Pulling ABS fuse(s) for the track

davekmoore · Postby **davekmoore** » Thu Jan 01, 2015 9:11 pm

Spent this arvo trying to isolate the parasitic battery drain in my car so got familiar with the fuses.

A 20a fuse under the bonnet is allocated to "antilock brake system" and a 10a fuse by the driver's right knee says "supplementary restraint system, antilock brake system".

So does pulling the 20a disable the ABS, or do both need to be pulled? Or does the 10a just control airbags, seatbelt pretensioners and/or any other features?

Reason I ask is that with decent front brakes now on the car I might want to only use ABS in the wet .

mattyredlocks · Postby **mattyredlocks** » Thu Jan 01, 2015 9:42 pm

Quick - before this thread turns into an ABS vs Non-ABS dirt slinging match!

I'll just keep my opinion of ABS removal to myself (*cough* ABS saved my arse a handful of times *cough*), but from memory reading a prior thread, it's just the one fuse to disable ABS.

I think insurance can become an issue though (both normal and CTP), as you will have intentionally disabled a safety system for the car they insure.

davekmoore · Postby **davekmoore** » Thu Jan 01, 2015 9:56 pm

I would never disable ABS or any other safety system for road use.

I, too, prefer this thread to only be about which fuses to pull for the track please, and not to be about whether ABS is "better".

Dweezle · Postby **Dweezle** » Thu Jan 01, 2015 10:12 pm

Not sure in MX5s but in my Clio if you pulled the fuse you lost the correct distribution between front and rear pressure.
It made the car far worse.
Heavily rear biased.

Sent from my SM-N9005 using Tapatalk

mattyredlocks · Postby **mattyredlocks** » Thu Jan 01, 2015 10:13 pm

My service/repair manual doesn't say much about disabling it (wonder why), just that if the "check airbag" light comes on, to replace the fuse and take it to a dealer if it stays on after that.

If you're at the track and under a CTP rally/race extension (that's they way we do it on the QLD MX-5 club days for road registered cars, anyway), you might still want to check what the rules are - technically you're still covered by CTP under one of these extensions, though to what extent I don't pretend to know.

davekmoore · Postby **davekmoore** » Thu Jan 01, 2015 10:18 pm

Dweezle wrote:Not sure in MX5s but in my Clio if you pulled the fuse you lost the correct distribution between front and rear pressure.
It made the car far worse.
Heavily rear biased. Sent from my SM-N9005 using Tapatalk

The plot thickens.
Electronic Brakeforce Distibution eh?
Perhaps this is why some MX5ers add proportioning valves for if they disable the ABS?
And perhaps I'd be better advised to stay out of the ABS zone on the track?

mattyredlocks · Postby **mattyredlocks** » Thu Jan 01, 2015 11:41 pm

I'm curious, have you actually had ABS kick in, in an unfavorable way at the track?

I only ask because I have, and I've welcomed it. Stopped me locking and wearing big flat spots into my tyres a couple times. What advantage do you have *not* having ABS?

Not trying to have a go here, I'm mostly just curious. I suppose I learnt to drive in cars with ABS, and I've never dríven a non-ABS car fast. Shows my age there.

davekmoore · Postby **davekmoore** » Fri Jan 02, 2015 7:58 am

I'd be at the opposite end of the age spectrum then.

Happy to keep ABS for in the wet and probably for in the dry, but a little reading (always dangerous) has suggested it might be better for the front Wilwoods if they're not subjected to the 60 pulses per second that normal ABS will give them rather than many more pulses per second they'd get from race ABS (which costs 10s of $1,000s).

The alternative is to avoid heavy braking, but I'm well known for braking heavily, late, and too much, so that would involve changing the habits of a lifetime.

greenMachine · Postby **greenMachine** » Fri Jan 02, 2015 9:04 am

Got a source for that Dave? As I run ABS with my Wilwoods, I would be interested in finding out why that might be so.

:mrgreen:

Magpie · Postby **Magpie** » Fri Jan 02, 2015 9:18 am

I would say pl the fuse and go for a few laps and see for yourself and don't forget to report back your experience(s).

davekmoore · Postby **davekmoore** » Fri Jan 02, 2015 10:40 am

greenMachine wrote:Got a source for that Dave? As I run ABS with my Wilwoods, I would be interested in finding out why that might be so.

From the big forum. Didn't save the page references, sorry. The suggestion is that such a slow pulse rate (60 cycles per second) is not good for the longevity of Wilwoods.

There was also a suggestion that a prop valve can be added with the ABS disabled, then you set up the balance, and then re-enable the ABS. This is apparently to avoid the 50/50 front/rear bias that would otherwise exist with the ABS disabled, which even I know would be a Very Bad Thing.

Postby **beavis** » Fri Jan 02, 2015 10:58 am

Dave, I have pulled the single fuse under the bonnet to disable ABS.

de Bounce · Postby **de Bounce** » Fri Jan 02, 2015 12:38 pm

beavis wrote:Dave, I have pulled the single fuse under the bonnet to disable ABS.

As per beavis quote.
Done it heaps of times for Motorkhana.
Found I could stop faster than the ABS would allow me at slower speeds (sub 50Kph) either dirt or bitumen.

Postby **beavis** » Fri Jan 02, 2015 12:45 pm

de Bounce wrote:
beavis wrote:Dave, I have pulled the single fuse under the bonnet to disable ABS.
As per beavis quote.
Done it heaps of times for Motorkhana.
Found I could stop faster than the ABS would allow me at slower speeds (sub 50Kph) either dirt or bitumen.

I'm seeing your old car a lot around Mulgrave.

de Bounce · Postby **de Bounce** » Fri Jan 02, 2015 1:49 pm

beavis wrote:
de Bounce wrote:
beavis wrote:Dave, I have pulled the single fuse under the bonnet to disable ABS.
As per beavis quote.
Done it heaps of times for Motorkhana.
Found I could stop faster than the ABS would allow me at slower speeds (sub 50Kph) either dirt or bitumen.

I'm seeing your old car a lot around Mulgrave.

That would be it.
New owner is very happy with her!