11-1/4" LeBaron brake upgrade guide (Page 3/5)
Fieroseverywhere AUG 08, 10:08 PM
A couple small notes on the use of the subaru spare wheel with F-body tire.

First: Credit goes to Fierosound on the subaru wheel. He pointed me in the right direction.

Second: This setup will not work if you plan to stow your sunroof glass under the hood with the larger spare. The spare is the max that will fit and takes up the small amount of room needed for the sunroof glass.

Third: I found out later that the spacer is not needed. There was an issue with my caliper brackets that was corrected. Thats why I only had the issue in the front.

Lastly: If you have a front mount battery the suby spare will not hold it in place. Another solution will need to be found. I just built a simple mounting strap.

Nice write up pmbrunelle. I'm with you on all points!

[This message has been edited by Fieroseverywhere (edited 08-08-2011).]

pmbrunelle AUG 08, 11:56 PM
Fastenal has the proper bolts (and shaft collars too):

http://www.fastenal.com/web/home.ex

Fasteners
Bolts
Cap Screws & Hex Bolts

I agree they're hard to find.

The front knuckles are already tapped for M12 x 1.5 stock, so you're pretty much stuck with that size unless you want to drill oversize and retap. If you're using oversize fasteners, then get spacers with a hole large enough to accommodate them. If you find a source for M12 x 1.5 bolts, then it's a no-brainer to get matching bolts for the rear. But if you wish, 7/16" bolts, 1" long can be used in the back, preferably fine thread.

As far as the hub-to-knuckle bolts go, you'll probably be okay, but don't shoot me if you end up handicapped. But if you're going to order from Fastenal though, might as well order the correct hub bolts also... It's never really advisable to downgrade a part like that from its original specification.

Yep, I can't stow away the sunroof when I carry the Subaru spare (mine has a Jeep tire on it I think, I don't remember the size). I don't know if the stock Fiero spare would fit over these brakes with the help of a ~5 mm spacer. That would solve the sunroof storage issue.

If someone wants to argue with me about the safety of a spare tire installed with a spacer such that the centerbore is no longer touching the shoulder on the hub, please keep this brake modification thread clean. Concerns about thread engagement with a spacer are legitimate and to be verified before use.

[This message has been edited by pmbrunelle (edited 08-08-2011).]

InTheLead AUG 09, 12:37 AM
Okay I read it a few times for the 84-87 Lebaron upgrade. So if I do these there is no way to hook up a parking brake? Little confused on that.

Thx for the write-up
pmbrunelle AUG 12, 08:58 PM
I suggested two calipers with parking brake functionality.
pmbrunelle AUG 12, 09:23 PM
So I just picked up a set of silver ASA AR1 wheels and Bridgestone Potenza RE-11 tires from tirerack. The quality of these wheels leaves something to be desired, but they look good when you're not looking too carefully.

17x8 rear, 35 mm offset. Good size for 245/40R17

17x7 front, 48 mm offset - to compensate for the spacer effect of the LeBaron rotor hats. Reduce scrub radius and thus kickback over bumps, steering effort.. Good size for 205/45R17

The rear lug nuts go on fine.

It appears that the position of the "virtual cone vertex" of the lug nut seat is further inboard than with my old MSR Style 113 wheels. Result - the closed-end lug nuts bottom out on the DORMAN 610-323 lug studs I suggested.

You may want to evaluate your situation before jumping straight to the extra-long studs I mentioned.

Tomorrow when it's bright, I'll see if I revert to the stock DORMAN 610-254, or maybe I'll need to trim the 610-323s.

Figured I'd post the stud info here:

610-254

Type : Serrated Stud
Thread : M12-1.5
Knurl Dia. : 12.73mm
Length : 41.5mm
Shoulder Length : 8mm

610-323

Type : Serrated Stud
Thread : M12-1.5
Knurl Dia. : 12.80mm
Length : 54mm
Shoulder Length : 8mm

[This message has been edited by pmbrunelle (edited 08-12-2011).]

pmbrunelle AUG 13, 11:41 AM
I'm trimming down the 610-323s to an under head length of 44 mm.

This will give the same stud protrusion as in the rear. (which doesn't have issues with closed-end lugs bottoming)

In my case, I'm getting ~9 turns before the lug nuts are touching the wheel. At 1.5 mm pitch, that's ~13.5 mm of thread engagement. It's above the classic recommendation of having thread engagement length equal to the diameter of the fastener.

Anyway, so a mechanical engineer I trust tells me, often 2-3 threads is all that is needed to develop the full tensile strength of a fastener.

[This message has been edited by pmbrunelle (edited 08-13-2011).]

Trinten MAY 17, 08:19 PM
Thanks for putting the work into making this thread. I know it's going to come in handy!

Also, as another Caliper option, it appears Wilwood does have some calipers that work when using the 10 degree brackets - still waiting to hear if they'll clear the GT wheels. Here's a link to the thread of the guy using them.

http://ncmidengine.47.forum...upgrade-t302009.html

A request - would it be too much to ask if you could post pics of your car with your wheels on?

I ask because I *thought* I knew what offset I was going to need, then I saw your post with the ones you used, which were fairly different from mine, so I'd like to see how yours sit. I'd hate to get new wheels and find out that things aren't going to fit/clear because I messed up with how the swap changed things!

[This message has been edited by Trinten (edited 05-17-2012).]

Tom Corey MAY 17, 09:51 PM
I've been doing modified Fieros for a lot of years and I've had the Lebaron brakes for a few years on my 87 GT. I've run them hard and a lot. In my opinion, they are little improvement over the stock brakes althought mine are cross drilled, the calipers are powdercoated, and the rotors are vented so they look great - great for show but not for go. In addition, the Lebaron ebrake setup sucks. I've never been able to adjust the ebrake to where it would hold the car on the slightest incline. That is my opinion and my experience with the lebaron swap. I'm currently switching to the C4 12" brake swap. Hopefully they will fill the bill. If not, they'll look even better anyway.

------------------

Tom Corey
Melbourne, FL
87 T-Top GT, 6-Spd, RamJet 350 SBC

[This message has been edited by Tom Corey (edited 05-17-2012).]

Fierobsessed MAY 18, 07:47 AM
I've been seriously considering using these rotors:


as opposed to the lebaron rotors:


The size difference isn't much, The lebaron rotors are 11.27" and the Subaru Forester rotors are 11.56" The offset on the rotor is a bit deeper, don't know if thats ok till it's tried. They weigh the same, but the Forester rotors are thicker. I found that the Cadillac calipers, with the pistons completely retracted, and with new pads measure 1.2" between the friction surfaces, but they can only be used practically to about 1" thick. The Lebaron rotors are only .870 thick, and the Forester rotors are .945" thick, so there is a slight advantage there. The snout on the Fiero's bearing is the same size as the both of the rotors too. They look like a perfect fit. They vent from the inside, as opposed to the lebaron rotors venting from the outside. If these rotors work, it's a nice alternative, but it might rule out factory 15" wheels, as it would push the calipers out .129" and that might be the point of scraping the wheel... or maybe not?

They are more money but they are somewhat a better rotor. I just wonder if they would fit over the hub's hat OD. These look a bit small in that dimension.


Anyone want to test these?
Riceburner98 MAY 23, 02:51 PM
Quick mounting bolt question... I see people recommend drilling + tapping the rear knuckles to M12x1.5. Is this purely because the M11x1.5 thread bolts are hard to find? Anyone think using M11x1.5 bolts would be a problem? GM LS flywheel / flexplate bolts are M11x1.5, and come in 1" (25mm) and .880" (22.3mm) lengths, which should fit the rear perfectly. Summit (and I'm sure others) carry a few brands of these bolts (ex: http://www.summitracing.com...1mm%20x%201.5&dds=1) I can't find a grade on the GM ones but shouldn't they be at least 10.9 rated being flywheel bolts? Sure, they're $6 a piece if you get them full-price, but at least you don't have to worry about messing up the knuckle threads... And it seems an M12x1.5 tap from McMaster runs almost $40 anyway..


------------------
Bob Williams
(still) working on the 3800 swap... It'll drive some day!

[This message has been edited by Riceburner98 (edited 07-09-2012).]