Alfa Romeo Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
91 Posts
Discussion Starter #1
It is a question that I am trying to solve. Especially in track-day, when you need to brake many times from 220 to 80Km/h (130 to 50 mph), the pedal loses consistency, and the back calipers warm up in excess.
I finish of replacing 2 rear calipers again. My rear discs are drilled, the pads are very good, I have DOT 5 and metalic hoses in the 4 calipers. I am thinking the best serious solution about being able to canalize cold air laterally to the rear rotors, But it is not not easy at all, and in view of the movement of DION, must to take the air from a point of the chassis and to canalize it near the rotors.
The front calipers, I did some work with a hose to take cold air (I will show you some pictures)
Did some of you something to solve this problem?



I have been the last days tryng to do something, but is not easy at all !!!
if some of you did something, will be nice to see pictures.
THANKS
 

·
Registered
Joined
·
1,898 Posts
DOT 5 or 5.1? DOT 5 is silicone based crap that was only developed to make the ABS work in sever cold, NEVER use it in a track car!

Usually race fluids are DOT 4 or even DOT 3, that doesn't mean they are bad compared to a DOT 5.1, usually it means they are more hygroscopic, i.e. they absorb water faster.

I have no solution to the heat issue but it's an important topic that I also need to address on my car, the rears seem to be hotter this year. :|
 

·
Registered
Joined
·
2,984 Posts
I seen some pics here on the BB where some of the preped race cars had big hoses feeding air to them. looked like the vent hose on a close dryer.
also the use of the vented disks off the SZ should help a whole lot..
The vented work like a blower so the air gets sucked in the inside and ejected to the outside.
so if the fresh air is feed to the center, the spinning disk will pump the air.

but I think you need both the vented disks and a hose feeding air for it to work well.
 

·
Registered
Joined
·
91 Posts
Discussion Starter #4
DOT 5 or 5.1? DOT 5 is silicone based crap that was only developed to make the ABS work in sever cold, NEVER use it in a track car!:
I use 5.1, my car has ABS and since I have put this fluid, the pedal touch is great !!!

I have no solution to the heat issue but it's an important topic that I also need to address on my car, the rears seem to be hotter this year. :|
THIS is the real problem, also because the exhaust piping is very close to the rear right caliper.
I am doing something, but it is very difficult.......to find the way to do it, specialy in the right side.
 

·
Registered
Joined
·
2,356 Posts
if you made a sheetmetal scoop that attatched and hung down off the tube in theory you could use it to catch and deflect air to the rotors

otherwise your going to have to get creative with dryer tubeing
 

·
Registered
Joined
·
1,898 Posts
yes, 5.1 is ok. :)

I have added a small heat shield on my exhaust just to protect the caliper and halfshaft boot from the worst heat. works well.
 

·
Registered
Joined
·
625 Posts
I would start by wrapping the exhaust, and finding some better fluid. Also people have tried making heat sinks for the back of the calipers, which seemed like a novel idea. I would re-design the black/grey trunk vents as scoops, but it seems like that would get complicated quickly. I think a scoop that mounted under the car to the floor, then followed the floor to the brakes would work nicely, but I am just converting to outboard brakes to avoid the whole problem.
 

·
Registered
Joined
·
1,230 Posts
In a rally GTV, have seen scoops in the rear sid windows (the wind down ones) that feed into a duct pipe that went down through the rear floor area (where the seat would go) to supply cool air right over the top of the disc/caliper area. A BIT radical but could help.

Another option is side pipes to take the exhaust away from the brakes altogether.

Not so practical for road cars though!

I have the same problem with my GTV6 for track work. Am going down the traditional route of wrapping the exhaust near the caliper and plan to investigate some scoops attached to the fwd arms of the dedion that feed some flex tube pointing air at the calipers.
 

·
Registered
Joined
·
5,799 Posts
My friend Ron Weddle has a ducted cold air system which drives cold air from the rear window area down through two small holes in the rear floor and then directly forward of the rear discs. The ducting and modifications were inexpensive and easy to do and he has no trouble with his brakes now.
 

·
Registered
Joined
·
91 Posts
Discussion Starter #11 (Edited)
it looks that there are just two options. Use the vented Kit SZ or do something to take cold air.
I will try the second option, cause i bought these rotors one year ago, and replaced rear calipers few months ago.
I have been for a long time thinking about to take air cold from under the car and bring it as closer as I can to the rotors.
Yesterday I began to do something.


I tryed different options, but, as the exhaust piping in the right side is very close to the caliper, I thought that the best way is use a hose as far as possible to exhaust (on the right side), this way, i must do the work thinking to do both sides.The pictures are in the left side, this way will be possible to do both sides at the same way...



All this work is provisional, now the problem is to channel the air near the disc, considering the movement of the gear box with respect to the DION
If some of you have a better idea to do these tubeing.
 

·
Registered
Joined
·
157 Posts
The Group 2 package solved all heat issues with these brakes. The disc is vented, slotted, and mounted on an aluminum hat with floating fasteners. I have ten track days and nearly three years on this brake package, and I am about 30% remaining on the Ferodo DS2500 pads! It just works.
 

·
Registered
Joined
·
91 Posts
Discussion Starter #13
Vented SZ disks solved my problem. I purchased through G2 in Seattle - Specific design for Alfa transaxle by GiroDisc. I haven't had to increase venting yet as of my most track days are here in the Pacific Northwest.
The Group 2 package solved all heat issues with these brakes. The disc is vented, slotted, and mounted on an aluminum hat with floating fasteners. I have ten track days and nearly three years on this brake package, and I am about 30% remaining on the Ferodo DS2500 pads! It just works.
It looks GREAT!!!!
How much did you pay for this KIT?. Me, by the moment, I will keep working in this "Hosing project", cause my rear calipers ran maybe 500 Km ( 300 miles), and the calipers I just repaced few months ago, and the car still hasn´t run since the calipers were replaced.
When the "project" is finished, i will show the pics.
THANKS
 

·
Registered
Joined
·
4,090 Posts
It looks GREAT!!!!
...my rear calipers ran maybe 500 Km ( 300 miles), and the calipers I just repaced few months ago...
You can buy the SZ vented rotors, and then only the caliper spacing kit and add them to your new calipers. I think the caliper spacing kit is $165.
Jes
 

·
Registered
Joined
·
87 Posts
not sure if the milano undercarriage is same as the 75TS, i have 2 flexible rubber hoses blowing at the rear calipers area. the air is taken from somewhere in the middle of the undercarriage, tube facing towards the front, slightly downward pointing. will take some pictures when i get to it.
 

·
Registered
Joined
·
2,269 Posts
I used to have the cross-drilled rear rotors and a heat glove on the exhaust. I think the $16 glove was the better investment. The problem for these rear brakes is lack of mass - and little-to-no-airflow. SZ kit is probably the best bet. But add $350.00 for rotors (to the $165.00 caliper kit) Giro, or TAR*OX are even more (...even more better!).:D

I think your ducting looks pretty good - all I would suggest is figure out how to mate a couple of PC fans (12v) in the middle between your molded intake and the flex tube (on both sides). That'll get you some pressure that's hard to grab from under the car.
 

·
Registered
Joined
·
91 Posts
Discussion Starter #18
I think your ducting looks pretty good - all I would suggest is figure out how to mate a couple of PC fans (12v) in the middle between your molded intake and the flex tube (on both sides). That'll get you some pressure that's hard to grab from under the car.
I am working on this, but not using PC fans. I think that with these ducting will be enought. In first, i was thinking to take the air to the rotors, but it is difficult. I am working now in part of the idea that gave in this thread JJ75. it means, get the air under the car, and take it straight over to the rear calipers. There is not much room to do it, but I am alomst to the 50% to have finish the project. The biggest problem is to found something ( as a metalic pipeline ) to focus the air and hook it over the calipers.
 

·
Registered
Joined
·
2,356 Posts
2 1 inch tubes of steel or aluminum conduit with a funnel to down size from your 2+inch tube..it should give you double the air pressure as well as allow you to bend and channel it to exactly where you want it
 
1 - 20 of 21 Posts
Top