Why Disable Hicas?

[salad]

They do lock the HICAS on some racecars.

The red coloured Bathurst R32 GTR would be one example.

It looked like they used the stock HICAS rack but locked it

and sealed the inlets up.

If you are refering to the Gibson GTR, they replaced the whole rack with a lockbar.

I dont think there are any race cars that retain HICAS unless they have to.

Edited May 21, 2007 by salad

[SKYPER]

Interesting.

The photo I saw had what looked like a stock HICAS rack.

I wonder if the lockbar was added later on????

Or was it the other racecar????

I think it's N1 racecars that have to retain HICAS.

Edited May 21, 2007 by SKYPER

[Snowman]

I reckon a lot of people unnecessarily lock the HICAS just so they can appear to be cool or hardcore or something. When I first started doing some track work I actually think it was a benifit to me. It wasn't until about 18 month of regular track work when I started to really find the limit that I found the HICAS started to do some things that unnerved me and made me want to get it locked. Especially on long sweepers like at Phillip Island. But it was still a good thing at tighter places like Winton.

But until you reach that stage I see no reason to lock it unless it's playing up.

[DaveO74]

Wow! thanks everyone for such a large amount of replies. Like what has been said by a few of you I have never actually had a problem or anything with my HICAS I was just curious why people locked it. So I guess Ill have to wait till I get to a track day to see if I notice any probs at high speed (Because of course I have NEVEREVER been over 110kph on the street,Honest!!)

Thanks again guys for not treating it like a dumb question

[SS8_Gohan]

isn't there a decent weight saving to be had when removing HICAS? another reason people get the lock bars? because that was what i was using to justify getting a lock bar...

[Kinks]

you'd get a much bigger weight saving by pulling the back seat out

HICAS is only a couple of valves and some high pressure hose, for R32 and R33 S1. R33 S2 is even lighter because it's electrically actuated, no hydraulics at all.

[SKYPER]

I weighed the R32 GTS-T HICAS rack with arms attached + piping to rear wheels.

From what I remember it was around 7.5kg. The HICAS rack is said to weigh 5kg.

I wonder how much the R33, R34 HICAS weighs????

Also HICAS is removed on high HP drag GTR's.

I gather it's something to do with stability.

Edited May 22, 2007 by SKYPER

[Kinks]

in a serious drag car weight matters.. any chance to shed 5-7kg would be worthwhile.

[Hardman69]

Also HICAS is removed on high HP drag GTR's.

I gather it's something to do with stability.

Drag cars are for going straight, HICAS is for turning.. . . .

Seriously though - any variance in the rear-end is a disaster with big HP drag cars, and there's no reason to keep a rear-steering rack for going straight ahead! ! If You had MAD programming skills, U could do a custom calibration for super drag racing stability, but that'd require a drag-racer who knew how to use a computer ! ! !

[SKYPER]

Hardman69

I was looking at some photo's of the Mines R34 GTR demo car and it still has HICAS.

Not sure if they have modified the HICAS (locked HICAS rack via using shims).

Kinks, 7.5kg is the rack + arms and piping to rear wheels. It's not including the piping

from rear wheels to engine bay and the parts inside the engine bay.

Edited May 23, 2007 by SKYPER

[RBwhatever]

Has anyone here that has installed the lock bar on a R33 experienced this so called "heavy steering" at low speeds?

[deant1]

isn't that only when people remove the HICAS chip? (to disable the dash light) effects the powersteering or something? Not sure.

[SKYPER]

Below is what affects the R32 GTS-T (not sure about R33) -

The steering on my car went hard while cornering at low speed.

It was traced back to a faulty HICAS ECU.

Tried to repair it, but ended up replacing it with a second hand

HICAS ECU and problem was fixed.

Somehow water entered the breathing holes (watermarks leading to

breather holes) on top of the ECU. I hear that leaking rear windows

can cause this problem. But in my case it was the boot not being pulled

down enough (needed to adjust latch on lower part of the back of boot).

The HICAS ECU was turned upside down, so breather holes were facing

the bottom of the boot. Haven't had any problems with replacement

HICAS ECU.

Also be careful with HICAS ECU part no, as a HICAS ECU is different

between GTR, GTS-T, etc.

[siksII]

Has anyone here that has installed the lock bar on a R33 experienced this so called "heavy steering" at low speeds?

I installed the lock bar and it did not make the steering go heavy. I was worried that it would happen, and there were no clear answers on the forum, so very relieved when the steering felt normal after installing it!

[RBwhatever]

I installed the lock bar and it did not make the steering go heavy. I was worried that it would happen, and there were no clear answers on the forum, so very relieved when the steering felt normal after installing it!

Thats good to hear, thanks . Yeah i couldn't find any definite answers either. I got my lock bar recently and am going to install it soon. I was a bit worried it would affect the drivability of the car.

[Hardman69]

Re: Lockbar, heavy steering.. . .

Yeah i couldn't find any definite answers either. I got my lock bar recently and am going to install it soon. I was a bit worried it would affect the drivability of the car.

Two things affect the steering, on (my) R33:

1. Variable power-steering valving - the (HICAS, I THINK) computer runs a map for steering assistance vs. speed, so that it backs-off the assistance at high speed, to give more feel & weight, and increases assistance at low-speed, to make carpark work nice 'n easy. If HICAS gets unhappy with the world, it goes to limp-home mode, which is rear-rack locked to straight-ahead, and steering set to full-heavy.

2. HICAS rear rack - The rear-steer actually makes the steering heavier at speed as it does it's thing. This is 'coz it artificially increases the rear toe-in as You turn, which loads-up the front wheels with more "responsibility" for making the car change direction. As a comparison, many Front-Wheel-Drive cars typically have some passive rear-steer built into the rear suspension geometry, which actually toes the rear wheels OUT very slightly, lightening the steering & try'n to reduce understeer.

[benm]

Kinks, 7.5kg is the rack + arms and piping to rear wheels. It's not including the piping from rear wheels to engine bay and the parts inside the engine bay.

Then add another 7.5kg for everything in the engine bay (I have it all sitting on the floor in my garage) not to mention it would be way easier to do an oil filter change.

[SKYPER]

So that's roughly 7.5kg + 7.5kg + 2.5-3.5kg??? (piping from rear wheels to engine bay) = 17.5kg-18.5kg.

Edited May 26, 2007 by SKYPER

[benm]

Well it would definitely be 15-20kg that's for sure.

[noone]

It does end up a big pile a stuff on the garage floor when its all removed, couple of the brackets are handy though for reuse to hold other things