Thread: 10" or 11"... baby!

G'day TeZZaP

The 11" drums are from the LWB vehicles, and are a VERY good upgrade from the old SWB 10" single leading shoe design and I would say that it would balmost be mandatory to upgrade to 11" for today's traffic conditions the 11" brakes came in 2 types, the 4 cylinder vehicles had 2 1/4 wide shoes and the 6 cylinder vehicles had 3" wide front shoes, right up including the Stage 1 V8's, the Series 2a-3 6 cylinder vehicles all had boosted brakes, with later Series 3' s having twin circut brakes to really bring up your brakes to todays quality I would suggest that you fit a booster, either by using a Series 3 brake pedal box with booster, and the top panel of a series 3 Right front guard (has the cutout for the booster) the 10" inch brakes were only marginal way back in the 70's in Australia and I drive an Unboosted Series 2a LWB and there have been times when I have been cut-off I have wished I had Boosted 3" fronts if the Front drum has a 90deg, outer corner it is a 3" front drum from a 6cylinder, if a 45deg outer corner it is 4 cylinder LWB(they are the same as the rears)

SWB's have 10" single leading shoe brakes,(1cylinder per wheel) and LWB's have twin leading shoe brakes on the front 2 w/cylinders per wheel)


cheers

An extra inch in dia gives the brakes a larger operating circumference,with that and the twin pistons makes for a much better brake.If you can get the 3" wide drums for the front grab them,they are great.You need the matching 3" backing plates as they are different to 2 1/4"
Andrew

The above pretty much covers it - hower just make sure you fit a LWB master cylinder if you do the swap. They have a bigger bore.

Don't fit the larger MC with the 10" brakes though - all it will do is give you a heavier pedal.

I will say though - a SWB with 10" brakes (unboosted) requires a lot less pedal pressure to stoip than a LWB with 11" brakes (unboosted). When I got my IIA it had a SWB MC. The pedal was quite light, but if the adjustment wasn't 100% it went to the floor.

Seconding the posts from Andrew and Kevin.

The 11" brakes are a very worthwhile addition to the an 88. As well as increasing the area, the extra inch increases the leverage of the braking relative to the wheel. However, I feel that the major advantage is going from one leading and one trailing shoe to two leading shoes on the front. With this I would not feel that a booster was necessary for the 88. But you must make sure that if you are using 11" brakes that you use the lwb master cylinder, as you are now operating six wheel cylinders not four.

I doubt that the wider drums would be much advantage in an 88 with an original engine, unless you live in a very hilly area - remember that brake area only affects resistance to fade, not overall braking effectiveness.

John

The 11" x 2 1/4" brakes will be a good upgrade for a SWB. Remember that a brake booster does not improve braking performance, but means that you do not have to push as hard on the brake pedal.
Aaron.

G'day TeZZaP

Yes, you must use the 1 inch bore Master Cylinder in either the CV type or the CB type ( one with the big nut on the end) as the SWB 3 /4 inch master cylinder will make it dangerously under braked, I know of 3 fatals that were caused by the wrong master cylinder being fitted.

cheers

Yeah but when you buy 11" brake shoes there is more friction material so they cost more!

WHAT PRICE SAFETY