**RB2530**

Basically the harder you brake the hotter the discs get...A moving car has kinetic energy...Energy is always conserved and the brakes absorb the kinetic energy of the car and converts it mainly into heat. Harder braking leads to higher rate of energy transfer into the brakes. The brakes dispate the energy in the form of heat...And if you put energy into the brakes at a much faster rate than what can be disipated they will get much hotter. Bigger brakes have more surface area to dissipate heat plus larger thermal mass...So they can absorb more heat... Discs buckle due to the following reason...When steel gets hot it expands...If the temperature throughout the disc is even, it expands evenly...so there is no problem with high temperature until the steel starts to soften..Discs will glow before this happens... The problems occurs when the disc cools unevenly. The disc cools down as soon the brakes release...(because they are no longer absorbing energy). If the disc cools evenly there is no problem as the disc contracts consistently ie Everything shrinks at the same rate (or close enough to the same) If the disc cools very unevenly some of the steel is trying to shrink more than the neighbouring steel it is connected to...The differnce in shrinkage is directly proportional to the temperature differential...In discs the difference can be 1/100ths to 1/10ths of millimetres at a guess for normal, slightly uneven cooling. Steel is elastic (will recover after being stretch or compressed to a certain point) but if you try and stretch it too much, it becomes plastic. ie stretches or compresses in permanent way.. So if you start with a very hot disc at say 500-600degC and stop the car suddenly, the section of disc under brake pad will not cool nearly as fast as the rest of the disc which is exposed to air...'Newtons law of cooling' comes in here...maybe you could Google that cos I wont explain it here Therefore the section of disc under the pad in the caliper will remain larger or more expanded than the rest of the disc whcih is cooler. If the difference in shrinkage between the hotter and cooler steel is too great, the stress in the steel will exceed the elastic limit of the steel, and permanent deformation will result. Even when the discs cools down to ambient temperature it will remain deformed and buckled... The morale of the story is if your brakes are very hot don't stop the car straight away...The idea is too cool the brakes (while they are still rotating) down enough so that when the car is stopped, the difference in rate of cooling of the entire disc is uniform enough such that difference in expansion across entire disc doesn't permanently deform it.

Something else that can happen with discs is fat spots. Basically brake discs are cast steel that is subsequently heat treated to achieve a harder surface for better wear life...What can happen is that if the heat treatment is not uniform around the disc, the depth of the harder skin varies and so once the disc starts to wear, softer spots get exposed. They then in turn wear faster. This produces fat and thin spots around the disc and causes the bad brake shake... OEM Ford Falcon discs are notorious for this...Sometimes they do it within 20,000km from new. Machining fixes it for a while but the fact is non-uniform hardness around the disc..They do it again in another 20,000km..Solution- DONT BUY A FORD!! Disc warp is mainly caused by non-uniform cooling of the disc. ie if the discs is very hot and you dont cool down your brakes, when you stop, the disc area exposed to air cools much faster than the disc underneath the brake pad. This induces high temperature differential and therefore thermo-stress in the disc and you get plastic deformation (cooler metal gets stretched and hotter gets compressed) around the disc which can warp them.... Warped discs can cause brake shudder but also bad for calipers. In opposing piston calipers the pistons will shuttle in and out to suit the disc warp at the wheel rotation frequency..This will accelerate caliper seal wear no end. In floating single and dual piston calipers the floating pins cop it... anyway back to work... cheers

Internet mechanics diagnosing brake problems.....scary thought.... btw 'breaks' is what happens when you drop a glass...'brakes' are what you use to stop... 'disk' is interchangeable with 'disc' however disc is more commonly accepted Can't sleep so I have chosen to become the spelling police...sorry Morale of my post is do somebody elses rear bumper a favour and get a mechanic to look at you brakes...

Yep understand...You'd better take me off the list then...haven't paid yet anyway...My car is not that loud, and I am sure there are many cars louder with plumbed back wgs, but I dont want to risk causing a drama.. Just curious how far the guy is away when he is measuring the sound level...if he is more than say 100m away, wind speed and direction can influence what he measures by +/- 1 or 2dB anyway...Btw a carton of Crownies has often been know to reduce how far noise carries too...

What if your screamer pipe has a muffler on it?? It is the same setup I had Wakefield...and i dont think anybody noticed it...I have also had it on a dyno and you can hear it but only very slightly...Guilt-toy can verify this...

Hey guys just wondering how fast this event is filling up?? I broke my hand a couple weeks ago but it should be right by mid September...The plaster comes off in two weeks time and I'll know then for sure then if it'll be ok...do you think you'll be full by then??

PMs sent... Wastegate is now sold...

An event near Newcastle at last!! I'll be there....

yes it does yes it does yes it does

No i didn't post it three times...sometimes when I post or reply when logged on at work this happens...dont know why??? Just must be something with the CIAs computer system At the moment i am more concerned about my dent....

No i didn't post it three times...sometimes when I post or reply when logged on at work this happens...dont know why??? Just must be something with the CIAs computer system At the moment i am more concerned about my dent....

No i didn't post it three times...sometimes when I post or reply when logged on at work this happens...dont know why??? Just must be something with the CIAs computer system At the moment i am more concerned about my dent....

Hey all, Well my perfectly straight black GTST is not perfectly straight anymore...victim of the side gate and this f^&ckin wind... Can anyone recommend a good paintless dent removal place in Newcastle / Raymond Terrace area... I am after topic replies of good experiences and PMs of bad experiences.... many thanks..

Hey all, Well my perfectly straight black GTST is not perfectly straight anymore...victim of the side gate and this f^&ckin wind... Can anyone recommend a good paintless dent removal place in Newcastle / Raymond Terrace area... I am after topic replies of good experiences and PMs of bad experiences.... many thanks..

Hey all, Well my perfectly straight black GTST is not perfectly straight anymore...victim of the side gate and this f^&ckin wind... Can anyone recommend a good paintless dent removal place in Newcastle / Raymond Terrace area... I am after topic replies of good experiences and PMs of bad experiences.... many thanks..

I am selling a Tial 38mm WG atm...check out my profile for the FS post...

I am keen ..put me on the list...

I would expect that if it is unburnt fuel it would almost certainly ignite as soon as it hits the exhaust manifold...I am sure you would notice this straight away... Try getting a sample of it (only small) and igniting it with a lighter...obviously be very careful...alternatively check its SG but to do this at home you would need either a big sample or fairly precise scales...SG of fuel is about 0.7g/cc...Also see if it mixes with water...

Item: Tial Sport 38mm wastegate with 0.5, 0.7 and 1.0 bar springs...you can change them as required... Age: 20,000km Condition: Perfect Price: $300 including springs ono + freight if required Location: Newcastle NSW Contact: Paul 0402 433374 Comments: This a genuine USA manufactured Tial 38mm wastegate purchased from USA...Not a Chinese copy...'it has a serial number' that can be viewed in attached photographs. These WGs retail for $600-700 over here and the springs are $70ea to buy...I am selling because I bought an HKS manifold with HKS WG already bolted to it...

PM sent...wastegate is still available

Yep...good luck...be patient with it...dont get the shits and break it...

Keep trying the WD40...Spray and leave it for 20mins then spray again and leave and so on... I have also seen some freezing spray at Repco..never tried it but give it a go...Only spray the nut though...dont spray the whole thing otherwise you defeat the purpose of freezing it..

So ive never been to Oran before...is the parking crap??? Also is there gonna be any pit passes happening...i am coming down by myself and dont wanna get lonely??

Price drop $300 plus pics added

I am thinkin about coming down for a look...