Disable ABS for rallyx.

[ehsnils]

OK, trial and error is your best bet. Just because the light doesn't come on does not mean that it works, it can be that the fuse did pull the power to the light.

 

But if you mount some switches to cut various fuses and then throw the switches during brake tests (on a closed area) you may be able to see if the EBD tuning "sticks" to a certain setting when the power is cut or if it resets to the default value.

 

So it will be a semi-manual approach. And a lot of test runs to determine what will work best for you.

[dmanaenk]

Just because the light doesn't come on does not mean that it works, it can be that the fuse did pull the power to the light.

Nah, the light itself works. It comes on when e-brake is engaged, it is not in the direct current flow of any of the fuses and is switched on/off by the ABS/VDC/ECM computer. And it did come on steady (with e-brake dis-engaged) when I pulled the other fuses I listed.

[dmanaenk]

Ok, tested it out. EBD definitely works. Tried a few times braking hard in the parking lot during a mild turn. Front wheels lock up first, resulting in understeer, and I felt some pulsing in the brake pedal, which should happen when the EBD adjusts front/rear pressure.

[ehsnils]

Fine - problem solved then?

[FPerron]

Just a rather late note about ABS. The president of my racing club was killed a few years ago when he lost the rear end of his Corvette on the banking at Pocono. We're taught to react to high speed, out of control situations by "putting both feet in" - basically locking up the brakes so that the car takes a relatively straight and predictable path. Well, the Corvette had working ABS which prevented brake lockup. The car then spun sideways down the banking and into a concrete barrier - game over. Another friend of mine destroyed his Mazda RX-7 on an icy road for the same reason.

[dmanaenk]

Fine - problem solved then?

On the acceptable minimum level - yes.

 

I'll still try to make it on/off 'on the fly'. I think screwing up (not turning off completely) the steering angle sensor is what's required, so I gotta think it through.

[dmanaenk]

Just a rather late note about ABS. The president of my racing club was killed a few years ago when he lost the rear end of his Corvette on the banking at Pocono. We're taught to react to high speed, out of control situations by "putting both feet in" - basically locking up the brakes so that the car takes a relatively straight and predictable path. Well, the Corvette had working ABS which prevented brake lockup. The car then spun sideways down the banking and into a concrete barrier - game over. Another friend of mine destroyed his Mazda RX-7 on an icy road for the same reason.

That's a sad story, but not exactly typical, I think a lot more wrecks at the track are due to ABS preventing braking on the run-off surface.

[ehsnils]

On the acceptable minimum level - yes.

 

I'll still try to make it on/off 'on the fly'. I think screwing up (not turning off completely) the steering angle sensor is what's required, so I gotta think it through.

 

Fine tuning for racing is always a problem. There is always something you can make better - and then conditions change.

 

But how much impact do the steering sensor have for EBD? That's an important question, but the easiest way to figure that one out is to test having it both connected and disconnected and see if there is a difference. If there is no difference then you can forget about it.

[dmanaenk]

But how much impact do the steering sensor have for EBD? That's an important question, but the easiest way to figure that one

From what I know - none. EBD looks at either wheel speed sensors or g-sensor/yaw rate sensor. Steering angle sensor goes into VDC calculations and possibly into ABS logic.

[dmanaenk]

Disabling the ABS also disables the EBD. Be ready for a a lot of push under braking.

Ok, I tried my best to get a coherent explanation of this from the author of this comment. Only got some random irrelevant/unsolicited life/driving advice.

 

Anyone else willing to take stab at a logical explanation of why would "no EBD" mode (ABS/VDC already disabled) will make LGT understeer/push in corners more than an LGT with working EBD (ABS/VDC still off)?

 

To me it seems its the other way around. No EBD for hard braking = more rear brake bias = earlier lock-up of the rear tires = more prone to spin-out/back end stepping out.

 

Cause if this is somehow true - it would make me want to disable EBD, instead of try to keep it.

 

Thanks.

[ehsnils]

The absolutely best way to figure out how well it works is to find a flat gravel area without obstacles and then do some test runs with different configurations. That will tell you a lot about how well the car is behaving during braking.

 

Slight turn to left or right and then brake and see if it consistently oversteers or understeers.

[robinlsb]

Ok, I tried my best to get a coherent explanation of this from the author of this comment. Only got some random irrelevant/unsolicited life/driving advice.

 

Anyone else willing to take stab at a logical explanation of why would "no EBD" mode (ABS/VDC already disabled) will make LGT understeer/push in corners more than an LGT with working EBD (ABS/VDC still off)?

 

To me it seems its the other way around. No EBD for hard braking = more rear brake bias = earlier lock-up of the rear tires = more prone to spin-out/back end stepping out.

 

Cause if this is somehow true - it would make me want to disable EBD, instead of try to keep it.

 

Thanks.

 

I have tried to explain to you there is more to high speed cornering than simple entrance to a corner. I have tried to explain to you that what happens when you let OFF the brakes( and how hard) in a corner is important,I have tried to explain to you that counter steer in an adw car ends up with push of the worst kind in a corner

 

So I suggest, that you prove your point , that a 50/50 bias is perfect in a race car:lol::lol: What will be really wild, is what happens in an AWD car, with an open front differential and a rear LSD:lol:

[dmanaenk]

The absolutely best way to figure out how well it works is to find a flat gravel area without obstacles and then do some test runs with different configurations. That will tell you a lot about how well the car is behaving during braking.

 

Slight turn to left or right and then brake and see if it consistently oversteers or understeers.

To engage EBD the braking pressure should be fairly high, on the gravel it is in fact irrelevant, now that I think about it, since even moderate pressure will be enough lock-up the wheels long before the EBD has a chance to kick in.

 

On the track though - it wouldn't be irrelevant. I'm not disabling ABS for track though, but someone who would (for reasons like the above story or if the run-off area is sand/gravel and there's not much of it there). And as I said - I tested this on pavement. No-EBD=spin-out.

 

 

 

 

I have tried to explain to you there is more to high speed cornering than simple entrance to a corner. I have tried to explain to you that what happens when you let OFF the brakes( and how hard) in a corner is important,I have tried to explain to you that counter steer in an adw car ends up with push of the worst kind in a corner

 

So I suggest, that you prove your point , that a 50/50 bias is perfect in a race car:lol::lol: What will be really wild, is what happens in an AWD car, with an open front differential and a rear LSD:lol:

 

50/50 bias? I was talking about brake fluid pressure split mode in EBD vs noEBD. If you can't read - that's not my problem.

 

Anyway, like I said - all you are giving me is some unsolicited advice on stuff I did not ask about. I have plenty of racing experience, and have met plenty of guys who are quick, but have no idea how things work (or have insane ideas about why they are quick). So I prefer to take advice from those who can explain their reasoning using car physics.

 

If your definition of a "push" is when the rear looses grip and spins while the front brakes are still not locked-up - then we just have a difference in definition. To me the "push" means understeer, so your definition seems crazy.

[ehsnils]

I made sense about Robins post - and she should know what she's talking about.

[robinlsb]

To engage EBD the braking pressure should be fairly high, on the gravel it is in fact irrelevant, now that I think about it, since even moderate pressure will be enough lock-up the wheels long before the EBD has a chance to kick in.

 

You are under the impression that EBD ENGAGES , I think not. ABS, yes, EBD no, under low gee situations.

 

 

 

On the track though - it wouldn't be irrelevant. I'm not disabling ABS for track though, but someone who would (for reasons like the above story or if the run-off area is sand/gravel and there's not much of it there). And as I said - I tested this on pavement. No-EBD=spin-out.

 

 

You haven't proved anything.

 

50/50 bias? I was talking about brake fluid pressure split mode in EBD vs noEBD. If you can't read - that's not my problem.

 

I hate to tell you this, but there are more things about brakes than brake pressure. For example the disk diameter.

 

 

 

 

Anyway, like I said - all you are giving me is some unsolicited advice on stuff I did not ask about. I have plenty of racing experience, and have met plenty of guys who are quick, but have no idea how things work (or have insane ideas about why they are quick). So I prefer to take advice from those who can explain their reasoning using car physics.

 

If it was physics, you would not see people run away and "hide' in racing. I'll give you a clue, it wasn't the motor.

 

If your definition of a "push" is when the rear looses grip and spins while the front brakes are still not locked-up - then we just have a difference in definition. To me the "push" means under steer, so your definition seems crazy.

 

We are talking about awd here. If you don't understand the difference between AWD push, FWD push and RWD push, I can't help you.

[robinlsb]

I made sense about Robins post - and she should know what she's talking about.

 

That was nice, but most people here think I am an idiot.

I just know how to win races:lol:

[dmanaenk]

You are under the impression that EBD ENGAGES , I think not. ABS, yes, EBD no, under low gee situations.

I have no interest in communicating with someone who has reading comprehension issues, sorry.

 

I can't see how can anyone with reasonable reading skills interpret what I wrote in the message you're quoting as if I'm thinking that:

1) EBD engages on the gravel

2) 50/50 brake fluid pressure split meaning 50/50 brake bias.

 

You mis-understood what I wrote you in PM, took it for 50/50 brake bias for some twisted reason and trying to blame me for saying stupid stuff.

 

Re-read again and again until you get what I'm actually saying and then comment.

 

 

I can't help you.

I agree, you can't help me, until you read what I'm writing.

[robinlsb]

I have no interest in communicating with someone who has reading comprehension issues, sorry.

 

I can't see how can anyone with reasonable reading skills interpret what I wrote in the message you're quoting as if I'm thinking that:

1) EBD engages on the gravel

2) 50/50 brake fluid pressure split meaning 50/50 brake bias.

 

You mis-understood what I wrote you in PM, took it for 50/50 brake bias for some twisted reason and trying to blame me for saying stupid stuff.

 

Re-read again and again until you get what I'm actually saying and then comment.

 

OK:lol:

 

 

 

I agree, you can't help me, until you read what I'm writing.

[robinlsb]

That's a sad story, but not exactly typical, I think a lot more wrecks at the track are due to ABS preventing braking on the run-off surface.

 

What crap. Talk about workmen blaming their tools:lol: Maybe it was their lousy tires, maybe their lousy brake pads. You see it all the time, people sniveling that it was the tires, the suspension, the brakes that led them to grief.

 

Grow up:rolleyes:

[mwiener2]

From what I can discern from the shop manual, the ABS and EBD work hand in hand. If you disable one, you disable the other.

 

ABS is a re-active system. It only kicks in when wheel slip is present. If you are threshold braking properly, ABS won't kick in.

[ece_tim]

In case anyone was wondering, yes, the OP is a prick. He solicits advice, but we must give him ONLY the advice he wants. No other advice. Yes, this is how forums work...

[dmanaenk]

Yes, I only want advice on the topic I asked about. All other advice should be posted somewhere else. This is how themed sub-forums are supposed to work. Of course there are always people who come to comment on some irrelevant staff nobody asked them about. But then again there are always people posting pictures and for-sale ads in the topmost sub-forum...

[ece_tim]

Did you hear that Subaru ran the 2010 STi sedan at the Nurburgring?

[AZP Installs]

What crap. Talk about workmen blaming their tools:lol: Maybe it was their lousy tires, maybe their lousy brake pads. You see it all the time, people sniveling that it was the tires, the suspension, the brakes that led them to grief.

 

Grow up:rolleyes:

 

Can't agree with you more. I am a track instructor and race director. If I had a penny for every time someone blamed their equipment for why they weren't as fast as my slow crappy car, I'd be a millionaire by now!

 

Tire pressure was off

Didn't have my JDM Blinker fluid

sun was in my eyes

tune isn't correct

tires are old

brakes are old

fuel is only 92 octane instead of 93

ABS caused me to be slower

 

It makes me sick as a racer to hear the whining and bitching. I go out in just about any car and as a good driver I adapt to the condition, to the car, etc. THAT is what makes a good driver, not the equipment.

 

-mike

[dmanaenk]

So nothing on topic then? I thought so.