I just sent this to Stop Tech " Hello, I would appreciate if you could take a few minutes to look this through, I am doing a popular custom brake swap using 4 rear rotors from 90-94 Chrysler Le Baron. These are vented 11.26 rear rotors adapted for Pontiac Fiero. This is a very popular swap. Do you have a two piece rotor with hats to match the 5x100 mm pattern with 57.1 centerbore or could I order (un) / drilled to match hats and discs to match this particular rotor. Here is a step by step link that many people refer to, http://myfiero.oceanmoon.co...80%99s-brake-upgrade I would appeciate this info, and will post the information on the Pennock's Fiero forum, including prices etc. possibly Stop Tech could offer this to the forum members as a group buy. https://www.fiero.nl/cgi-bin...ate.cgi?action=intro Thank you Rob." I will post the response from them.

sales@stoptech.com

http://www.wilwood.com/HatList1.aspx

Wilwood makes LOTS of hats.

Look for 5 holes on 3.93 or 5 holes on 3.94.

Thanks Will , I've looked through that chart, but haven't found what I'm looking for, centerbore etc. I don't want 12" or larger brakes either. reason I haven't contacted Wilwood about a custom order. I want to go with a light weight combination and still be able to use a 15" wheel on occasion. I'll wait for a response from Stop Tech, If they are reasonable then I will custom order, to the Le Baron specifications. Maybe I'll get a reference number, then anyone with the Le Baron swap or considering the swap could just order up a pair or a set.

I linked the Wilwood page because what you're looking for doesn't exist.

However, if you do some research on the 11.25" brake upgrade, you'll find that there are spacers required between the caliper bracket and the caliper mounting ears on the knuckle. These spacers can be any thickness within reason. You are not required to use the same offset as the LeBaron rotors use.

Personally I prefer the LeBaron front rotors over the rears, but they have a larger pilot bore diameter and require a centering ring in order to be used on a Fiero hub.

I haven't done this swap yet but I have been researching this for a while, comparing different swaps, I realize what I'm looking for doesn't exist, to my knowledge. Brembo has Le Baron rotors, part # 27342 . I am going to order a couple in the next week, The only distributor for Brembo in Canada is Northern Motorsports in Hamilton Ontario, about an hour away, I'm going to call them about pricing tomorrow, vs. ordering online, but I am trying to gather the info to have a custom hats made. I'm looking for a very lightweight setup. I have front relocation brackets already powder coated black, polished SSBC A181 front calipers and SSBC A182 rear calipers with D154 Z rated extreme pads so I can use them with Le Baron or Corvette rotor, 87-88 mixed set up etc.

The '88 Corvette rotor setup typically uses the '88 calipers which have a different mounting center than the early calipers.

That last pound of weight reduction gets very expensive. Call up Ross at Street Dreams and see if he has any aluminum lowering knuckles left. THey save 4 pounds of unsprung weight from each front corner.

https://www.fiero.nl/forum/A...060206-1-034430.html

[This message has been edited by Will (edited 03-18-2010).]

Will, thanks for the that information, I have not read that thread yet but that would be another project entirely. I want it to be lightweight, I already have 17" forged Centerline wheels with 42 offset. SSBC calipers, as for the rotors, my reason for wanting the lighter weight is less about unspung weight, but more about the inertia of a heavier disc, rotating mass. I'm just going through the possibilities and options, thinking maybe instead of parting off the entire stock fiero rotor, enough could be left and machined to accept a floating Stop Tech Aero rotor with 8 x 163.5 mm bolt circle, or another equivalent, I have been looking for machine shops in my area, I will need to provide the specifications with exact measurements. I have been doing google searches and reading different postings, regarding rotor thickness, offset, etc. the information I'm looking just seems buried in unrelated material.

[This message has been edited by rourke_87_T-Top (edited 03-18-2010).]

The rotor hat has such a small diameter compared to the rotor and the wheel that its effect on the moment of inertia of the driveline can be ignored.

The only reason to go to two-piece rotors is to reduce unsprung weight.

If you're looking for MoI reduction, use one piece cast iron rotors and put the money you would have spent on two piece rotors into top shelf light weight wheels and tires.

Exactly what information *are* you looking for?

[This message has been edited by Will (edited 03-19-2010).]

I originally posted to see if anyone else had done a two piece rotor, that is what I'm looking for. We have different ideas about unsprung weight vs. rotating mass.

There's only one idea about rotating mass. That idea is that Moment of Inertia = mass * radius^2.

Because of the ^2, mass at a small radius is inconsequential compared to the same mass at a much larger radius. Taking a pound out of your tire will give you a much greater effect in terms of reducing moment of inertia than will taking a pound out of your rotor hat.

The hat might be like a 6" OD, so the actual mean radius is going to be like 2". (not sure about the details, I've only just started a basic calculus course). So basically, it's not significant.

Plus, it's spinning pretty slowly.

For the best bang/buck, I'd look into a lightened flywheel.

I have an aluminum flywheel for the '87 5spd. I'm using a custom 2500 stall from Alan Johnson, Diane shipped it yesterday. I also have two sets of 17" Centerline forged. https://www.fiero.nl/forum/Forum1/HTML/074248.html

i have the street dreams by Ross drop spindles .they have AL hubs and when i weighed them they are about 2 lbs lighter per wheel .i am using front lebaron vented 11.25" discs and i had to increase the centre hole to get them to fit .this was pretty easy , i just used a cylinder hone with sandpaper over the stones .came out perfect .i have hunted in vain on the net for a two piece rotor and top hat but none of them come in a small size rotor so i am sticking with the front lebarons .part # 's for the lebaron are qualis 016-9667-4 wagner bd61958 as far as i can tell .this disc is sloppy on the stock front hubs so you need a spacer .

I received the first hubs produced. The OD of the flange should fit perfectly into the ID of the hat on the LeBaron front rotor and locate the rotor that way, rather thn on the pilot journal on which the rear rotors would locate. I designed them this way because the front rotor has a larger center pilot bore than the rear. Maybe whoever manufactured the rotor you have used different millimeters than the one who manufactured the rotor I have.

[This message has been edited by Will (edited 03-19-2010).]

quote Originally posted by rourke_87_T-Top: http://www.stoptech.com/tec...s/98-240-2430-00.pdf

Is the factory PT Loser rotor similar to the LeBaron rotor?

That 12.9" / 328 mm x 28 SRT-4 big brake upgrade rotor has the 57mm centerbore with the 5x100mm pattern, It is also only 11.75 lbs. with very good ventillation. I'm not sure what the offset of a LeBaron rotor is. I have not done the LeBaron swap, just looking at alternative ideas. It should fit my 17" wheels but I'm going to make a template to check clearance on my wheels, possibly I could have a relocation bracket with bosses to accept calipers in two positions, just an idea in case I want to run 15" wheels. It is not imperitive. I do have the LeBaron brackets, but obviously they would not work. I will check if this rotor caliper combination will fit, I believe it will and then order one rotor and hat to work with. I could use the LeBaron set up on the T-Top, I don't drive it very hard anyway.

[This message has been edited by rourke_87_T-Top (edited 04-08-2010).]

http://www.zeckhausen.com/Dodge/SRT-4.htm

http://www.zeckhausen.com/StopTech/consumables.htm