Has anybody looked into replacing GT calipers or sedan brakes to use 4 pot calipers from a Toyota. (Brett, do you have these on your racecar?)

eg eBay has new:

"2 Front Disc Brake Caliper Assembly suits Toyota Landcruiser 90~98 70 75 Series" (These suit a 20mm thick disk.)

I'm wondering just how big they actually are etc? I don't need to upgrade my brakes yet but eventually we may have an issue with disk rotors under size, for a RWC.

I know a member has a kit to fit disks to sedans which has been engineer approved, but the donor cars the parts come off, are getting rarer in wrecker yards. viewtopic.php?f=35&t=3038&start=0

Yes my race car has 4 spot front calipers.
Yes they're Toyota ones but not those. Toyota has used a heap of different ones over the years so being year and model specific with them is vital.
Mine are not on Bellett rotors. Or even GT hubs. They're a combination of parts I put together.
There was a ton of work to make it all fit together too.... not the least was custom made bracketry.
And they need at least 14" wheels.
And a massive booster. Anyone who thinks they can make a Bellett stop with 4 spot calipers without a booster has no idea what they're talking about at all. They do not work.
The ones you mentioned are way too big for a Bellett. We put a similar set as those mentioned on an XE Falcon I race as well. Again, alot of work but at least we kept the standard rotors on it so that saved a heap of hassles.
You need 15" wheels as a minimum because you need a bigger rotor than I use to get the correct swept area inside the caliper so the pads work properly.
You have to be very careful with how wide across the rotor they are as well because some wheels still won't fit as they hit the caliper at the back of the wheel spokes. We had to modify the 15" wheels I use and the calipers I use on the Bellett to make it all clear.... And I use the smaller Toyota ones. The ones mentioned are massive.
Drum brakes at the rear of a Bellett are useless with 4 spot calipers too. In fact, anything decent size caliper you put on them to be honest. The bias is miles out of whack and they will lock fronts dangerously. I know because I tried mine... it was deadly. You need decent sized rear discs and calipers as well and then a bias valve plumbed into the years so you can get the balance correct again.

The kit you mentioned is far from getting rare for donor parts. They're everywhere. I saw 2 in a wreckers only last month.... And that was just 1 wrecker.
The best part about that conversion is it all bolts together, fits inside standard 13" wheels, doesn't need disc brake rear and parts are on the shelf at any Burson or Repco.
Bellett people aren't using them tho as much as was thought they would tho because a few hundred dollars for a bolt on disc brake conversion is nothing these days, especially when you look at some that are available for more common cars that cost thousands, but Bellett people seem to want everything for nothing so they still drive around on drum brakes that were notoriously inadequate when new and every other car on the road was drum braked as well, so they're death traps in 2020 when compared to the cars of today that they share the road with in my opinion.

Thanks for detailed reply Brett. Just doodling around on ebay: I just happened to see those calipers on ebay and its hard to gauge size from the pictures. I did think they would be large though coming off a landcruiser.

I have 14" Watanabe wheels so that's a help. I also have two brand new TP Magna vented Disks here. They are 266mm diameter and 24mm thick. (and very heavy, certainly not ideal) Somebody in Sydney I think (blue GT) adapted these to his car, although don't know his wheel size.. Peter Mc was looking at this conversion years back too. At one stage i had the matching calipers too but got lost in the shift to new place. But at the time I couldn't see how they (calipers) could fit as it was very tight. And Peters caliper picture did not match the ones i had either. Other than that I turned the centres out on my lath to fit the hubs. Just a mm or so is needed.

The 24mm thick is a problem, bearing in mind the calipers I had at the time won't fit and 24mm calipers seem not too common, judging by my perusals of the DBA catalogue. But S40/V40 Volvo calipers would fit the disk, thickness wise. No idea how big they are or even what they are (maybe 4 spot too on a Volvo?), though to fit the wheels.

All this is just window shopping really, my current GT brakes on the Sport are working fine. I have a VH44 booster which needs reco to fit maybe some time. But "looking ahead" for maybe sometime when the disks or calipers no longer function. ie need fairly expensive reco'. BGT charges $250 per GT caliper for example and that was some time ago. BGT appear to have moved to Keysborough, by the way. Same people.

The reason for not looking at the conversion you mention is because of the GT hubs I have. I would need disks which fit over the studs. And apart from the Magna ones, have not got all down and dirty in a wreckers yard to see what might fit etc!!!

Every now and then I check u-pullit for the 13" conversion caliper and rotor and there at least, becoming harder, OK, not impossible, to find them. In any case DBA and ebay do new rotors.

Other than a GT (or Sport), the 13" conversion is very good. Yes, people pull back with costs. I don't know why it is actually, but considering it's all engineered and works well, must be good value.

I wonder what Mark in the UK uses on his race Bellett. I know he uses Mini-Metro 4 spot calipers though. Still solid disks? Probably.
glenn

Yes Glen we've had decent results using the Mazda discs discussed here...

viewtopic.php?f=40&t=2176

We were regularly cooking them, until we changed from Ferodo to Hawk pads and since then we've not looked back.
If I remember correctly the Metro calipers bolted straight onto the GT stubs.

Cheers Mark

Thanks Mark

It appears that those disks you used are Mazda 626, GC FWD series. 2/83 to 2/84 in Australia at least, from the DBA catalogue. Known as DB119.

They are 14mm thick, compared to original GT at 10mm. Not compared anything else as I would have to get under the car.

How common and cheap are those Metro calipers in UK? I doubt they were ever available here. Interesting that they bolt on to GT.

Long long ago, apparently the Toyota Corona disk was a possible fit to Bellett GT with some work i guess.. Again from DB cat: DB139 part. 10mm thick (9 min) and 228mm diameter. Total height 17.9mm which seems a bit on the short side!

glenn

Glenn, with the conversion I spoke about and fitting onto a GT, all you do is remove the GT hub and caliper bracket and use sedan drum brake hub and the bracket supplied. Then it's all bolt on as normal.
There's definitely enough drum hubs around to look after any GT in the future too. I know I've got multiple myself.

The Magna conversion I looked at on the car you mentioned and honestly it was terrible quality. The bracket was not right as the caliper was not located over the rotor properly and it only used 2 of the mounting holes in the upright, not all 4 around the stub axle.
They machining you mentioned on the rotor was just the start of it. They need alpt more stuffing around than was ever revealed.
I never drove that car so I can't comment on front to rear bias but as the fronts came from a car with 4 wheel disc and were fitted to a standard drum rear Bellett, if be surprised if they worked correctly to be honest.
And as said, 14" wheels minimum. I can't see Bellett owners, especially those with nice cars and even more so nice GTs willingly changing to aftermarket wheels for those brakes too.
As stated much earlier, $500 gets a engineer certified kit that bolts on in an afternoon using over the counter parts that can be hidden behind original Bellett wheels, and they work brilliantly. Cheaper than rebuilding drums when they inevitably fail (because they all do) and makes them far nicer to drive.

Hi Brett
Yes I had my fair share of Bellett drums on two cars, both converted to popular at the time, conversion.

Afraid I only have the TP disks. I did have the calipers but they got lost during the move. Even when I had them, i could see major problems actually fitting them. Not to mention they are dam heavy.

Thinking about this in last week or so and to use the GT hub would require a rotor that has the inside bearing to suit a Bellett. That could be a very long search !

I have virtually no parts these days, definately no sedan hubs. The other thing I am uncertain about is; are the late model front ends suitable for the conversion also? Right now I am just mulling this over. The brakes are working OK as is. I measured the rotor yesterday actually and its 8.4mm thick, so plenty left on it. I think min on GT disks is 7mm.

I do have a power booster but it needs re-coing. The other variation to the engineer approved conversion is my Sport has a dual master cylinder.

glenn

Brett
Whats included in the $500 kit.