pontiac

only available traction control i've found is racelogic and it cost too much to be attractive. i know Thirgen.org is full of electronic guru's, so designing DYI TC is a walk for most of them, right?
i've an idea how it should be implemented in general:

inputs:
- VSS for rear wheel speed
- custom speed sensor for front wheel (left or right doesn't matter), maybe sensors from some ABS systems could be used?

output:
- on/off switch between distributor to ECM connection

operation:
when difference between pulses from the inputs grow too big (wheel spin) system disables connection between distributor and ECM. when ECM detects no pulse from distributor it cause no injector pulse or spark. connection is returned when difference between pulses is back to normal.
i think this system could be implemented digital or even analog circuit since the operation is really simple. only problem i could think of right away is flashing S.E.S light when ECM detects no pulse from distributor?

any ideas of the control module/circuit?

this "mod" could make our cars driveable in wet and snow conditions, expanding time to enjoy driving 3rd genner around the year.



-P

92RSB4C

Your engine will shut off and you'll have to crank it again.

pontiac

that's the way traction control works! it cuts the fuel until traction is restored. for sure i don't have to crank the engine again if for ex. cylinder #2 has missed its fuel and spark because of traction control. operation is done in milli seconds, not cutting spark and fuel until engine dies

injector cutoff is the method for 2002 C5 or Z28 traction control, so what makes you think it wont work in our cars?


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Jza

because our cars are batch-fired. you'd be cutting fuel to all eight cylinders, not just #2 like in your example.

pontiac

you lose traction when engine speed is 3000rpm -> 50 rounds per second -> one injector pulse or spark lasts 2 milliseconds. cutting one or 2 doesn't make engine die for sure. it wont stop right away. traction control in carburated vehicles is done by cutting spark only, but IMO it's too agressive way to adjust power (like old style rev limiter). unburned gas is no good for catalytic converters...
so, logic cut pulses until traction is restored OR engine speed is below set minimum for ex. 1000rpm. there's a need for one more input: engine speed and that could probably get from distributor.

how does the circuit look like?



-P

deadbird

Here's my DIY traction control setup

pontiac

what it has to do with traction control?
how can you apply brakes at 60mph when overtaking a trailer in winter?


-P

deadbird

I guess my sense of humor varies for others... traction control... gas & brake pedal (used together or individually to control traction.. haha).
It's fairly easy to use good judgement in bad weather conditions to regulate your traction instead of relying on something to do the 'thinking' for you.

No offence was intended from the above post or this one, it was meant to just be a little humor...
I suppose it wasn't as funny as I though tho.

z28esser

I thought it was funny lol...Sorry but I prefer to control my car myself.If you live where it snows.Look in the ditch after the first big snow.Guess what kind of vehicles you will see.New ones with traction control and abs.No amount of electronics can over rule physics and common sense

pontiac

actually when you're driving front wheel driven cars you can apply certain amount of brakes to enhange traction by using brakes. i don't know physics behind it, but gentle touch of brake while turning steady on gas helps a lot while driving FWD in snow.
if you haven't experienced following conditions at same time:
- automatic transmission
- V8 torque
- RWD
- snow
- over taking at 60mph

please don't try to be funny with this topic. i was looking for someone who can design this simple traction control circuit and i can be the test mule. 95% of V8-powered thirdgens are garaged during real winter simply because it's far away from nice winter vehicle. in other words, my GTA sits in garage during winter because it's hardly driveable when road is just wet!



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LT1maro

Hey, how much is that traction control unit that u were talking about? if its under a grand, i might be interested in getting it, o, whats the sites name? thanks

Chris Luongo

pontiac,

Our cars aren't all that light overall, and in stock form, there isn't much more torque than many other V8-equipped vehicles. I'd say the main two drawbacks are that the rear-end of the car probably isn't as heavy as a larger car, and most of our cars are equipped with very wide tires.

For extreme winter driving, you might consider getting some steel 14" GM wheels, and putting something like 205/75/14 tires on them. That, as well as putting some heavy objects in the trunk, should at least get a thirdgen to equal the winter performance of, say, an '80s model Monte Carlo or Thunderbird.

But anyway, to attempt to answer your question.

Most cars only have low-speed traction control; it is designed for use below 25mph, so you don't get stuck; not to help you make high speed passes.

I'm pretty sure that the basic system goes something like this:

There's a speed sensor on each drive wheel.
The car is designed with the ability to control each brake individually.
The eletronic controller in the car senses that one wheel is spinning way faster than the other, and applies that wheel's brake to slow it down.

A few cars, mainly high-performance ones, have high-speed traction control. There's a low-speed system similar to the one above, and if the brakes aren't strong enough to keep you from spinning the wheels, the controller also reduces power to the engine.

I once remember reading a review of a Corvette with traction controls; the testers liked the unique way the high-speed system worked: First, the car would push the gas pedal back against your foot, to a throttle level where the car had grip-----but if the driver for some reason wanted the wheels to spin, he could simply push harder with his foot.

By the way, those speed sensors and independent-brake-control are also required by antilock braking systems, which is why on most new cars, you'll see ABS and traction control sold as a package deal.

Anyway, you could theoretically, I suppose, try to get a salvage GM car with traction control and retrofit all the parts, but you'd be talking about major R&D time, completely redesigning your car's braking system from scratch, and probably lots of fabrication, welding, et cetera. Not impossible, but not worth doing either.

99Hawk120

Actually, the OEM TCS on the LS1's doesn't appear to cut fuel or timing, it appears to retard timing and/or apply the brakes.

Of course, I always turn the TCS off anyway, for a couple reasons:

1) It's slow to react.
2) It's slow to turn off
3) It MASSIVELY overreacts in many cases to slight traction loss

I prefer to do my thinking with my feet.

92RSB4C

There are 4 wires going to the dist. module.

Dist. reference Hi- Engine RPM
Dist. Reference Low- Engine RPM
Spark Timing Output- Spark Timing
Ignition Module Bypass- ECM can ground this to bypass spark advance, a connector can be disconnected to set base timing

Which one were you thinking of interrupting?

92RSB4C

According to my shop manual, if Dist. Reference Low becomes open, it will run poorly. You could interrupt that wire.

2vmodular

traction control rocks in the rain & light snow. hit the gas hard and an rwd car goes straight ahead, no fishtailing or "donuts". if one wants to mess around and do burnouts, make sure to knock the t/c off ahead of time.

would be cost prohibitive to retrofit t/c into a thirdgen. would first need to put an abs modulator under the hood to be able to individually pulse the back brakes, then need to install some wheel speed sensors, rerun brake lines, wire the system up. finally figure out a way to reduce engine torque. some cars accomplish this electronically by having the pcm retard spark timing and altering the injector pulse rate (sequential fuel injection is a definite plus), others such as ls1 have a mechanical linkage to the accelerator cable.

99Hawk120

If you say so.

I daily drove my 99 for two years, which is a 6-speed and traction control, and let me assure you it does not work that well.

It's more like:

1) Hit gas hard
2) Rear wheels spin and car drifts sideways
3) Countersteer to correct drift
4) Traction control kicks on, kicking the gas pedal back at your foot
5) Let off on gas and apply again, lighter
6) Traction control has not kicked off yet, so you're not going anywhere
7) Traction control turns off
8) Regain control of vehicle

Oh, and just so you know, in order to get out of my driveway when it was covered with snow, I had to turn the traction control off. Do you know why?

It's because all it cares about is the rear wheels are turning faster than the fronts. Forget about the fact that I'm actually making it up the hill... no, no, we have wheelspin, and that can't be allowed. Plus, at such low speeds, I had to ride the clutch to keep the traction control system from STALLING the car when it kicked in. Yeah, traction control is wonderful... My friend's C5 had the same problem on that day.

I figured, okay, I'll turn it off when I know the weather is bad, because I can actually anticipate road conditions (i.e. getting a running start up a snow covered hill), unlike a stupid computer. But I'll leave it on the rest the time, just in case I hit something unexpected. It can't hurt, right?

Wrong.

Picture this: I'm coming out of my neighborhood onto a main, 50mph two lane road. The end of my neighborhood road tends to have some loose gravel lying around. I make a right turn in front of a semi with plenty of room and stomp on the gas. One of the wheels chirped a bit (probably found some gravel), and by the time I was completely in the lain on the main road, the traction control kicked in and cut my power--with a semi barelling down on me no less. I stomped the gas pedal immediately and managed to avoid getting run over... barely.

I don't like being second guessed by a computer that's often slow to react and sometimes even wrong. If I could figure out how to disable the traction control on my car permanently, I would. Ordering that option was the single biggest mistake I made with that car, and the 4-channel ABS (vs. 3-channel) doesn't make up for it.

Instead of traction control, why don't you look into retrofitting an ABS system. That would provide a REAL safety benefit, and if you were still interested in traction control, you'd have the ABS sensors to use for wheelspin indicators.

2vmodular

yep, traction control won't allow the drive wheels to "dig in" to the snow or mud. so if snow is deep or you're stuck in mud, disabling t/c temporarily is the way to go.

by light snow, meant a road that has been plowed but is still a little slick. t/c works well in this situation. works well in rain too.

electronic t/c + mechanical posi rear isn't the greatest combo. electronic t/c + open differential is preferable. but this issue is a double edged sword in the sense that when t/c is disabled, a limited slip differential gives considerably better traction than an "open rear".

as for disabling t/c automatically whenever starting the car, dei makes an door lock pulse generator that would work well for this task. everytime key is turned from the off position to run, a ~1 second pulse would be sent to emulate the t/c switch being pressed.

pontiac

at first, thanks for all of you good ideas and comments
commercial traction control devices are available from:
http://www.racelogic.co.uk/
http://www.omextechnology.co.uk/

traction control (TC) in general are not optimised for sports driving and will give you some head aches during extreme driving conditions (made by driver or weather). anyway, the one i'd like to make is for sport type of driving, where you allow some wheel spin to happen ie. rear wheel may rotate 20% faster than front wheel until traction control is activated. that would enable driver to enjoy never-ending-slides since rear wheel slippage is controlled by computer, not fuzzy "right foot/V8 grunt/automatic"-combination but TC gives you huge edge if TC is made correctly. you simply cannot beat the computer. all F1 racing cars are using it for reason. 700hp and 1500 pounds.. you would use as well if that's your daily ride

ABS parts are cheap, sensors can be fitted to any car and those are plenty available new or used, original or aftermarket. just like any other parts made millions already. like spark plugs.

basicly function of traction control is simple: detect the true speed of vehicle and then adjust propulsive wheel speed to match to the vehicle speed by adjusting engine power.

i'd go simply cutting the fuel for cutting power. it will react most fastest and latency between inputs and output will be minimised. the way how to cut power, i'm not sure anymore. ideas welcome

but first of all, is there anyone who can design the circuit? just 3 inputs and one output, that's all. i can test it if someone come with an idea.




-P

92RSB4C

So basically, this is what you want?

You could program the circuit to cut fuel pulses every other time. For instance, if the fuel pulses getting by the TC device were represented by a +, and the fuel pulses not getting by the TC device were represented by a -, then it would look something like this: + - + - + - + - or you could do this: + + - + + - + + -

99Hawk120

You might want to simply use a frequency to voltage converter on each sensor coupled with your own functions.

One idea would be to take the three signals and compare them each to each other:

Front Left v Front Right
Front Left v Rear
Front Right v Rear

Use a differentiator of some sort such that when the difference between any two of the signals greater than a certain preset amount trip the TCS on. If you're cutting fuel or spark, you could simply OR the results of the three comparisons together such that the TCS will trip when any of the three comparisons fail.

Using a relay would be a bad idea--it would wear out quickly, not to mention the chattering would get highly annoying. I'd suggest using a transistorized switch of some sort.

92RSB4C

Maybe an EPROM of some sort to change up the pre-set level.

I'm not familiar w/ transistors. Please educate me. Dam school aint good for nothing!

99Hawk120

If you look at the post I made earlier about the frequency switch, there's a discussion about using a MOSFET as an electronic "switch" You can get one that does 75A and 12V, so I would think that would be sufficient...

92RSB4C

I'm definately in over my head.

pontiac

92RSB4C :hail:
the circuit is exactly what i was thinking of. it just need some electronic Guru to compose logic with electronic components.

the traction control unit should then recognize and analyse these type of inputs:
- ABS sensor type of input for front wheel speed
- VSS sensor type of input for rear wheel speed
- distributor type of input for engine speed (missing in picture)
- only required output is injector on/off switch.
ABS vs. VSS relation should have some kind of calibration **** for sensitivity ie. maximum number of pulses from VSS vs. ABS pulses until traction control gets activated. one front wheel sensor should be enough, just to keep this thing as simple as possible.



-P

[edit] oh yeah, it's good idea to not totally cut off fuel and save some pulses in between. probably engine will face lean condition if driver is stupid enough to hold gas pedal at WOT for long time while TC kicking in

92RSB4C

Here's the revised drawing w/ the transistor and an adjustment ****.

The relay explained: The relay will allow normal operation of the car if the TC device is turned off. It will allow for longer life of the transistor.

Operation: When the logic controller senses X% (adjustable by ****) of voltage difference between front and rear, the logic will turn on the relay, thus cutting fuel supply to engine, and simotaniously activate the transistor. The logic will not active the transistor every 2 or every 3 times a pulse is detected. We should also make this adjustable.

92RSB4C

How would somebody wire up a frequency to voltage converter? I've been looking for a diagram but can't find one. Also, what kind of transistor would be needed?

99Hawk120

Damned if I know. I buy frequency to voltage ICs and they have lots of little stuff inside it that makes it work. Just don't let the smoke out...

Grumpy

Are you talking about or want to control wheelspin on intial accleration, wheelspin at all times?, and are you including yaw control?.

For road racing you'll want to allow about 10-15% rear wheel overspin, since oversteering is the fastest way thru a turn.

Most initial spin controls cut off at 40 MPH.

I built a Launch Assist.
Rather then have to letting feature creep get the best of things, all I did was disallow any sudden engine rpm change over X percent. I trggered 2-555s off of each ignition event, they charged two differnet MFD capacitors. Then used voltage divide by 10 devise to divide the difference from the two caps, when the vaoltage exceeded X it triggered a logic circuit to start dropping cylinders. I dropped cylinders as a function of prime numbers to min loading up any one cylinder.

But, you can do better with just a code patch to limit the HP in 1st gear (road speed), or if an auto just getting clever with the HP below the stall speed of the converter will also work.

Incorporating all the feature creep is nice, just need to work out a fly by wire throttle, incrporate the ABS, and then a steering input.

pontiac

the traction control i'm talking about works from 0 to max mph. it simply reduce engine power when traction is lost, and by reducing the available power it gives the traction back

the logic behind the idea is very simple:

if ( rear_wheel_speed > front_wheel_speed )
{
cut every second injector pulse to reduce power
}

i've explained what are the inputs and output, also how to control engine power. 92RSB4C has visualized it, only thing missing is part list and logic control circuit design, right?
just wondering where we need "fly by wire throttle" and factory installed ABS system?



-P

Grumpy

If you try to make it that simple very time you make a fast turn you'll trigger it. Any swerve, and you'll have a power cut.
Ever second injector pulse is way too massive of power cut.
Traction control implies more then in just a straight line, until this post you hadn't defined what you were looking for.

So how do you plan to not have it apply when making a turn?.
What resolution do you plan on for the wheel speed sensors?.

Hint, you might look at a 4 channel ABS system off of syclone/typhon for rear wheel speed sensors for drum applications. trouble is they are AWD and the front rotors won't reto to the FBodies.

the fly by wire, and abs would accomplise actual traction control, which is what you first mentioned. using a fly by wire would be better then injector or cylinder dropping. It hard just hammering an engine on and off.

pontiac

for sure system "as is" now wont work perfectly right away, but principle should be sound enough.

there's a need for 2 adjusting *****:
- setting front vs. rear wheel speed maximum difference (should allow make a turn and some wheel slippage as well)
- switch you can deside how many pulses are between cuts when traction control is activated

with those adjustment should not be too difficult to make TC work smoothly



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92RSB4C

Like this?

pontiac

92RSB4C :hail:, drop the relay from diagram. that's not needed when we're dealing with electronics, transistor can do that job and another things as well. other connections are sound. logic and frequency/voltage conversion... we're about to cut this one in bit and pieces. after puzzles is solved we have working traction control



-P

92RSB4C

Ok, I'm just a little confused about how this device is going to get power. I thought you were going to mount a switch on the console or something to turn it on or off. In that case, the relay would be a necessity to keep the engine running. If you had it on all the time, it would wear out very quickly. If it were on all the time, a relay would save the transistor from wearing out so quickly. I think it ought to stay.

V8Astro Captain

iTrader: (1)

IMO the only traction control that works worth a $hit are the ones that are tied into the ABS system.

I think if you made the gizmo shown above, and tied it into an ABS system it would work great. Easier said than done I suppose.

My van is equipped with ABS. Althought it $ucks really bad I think it could be used for this.

Take the wheel speed sensor inputs from the rear and input that into the t/c box. Then when the difference in wheel speed reaches a certain point (don't want it going off around corners) you could cut power to the engine, and apply the ABS to the rear. Unfortunatly the rear brakes run off the same line so you couldn't activate them independantly. That way, you cut power to the wheels, and at the same time you get the spinning wheel to stop...and thru the differential the power would go to the wheel with traction.

99Hawk120

Grumpy,

That was kind of my point. Installing ABS could be an intermediate step towards getting working traction control, and give you a nice safety feature as a bonus. I would look for some vehicle that has a stand alone ABS controller and try adapting that.

If you can get the ABS done, THEN considering adding the TCS on top of it. At that point you'll ALREADY have all the input signals you need.

For the rear wheel sensors, consider grabbing them off a 4th gen with TCS/ASR; they're mounted at the ends of the axles instead of in the pumpkin. For front wheel sensors, you may have to get creative.