Brake Upgrade - KE20 with Twin Piston Caliper - Research Stage

[twentyEight]

Background

My girlfriend has a ’73 KE20 and would like to put in either a 5K or possibly a 20V in a year or two, and will most likely need better brakes for the Engineer’s Cert…

But she would like the 12” (possibly 13") steel wheels and hub caps to remain…


Purpose

I would like to find a disc, preferably vented, that fits similarly to the original KE20 disc, and a suitable twin piston calliper to match, whilst still allowing the 12” (possibly 13") wheels to fit over the top…


Current Research Findings

Original KE20 disc specifications:

200mm x 10mm with a total height of 36mm, a 64mm centre hole, and a 4 x 110 PCD (Solid)

RX-7 Series 1/2 disc specifications:

228mm x 18mm with a total height of 59mm, a one-piece hub, and a 4 x 110 PCD (Vented)

AE90/92/93 (DOHC) disc specifications:

238mm x 18mm with a total height of 48mm, a 54mm centre hole, and a 4 x 100 PCD (Vented)

AE101 disc specifications:

238mm x 22mm with a total height of 48mm, a 55mm centre hole, and a 4 x 100 PCD (Vented)

NCP10/12 disc specifications:

235mm x 18mm with a total height of 43mm, a 55mm centre hole, and a 4 x 100 PCD (Vented)

Conclusion

So far I believe the RX-7 Series 1/2 disc with an alloy twin piston caliper like the R32 GTR/GTS-T Rear Caliper (suits 18mm disc) would possibly make a suitable combo, and would provide excellent braking characteristics…

Another option is the NCP10/12 (Echo) disc with an alloy twin piston caliper like the R32 GTR/GTS-T Rear Caliper…

Both discs could be machined down ~5mm, and this would give more chance of the 12” wheels fitting, and 13" wheels should (may) fit without the machining…

Will further the research over the weekend…

[oldcorollas]

well.. the 218mm discs witht he sliding calipers don't fit under 12".

better brakes means bigger disc. even if vented, the brakes will still be as hard to push, and not slow the car any faster.. but you will have more fase resistance.

early Galants had opposed twin pots, but still the disc size is the issue.

why can't she go to 13" (and then KE30 brakes) and still have hubcaps?

[Megz]

Could you look at something from a Charade? That would have similiar characteristics to the Echo/Yaris. Just an idea,
Mic

[Joshstix]

Isn't the KE20 4x110?

[twentyEight]

Isn't the KE20 4x110?

I have a feeling you're right, which has just ruined half an hour's research... Meh, I was bored at work anyway...

[Megz]

Yeah early rolla's ke1X-ke2X are 4x110
Mic

[oldcorollas]

but KE30 hubs go onto KE10 and KE20 stub axles with a change of bearings .. so 4x114.3 is still in the game

rear is just modified axles etc away

[twentyEight]

Back to the drawing board... I shall continue to find a suitable upgrade, and will look into going the 13" wheels with hub caps... (These would be 4 x 114.3???)

I was after I read the specs from http://www.thansen.dk/wm_car.asp?c=1...2&wn=360272154 and remembered the late rollas are 4 x 100 also, but the KE20 specs must be wrong on that site...

[Megz]

Yeah it would be 4 X 114.3. My old 25 use to run mazda rx7 stockies 13" as they have the 4x110 pattern.
Mic

[twentyEight]

My old 25 use to run mazda rx7 stockies 13" as they have the 4x110 pattern.

That's very handy info... (Damn, now I have that "This is Handy" ad in my head... )

[Megz]

Wonder what the brakes are like from early mazda's? Maybe look at that as well for ideas.
Mic

[twentyEight]

Look's pretty good...

RX-7 Series 1/2 disc specifications:

228mm x 18mm with a total height of 59mm, a one-piece hub, and a 4 x 110 PCD (Vented)

[YLD-16L]

but KE30 hubs go onto KE10 and KE20 stub axles with a change of bearings ..

......and a different inner dust seal as the KE20 is tool small OD for the later model hub. I did the swap a month or two ago.

[Megz]

Look's pretty good...

RX-7 Series 1/2 disc specifications:

228mm x 18mm with a total height of 59mm and a ??mm centre hole and a 4 x 110 PCD (Vented)

Should add that info to the first post as it keeps all the comparisons together,
Mic

[twentyEight]

Few steps ahead of you... Actually, we seem to be thinking the same at the same time...

Conclusion has also been edited...

[twentyEight]

In the DBA catalog, what does it mean when it lists the Centre Hole Diameter as HUB or HUB TYPE?

[Megz]

Haha, great minds think alike! On that note. i have rotors and calipers here which i got with my ke25. The stud pattern is 4x110 they are also vent.The calipers are only a big single piston tho. I will take a pic and show you. If i remember correctly i don't think they fit on the 20/25 struts? Will take a pic.
Cheers
MIc

[YLD-16L]

Are you going to bolt the disc to the back of the hub as per Corolla OEM or are you going disc over hub?

Once you start looking at those tall hat heights youll very quickly start fouling on the strut and caliper mounting face.

[Hen]

Hub type means the disc and hub are all one casting (ridiculous I know). So to replace your discs on a first gen RX7 you need to replace the whole hub too.

Also note that the PCD on the rear of the hub to which the disc bolts on a KE20 (if that is how they are setup) is a different PCD to the wheel studs on the front. But in any case, redrilling a 4 stud disc to suit the 4 holes on the back of the hub is an easy task. The hat height is more important than the PCD.

Hen

[twentyEight]

With the RX-7 disc (59mm height) I'd most likely look at mounting it ove the hub, rather than on the back of the hub...

You're correct in the fact it would foul the strut...