Saab/Vectra Front Brake Upgrade

[tweetdriver63]

I've just completed the upgrade of my front brakes using Bob Brown's help. He's the man with the plan. My upgrade used Saab 9-3 calipers and Subaru Legacy rotors.

Here's the parts list and where I got them:
From Rockauto:
2000 Saab 9-3 calipers, NASTRA Part # 8305455 Loaded; Set of 2; Reman Front Loaded Pair $154.79
2003 Subaru Legacy rotors, Raybestos Part# 980141R Professional Grade; Outside Diameter 11.545" / 5 Bolt Holes $29.79 (each)

Supplied by bobbrown:
4 15mm spacers for mounting calipers to hub
2 Hub-centric rings
4 bolts for mounting calipers (must be 15mm longer than the originals)

From local parts supplier:
2 12oz Prestone synthetic Dot4 brake fluid
1 tube of anti-seize compound (for caliper bolts)

Total cost (US dollars) approximately $250.00 (+ whatever bob asks for the bits he made for me)

The job is very straight-forward. I chose to got the easy route and got a pair of loaded calipers. Obviously, anyone doing this upgrade can get them unloaded or semi-loaded (whatever that means) and get different pads to their liking. Bob sent me a word document with some brief instructions, but once I started, I could have done without it. In fact, I took my laptop with me, but never actually looked at the instructions.

Here is the (sort of) step-by-step, in pictures:
These little dust covers hide the caliper mounting bolts. I just grabbed them with pliers and worked them off. (they won't be needed with the new calipers)

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Remove the two caliper mounting bolts with a 10mm allen wrench/socket.

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I swung the calipers up out of the way and rested them on that bar/control arm/whatever it is (see pic).

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The hubs needed some sanding to get rid of most of the rust, specially on the center part so that the little rings would go on. I used 150 grit paper. Once I had sanded enough to get the rings part way on, I used the new rotor to push them all the way back. Then I put a couple of the lugs into the rotor to hold it in place, although not tightened.

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I had loaded calipers, so I mounted them all at once that way. Put some of the anti-seize commpound on the ends of the mounting bolt threads, then put them through the mounting holes on the caliper, the 15mm spacer, and mount those puppies. Torque the bolts to 70 ft/lb.

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After everything was mounted and fit properly, I moved the brake hoses from the old calipers to the new ones. 11mm or 7/16" sockets both will work. Somehow I managed to forget to take a picture of the completed job before the wheels were back on. Sorry. Here's what you can see through the Fed 16" alloy:

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[tweetdriver63]

After bleeding the system, I did a bed-in of the pads. About 10 times slowing from 60 mph to about 10-15 mph. That made the brake tell-tale light come on. (that's probably because the piston in the new caliper is bigger than the original, and I hadn't added any extra fluid yet) I then took it to the local Midas shop and had them flush the old fluid and refill with the new stuff.

When they were done, I had a car that will, no s**t, stop when I push on the brake pedal! The pedal doesn't feel much different, but when you get it depressed just past where it's about even with the accelerator pedal, the car REALLY, REALLY wants to stop! It is a very noticable difference. I haven't ever driven one with the Wilwoods or other upgrade, but this is a huge improvement over stock, for a pretty small investment. I no longer feel like I may find myself going off into the grass because I can't stop in time to avoid the guy ahead of me (that's happened 4 times since I've had this car).

Thank you bobbrown!

[HJ2]

wow, this is great info & pics!
Welcome to the fast stopping club

I am looking foreward to read some real live experiences with this setup!

[Denny]

Nice work

Would these fit / or is their an alternative for the 15" wheels?

[Monty]

Nice work chris

Bob to the rescue again

[tweetdriver63]

Nice work

Would these fit / or is their an alternative for the 15" wheels?

No, I don't think they'll fit inside the 15" wheels. As you can see in the last picture, there isn't that much clearance between the caliper and the inside of the rim.

[steve matthews]

Chris, nice piece of work. They fill the wheel cavity and stop the car
Steve

[Doug]

what was the reason to use Saab 9-3 calipers? I drive a Saab 9-3 and wouldn't say the brakes are that great.

[tweetdriver63]

what was the reason to use Saab 9-3 calipers? I drive a Saab 9-3 and wouldn't say the brakes are that great.

They are a similar GM caliper with a bracket that allows them to be mounted directly to the Elan's hub. If you wanted to use the Elan's stock calipers with larger discs, you would have to make a bracket adapter to move the caliper farther out from the hub. The Saab's have that built in. Remember, if you move the clamping force farther from the pivot point, you increase the stopping force (longer moment arm). That's why everybody wants to upgrade to bigger discs. They have a slightly larger pad surface area too. Beyond that, a side-by-side visual comparison reveals a larger piston. I don't know the detailed specs, but my educated guess is that translates into more clamping force.

All that said, the answer to your direct question is that they accomodate a much larger disc diameter while mounting directly to the stock hub. The 15mm spacers move the caliper inboard because the taller hat on the Subaru discs moves their surface 15mm inboard compared to the stock discs. If somebody could find a disc with all of the stock disc's dimensions except a diameter of about 295mm, it would be even easier to upgrade.

If I am wrong about any of this, Bob or somebody else, please chime in. Remember, I'm the student, not the teacher.

[bobbrown]

The disc has to be moved inboard to get the caliper inside the wheel if you try to mount the caliper in the same relative position as the original it will hit the spokes as they curve in as you come out towards the tyre.
The original conversion was done with an ATE caliper that Vauxhall used on the Vectra but it also is used on some Saab's as they use the same floor pan/ running gear.
If I could find a disc with a overall height around 57mm and a diameter around 266 or one with a diameter of around 288 and a disc thickness of 25 to 24 mm with a mounting that will either fit or is close enough to modify then a similar caliper could be used with 15" rims but as yet not luck sourcing one.
I may be possible to do it with a two part disc but the costs would increase as the discs and bells would probably be cost prohibitive but it may be possible to use the original Vectra disc and machine the center out of it and then fit it with a bell/hat.
The trick with this as a conversion is it's low cost and does improve the brakes although others have argued in favour of the originals personally I see as no contest with any of the upgrades be they Wilwood, AP Racing, Hi Spec or these.

[Dave Eds]

what was the reason to use Saab 9-3 calipers? I drive a Saab 9-3 and wouldn't say the brakes are that great.

Saab is heavier? Your brakes on a lighter car so it's stops better?

And all the technical stuff of the previous two posts of course if (like me ) you know WTF they're banging on about!

[tweetdriver63]

Thanks Bob for that explanation of moving the disc and caliper inboard. I knew I would get something wrong.

I don't have experience with any of the bigger, more expensive upgrades, but I'd say ....

Stock brakes in average condition for 20 year old car = Oh My God! I'm going to die!
Stock brakes in new/refurb condition = adequate for normal driving, but don't follow too close.
Stock brakes in new/refurb condition w/upgraded pads = a little better.
This upgrade = Definitely wants to stop.
Wilwoods/AP/Hi-spec = Have the seat belt buckled or you may go through the windscreen.

Does that sound about right?

[bobbrown]

Ask ShaunM about his test drive of RIp's car with the same brake upgrade as you have just fitted, I believe he was trying to do the windscreen option as he treated the brakes as he did in his own car on the standard setup.

Bob

[Dave Eds]

and after Shaun did i had a go too Bob! Tested his Toyos as well!

[racerstev]

Does the pedal seem to move farther now with the larger piston in the caliper?? My pedal already moves more then I would like..

Steve Lockett

[Dave Eds]

not that I noticed - just felt a whole lot better!

[tweetdriver63]

I don't notice any more travel. Just in that last 25% or so I think it gets more firm than it used to, and the car really stops

[racerstev]

This sounds like a great way to go then, time to start looking for parts!

Seems ever since I raised the boost the brakes went to hell!

[nitroman]

Dear Bob,

I've got a used cotter pin from one of the rear drums of a 1923 Templar roadster. I'm sure that I'm only slowing you down by mentioning that 1923 is the first year Templar started putting brakes on all four wheels, as by now I'll bet you've already come up with a great series of linkages for the Elan to modulate these mechanically-actuated, pre-hydraulic-era drum brakes.

When the conversion/installation package is ready mail it to me and I'll reciprocate with payment in kind, plus a little extra. Sorry to bore you with so trivial a task.

Cheers, Matt

[nitroman]

:agree:

I don't notice any more travel. Just in that last 25% or so I think it gets more firm than it used to, and the car really stops

Chris, (at least) three factors would account for the firmer feeling:
(1) The larger disc... When you extend the length of your lever (pad contacting disc farther away) from the fulcrum (center of disc) you more than proportionally gain a mechanical advantage called leverage.
(2) Larger piston in your caliper means your piston moves more slowly for a given amount of fluid. It is only the piston moving forward against the pads which causes the car to stop. Now you must move the brake-pedal/master-cylinder farther to accomplish this, thus you are spreading the same amount of force (moving piston towards pad) as before over a longer master-cylinder stroke, which results in a lighter pedal feel, which begats greater pedal feedback/sensitivity. This reduces the former mushy/"dead" pedal feeling, instead returning a sensation of responsive, fine, direct control.
(3) Larger pads placed roughly .65" farther-out on the disc lead to a greater swept area. This spreads the force being applied by your foot (let's assume that's the same overall force as before... otherwise we'll only begin another entire conversation!) over a greater area, which leads to increased pedal feedback, ie, everything mentioned at the very end of item #2.