Good ****:
http://farnorthracing.com/autocross_secrets9.html

 

Indirectly the link above shows us the different between a time trial (time attack) mentality and a race mentality. While a good race driver can beat most ABS systems in ultimate braking, its takes a great race driver to beat the ABS system going into a corner, while passing a car on the inside, while being passed on the inside by a third car.

The additional stress of passing and being passed is almost non-existent in time trials or time attack. If your car is involved in a pass, you've blown the lap and need to start over.

 

Although the author, Dennis Grant, discusses the ability of beating the ABS system, regardless of the situation W2W or TT, at the bottom of the article he recommends having ABS for similar reasons that you just mentioned.

 

Thanks guys. That's what I thought. I see the brake balance is off from uneven tire and brake pad wear over the long term. That's very annoying, especially since I can't fix it without redoing the whole system. ABS shouldn't be a crutch to fix a design flaw.

 

Yeah, without ABS the front/rear bias is completely off. When mine went out it would easily lock up the rear wheels just test driving it around the block. I wouldn't take it to the track in that condition without at least adding a brake bias adjuster first. I debated ripping ABS out but opted to find a replacement unit and keep ABS. Although I rarely engage ABS on track it's nice having it for racing in the rain.

 

I use to stop buy Steve Mitchell's shop M-Workz to see what his latest project was or to get my car aligned. His Redline Time attack car driven by Billy Johnson had the ABS disabled and they had great success with that car.
Sport Compact car once did a test and showed breaking distance was reduced with ABS disabled if the person driving understands and is skilled at threshold breaking.

 

Yes, Threshold braking will always out brake ABS braking because it is just that...threshold braking at the top of the tires traction. 99%-100% of the available traction is dedicated to just braking and doesn't leave any for turning or any type of course change. ABS tends to leave about 10% for directional changes...they aren't really just Anti-lock anymore, but closer to a traction control system. They still pulse but that is to measure the traction limit then the system is smart enough to knwo what 90% is after that.

 

You guys seem to be assuming that the ABS engages exactly when you would lock up a tire. I imagine the unit engages well BEFORE lock up would occur and not at the very last second, thus, leaving plenty of room for non-ABS threshold braking to be a superior choice.

Having said that, the imbalance of brake bias is a legitimate reason to keep the ABS.

My ABS actuator is done, per Tynan's Nissan of Fort Collins, CO. They want $1300 for the unit and $400 for labor to install it. For my situation, ABS is engaging at the end of a stop, every stop, hard and light. The ABS light comes on under hard braking and intermittently during regular driving. The diagnostic tests run on my car show the Right Front IN and Right Front OUT solenoids are intermittently engaging, even if the brake is not touched.

Having said that, I have been considering running my car without ABS. I realize from this post that the brake bias is designed around the presence of an ABS system.

My question is, would an aftermarket brake bias controller resolve this issue? Or is this something our main ECU governs, so I would need to alter this in some way (aftermarket engine management, etc.)? I'm sure there is a race team out there with a non-ABS Z that has (near) perfect brake bias.

 

Most ABS systems are heavily front biased both mechanically and hydraulically when the ABS system is inactivated. A prop valve would have almost no effect on this. At a minimum you'll need to change MC and/or caliper piston sizes to balance the built in mechanical/hydraulic imbalance.

 

that sucks, as my ABS activated at every stop as well. I just unplugged it the other day and what a great feeling not having that crunchy pedal at every sub 10mph stop at a red light.

Acidhex, do you have an ABS light on? My ABS light never comes on, even though the ABS is always activating. I need to log it all with a Cipher cable this week

 

My abs light came on one time and then shortly disappeared. I never thought anything of it and now 15k miles later it is intermittent and very crunchy and annoying. I cleaned my front sensors last night, just waiting on my rear pads to arrive to put em on and clean the rear

 

Zombie thread. Anyway, I vote no on the ABS, def for drifting, and 90% of the time in AutoX it actually works against me. There have been multiple times when it kicks on in a straight line when I'm nowhere near the traction limit of my tires and so I plow through a couple cones. I try holding them then pumping them when that fails. Neither tends to work much until I come to a complete stop so...that's why I only run ABS on the street.

 

The 350z will not benefit from no abs but some other cars do like the miata. Some cars have systems that are even worse such as the Z06 which is called active handling that causes the brakes to kick in on each individual wheel.

Again, no benefit to no ABS unless it's for drifting or something like that. We're not F1 drivers nor is the 350z an F1 car.

 

Keep it, especially in the wet. I had my ABS go out for no reason during a rain session, went straight off the track in the first braking zone.

 

I'd say it depends a lot on your preference and skill.

I've found that with the ballasting we've had to do to make weight in T3 (lots of rear weight ballast in the car and 8 inch wheels front/rear) the rear bias of the brake system is not terribly bad (especially on a full fuel load where there's even more weight in the rear).

My ABS crapped out at Summit Point so I've now run without it (again) since then and not had nearly the issues I had earlier with a lighter T2 car where most of the weight reduction came in the rear end (which increased the chances of a rear-end lockup).

Another very interesting thing I discovered by accident at the Glen this weekend - the brake pedal throttle-cut seems to be managed by the ABS computer - disable the ABS and you can left-foot brake while maintaining 100% throttle.

So for auto-x, the lack of an over zealous ABS and the addition of left-foot braking capability, I'd seriously consider disabling it. For road racing in the dry it's a toss-up, but in the wet, I'd want it on.

Brian

 

For left foot braking you can control that via some standalones if I'm not mistaken.

 

i realise this is a bit of a thread revival but i thought it might help someone..

i raced my car for a year with ABS using a 356mm front and slightly smaller rear AP calipers and then disabled the ABS for a year to see what difference it made.

For me it completely depends on the weather. I have found in dry hot conditions it makes some difference, probably marginally better into medium braking zones, in hard brake zones/ hairpins etc ive found no difference. This is on Dunlop slicks

In rain, on Michellin Race Wets once there is heat in the tyres again similar to dry, maybe marginally better, easier to recover from a moment, if the car properly locks up with ABS then you dont have as much control other than to come off the pedal completely rather than modulate it without

The worst is slicks/wets in greasey conditions, the ABS is magical and i would like it back for this,

i think from my expereince the ABS just isnt required when the car has heat in the tyres and a decent setup, doesnt matter if its enabled or not, the car doesnt need to use it, in the greasey post rain conditions though ive not had much luck, maybe i just need inters and more practice...

If i had known the above a couple of years ago i wouldnt have bothered spending the time disabling it, the only potential advantage is to remove the whole ABS system if it weighs anything

 

I have to turn it off because since I have a 2-way LSD it always thinks I'm losing traction.

 

is disconnecting the brake fuse the only way to disable ABS? Kinda sucks to know the brake lights don't work if you disconnect the fuse.

 

The only place where a driver can utilize the brakes sans ABS is on the track. Why would you care about your brake lights on the track anyway?