

so I was driving and thinking.
how does the computer use the input from the driveshaft in relation to the transmission. Since we have a transaxle setup. wouldn't the driveshaft speed always be related to RPM, we already have that input, which is good news, because mounting anything to the driveshaft will be a PITA, and will easier to rig something to the diff or axle.

 

I plan on talking with Los and Jay regarding the wheel speed variation(front to back) as the easiest possible route. Axle speed I would imagine would be the same as wheel speed.