Tr6 Ventilated Disc Conversion Using Stock Parts ?

[GLarsen]

Calipers and pads arrived today, discs were held up a bit in domestic transportation but are confirmed on Monday. I'm mildly excited .....

[Triumph-V8]

They look pretty nice!

Good luck and keep us informed!

[GLarsen]

Rotors arrived today, I'm *very* optimistic for an easy conversion

 

Overall height is about 40 mm compared to the TR6 rotor's 38.2

 

The height from the inner edge of the braking surface to the inside mounting surface is 34 mm vs the stock rotor's 31.5, so the inner edge of the rotor will be about 2.5 mm closer to the center line of the car, which is probably good news as this can be adjusted with shims/spacers if needed. Much easier than removing material.

 

Center hole will need to be enlarged and new holes drilled of course but that's easy stuff for a machine shop

 

It'll probably be a couple of weeks before I can do a test mount on the car but I'll post back when I've done so

 

So far I've spent 255 dollars, or 170 GBP on the parts, shipping and taxes, I'll still have to get some flexible brake hoses but they're about 50 dollars/35 GBP plus shipping so that's no big deal. This could be a very cost effective way to do this even with shipping from the US

[GLarsen]

So, my brother finally found time to machine the center holes of my vented rotors last week and today was the big day, the test fit ......

 

The calipers bolt right up for those of us with "metric" calipers but you will need to trim back the dust shield a little because the 4 pot caliper is larger. As you can see the rotor sit dead center in the caliper as if they were made for this car and considering we're mixing and matching parts from two different cars and bolting them them up to a third car that's nothing short of amazing. The custom brake lines are from Ted Schumacher of TSI in the US

 

I have to give a HUGE thx to the members on the 6-pack forum for info on this conversion, I've yet to test fit a wheel but assuming I don't hit a snag there this will be a very straightforward conversion, not to mention dead cheap. The only downside is that the rotors are from a model not sold in Europe at all and the calipers are from a truck that's not very common on this side of the pond but if you can figure out the shipping the parts themselves are cheap

 

 

 

 

[Nick Jones]

That looks very good.  Pity there's no way it'll go under a 13" wheel!  Can you get the pads easily - and in decent materials (No, I don't mean EBC....)

 

Nick

[GLarsen]

That looks very good.  Pity there's no way it'll go under a 13" wheel!  Can you get the pads easily - and in decent materials (No, I don't mean EBC....)

 

Nick

 

I would assume so, these are the pads I ordered as I didn't wan to spend a ton of money on pads until I knew it all fit and that I actually needed something better considering these brakes ought to operate at much lower temperature even with my driving

 

http://www.rockauto.com/en/moreinfo.php?pk=1621922&jsn=10437

[Triumph-V8]

Looks like it have should been ex works!

Congratulations!

[GLarsen]

Final assembly delayed a little bit as I just couldn't stand the idea of driving around with silver calipers, calipers are supposed to be black ....

 

 

While those were baking the dust shields on both side were trimmed to accept larger calipers and the rotors on both sides mounted. Brake shields on both sides are rubbing a little bit in one place but until the calipers are bolted in place it's difficult to assess if any adjusting is needed as the dust shield is also bolted to the calipers.

 

Tomorrow .....

 

[GLarsen]

Today I got some more work done on this and discovered that the stock wheel was rubbing on the caliper on the driver's side and that the caliper on the passenger side wasn't dead centered on the rotor and was actually touching the rotor on the inside but strangely enough it was clearing the wheel.

 

A little bit of grinding on the outside of the calipers, I did both sides just to make sure since I understand the stub axles are kinda weak and didn't want any interference should the axles flex a little

 

 

Sorry for the bad pic, should have turned off the flash

 

Then it was a matter of using a Dremel to make sure the caliper on the passenger side cleared the rotor, sorry no pics but it was just the tiniest amount that needed to be removed and in a non critical area.

 

Calipers in place, pads in place, the only thing left to do is route the brake lines and I have an idea on how to do that using a modified stock bracket and some rubber grommets. This car still have to pass a bi-yearly inspection so I need to make 100% sure the brake lines don't rub on anything even if they're the metal spun kind. Not to mention that I'm kinda anal when it comes to brakes as I tend to use them "quite a bit"

 

 

 

[Sprint95m]

Hmmm, I feel kind of bad suggesting this, given that you already have purchased hoses with they expensive elbows, but

can you not use standard hoses, located in standard brackets, connected to the calipers via kunifer brake pipes?

 

 

 

 

 

Ian.

[GLarsen]

No need to feel bad, I'm actually thinking about having a new set made, there's a company local to me that will make you high end "hydraulic hoses" but aren't allowed to make brake hoses, with banjo fittings instead of that elbow fitting.

 

Not quite sure what the thinking behind those elbows were as this is a set TSI makes specifically for using Toyota calipers on the TR6 but to me it's not the best solution.

 

Your idea of using hard lines as the stock caliper does and then a flexible hose from the stock bracket would have been a more elegant solution as well.

 

I haven't had the time to look into a solution yet but there are others using these hoses with both these calipers and a similar set of calipers for non vented rotors so it's doable, just not a very elegant solution if you ask me. Not to mention that inspections in the US may not be as stringent for older cars as they are here. I'll figure it out somehow

[GLarsen]

Hmmm, I feel kind of bad suggesting this, given that you already have purchased hoses with they expensive elbows, but

can you not use standard hoses, located in standard brackets, connected to the calipers via kunifer brake pipes?

 

 

 

 

 

Ian.

 

.... and that's exactly what I'll have to do because that elbow is interfering with the spring at full lock, there's no way I can see to route that particular hose in a way that would satisfy an inspector, not to mention my myself. I'm guessing my calipers are cast differently than the ones used when thesey came up with these hoses because Ted Schumacher doesn't peddle junk.

 

No biggie, I have the tools to make my own hard lines and found the correct nipples today so it's a quick fix. The stock flexible hoses look almost brand new so I'll replace them with steel braided ones when I replace the rear wheel cylinders with bigger ones later as I can't occupy the lift much longer and need to get the car rolling again.

[GLarsen]

Quite pleased with the end result, thx for the suggestion. It really was the obvious thing to do, too obvious for me to see ....

 

Bit of fiddling to get it to clear the caliper bolt (it seemed like a good idea to be able to remove the caliper without having to remove the brake line first) as well as the coil spring but I'm quite pleased with the end result

 

 

 

 

[Nick Jones]

Looks factory now.  Nice work.

 

Nick

[Triumph-V8]

Agree, like it should have been ex works.

[GLarsen]

Brakes were bled last night, first test drive today.

 

Brake pedal is rock solid and I can't say I noticed any serious increase in pedal travel. I'm sure there's some increase since we're talking 4 pot calipers vs 2 pot calipers but someone driving my car for the first time would never comment on the long travel of the brake pedal.

 

Brakes pulled up nice and straight and didn't drag but I can hear one of the pads rubbing slightly, it goes away when I turn the steering wheel or lightly touch the brakes, so a quick inspection is in order but all in all I'm going to call this conversion finished and I'll recommend the conversion itself to anyone who isn't afraid to get their hands dirty.

 

What I can't comment on yet is the F/R braking distribution and whether or not it's been noticeably disturbed as I didn't have anywhere to do tests like that today. My guess is that the brake balance has been moved forward slightly but I'm hoping to reclaim that with larger wheel cylinders later in the season 

[oldtuckunder]

 

What I can't comment on yet is the F/R braking distribution and whether or not it's been noticeably disturbed as I didn't have anywhere to do tests like that today. My guess is that the brake balance has been moved forward slightly but I'm hoping to reclaim that with larger wheel cylinders later in the season 

 

Only because I'm thick and I learn more when people correct me, but don't you need smaller cylinders?  Given that the Master Cylinder excerts a given force/displacement and thus fluid movement at the the rear cylinders, doesn't increasing the area of the rear piston actually reduce the pressure on it and the force it excerts on the rear shoes, thus reducing braking effort?

 

Alan 

[Nick Jones]

So how does the piston area of the new calipers compare with the originals?  May not be that much different.......

 

Smaller master cylinder bore will give higher hydraulic pressures as the expense of longer pedal travel.  Larger slave cylinder bore will transfer higher force to the shoes and also increase pedal travel.

 

I've got a 5/8" master on my Vitesse (normally 11/16 or 3/4") to reduce pedal effort a bit.  It works and the pedal travel is fine provided the rear brakes are kept adjusted.

 

Nick

[GT6 Nick]

I think Alan was referring to the rear brake cylinders, not the master cylinder. If the rear brakes are too powerful, the back end could swing around under braking.

 

I've been pondering the same question with my car, complificated by the addition of a servo on the fronts only. No conclusions yet, I'm still enjoying the sensation of a firm pedal and (as of last week) no leaks!

[GLarsen]

In hydraulics the piston diameters are the equivalent of gear sizes basically. If you increase the size of the slave cylinder (or wheel cylinder) and keep the master cylinder the same size you will need to push the pedal further to get the same amount of movement at the slave cylinder but it will be "lower geared" and apply more force for the same mount of force on the pedal.

 

I can't think of a simpler way to explain it than gearing really, it's how my teacher explained it to the class oh so many years ago .....

 

Nick, about the piston area, I'm not sure and I will need to look into that and it's entirely possible those two smaller diameter pistons doesn't have that much more total piston area then the stock TR6 caliper, bit surprising but if so then it's an even more ideal solution as it doesn't disturb things too much

[GLarsen]

A final update on this conversion

 

Initially I wasn't too happy with this setup once I had the opportunity to give it a proper shakedown because it took a massive amount of pedal pressure to get the brakes to the point where I could lock the front wheels. Tired "bedding in" the pads, which isn't something you should have to do on stock pads in my opinion, and noticed that after several stops from 80-0 or after riding the brakes for a few second with my left foot while driving the brakes seemed to grab a bit better but then they quickly returned to not doing so after the brakes cooled off again.

 

So perhaps the pads didn't reach proper operating temps so this spring I replaced the semi metallic pads with the cheapest softest organic pads I could find and voila ....excellent brakes that don't require any more pedal pressure than the stock brakes, perhaps even less, and even though I haven't had the opportunity to *really* test them they seem rock solid and several stops in a row from 80-0 didn't faze them at all and at this point I'm quite happy to recommendd this conversion to anyone looking for an inexpensive way to improve their brakes using off the shelf parts that need very little modification to fit a TR6, and possibly other models as well but you'll def need 15" wheels

[motov8id]

I calculated the area of the 4 piston caliper pistons and the 2 piston caliper pistons and surprisingly to me they are nearly egual. So the same volume of fluid to apply the brakes in either application meaning equal pedal travel. I just installed a pair of 16pb calipers on my GT6 and was surprised how heavy they were. Did you do a weight comparison?

[GLarsen]

I calculated the area of the 4 piston caliper pistons and the 2 piston caliper pistons and surprisingly to me they are nearly egual. So the same volume of fluid to apply the brakes in either application meaning equal pedal travel. I just installed a pair of 16pb calipers on my GT6 and was surprised how heavy they were. Did you do a weight comparison?

 

Never occurred to me to do so, not sure why, but they did feel quite heavy so gut feeling says you're adding unsprung weight. Considering they're from a fairly large pickup I'm guessing weight wouldn't have been a consideration for Toyota so they probably weigh quite a bit

 

Rotors are quite heavy too but that's a more reasonable trade off as you need mass to absorb heat

[JohnD]

A further suggestion: Capri 2.8i vented discs work in 13" wheels on my Vitesse.

£100 a pair: http://www.burtonpower.com/brake-discs-f-capri-2-8-v6-escort-mk1-mk2-vented-pair-di951082.html?utm_source=google&utm_medium=prodlistad&utm_campaign=gb_feed?WbRf=ProdListAd&gclid=Cj0KEQjw5YfHBRDzjNnioYq3_swBEiQArj4pdJhNitvuhWHKBv7DxC0nFvbOsGJx4QMOcqJVvf42KPoaAntL8P8HAQ

 

John

[Gt6s]

I use Citroen Peugeot 11 1/4 inch discs on a Gt6. With these Peugeot Citroen type discs the critical thing about them is that the inside face is located the same as Triumph. You will also need to get the centre hole turned out just a shave this takes very little, one pass of the cutting tool is enough.

 

Laurence