IS250 - best brake upgrade?
03-25-12, 02:58 PM
#1
Rookie
Thread Starter
IS250 - best brake upgrade?
I've seen members here installing is350 brakes on the 250, and isF brakes on a 350. My question is, can I swap isF brakes on my 250? Or would the Fsport brakes be a better solution?
I plan on tracking the car once every couple of months, and the 250 brakes just don't seem up to the task of a full day at the track - too small so i assume they'll fade under sustained heavy loads.
I have the sways and shocks on the way, may retain the stock sport package springs as I like the pillow cushion ride for my daily commutes across town (I'm in outside sales & drive alot).
+1 for input or links to threads/members who've upgraded the is250 brakes.
I plan on tracking the car once every couple of months, and the 250 brakes just don't seem up to the task of a full day at the track - too small so i assume they'll fade under sustained heavy loads.
I have the sways and shocks on the way, may retain the stock sport package springs as I like the pillow cushion ride for my daily commutes across town (I'm in outside sales & drive alot).
+1 for input or links to threads/members who've upgraded the is250 brakes.
03-25-12, 05:44 PM
#2
Pole Position
Join Date: Jul 2011
Location: TX
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
BBK's are of course the best w/slotted and drilled rotors to keep em cool. However with the F Sport or Brembo (ISF uses these) you will have to get a bigger rim because they won't fit in the stock 17"er.
Last edited by Sffd103; 03-25-12 at 09:53 PM.
03-25-12, 09:02 PM
#4
Rookie
Thread Starter
Nice myth, but driling doesn't make them weaker. AMG, Ferrari, Lamborghini, and every high performance car has drilled rotors - not slotted.
Are ISF and Fsport the same? Just rebadged 6 piston Brembos?
I found stop tech drilled rotors and hawk pads - anyone ran this on stock is250?
Are ISF and Fsport the same? Just rebadged 6 piston Brembos?
I found stop tech drilled rotors and hawk pads - anyone ran this on stock is250?
03-26-12, 08:44 AM
#7
Yes, it DOES make it weaker.
It's not a myth, it's basic physics.
Drilling holes in a heat sink removes useful mass, and it also makes the rotor significantly more prone to cracks.
Thems the facts,
because they're mostly bought by people who never go on a race track but want it to look nice.
Lobuxracer has posted pics before of his IS-F stock drilled rotors with stress cracks starting to show after just ONE track session.
Now go look at a NASCAR vehicle.
notice no drilled rotors? there's a reason for that.
Or just ask folks who actually sell the things-
http://www.stoptech.com/technical-su...rade-selection
Or ask a guy who designs brake systems for a living for OEM and aftermarket vendors and has literally written books on the topic-
http://www.scirocco.org/faq/brakes/p...oorrotors.html
There is simply no good reason to put holes in rotors, and there hasn't been for decades...and there's good reasons not to.
They'll happily sell you whatever you want if you don't know any better though.
On a street driven car your best results will be with blank rotors.
On a car that sees track use your best results will be slotted, not drilled rotors. You'll still get less pad life (about 25% less) compared to blanks.. but you'll find it worth the trade for the deglazing effect of the slots, something not usually relevant in street use.
It's not a myth, it's basic physics.
Drilling holes in a heat sink removes useful mass, and it also makes the rotor significantly more prone to cracks.
Thems the facts,
Lobuxracer has posted pics before of his IS-F stock drilled rotors with stress cracks starting to show after just ONE track session.
Now go look at a NASCAR vehicle.
notice no drilled rotors? there's a reason for that.
Or just ask folks who actually sell the things-
http://www.stoptech.com/technical-su...rade-selection
Originally Posted by Stoptech
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".
Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.
Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.
Or ask a guy who designs brake systems for a living for OEM and aftermarket vendors and has literally written books on the topic-
http://www.scirocco.org/faq/brakes/p...oorrotors.html
Originally Posted by James Walker Jr
Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the '40s and 50s, not a whole lot. Rotors were first drilled because early brake pad materials gave off gasses when heated to racing temperatures, a process known as "gassing out." These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses somewhere to go. It was an effective solution, but today's friction materials do not exhibit the some gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.) These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads--sort of like a cheese grater rubbing against them at every stop. Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.) These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads--sort of like a cheese grater rubbing against them at every stop. Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.
They'll happily sell you whatever you want if you don't know any better though.
On a street driven car your best results will be with blank rotors.
On a car that sees track use your best results will be slotted, not drilled rotors. You'll still get less pad life (about 25% less) compared to blanks.. but you'll find it worth the trade for the deglazing effect of the slots, something not usually relevant in street use.
Last edited by Kurtz; 03-26-12 at 08:52 AM.
Trending Topics
The following users liked this post:
breeza (04-04-23)
03-27-12, 05:59 AM
#9
Rookie
Thread Starter
Respectfully, you're an idiot and know nothing about tracking cars. You lost credibility here:
because they're mostly bought by people who never go on a racetrackbut want it to look nice.
Obviously you're not well informed on their engineering, construction, and purpose of the cars mentioned.
Nascar is a completely different philosophy, those cars don't stop repetitively. LeMans cars have drilled rotors. Every track ready car does. Think Porsche GT2. And GT3. They aren't made for street use those are track ready race cars. In fact, I can't think of a track car that runs slotted brakes.
According to Brembo, drilled is a 70% decrease in heat and fade while slotted is only 40%.
Respectfully,
CB
because they're mostly bought by people who never go on a racetrackbut want it to look nice.
Obviously you're not well informed on their engineering, construction, and purpose of the cars mentioned.
Nascar is a completely different philosophy, those cars don't stop repetitively. LeMans cars have drilled rotors. Every track ready car does. Think Porsche GT2. And GT3. They aren't made for street use those are track ready race cars. In fact, I can't think of a track car that runs slotted brakes.
According to Brembo, drilled is a 70% decrease in heat and fade while slotted is only 40%.
Respectfully,
CB
03-27-12, 07:46 AM
#10
Respectfully, you're an idiot and know nothing about tracking cars. You lost credibility here:
because they're mostly bought by people who never go on a racetrackbut want it to look nice.
Obviously you're not well informed on their engineering, construction, and purpose of the cars mentioned.
because they're mostly bought by people who never go on a racetrackbut want it to look nice.
Obviously you're not well informed on their engineering, construction, and purpose of the cars mentioned.
because I just presented you with a guy who designed brake systems for a living suggesting you're wrong and I'm right. What company do you design braking systems for to say he's incorrect? Which books have you had published on brake system design to say he's wrong?
And also Stoptech, a major maker of both OEM and aftermarket brakes, also saying you're wrong and I'm right. What brake company do you own to disagree with them?
You haven't presented anything all all besides telling people they're idiots.
So you'l forgive me if you're not only wrong, but less than compelling in your arguments and evidence (or utter lack thereof)
Nascar is a completely different philosophy, those cars don't stop repetitively. LeMans cars have drilled rotors. Every track ready car does. Think Porsche GT2. And GT3. They aren't made for street use those are track ready race cars. In fact, I can't think of a track car that runs slotted brakes.
F1 doesn't drive on a track?
but since you mention Le Mans-
http://www.m5board.com/vbulletin/off...tml#post339652
The Brembo Le Mans brakes are used extensively on cars that run the 24 Hours of Le Mans (24 Heures du Mans) race
You know, like the things I provided? where you can actually show Brembo saying that?
Speaking of brembo... here is their catalog for racing parts-
http://www.brembo.com/it/Auto/Racing...acing_2011.pdf
Here's what they say on their website about these parts:
Originally Posted by Brembo
Brembo offers a comprehensive range of products dedicated exclusively to motorsports and designed to deliver the best in the most extreme conditions: consistent performance, superior braking power, precision and control, and resistance to very high temperatures. All Brembo products for racing applications are the result of ongoing research and development in collaboration with the world's most prestigious teams, and of a manufacturing process conducted entirely in-house, from design and machining to bench and track testing.
Notice how the rotors do not have holes drilled in them?
Many do have slots though.
So it seems like while Brembo is happy to sell drilled rotors to suckers who don't know better on "street" cars, their actual racing applications avoid drilled holes.
Any idea why?
Probably because you're wrong and slots are the preferred solution
It's page 43 if you're having trouble finding it. They have blank rotors, and several patterns of grooves/slots. No holes though (other than the mounting ones)
Because, as I said, drilled rotors are generally for show for people who don't know any better.
How Stuff Works knows this:
http://auto.howstuffworks.com/auto-p...ke-rotors2.htm
Originally Posted by How Stuff Works
As we mentioned on the previous page, drilled rotors have been weakened, which makes them prone to cracking around the holes, particularly when they've been repeatedly driven hard. Because they tend to be a little more durable than the drilled brake rotors, slotted brake rotors may be a better brake part choice for some performance car drivers
Here's EBC, yet another company that unlike you actually does brakes for a living, on why drilling holes in rotors sucks-
http://www.ebcbrakes.com/cross_drill...d_rotors.shtml
Originally Posted by EBC
The very reason that EBC Brakes only uses dimple drilled rotors or slots up to a maximum of 1mm in depth is that the through drilling of brake rotors has been proven to not only weaken the rotor structure, but to promote cracks emanating from the drill holes.... It is still our firm opinion that through drilling ANY BRAKE ROTOR is bad news.
Here's Stillen on drilled rotors-
Originally Posted by Stillen
Cross-drilled rotors are not recommended for serious track duty – choose Slotted or Hook Slot rotors (when available) instead for elevated temperature use.
http://www.tirerack.com/brakes/brake...Slotted+Rotors
Compared to cross-drilled rotors, machined slots have been widely adopted for racing and street use because they minimize the cracking caused by repeated, high stress, high temperature brake applications.
Where you claimed drilling doesn't weaken the rotor. That seems more relevant to folks with a 2IS than if the brake is ok to run at Le Mans or not.
Because you're completely wrong about it, and every source I've given you agrees. So do all the pictures iin the IS-F area (and a ton of porsche forums for that matter) showing all the stress riser cracks around the drilled holes.
Got a source to back you up there either? or just more baseless namecalling?
Last edited by Kurtz; 03-27-12 at 12:26 PM.
The following users liked this post:
breeza (04-04-23)
The following users liked this post:
breeza (04-04-23)
03-28-12, 01:22 AM
#12
Lead Lap
iTrader: (4)
Join Date: May 2011
Location: tx
Posts: 721
Likes: 0
Received 0 Likes
on
0 Posts
Kurtz is right I have a 2007 gallardo with carbon ceramic brakes. No holes only slots. Even on my buddy's sls amf Benz he has slotted no holes. I personally don't track my cars just spirited driving from time to time around town. But Kurtz sounds on point IMO
03-28-12, 02:10 AM
#13
Pole Position
Join Date: Oct 2009
Location: TEXAS
Posts: 274
Likes: 0
Received 0 Likes
on
0 Posts
Kurtzzz youre the boss. Now that you mentioned that and i'm in the verge of getting a new rotor, i will get the SLOTTED ones. Thanksss
And by the way, if i do get the slotted rotors, which brand should i get? I have a 2008 IS350 with 18" stock wheels. I saw a bunch in eBay but not quite sure which ones i should get.
And by the way, if i do get the slotted rotors, which brand should i get? I have a 2008 IS350 with 18" stock wheels. I saw a bunch in eBay but not quite sure which ones i should get.
03-28-12, 04:22 AM
#14
Kurtzzz youre the boss. Now that you mentioned that and i'm in the verge of getting a new rotor, i will get the SLOTTED ones. Thanksss
And by the way, if i do get the slotted rotors, which brand should i get? I have a 2008 IS350 with 18" stock wheels. I saw a bunch in eBay but not quite sure which ones i should get.
And by the way, if i do get the slotted rotors, which brand should i get? I have a 2008 IS350 with 18" stock wheels. I saw a bunch in eBay but not quite sure which ones i should get.
if you track the car then yeah, slots are the way to go as their benefits in that environment are worth the shorter pad life... Stoptech and Brembo should both be names you won't go wrong with... I've had good luck with Powerslot rotors in the past as well (though on a different car so not sure if they have a 2IS application or not)
Careful on ebay rotors, check the seller feedback in detail- there's a lot of cheap knockoff rotors on there
