HSV MX5

Discussion about MX5s, Roadsters & Miatas, not directly fitting into one of the categories below. Please keep it on topic.

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Donovan
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Post by Donovan » Thu Aug 09, 2012 4:46 pm

na6*dori wrote:you could happily fit a small transmission cooler to the return line of the powersteering without issues of pressure, may also help to have your pump stripped and make sure its not a pressure relief valve issue, just as an idea. and if it still does it then fabricate up a bigger resevior but keep fluid level the same, thus allowing for the expansion of fluid without sending it skyway
At the moment I am not running the cooling tube in front of the radiator for the power steer, so just doing that will make a huge difference. There is a new larger resevior that has been made up for it and in there, but I am starting to think about putting it in the boot and running lines front and aft, and that should help with the cooling as it should radiate the heat out when travelling the length of the car underneath it, and secondly, cause it is just in the way where it is, engine takes up too much room.

Donovan
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Post by Donovan » Thu Aug 09, 2012 4:51 pm

Well the brake saga continues, I have pulled off the front calipers in the process of pulling the shocks out to put beefier springs in there, and when I did that, could see the front half of the pad was worn to the metal, where as the back half still had about 50% left on it.

So now I have a major issue to sort out, either I have some sticking pistons in my calipers, which could have been caused from the fire incident from the first track day, or the other suggestion was, that my whole front suspension setup is shot and all about to collapse on me.

Great, just what I need.

Donovan
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Post by Donovan » Thu Aug 09, 2012 4:53 pm

Not a good picture of the problem, but you get the idea
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Growler
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Post by Growler » Thu Aug 09, 2012 5:24 pm

Donovan wrote:Well the brake saga continues, I have pulled off the front calipers in the process of pulling the shocks out to put beefier springs in there, and when I did that, could see the front half of the pad was worn to the metal, where as the back half still had about 50% left on it.

So now I have a major issue to sort out, either I have some sticking pistons in my calipers, which could have been caused from the fire incident from the first track day, or the other suggestion was, that my whole front suspension setup is shot and all about to collapse on me.

Great, just what I need.
Or the original pads are way too soft...

2low2c
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Post by 2low2c » Thu Aug 09, 2012 5:24 pm

from that photo i would say that your master cylinder was to small and not pushing enough fluid to fill the caliper properly. iwould replace the master with a 15/16 one .

Donovan
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Post by Donovan » Thu Aug 09, 2012 5:35 pm

Where do I get one of those from?

Growler
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Post by Growler » Thu Aug 09, 2012 5:36 pm

Donovan wrote:So now I have a major issue to sort out, either I have some sticking pistons in my calipers, which could have been caused from the fire incident from the first track day, or the other suggestion was, that my whole front suspension setup is shot and all about to collapse on me.
Why would the suspension collapse from braking issues?
2low2c wrote:from that photo i would say that your master cylinder was to small and not pushing enough fluid to fill the caliper properly. iwould replace the master with a 15/16 one .
...but if it is the standard Commodore one it should sufficient.

Donovan
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Post by Donovan » Thu Aug 09, 2012 5:40 pm

The suspension thing was from Goodwin racing it was his suggestion that this was a sign showing that the hubs or suspensions arms where moving too much causing the rotor to move around which is a sign that the suspension is about to give up.

The BMC and booster are the original MX5 unit
Last edited by Donovan on Fri Aug 10, 2012 8:32 am, edited 1 time in total.

Donovan
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Post by Donovan » Thu Aug 09, 2012 6:50 pm

The only thing with replacing the BMC with a larger unit, is that the first set of pads that caught on fire had pretty even wear across them, just a bit singed.

So I am wondering whether I did some damage to the calipers from them getting too hot from that first running session.

WideOpenThrottle
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Post by WideOpenThrottle » Thu Aug 09, 2012 7:46 pm

Looks like your pistons are pushing unevenly so i suspect seizure or binding
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Euen
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Post by Euen » Thu Aug 09, 2012 8:05 pm

I'm not sure of the bleeding arrangement on your calipers but my Wilwoods have a bleeder for each piston. If you have air in a piston, it would reduce the pressure on that part of the pad causing uneven wear.
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Donovan
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Post by Donovan » Thu Aug 09, 2012 10:12 pm

The calipers have 4 bleed nipples on it, but according to the wildwood website it said that the two top ones are only needed to be bleed when they are sitting in a vertical position, and that's all I did.

I'll try bleeding all 4 and see if any air comes out of the bottom ones.

Donovan
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Post by Donovan » Mon Aug 13, 2012 8:46 am

Well I thought I was slightly touched chasing after 400hp in my MX5 once I have the brakes and suspension sorted out, but this guy is chasing after 700hp with a turbo LS1!!

http://clubroadster.net/vb_forum/showthread.php?t=35261

Angreal
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Post by Angreal » Mon Aug 13, 2012 8:57 am

I was following that thread and thought of you when I first found it (then probably forgot about you the more I read on and got distracted)

So if you're having big problems with only 400hp? I guess he'd have bigger problems/

Donovan
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Post by Donovan » Mon Aug 13, 2012 9:00 am

Decided to stop sulking about the brakes and at least pull the pads out and have a look at them. Not the easiest to pull out since they had all warped and bent.

You most likely can't tell, but the piston from the caliper has just about pushed itself thru the metal backing, wasn't far to go.

Seems my calipers are on back to front, they have a left and right side, two of the six pistons are larger than the others, the larger set are supposed to be the trailing ones, at the moment they are the forward ones on the disc rotation. Not sure if this is the b all and end all of my brake problems, but it certainly wouldn't be helping.
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Donovan
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Post by Donovan » Mon Aug 13, 2012 9:04 am

Angreal wrote:I was following that thread and thought of you when I first found it (then probably forgot about you the more I read on and got distracted)

So if you're having big problems with only 400hp? I guess he'd have bigger problems/
My problems haven't really been about the engine or drivetrain (touch wood), mine have been handling, braking, air intake and power steering issues so far, but then again, I don't know what I am doing, and he looks like he does.

I just don't know how he is going to cool that thing, he has got a hairdryer in there, and a radiator about half the size of my one, be interesting to see when it is running, and how he goes on the track.

dynofiend
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Post by dynofiend » Mon Aug 13, 2012 11:06 am

Its possible that the pads have only really been 'used' where the larger piston was contacting. With all the brake pressure in one area, they have heated up far more in that area than if the pressure across the pads was even, making them catch fire/warp. The warping of the back plate from that heat is probably what has caused the uneven wear, which then explains why your first set didnt have the same wear. I cant really see how a smaller MC would cause uneven brake piston pressure. From the callipers POV, a smaller MC would just seem like less brake pressure was being applied at the pedal, ie you werent braking as hard.

Donovan
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Post by Donovan » Mon Aug 13, 2012 11:19 am

Yes, it is the larger set of pistons that all the wear/warping has come from.

Angreal
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Post by Angreal » Mon Aug 13, 2012 11:28 am

Donovan wrote:I just don't know how he is going to cool that thing, he has got a hairdryer in there, and a radiator about half the size of my one, be interesting to see when it is running, and how he goes on the track.
I'd guess those bonnets with the giant vents that are made out of carbon fibre (not sure how good they are in the rain though)?

Donovan
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Post by Donovan » Tue Aug 14, 2012 9:22 pm

Trying out new front springs, little skinny ones next to big fat replacement ones.

Internal diamater between the two is different, so Keith helped me out, and milled off a couple of mm off the perches of my coil overs.

And yes, bad photo I know.

The replacement ones are taller, but the original ones had helper springs on them which gave the coilovers a greater range of adjustment, I am just hoping that when I put the car on the deck with the replacement ones in there I can get the right ride height, and that I can adjust them with my coilovers.
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na6*dori
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Post by na6*dori » Tue Aug 14, 2012 9:57 pm

by reducing the pulley size on your power steering you will put less strain on the pump with the constant high revs, that in turn will stop the boiling of your fluid, running the lines to your boot seems like a waste of money tbh, id just put a trans cooler in the return line and fit a larger pulley if it was me, cheap and effective, and then last case i can show you how to modify your press.relief valve
In which i trust, a cable ties a must

Donovan
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Post by Donovan » Wed Aug 22, 2012 3:50 pm

Due to this being a public forum and the potential crap I am heading for, have decided to remove the post as it originally was, will put it back once the dust has settled.
Last edited by Donovan on Thu Aug 23, 2012 9:11 am, edited 1 time in total.

Furai
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Post by Furai » Wed Aug 22, 2012 3:58 pm

They cant do that can they?

Donovan
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Post by Donovan » Wed Aug 22, 2012 4:01 pm

I don't know, I need to have a chat to someone with a legal perspective on it. The problem I have nothing down in writing on what we agreed to, so not really sure where I stand.

Anyone know a good lawyer that I can ask a quick question, can't afford to pay much now, am broke.

last_resort14
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Post by last_resort14 » Wed Aug 22, 2012 4:12 pm

They have got to be taking the piss, that is just crazy.

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