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Messages - andrewrx7

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1
General Technical / Re: Brake temp on track days
« on: May 09, 2015, 09:10:03 PM »
Thermal paint

Huh?  ;D

To put my question into context, just trying to decide on what pads to use. Can't decide! I 've been through a set of Yellowstuff, and while the brakes were still good after a number of laps, they certainly seemed softer with less bite/grip, which I am thinking is a bit of brake fade cropping up. So, been thinking about trying Mintex Racing (M11 compounds) or Ferodo DS compound. But it seems DS2500 and the 1144 pads top out at around 500'C, while the DS3000 and 1155 have a higher temp range. Yellowstuffs, as far as I can see, have a top end of anything from 500-700'C depending on where you look, so pretty much the same as the 2500's and 1144's.
So, if the fronts on an average road car doing half a dozen laps round a track (specifically Bedford, GT circuit), only see a few hundred 'C, then any of the above would be suitable. But if they do go way above 500, then obviously the 1155 or 3000 are potentially more suitable.
My reasoning may be flawed, in which case, I'm happy to be corrected!
(BTW, the fluid has also been changed to ATE Racing fluid).

2
General Technical / Brake temp on track days
« on: May 09, 2015, 06:38:20 PM »
Hi,

I've got an cheap run around that I want to use for a bit of track day fun. I'm curious to see what kind of temps the front brakes can get up to (approximately, on standard brakes) after a few laps round a track. Not specifically a rotary, any car would do.

Has anyone measured these temps when they've been out?

Ta!

3
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 03, 2015, 08:59:27 PM »
I use ATE Super Blue, which seems to have a very good rep too, with a boiling spec just under the Endless (RF 650), having just looked. But then it is a fraction of the cost to! Wow, the Endless is pricey, but then if it works under extremes on the track, then the cost can to be justified.

4
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 03, 2015, 04:35:22 PM »
but i'd investigate/fix the issue first.

Indeed and agree totally, but I wonder whether heat from 4 track days (well, 1 day and 3 half days to be more accurate!) in the last 6 months has caused deterioriation in the rubber lines making them a bit more flexible than they should be? The car is almost 12 years old now, so could these lines be the issue? Just eliminating possibilities as I go along and this is at least a place to start!

5
Rotary and General Chit-Chat / Got myself another Mazda...
« on: January 03, 2015, 03:38:52 PM »
...and have just bought a CX-7. Not the earlier one with the MPS engine though, the later updated version with the diesel. Not a bad motor for the money, even if I do say so myself! :-)

6
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 03, 2015, 12:59:50 PM »
Cheers. Got an mot testing garage near to where I work so hopefully they will be willing to help when needed. For £60-70 I may just invest in a braided hose kit.

7
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 03, 2015, 09:25:20 AM »
Sliding pins move freely, definitely checked those when I did the front pad change. Rears were seized but I replaed the pins and repacked with grease about 8 weeks ago so they are also good. Thanks for the suggestion.

I have read that when pushing back pistons into calipers you should really vent the brake fluid via the bleed nipple so as not to force fluid the wrong way through the master cylinder, since this can cause a seal to flip or unseat and hence leak during use causing a lack of hydraulic pressure. Not sure how true this is though!

What about the rubber flexible hoses? Do these "relax" over time and allow some bulging hence loss of pressure upon initial press of the pedal, or are they more "all or nothing", by which I mean they work ok or catastrophically fail? Would a braided kit actually do some good? Could the heat from several track days have caused the rubber hoses to weaken? Just another option (right or wrong) into the mixing pot!

8
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 03, 2015, 07:22:00 AM »
Thanks for the replies. I was wondering servo, but thought that if the servo was not working then the problem would be the opposite...with the pedal very hard but with a lack of brake effect (I am thinking back to old Polo's for example). I wonder about popping off the vacuum hose to the servo unit and see what happens...not necessarily on the road, by the way!
If I double or triple press the pedal in quick succession, the pedal is harder, but if I keep the pressure on the pedal will slowly move.
The car is an MG ZS 180. Oddly,  the brakes work well on the track, when hot. I had ebc yellows stuff pads in which are good when hot and used hard, and I initiallythought these were the problem, glazed and cold for the road. But putting a new set of oem equivalent Mintex in and the normal road driving is still unchanged, as described in my posts, so not the pads.
So, I was wondering whether anyone would say 'yes the problem is this' from the description, so I don't end up buying new parts that are not needed.

Thanks again!

9
Rotary and General Chit-Chat / Re: Advice on strange brake pedal feel
« on: January 02, 2015, 06:29:06 PM »
The pedal does have some compression when pressed and does move a little if I keep the pressure on, but then it is the same for the other cars I drive. Maybe the pedal does feel a bit softer, but it doesn't go to the floor if, for example, there were a leak releasing pressure in the hydraulic line. When I press the pedal, and quite hard, the pedal feels ok, but there is just this lack of response from the brakes - there is no bite or grip, then something tends to happen. From my own description, I'd say it were sticky pistons in the calipers, taking time push out against the discs. But having put new pads on the front, the pistons in both calipers pushed back relatively easily. Scratching my head, to be honest, about this!

10
Rotary and General Chit-Chat / Advice on strange brake pedal feel
« on: January 02, 2015, 04:44:01 PM »
Hi,
I'm after a bit of technical advice, if anyone can help. It is a question about brakes but not on a rotary car, but not that that really matters.
One of the cars I have, seems to have a delayed action on the brakes after I press the pedal. By this, I mean that if I press the pedal, even very hard, there seems to be a couple of seconds delay before I feel any braking effect. This is also the case if I emergency stop. Discs are all good, virtually new condition, almost new pads all round, fully bled the system with new fluid. I've checked all four calipers, and carriers and slider pins are all free to move. Pistons seem to move ok. No fluid leaks anywhere.
So why the scary feeling brakes? There seems to be no initial bite until the pedal is pressed pretty hard even then it feels like there is little braking effort. If I emergency stop the car just slows down rather than the ABS kicking in as with the other cars. It is just very disconcerting pressing the pedal and waiting for the brakes to apply...!
Any ideas what could cause this? I've bled the system several times, never got any air from any of the calipers. I keep thinking a master cylinder issue, so do these symptoms sound like it could be?
I'd appreciate any pointers of what may be wrong!
Thanks
Andrew


11
General Technical / Question about oil change intervals in track cars
« on: August 26, 2014, 12:17:38 PM »
Thanks for sharing your opinions, appreciated!

12
General Technical / Question about oil change intervals in track cars
« on: August 24, 2014, 08:25:20 PM »
Hi,
Just want to ask a general question regarding oil change intervals on tracked cars. Not necessarily rotaries, but engines in general. For those that enjoy tracking cars, how often would you look at changing the oil and filter?  Got myself a runabout for the track, but would like some advice on  what others do about frequency of changing their oils. Every few track days, or time spent on the track? By mileage? Would appreciate some advice, thanks!

13
Great video, enjoyed that!

14
General Technical / Road tyres with the occasional track day
« on: June 11, 2014, 08:58:00 PM »
Quote from: boosted;880032
I got a set of these as well....very good in the wet on track also(compared to 888!). Once you get down to 4-5mm they will come alive as the tread blocks stop squirming about.


Good to hear!:driving:Giggle

15
General Technical / Road tyres with the occasional track day
« on: June 11, 2014, 03:09:46 PM »
Quick update for reference: due to the size of tyre and limited budget, I didn\'t go for a semi-slick this time. I did veer back to just ruining the tyres that were on the car, but after finding a number of reviews of the front tyres, where delamination of the rubber was reported several times, I decided that a new set was called for. After all, it is the only contact point to the track/road, and I wanted to enjoy cornering, rather than slipping and sliding everywhere.
So after much reading around I opted for Yokohama Parada Spec 2. I have to say, I am pretty impressed with the dry grip these things have! I was pushing pretty hard into the corners round the track and they were certainly hanging on incredibly well. I\'m no expert, but for an almost budget tyre price, these may well be something others could consider. All 4 fitted etc, price was £360.

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