Brake more confident without ABS (or ALB)

[Eddy]

Thought I share something and see if you get the same feel with your NSX.

I got a 91 that I take to the track regularly.. Fairly stock with 02 Type-R shocks and sway bars. Hawk HP Plus front and HPS rear. Currently on Toyo T1Rs.

So I have always ran without traction control and the car always felt loose and lack of confidence on braking at the limit. I thought maybe my alignment was not at the greatest setup.

Now my ABS (or ALB if you want to be technical) motor died a few months ago so I figure I go without it. And to my surprise, the car is quite a bit more predictable when braking at the limit. I can actually modulate the brake at the limit and brake deeper into a corner and still bring the car around. This is particularly obvious at tight tracks like Streets of Willow.

Anyone had the same experience?

I was thinking about converting to NA-2 Type-R ABS but now I am thinking of just by passing the whole thing.

Cheers!

 

[MrHugo]

I was braking at low speed and hit a pot hole or bump, and my 92 ABS activated. I lost control of the brakes and almost hit the car in front of me. Thanks god it regained control and stopped. NA2 ABS is my next mod.

 

[NSXAMG996TT]

I've been tracking my NSX for the past 3 yrs without both TCS and ABS. Braking is very predictable thanks to the Stoptechs (with Carbotech XP10s) on all four corners.

I'll probably also do the NA2 ABS kit upgrade from SOS, but not in a hurry to drop $2K for peace of mind.

 

[SFNSXguy]

You can always just turn off both the TCS an ALB when on the track. (I did the SoS 2001 upgrade though.)

 

[nils]

yup.. abs is deactivated permanently in my nsx...

 

[liftnot]

I don't like the way my 93 ABS works so I decided to by-pass it using the Dali kit. That was over a year ago and its working just fine. I don;t track my car but went on a few spirited drives with no ill effect. If I get caught in the rain, I'll just be extra careful with my brakes knowing I don;t have ABS.

I plan to do the NA2 ABS conversion one of these days.

 

[docjohn]

I ran a season of hpde with my oem 96 abs deactivated(fuse pulled) and did'nt think there was that much of a diference with the indy brembo front with 12.4 in rotors,I now have the sos upgrade,I'm getting new indy calipers for this season I'll let you know how it goes.

 

[dquarasr2]

I took my NSX to an autocross and ended up spinning it. I seriously invoked the ABS and it's a good thing there was braking zone before the finish line of the course, 'cuz apparently the ABS pumped a whole lotta air into the main system. I had to pump the brakes feverishly to get any pedal pressure. Luckily I wasn't doing this at the finish line.

Of course I used Drew's ABS bleeder tool to purge the entire system and didn't have any problems related to bleeding the system at track days thereafter.

Is it possible that when you have gotten into the ABS you introduced a very small amount of air into the main lines? Mine was dramatic. Maybe yours is just enough to cause a degradation of braking performance but not enough to be blatantly obvious.

Just a thought.

In most cars I have driven where I have activated ABS I am usually surprised by the way the ABS seems to extend braking distances. In general I do not like that feeling (at least those from early ABS like on my '91 NSX).

 

[nsxtasy]

When you go to the track, you typically learn how to do "threshold braking". With this technique, you brake the car with the tires at the threshold of locking up without actually doing so. This is how to brake in the shortest distance possible. If you're doing it right, you never activate the ABS, so it doesn't matter whether the ABS is active or disconnected.

ABS does not extend braking distances (although it may give the perception of doing so), but it doesn't necessarily shorten them either. The main advantage of ABS is that it will let you steer while braking. In the NSX, the ABS doesn't activate in most braking situations, because the car can grip and the tires don't lock up. You really have to slam on the brakes HARD to get ABS to activate. This is what people generally do in a panic emergency situation, when someone cuts out in front of you and you slam the brake pedal to the floor. And that's exactly the situation when you want to be able to steer at the same time if needed.

I have a lot of track miles on my NSX. I always keep my ABS connected. On the track, I do threshold braking and I almost never activate it. On the street, I would hope that I would also do so in a panic emergency situation, but if I instead just jammed on the brake pedal, I would like the ABS to be there to pump the brakes and help me steer.

$.02

 

[stuntman]

I personally don't like the 1st Gen ABS system and feel in most cases, when it engages it makes the braking distances longer. Thus (I feel) if you keep the car just before ABS engages, the car will stop better than if you're engaging ABS (but you need to modulate the brakes and keep it at this threshold and limit -which takes a lot of practice).

The NA2 ABS system is FAR more advanced and modern and I really like it alot and am planning on upgrading my 1992 to this system. Ryneen did this retrofit and its VERY good. I feel most drivers can just stick their foot to the floor and let the ABS do all the work and for most people, brake deeper than they could without ABS. it enables the driver more confidence and safety than the NA1 system or without ABS and I highly recommend it.


Billy

 

[Eddy]

liftnot,
That's a great idea! I looked at Dali's kit but I don't like flexible hoses; especially coming out the MC; your lifeline for stopping the car.. So maybe I'll go get some metal brake lines and bend and flare some lines to bypass the ALB.

dquarasr2,
I didn't get air in the main brake circuit like you did but on a few occasions, the ALB circuit did foam up while the pump was on and overflowed the reservoir. Maybe the foamed brake fluid got into the ALB circuit and ruined my ALB experience! :/

nsxtasy,
Agreed that ABS doesn't increase braking distance but I think we should make it clear that activating the ABS is a different story.

From shortest to longest braking distance.
1. With or without ABS, braking without locking the wheels would result in the shortest but same braking distance.

2a. At the limit of locking the wheels with ABS, the car will definitely need a longer distance to brake as the ABS module lowers (or pulses) the brake line pressure to prevent locking the wheels. I've had this happened on a Toyota that uses the Bosch 3-ch ABS module similar to the NSX NA2 (which uses 4-ch) and it's definitely very controllable but the braking distance is at least a car length beyond the driver's expectation from 30mph to full stop in the wet/slight down slope.

2b. At the limit of locking, an experienced driver (e.g. people who's driven in the snow a lot; pro racers, etc.) can modulate the brake to not lock the wheels but the distance will definitely be longer than if you didn't have to modulate (case 1). This should be similar to case 2a in braking distance but it's a battle between man and machine.

3. Locking the wheels without ABS, the car will skid and the distance would typically be longer than cars with ABS that is at the limit of locking. Most of all, you loose steering control; mighty scary.

Don't you agree?

Billy (stuntman),
I couldn't agree more with you that NA2 ABS is the way to go; now if I could only get the wife to ok the spending budget


Overall, I thought some more about how my car felt at the track after posting the original message and I think the reason I felt more confident without the ABS are 2-fold.

1. Confidence is meeting the expectation you have for something. So with the ALB (perhaps ALB with air in the circuit), as I approach a corner, I brake and I expect the car to slow at a certain speed up to the threshold where I think the tires will take. Then ALB kicks in, except it doesn't work well (be it design or air bubble) so my rate of slowing down drops significantly and I overshoot the corner with excessive speed; well, that's scary if you have only 30ft of pavement and doing 60-80mph. Result, no confidence in the braking. Next time around the corner, I learn and I brake early; afraid to touch that tire threshold. Per nsxtasy, I could try to brake up to a little bit before ALB kicks in but it's like falling off a cliff if you miss. I guess I am not that brave.

2. Without ALB, I do the same thing approaching the corner as brave as the first time, I brake and wheels slightly locks, I lighten the pedal pressure and I make the corner less than desirable but now I know where the limit is. Next time around, I adjust my brake point and pressure and braking as hard as I can up to the limit to make the turn. The limit this time is more like a downhill slope if I go past it. More inline with I expect, thus the car feels more confident.

Does this sound plausible?

Cheers!

 

[Hrant]

I must give kudos to all who are feeling confident at the track or street without the ABS.

I had my 98-T ABS act up last summer, and it was no fun at the track or the street with the Stoptech BBK. Slightest hard braking would luck up the front tires on street driving. Shad tried every trick to see if we could make/rebuild the ABS to work normally but to no avail. Went with the 2002 version upgrade. Once again I was the guinea pig for such an install on a 98 model year (seems no one had done this yet) - the circuitry in 98 was not the same.

Have not tested the upgrade kit on the track yet to comment further.