Anyone use the BavAuto cross drilled rotors? Thoughts?

[Johnny Riviera]

As the title implies, anyone use the BavAuto cross drilled stock size rotors? Worth the money?

https://www.bavauto.com/34-11-1-117422d

Thanks in advance,

 

John

['76mintgrün'02]

not me, sorry.

but I did type [cross drilled rotors] into the search window and got 64 hits.

 

Bav Auto's rotors are discussed in some of the threads.

Perhaps check those out, while you wait for some feedback.

Tom

[Johnny Riviera]

Thanks!

 

 

[TobyB]

ooo, I do feel a rant coming on....

 

Johnny, this isn't aimed AT you, it's for...well, it's for all of us.  heh...

 

I know the Porsche-cars still come from the factory that way,

but since the early 70's, there's only been one real reason to drill

or slot your rotors:  improved wet braking performance.  Like,

 

"watersplash, brake hard into L2 R3 don't cut"

 

The original reason for holes was that, in the 60's, organic pads gave off a significant

amount of gas as they heated.  This gas could float the brake pad off the rotor,

and suddenly, 3/4 of the way into a braking zone, your pedal went hard and the

car stopped slowing.  It was terrifying.  You either went faster through the corner than

you knew was possible, or you wrecked.

 

Now, racers already loved to drill 'lightening holes' into everything, http://kalecoauto.com/ so the solution proved

to be to drill holes into the brake rotors, too.  That gave the gas somewhere to go, and the problem

was pretty much solved.

 

However, 3 or 4 new problems emerged:

1: reduced thermal performance of the rotor.  Yes, it had more surface area, but now, less mass.  So while it cooled somewhat

faster, it also got hotter in the process, and less evenly than without the holes, which ties into

2: reduced structural integrity.  The holes create a whole bunch of places for cracks to form.  Add the extra heat, and

the rotors are MUCH weaker.

3; not much weight loss,  given the problems of #1 and #2.  Holes take most of the strength, while leaving 90% of the weight. (https://www.pegasusautoracing.com/group.asp?GroupID=CSMITH)

4: pad wear.  The holes tear at the pads.

5: Improved pads don't gas much at all, unless they're brand new.  (everything after about the mid- '70's).

6: Improved casting processes make internally vented (vaned) rotors cost almost nothing more than solid rotors,

don't weigh that much more, and are structurally far superior per gram.

 

Slots help somewhat with 1 and 2, but #5 trumps all- you don't NEED the darned things.

 

 

So, err, no, I guess if you want better brakes and have to change 'em anyway, I guess I'd recommend the '77 320 rotors,

and 320 hubs to suit your struts, along with either 528 or Volvo calipers (again, depending on struts)

 

Way more than you wanted to know, huh?

 

t

 

 

Edited February 16, 2018 by TobyB

[2002Scoob]

I always feel better about going into decisions or situations knowing more than I need to. 

[Conserv]

3 hours ago, TobyB said:

ooo, I do feel a rant coming on....

 

Johnny, this isn't aimed AT you, it's for...well, it's for all of us.  heh...

 

I know the Porsche-cars still come from the factory that way,

but since the early 70's, there's only been one real reason to drill

or slot your rotors:  improved wet braking performance.  Like,

 

"watersplash, brake hard into L2 R3 don't cut"

 

The original reason for holes was that, in the 60's, organic pads gave off a significant

amount of gas as they heated.  This gas could float the brake pad off the rotor,

and suddenly, 3/4 of the way into a braking zone, your pedal went hard and the

car stopped slowing.  It was terrifying.  You either went faster through the corner than

you knew was possible, or you wrecked.

 

Now, racers already loved to drill 'lightening holes' into everything, http://kalecoauto.com/ so the solution proved

to be to drill holes into the brake rotors, too.  That gave the gas somewhere to go, and the problem

was pretty much solved.

 

However, 3 or 4 new problems emerged:

1: reduced thermal performance of the rotor.  Yes, it had more surface area, but now, less mass.  So while it cooled somewhat

faster, it also got hotter in the process, and less evenly than without the holes, which ties into

2: reduced structural integrity.  The holes create a whole bunch of places for cracks to form.  Add the extra heat, and

the rotors are MUCH weaker.

3; not much weight loss,  given the problems of #1 and #2.  Holes take most of the strength, while leaving 90% of the weight. (https://www.pegasusautoracing.com/group.asp?GroupID=CSMITH)

4: pad wear.  The holes tear at the pads.

5: Improved pads don't gas much at all, unless they're brand new.  (everything after about the mid- '70's).

6: Improved casting processes make internally vented (vaned) rotors cost almost nothing more than solid rotors,

don't weigh that much more, and are structurally far superior per gram.

 

Slots help somewhat with 1 and 2, but #5 trumps all- you don't NEED the darned things.

 

 

So, err, no, I guess if you want better brakes and have to change 'em anyway, I guess I'd recommend the '77 320 rotors,

and 320 hubs to suit your struts, along with either 528 or Volvo calipers (again, depending on struts)

 

Way more than you wanted to know, huh?

 

t

 

 

 

So...Toby...does that mean you do or you don't use BavAuto cross-drilled rotors?.... 

 

I'm kidding!  I'm kidding!

 

Best regards,

 

Steve

 

 

[Johnny Riviera]

Actually, that’s exactly the kind of answer I was looking for! I prefer detail and facts to back up opinions. I experienced some brake fade last year during auto-x, and was searching for cheap-ish help. I agree that the vented e21 setup would be the way to go, but it’s not in the budget right now, as my few auto-x outings last year showed me an LSD and better tires were top of the list. Thought maybe these could be some easy low hanging fruit. I think I’ll just make sure I have good performance pads, and flush out my brake fluid. 

 

Thanks for the info guys!

 

John

[jireland2002]

A 2002 should not get brake fad at an autox.  Maybe bleed out the old fluid with fresh hi-temp fluid.  Maybe change pads.  All else fails put stainless steel shims behind the pads.to reduce heat transfer.

[Johnny Riviera]

I thought that too. I think you are spot on with pads and fluid change since they are currently “whatever was on the car when I bought it two years ago”

 

Edited February 17, 2018 by Johnny Riviera
Forgot a word

[jrhone]

While in theory Toby is correct.  I had 2 Porsche’s and yes it was a huge debate on whether they did it for performance or the “look”.  There are performance advantages.  There are disadvantages.  The material and how they were drilled is a factor as well. Slotted and drilled vented e21 rotors is what I got from Ireland.  Mostly for the bling factor.  Lol. I’d ask Jeff Ireland if he has seen any cracked drilled rotors. In the porsche world there were not many factory drilled rotor failures due to drilling on heavy track driven cars. Aftermarket? Happened more but again that depended on the rotors and how they were drilled.  

[jp5Touring]

A lot of what was stated was true a couple of decades ago, not so much today.

https://www.powerstop.com/drilled-vs-slotted-rotors-what-is-better/

http://www.brembo.com/en/car/sporting-use/discs

 

 

[ray_]

I think they are a good match for these lines:)

 

http://kalecoauto.com/index.php?main_page=product_info&cPath=11&products_id=39&zenid=TfmWavvenuozJjA9L4bya3

[2002Scoob]

10 hours ago, jireland2002 said:

A 2002 should not get brake fad at an autox.  Maybe bleed out the old fluid with fresh hi-temp fluid.  Maybe change pads.  All else fails put stainless steel shims behind the pads.to reduce heat transfer.

 

I just got a set of EBC's for my car, but just the red-stuffs, putting them in this weekend, I'm excited to try them out. They come with with a thermo-barrier shim for just what you reference. My stock brakes were just... bad. Fine for town toodling, but they've been the thing holding me back from driving hard since I got the car. 

 

On a previous Vehicle I owned which did DD/aggressive canyon duty, a switch to EBC pads made a massive difference. Stock, you had to really try to NOT over heat them, EBC's you had to be on the edge to get close to any feeling you'd consider as 'fade'. And boy did they grip. 

Edited February 17, 2018 by 2002Scoob

[Johnny Riviera]

Where did you find a part number for the Redstuffs? Didn’t see them in the EBC catalog. 

[jrhone]

13 hours ago, ray_ said:

I think they are a good match for these lines:)

 

http://kalecoauto.com/index.php?main_page=product_info&cPath=11&products_id=39&zenid=TfmWavvenuozJjA9L4bya3

 

WOW. Now I have seen it all!!!