RaceLogic Traction Control

[Phil Wall]

I have started this new post because we have a number of post about TC in other areas. I felt as we enter a period of poor road conditions and in the interest of member safety, certain observations about RLTC should be brought to members attention in a new thread.

 

 

Thanks to Graham’s lovely little program, the analysis of  RL setting  is quick and easy to do.

 

I spent several hours last  night comparing  dat files sent by various members, thanks for the amazing response guys. I even loaded a few in to my car  and tried  them on the road. Whoooooo no wonder some of you are having  trouble going anywhere with RL turned  on!!!!

 

It would appear that there are a number of problems common to both the Standard.dat file supplied  on the RL disc and the preloaded “Supra” settings and some specific to each.

 

After many lengthy discussions with other members, about this topic I wish to put forward the following personal opinions . I wish to stress my opinions  are  not intended as public criticism of the product, just observation regarding what  I consider to be flaws in the data in some files.

 

 

1. Grahams program is a must ask him for a copy.  It is so easy to use, where as the DOS  software is confusing cumbersome and a pig to use.

 

2. The standard.dat file supplied on the disc appears to be is a generic file possible intended  as low level baseline data for any application . In the examples analysed, if the data was load into the RL unit  in a MKIV supra, the car would not function particularly well above 2000 rev under acceleration, as the cut tables cause insufficient fuel injection. IMO dump it.

 

3. A copy of the internal preloaded dat file should be made using Graham's program as soon as there is power to the system. This file then becomes your BaselineSupra.dat. Keep it safe as a back up, in case you screw up the internal setting as I did when I first got the unit.

 

4. The wheel sensor pulse / rev data is pre set at  40 with a wheel diameter 550 ,  this should work with most wheel combinations. I have noticed some very  slight differences comparing 16” and  17" wheels. I can’t say anything about  larger wheels.

 

If you attempt to alter the wheel diameter to match your car, as it says you MUST  do on page 45 of the  RL booklet supplied, the unit is likely  to induce sever cut at any reasonable levels of acceleration. I would suggest that you do not change you wheel settings until we can establish what the correct pulse settings are for the MKIV.

 

 

I would like to compare a file from a differnt car. Richard could you send me the dat copied from you RL unit.

 

[Rich J]

Doubt it will be helpful as I've played around with my settings alot, and mine came from JF and never had a specific baseline file for the Integra.

[GavinL]

Quote: from Phil Wall on 11:58 am on Nov. 10, 2001[br]I spent several hours last  night comparing  dat files sent by various members, thanks for the amazing response guys. I even loaded a few in to my car  and tried  them on the road. Whoooooo no wonder some of you are having  trouble going anywhere with RL turned  on!!!!

 

Phil, can you put into words the way in which these differing profiles affect the car?

 

As you probably know I had my system fitted (adjustable only model on UK manual car) by Julian at Racelogic.  I have thrashed around both in the dry and the wet on really crappy tyres for a year now and the car is no problem at all.

 

 

regards...............

[Branners]

I agree the cut on Gavins car is much smoother than on mine. I would also say its set a little tight so it cuts in much sooner when it senses slip than I think it needs to, but thats just an observation from when he was pushing hard at BW a couple of weeks back.

 

JB

[Doughie]

OK some more info here.

 

Rang Racelogic this morning and they confirmed the the RL TC units supplied for the Supras (as a group buy) should have pre-loaded appropriate settings on them.    BUT theses settings are NOT saved onto the floppy disk supplied, so it would be a v v good idea for anyone to save these settings (via the supplied lead, a laptop, and Graham Rudd's nice little *freeware* app) as soon as they can.

 

With regards to the parameters available, I was trying something out and now, having spoken to Racelogic i know how the following 3 things interact :

A) The slip amount dialled in by the driver (0%, 5%, 10%, 15%, 20%)

B) The 3 levels of fuel-injector cut :  soft, medium, hard

C) Each level of cut (soft, medium, hard) has it's OWN %value of ADDITIONAL slip assigned.   By default these are 5%, 10%, 15%

 

What happens is that whatever level of slip dialled in (A), the Racelogic unit decides what level of cut to use by ADDING TO THAT VALUE (A) the value ©, and when the resulting value is reached, then it initiates the appropriate level of cut.

 

eg.  The driver dials in 10% rear-wheel slip.

Let's assume the driver boots it hard on a slippy road and the rear wheels start to spin.    THe following will happen:

1) Less than *15%* (i.e. 10+5 where A=10, C=5) rear-wheel slip = no cut

2) 15-20% (i.e. A10 + C5) rear-wheel slip = soft cut

3) 20-25% (i.e. A10 + C10) rear-wheel slip = medium cut

4) 25%+ (i.e. A10 + C15) rear-wheel slip = hard cut

 

You can change the values © assigned to each of these soft,medium,hard levels of cut, by using Graham Rudd's applet, and downloading the modified DAT file into the RL unit.

it is interesting to note that even when the driver dials in "wet" i.e. 0%, there is NO CUT UNTIL 5% slip is reached.

 

 

Also another setting that is very interesting is that the RL unit knows when you're going round a corner as opposed to a straight line, by comparing the wheel speeds on each side of the car.    When it knows that you're travelling in a straight line, it ADDS an additional % slip value to the dialled in values as more wheel-slip is fine in a straight line but isn't such a great idea when cornering hard.      This value is, as default 5%.

 

phew.  

this all makes sense now to me, hope it does to others too !

The RL TC manual is reasonably clear, but i wasn't sure how the above worked exactly until i called RL today.

[Phil Wall]

Just read the above, yep got that, I will add this just to aid confusion.

 

While some of  you were getting lost, tearing round the country and  terrorising the old folk in Suffolk, some of  us sad gits were working.  I have been giving a more thought to the wheel speed and  diameter  issue with RLTC.

 

See what you think of this theory. Insults accepted by e-mail only.

 

The  RL system uses the pulse count, currently set at 40 to measure  one revolution of the wheel.  It use the  diameter  of the wheel to calculate rotational distance travelled by each wheel. The system assumes you have a diameter  of  550 mm which gives and  rolling circumference of 1728.5 mm.  For my 17 Bridgestone rears the  diameter is 638 mm, which give a rolling circumference of  2005 mm.

 

The system uses pulse count data to measure wheel rotation Therefore system only  knows that  one revolution has taken place when 40 pulses have been counted.  I assume the MKIV has less pulse counts than this, lets assume (xp)pulses per revolution.  But the system will one see one revolution when 40 pulses have been counted.

 

If we assume that the MKIV is delivering (xp) pulses per revolution, then the systems sees [40-(xp)] pulses from the next revolution before it registers 40 pulses.

 

If this is correct the “ 550mm system”wheel will have done one revolution in (xp) pulses giving a rolling distance travelled of 1728mm.   After a few calculations I found the best fit pulse count to be  34.  So 1728 divided by 34 pulses = distance between each pulse = 50.8mm.  But the system expects 40 pulses which gives a total rolling distance 40 * 50.8  = 2032mm.  Not quite the   2005mm of my rear wheels, but close . I believe the small difference between actual rolling circumference and  that calculated by the system is with in safe limits and  hence the system works.

 

At  5.0% slip the system would not react  until the difference in rotating circumferences, causing slip, reached 86mm, using the 550/ 40 combination on front and rear wheels. ( and probably more if I undersatand the previous post)

 

As the Supra does not have identical wheel circumferences on the front and  rear, (on my car the difference in circumference is 22mm) the system is also picking up slight differences between wheel speed all the time, but these differences are with in limits. This would also explain why I can feel a slight difference in the responses of the TC system when I run my 16’s with a rolling circumference difference between front and rear of 56mm.  But  the system is able to give acceptable performance with both sets of wheels

 

But  acceptable is not good enough for me  I want perfection and nothing  less. The next step is to put my theory  to the test and  put the new pulse count and wheel diameter into RL and  try it.

 

Additional notes

 

I have spoken to Race Logic technical, (today)  who confirm that they do not  have data for the pulse count on the  Supra. They  said that the  550/40 combination works for  most  cars  with factory  fitted ABS  sensors. They also confirm that my assumptions above are correct and  in  the Supra’s case we are probably  counting pulses from the second turn of the wheel  to make 40 pulses. This is not a problem as the system expects the same from reference and  driven wheels.

 

The standar.dat.  file is, we  suspected, just a baseline file for any car, just a copy of what is printed in the booklet.  Therefore you do not have a copy of the file preloaded into you RLTC unit.  So a copy of you internal file is essential if you want a good back up.  The file supplied in the RLTC unit is basically a file for any six cylinder car fitted with ABS.

 

When I purchased the system I believed I was purchasing  a system optimised for the Supra. This is obviously not the case, and I presume everyone  else who took advantage to the group buy.

 

Owners with the system should not be concerned that the data does not match the car as with most wheel combinations the system should still offer acceptable TC.  Anyone wishing to optimise the system for their car, should enter correct wheel sizes and estimated pulse count data, do a safe test drive and  use tracread to analysis the  wheel sensor traces. By gradually altering the  pulse setting the system can be optimised and all four wheel traces should be superimposed.

 

If Graham can write  some software to make this possible in windows it will be a straightforward task, which could be completed in a few test runs. RL technical suggest it is a simple procedure to  get the traces to superimpose after a few test runs.

 

RL technical did suggest that  owners with higher powered cars, ie Supra’s may wish to fine tune the % slip figures for their car. ( ie alter the figures expalined in the previous post)

 

I intend to do a few tests, starting with the pulse figure I calculated. If I can get superimposed traces in tracread and the system survives my test track thrashing, I will post data and  make my Supra.dat file  available to anyone who would like a copy. I make no apology for being a perfectionist PITA.

 

 

 

(Edited by Phil Wall at 12:16 pm on Nov. 12, 2001)

[Branners]

to add to the confusion, my unit was not set up for a 6 cylinder car, it was set for 4cyl...so perhaps mine didnt even have the Supra basics in it.

 

If its not raining tomorrow I will fish out my wifes laptop and hope the battery lasts long enough to download my settings.

 

JB

[Phil Wall]

JB would you like my settings?

 

(Edited by Phil Wall at 8:43 pm on Nov. 12, 2001)

[Branners]

you already sent them over and Im planning on loading them in tomorrow once I have DLd the current settings.

 

JB

[Phil Wall]

Doh!!

 

Sent them all over the place, forgot.

[Doughie]

yep JB, will be v interesting to see what you make of the new settings that you've got from Phil.

 

I think it should be a big improvement.

 

I'm still working with Phil on identifying all the best settings for the Supra and there are several areas worht looking at and we'll be sure to advise everyone if we find anything worth changing.

 

cheers

[Phil Wall]

If its not raining tomorrow I will fish out my wifes laptop and hope the battery lasts long enough to download my settings.

 

JB

 

With Graham's program, including windows startup time that will take about 3.0 minutes tops.

 

In comms/setup, with the unit switched on and  ignition on, hit recieve then save, job done.

 

I hope my file improves your car!!!

 

Good luck

[Phil Wall]

Can you believe it!

 

Stu contacted Toyota  technical, yesterday, they don't  know the pulse count  from the  ABS sensors.

 

Only one way to go. Take it to bits and  have a look.

 

[Doughie]

Let's hope that the UK-spec ABS sensor has the same pulse count as the J-spec.

 

Only way to be sure (sigh..) is to check the ABS sensor on both the UK-spec and J-spec.   Phil has got the J-spec covered I think.    I may try to take the ABS sensor to bits on my UK-spec this w/e as I don't have a garage and so it's pitch-black in the week.

 

Ash - can you help here ?    do you know or can you find out how many metal teeth are on the cog in the ABS sensor on the J-spec AND on the UK-spec ?

 

[Guest Ash]

 

 

I can't see that the UK spec would be different. Well, not so much that it would matter. The only way of knowing is to remove the pickup and count the cogs. I only have J-specs to hand.

 

Phil......... if I take a hub apart and count the teeth then do I get a free copy of your settings when you have worked it all out?

 

BTW cheers for the in-depth post. Sounds like you know the RLTC back to front.

 

Yours,

J

[Phil Wall]

As many  as you like.

 

Plus my experimental launch for the auto box.

[Doughie]

My bet is that there are 34 or 35 teeth.

[Phil Wall]

Well my theory looked good and sounded good, even when I started from scratch agina, it had me convinced.

 

Well my theory is utter crap. So I am very sorry  for boring you all with it.

 

What are A levels  for any way.

 

I made the assumption that the pulse count had to be lower., so I guess the rest of the theory is pretty much correct.

 

Big mistake.

 

I gave up with theory and took the  front ABS sensor  off and  counted the teeth all (xp) of them.

 

So now I know. Assuming the front and rear sensors have the same number  of teeth.

 

Put (xp) in the system, added my wheel figures, and took the car for a thrash.

 

Oh I love this cold air, no cut all the way to 157?. feeling good. Hard get away felt tighter.  I think I have cracked it at last. Now for some rain and  my 0-100 test!

 

I was right all the time the number I was  looking  for was  (XP).

 

For one stupid moment after I had counted the teeth I wanted to work it out mathematically, but common sense prevailed even I am not that  sad.

 

[Guest Ash]

 

 

Phil, I tried to confirm your tooth-count figures as per your voice-mail message but I cannot find the locking wheel nut adaptor of the car I'm working on at the moment. My car is on the drive... but my drive is on such a slant, I cannot risk getting a jack underneath.

 

Tomorrow I'll dig out the locking nut adaptor and hopefully will be able to confirm your count. I'll check the rear also.

 

Yours,

J

[Doughie]

Hang on !!!

you can't keep me in suspense like this !!!

 

What is the number in the end ?  

XP = ??

[Doughie]

Hang on !!!

you can't keep me in suspense like this !!!

 

What is the number in the end ?  

XP = ??

[Guest Ash]

 

 

You lost your bet... big time.

 

Yours,

J

[Doughie]

heck I was only 13 out ...

 

:wink:

[Guest Ash]

 

 

Still, I bet you are glad you didn't put money on it. :biggrin:

 

Yours,

J

[Guest Martin F]

Quote: from Doughie on 8:09 pm on Nov. 13, 2001[br]heck I was only 13 out ...

 

:wink:

 

Close but no cigar