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Thread: Liberty RS - Rally/Track car

  1. #1
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    Liberty RS - Rally/Track car

    About time I introduced this car here...1994 Liberty RS ADM shell with 2004 Impreza STI running gear and mechanical bits. CAMS log booked as a rally car and with rally road rego.

    The engine is not modified apart from the exhaust and pod filter...stock turbo, ecu, fueling etc. All of the mechanical bits are from a JDM half cut including 6 speed DCCD gearbag. The bloke that originally built was told it might be a Spec C half cut but was not given any evidence to this when he bought it. It has been on the dyno at 200kw / 400nm.

    Obviously it has been stripped out and has a welded cage but it is fairly basic in its build...

    215/45/17 Nankang AR1 on Rota wheels
    Unknown coilovers with Cusco camber plates on top
    22mm rear sway bar, stock front (more on this later)
    Strut braces and under body H brace
    Forza brand tarmac rally brake pads, race brake fluid in stock STI brembos and with grooved discs
    Chasebays brake master cylinder / booster delete and bias adjuster
    Hydraulic handbrake
    No ABS so the DCCD is manual control only

    I have a couple of problems that maybe the collective on here can help me with:

    1. Mid-corner wheelspin. It is impossible to get on the power in the corners...inside rear on entry and inside front towards the exit. It is like the thing has gone open diff or its in neutral. It is slightly better with the DCCD wound more towards the rear. It likes to oversteer a bit to.

    I think the 22mm rear sway bar, stock front sway bar combo does not help here. 24mm rear and 22mm front seems to be a popular combo?

    2. The brakes are complete shit. An inconsistently spongy feel...might be firm for a corner and goes to the floor a couple of corners in to a run and not much stopping power available. No idea where to begin with this.

    Is it possible the hydraulic handbrake is affecting the brakes?

    The chasebays kit is a single outlet from the master cylinder, in to a splitter that sends 2 lines to the front, and 1 to the rear via the bias adjuster and passing through the handbrake (pulling the handbrake moves the foot pedal a lot).

    I have tried a stock Subaru master cylinder and it was not great even with the booster disconnected...spongy all the way to the floor and then zero modulation around locking up.


    Video from a Rallysprint I did on Sunday, only the second time I have driven it and with caution due to the brakes being crap and not being able to get on the power:









    Now has a different steering wheel and a switch panel in the centre console:



    Also ditched the 1kg fire extinguisher for a decent sized one:



    Maybe a Spec C...no idea...


  2. #2
    Down with ma homies Greg Rust's Avatar
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    Very cool, always have a soft spot for this model.
    xw Falcon 393 full race cam, NGK spark plugs.

  3. #3
    TJzone TJ's Avatar
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    Yes yes yes yes yes

    Brake booster might need to be upsized for brake feel?
    #teamtremolo
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    Quote Originally Posted by Greg Rust View Post
    Very cool, always have a soft spot for this model.
    Cheers. I have done a few MX5's and MR2's for motorsport stuff and did have a WRX a good few years back, I always told myself that motorsport is drowning in Imprezas and Evos and they aren't for me...but then there is a reason they are so popular (reliable, proven, lots of upgrade paths) so when a cool 90's jap shell with modern running gear in it came up I went for it.

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    Quote Originally Posted by TJ View Post
    Yes yes yes yes yes

    Brake booster might need to be upsized for brake feel?
    No booster on it at the moment. Just one of these:


  6. #6
    Registered User Teamgemini's Avatar
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    Had a few similar issues with the brakes on my evo. Ended up having to bleed the handbrake a few times and all came good. Getting rid of the booster is the best thing you can do on the dirt. Just check the pedal ratio, once that's right it's happy days.
    I have stuff...

  7. #7
    Registered User aerobrick's Avatar
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    Reach underneath the throttle body, if there's a temp sensor tapped into the back of the intake manifold then it's a spec C.
    That IAT sensor is used for automatic intercooler spray, and possibly other things, I'm not entirely across the spec C ROM.
    Last edited by aerobrick; 18-07-17 at 04:48 PM.

  8. #8
    Opens Guido's Avatar
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    Brake issue also sounds like knock off. Are your wheel bearings ok?
    Rust is lighter than carbon fibre.

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    Quote Originally Posted by papahet View Post
    No booster on it at the moment. Just one of these:

    I'd be putting that straight in the bin. It has no place in a braking system, any reason why you wouldn't use the standard master cylinder?

  10. #10
    Registered User AlexinPerth's Avatar
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    Needing a lot of foot pressure to stop could be the result of a poor pedal ratio, a poor master cyl to brake volume sizing, or pads that haven't warmed up yet. Or a combination. As previously suggested.

    If you're expecting the brakes to not need much effort, then you need to put the booster and factory m/cyl back in..

    The inconsistency has just got to be pad knock off, as previously suggested.

  11. #11
    Registered User AlexinPerth's Avatar
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    Oh, and that "bias adjuster" is just a pressure limiting valve. It will work to alter the bias, but not consistently through a range of braking pressures.

    Hope to see you out at a sprint - unless you want to rally it with us crazies on gravel?

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    Okie dokie...

    I had a feel around for a temp sensor under the inlet manifold but didn't have enough light to have a good go so I will give that another crack later.

    I am confident the brakes and handbrake are air free, they have been bled and bled recently and the fluid is all fresh race fluid.

    Wheel bearings are good...no wobbles or clicks...

    Quote Originally Posted by Roy928tt View Post
    I'd be putting that straight in the bin. It has no place in a braking system, any reason why you wouldn't use the standard master cylinder?
    Yeah...I am not that impressed with it but was sent down this path by someone that reckoned someone he knew had a mate that blah blah...

    So the Subaru master cylinder that was on the car is from something I can't identify (3 ports on it, STI has 4) BUT it is the correct 1 1/16 size for the big Brembos (STI MC is that size)...BUT it felt absolute shit, it felt like it was far to small for the system. The pedal would just squish to the floor with no feel and with no modulation at the bottom so it was to easy to lock up. I disconnected the booster but it didn't really improve it.

    I was just having a poke around the car and found that there was brake fluid all around the MC and looking at the brake discs, the fronts a mirror shiny and the rears are smeary and look like they got hot. Maybe to much rear bias and boiled the fluid out...there are no leaks when I smash the pedal hard.

    Maybe my next stop should be an actual STI MC and set the thing up like the factory intended.

    Quote Originally Posted by AlexinPerth View Post
    Needing a lot of foot pressure to stop could be the result of a poor pedal ratio, a poor master cyl to brake volume sizing, or pads that haven't warmed up yet. Or a combination. As previously suggested.

    If you're expecting the brakes to not need much effort, then you need to put the booster and factory m/cyl back in..

    The inconsistency has just got to be pad knock off, as previously suggested.
    High foot pressure I can deal with and like but this is just mush. The pedal sinks way down and it doesn't really pull up hard...once it has gone mushy it stays mushy for the run.

    Maybe I should give the thing to STechnic and say 'make it good please'.

    Quote Originally Posted by AlexinPerth View Post
    Oh, and that "bias adjuster" is just a pressure limiting valve. It will work to alter the bias, but not consistently through a range of braking pressures.

    Hope to see you out at a sprint - unless you want to rally it with us crazies on gravel?
    Make yourself known if you see me around with it!

    Gravel sure is tempting, but being AWD I would need to do state with the added cost that brings, that being said I am not averse to the idea of gravel and do have a mate already doing it which makes it a bit easier.

  13. #13
    Registered User AlexinPerth's Avatar
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    If you don't want to spend ages mucking around with it, take it to stechnic.

    The reason a 3 port m/cyl was used is the hydro handbrake.
    If you're leaking fluid, all bets are off, fix that first.

    Targa west 2018? 😁

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    Yeah when the car was built they had 2 ports for the front and 1 port ran to the rear via the handbrake. Is it possible the handbrake is introducing issues with feel?

    I think the fluid leak is either from boiling fluid or potentially pad knock off forcing fluid out. With the car sat in the garage I can stand on the brake as hard as possible and nothing is forced out anywhere.

    This is mighty nice but I think a trip to STechnic might be better value! http://www.compbrake.com/product-cat...i-2015/page/2/

    Targa West would be nice but having the money up front is another thing all together!

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    A few bits changed on the car recently. The Subaru master cylinder is fitted and booster disconnected and the car was given to the guys at STechnic for a couple of days, they have got the brakes set up really nicely now and put an alignment in it. They have found that the DCCD is not working properly, the Subaru switches that are fitted do a great job of moving the dash light up and down but don't actually do anything for the centre diff. I have got a manual DCCDPro controller on order to try, if that does not work then the DCCD may be broken and I will have to live with the wheelspin for the time being.

    The brakes feel more like unboosted brakes should and I have some confidence in them now. The Forza FP3 pads that are in there are shit for this application though, not enough initial bite so pedal pressure is high. They also don't bite hard through the whole range of pedal pressures. Thinking of trying the FR6 they do or maybe Intima Type D pads...Ijust don't have the budget for some of the other brands at the moment.

    I also did round 1 of the 2017/2018 Shannons Rallysprint series last week, first time I have been in the saddle for quite some time and only the 3rd time I have driven the car properly. I had a decent co-driver with a borrowed intercom so that made a big difference along with having some more confidence in the setup of the car. Run 1 was a very lazy 2.44 and my fastest of the night was a 2.33 with a shit launch. The wheelspin issue has been reduced with the alignment STechnic put in but I am still giving away seconds a run either waiting to get on the power or shooting the power out of an inside wheel that is off the ground (with working DCCD I can lock the centre diff and keep power going to the front wheels).


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    Registered User Tardinator's Avatar
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    Lol @ iphone map light! Looks like fun though.
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