Do HP-2 rotors come in more than one size? Where to order them?
08-22-2005, 08:48 AM
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Do HP-2 rotors come in more than one size? Where to order them?
One installer said I have to come in to see which size I have. I was surprised.
Also, their install rate is high. I wonder about ordering the rotors shipped to my house instead. What's a good source for Zimmerman or the like? (I'm told Stoptech has a stage 2 that includes steel lines and pads.)
Also, their install rate is high. I wonder about ordering the rotors shipped to my house instead. What's a good source for Zimmerman or the like? (I'm told Stoptech has a stage 2 that includes steel lines and pads.)
08-22-2005, 09:00 AM
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There are apparently two rotor hat sizes 16.7 and 22.7mm...
you have to measure between the wheel mounting surface and the braking surface to determine the rotor hat size.
If you go to ECS Tuning, they have good prices for Zimmerman rotors. Others have talked about iRotors,com, but recent posts indicate that they are sending generic rotors instead of Brembo or Zimmermans.<ul><li><a href="http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi?make=Audi&engine=4.2&mode l=C5%20A6&submodel=Quattro&category=Brakin g">4.2 brake products from ECS tuning</a></li></ul>
If you go to ECS Tuning, they have good prices for Zimmerman rotors. Others have talked about iRotors,com, but recent posts indicate that they are sending generic rotors instead of Brembo or Zimmermans.<ul><li><a href="http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi?make=Audi&engine=4.2&mode l=C5%20A6&submodel=Quattro&category=Brakin g">4.2 brake products from ECS tuning</a></li></ul>
08-22-2005, 09:07 AM
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Re: Do HP-2 rotors come in more than one size? Where to order them?
Not sure but according to the spec. sheet (not actual measurement), my '02 S-6 has 12.6 in. (321 mm) vented front rotors using the HP-2 calipers.
08-22-2005, 10:12 AM
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Yes, come in two sizes. I've got the "odd" size which has a different offset...
The part number is 4B3 615 301 and it has a 22.7mm offset. (you can call the dealer with your VIN to find out.) The only aftermarket compatible rotor I've found so far is the DBA version specifically for this part number.
<A HREF="http://www.awe-tuning.com/pages/shared/part_detail.cfm?PMaI=1&PMoI=28&PEI=6&PP=a6_27t_bra kes.cfm&PPT=Brakes&IL=a6dba">DBA Rotors for part no 4B3 615 301, at AWE Tuning</A>
The rotors sold by <A HREF="http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi?make=Audi&engine=4.2&model=C5%20A 6&submodel=Quattro&category=Braking">ECS Tuning</A> are stock OEM, machined in some cases with slots and holes. They'll still warp, AFAIK.
<A HREF="http://www.awe-tuning.com/pages/shared/part_detail.cfm?PMaI=1&PMoI=28&PEI=6&PP=a6_27t_bra kes.cfm&PPT=Brakes&IL=a6dba">DBA Rotors for part no 4B3 615 301, at AWE Tuning</A>
The rotors sold by <A HREF="http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi?make=Audi&engine=4.2&model=C5%20A 6&submodel=Quattro&category=Braking">ECS Tuning</A> are stock OEM, machined in some cases with slots and holes. They'll still warp, AFAIK.
08-22-2005, 10:14 AM
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As for pads, I may stick with stock, because of this info...
A message called <A HREF="https://forums.audiworld.com/a6/msgs/243246.phtml">Brake pads compared</A> lists stock as one of the pads that bite well. No mention of Porterfield, though. Any feedback on ones not mentioned?
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08-22-2005, 10:44 AM
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Did my HP-2s last weekend
I just put slotted/cross-drilled Zimmerman rotors and Mintex pads from ECS Tuning on the front of my 2001 A6 2.7T. $315 delivered. Plain rotors are $50 less/pair. Slotted/cross-drilled is mainly for looks. ECS Tuning provides guidance on their website on how to determine which rotor is right for you (16.7mm or 22.7mm rotor hat) but your gonna have to take your wheel off and measure it yourself. Probably 16.7mm.....
Reasonably simple DIY job, though a little different than what I read about in tech articles which seemed to recommend messing around with the caliper guide pins--don't. This is per an Audi tech at my dealer.
First removed the pad wear sensor connector from the brake line bracket behind the caliper. You rotate it clockwise 90 degrees after gently lifting the plastic tab on the connector that is pointing straight down on the front side of the brake line bracket. The connector then lifts straight out of the bracket. Getting the connector apart is a little tricky. Note how the sensor wire is routed before removing it completely.
Now remove the brake line bracket attached to the rear of the caliper. Its a single 10-12mm bolt. This allows access to the upper 21mm bolt at rear of caliper and, after removing the lower 21mm bolt, this also allows you to more easily swing the caliper out of the way without stressing the brake lines. Actually, a 13/16 inch socket was a better fit on these 21mm bolts. Be careful not to damage the metal brake line tubing when you remove the lower bolt.
They say the rotor will simply fall off once you remove the caliper--no such luck. I had to use penetrating oil and a sledge hammer to get it off. I temporarily secured the new rotor on the car with a couple of lug nuts and reinstalled the caliper after compressing the piston FULLY with a couple of clamps. Be careful not to damage the piston bushings when you do this. Remove the cap from your master cylinder and watch for overflow while compressing the piston.
Once the caliper is on, move it back and forth to expose the guide pins in the rear. Clean and lube them with caliper grease.
Now install the new pads. They drop right into place. I used spray-on adhesive on the outer pads to reduce potential for squeal. Route the sensor wire and connect it up. Reconnect the brake line bracket and put the sensor connector back on it. Be sure to pump the brake pedal to firm it up before you drive off.
I was amazed at the minimal clearance between my wheels and the caliper with new pads installed. I'm talking no more than 3-4mm. If you have aftermarket wheels, be sure to check clearance before you drive off.
Unfortunately had a busted CV joint boot on one side. What a mess. I'm leaving that job for a pro.
Good luck with your brake project.
Reasonably simple DIY job, though a little different than what I read about in tech articles which seemed to recommend messing around with the caliper guide pins--don't. This is per an Audi tech at my dealer.
First removed the pad wear sensor connector from the brake line bracket behind the caliper. You rotate it clockwise 90 degrees after gently lifting the plastic tab on the connector that is pointing straight down on the front side of the brake line bracket. The connector then lifts straight out of the bracket. Getting the connector apart is a little tricky. Note how the sensor wire is routed before removing it completely.
Now remove the brake line bracket attached to the rear of the caliper. Its a single 10-12mm bolt. This allows access to the upper 21mm bolt at rear of caliper and, after removing the lower 21mm bolt, this also allows you to more easily swing the caliper out of the way without stressing the brake lines. Actually, a 13/16 inch socket was a better fit on these 21mm bolts. Be careful not to damage the metal brake line tubing when you remove the lower bolt.
They say the rotor will simply fall off once you remove the caliper--no such luck. I had to use penetrating oil and a sledge hammer to get it off. I temporarily secured the new rotor on the car with a couple of lug nuts and reinstalled the caliper after compressing the piston FULLY with a couple of clamps. Be careful not to damage the piston bushings when you do this. Remove the cap from your master cylinder and watch for overflow while compressing the piston.
Once the caliper is on, move it back and forth to expose the guide pins in the rear. Clean and lube them with caliper grease.
Now install the new pads. They drop right into place. I used spray-on adhesive on the outer pads to reduce potential for squeal. Route the sensor wire and connect it up. Reconnect the brake line bracket and put the sensor connector back on it. Be sure to pump the brake pedal to firm it up before you drive off.
I was amazed at the minimal clearance between my wheels and the caliper with new pads installed. I'm talking no more than 3-4mm. If you have aftermarket wheels, be sure to check clearance before you drive off.
Unfortunately had a busted CV joint boot on one side. What a mess. I'm leaving that job for a pro.
Good luck with your brake project.
08-22-2005, 10:47 AM
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Thanks, good writeup. But mine are 22.7mm and ECS supplies OEM rotors for this size....
Those that thought they were getting Zimmermans may want to check again.