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Rotor Choices??? 4-lug ONLY.

 
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MugenRep  



Joined: 16 Nov 2017
Posts: 25
Location: Watkins Glen, NY

PostPosted: Thu Feb 08, 2018 9:18 am    Post subject: Rotor Choices??? 4-lug ONLY. Reply with quote

I know our chassis is getting older and I also know more than a few have converted to 5x130 944 brakes, however for those of us by choice or not who are stuck with the AGED 4x108 brakes, does anybody know of the rotor choices out there and part numbers associated with them?

I know Zimmerman is a high end, German made company that at one time offered both cross drilled and slotted SOLID 4x108 rotors, but I'm having trouble tracking them down in stock anywhere and I'd prefer the slotted design to keep pad surfaces fresh and clean (I don't care if pad wear increases).

I'm also aware of Brembo, Sebro, and ATE, but of those, I'm only away of Sebro offering drilled or slotted rotors.


Any help would be MUCH MUCH appreciated!
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MugenRep  



Joined: 16 Nov 2017
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Location: Watkins Glen, NY

PostPosted: Thu Feb 08, 2018 10:53 am    Post subject: Reply with quote

So far what I've found....

Sebro

Front, Rotor = Part# 105185
Rear, Drum = Part# 305180


Zimmerman-Otto

Front, Rotor = Part# 460.1011.20 (Weight of 12.88lbs if anybody cares)
Rear, Drum = Part# DISCONTINUED


Brembo

Front, Rotor = Part# 08.3963.10, (alt# AP 14141 & Breco BS 7219)
Rear, Drum = Part# 14.4724.10


ATE

Front, Rotor = Part# 24.0113-0170.1
Rear, Drum = Part# 24.0223-0004.1


The rotors listed above are all SOLID and BLANKs.
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Last edited by MugenRep on Sat Feb 10, 2018 7:33 am; edited 1 time in total
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CÚdric  



Joined: 27 Aug 2004
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Location: Sweden

PostPosted: Thu Feb 08, 2018 7:15 pm    Post subject: Reply with quote

How will you use the car? Is it for the bling factor? There are many machine shops who can slot rotors.

The 4lugs work very well, both for endurance racing and street driving. Ive done both. I just got annoyed by the constant need of adjustment at the back. And that i never could get a really nice pedal feel with the drums. Otherwise its a perfect setup for the weight and power of the na at least.
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MugenRep  



Joined: 16 Nov 2017
Posts: 25
Location: Watkins Glen, NY

PostPosted: Fri Feb 09, 2018 3:19 am    Post subject: Reply with quote

CÚdric wrote:
How will you use the car? Is it for the bling factor? There are many machine shops who can slot rotors.

The 4lugs work very well, both for endurance racing and street driving. Ive done both. I just got annoyed by the constant need of adjustment at the back. And that i never could get a really nice pedal feel with the drums. Otherwise its a perfect setup for the weight and power of the na at least.


First, thank you very much for your response and guidance.

Mostly "spirited" driving, but occasional AutoX or WGI. I'm definitely staying NA with the Webers and possibly a streetable cam.

I actually found something for this solid rotor I prefer over the slotted design (although it's nice to know they're an option). I managed to source already done Cryo-Treated solids which are even better option for long term reliability.
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CÚdric  



Joined: 27 Aug 2004
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PostPosted: Fri Feb 09, 2018 6:34 am    Post subject: Reply with quote

MugenRep wrote:
CÚdric wrote:
How will you use the car? Is it for the bling factor? There are many machine shops who can slot rotors.

The 4lugs work very well, both for endurance racing and street driving. Ive done both. I just got annoyed by the constant need of adjustment at the back. And that i never could get a really nice pedal feel with the drums. Otherwise its a perfect setup for the weight and power of the na at least.


First, thank you very much for your response and guidance.

Mostly "spirited" driving, but occasional AutoX or WGI. I'm definitely staying NA with the Webers and possibly a streetable cam.

I actually found something for this solid rotor I prefer over the slotted design (although it's nice to know they're an option). I managed to source already done Cryo-Treated solids which are even better option for long term reliability.



I wouldnt care so much, rotor life will probably be awesome anyway. I ran 3.5 seasons of track days and auto X, still had a lot of meat on those rotors, although a bit scored by the more aggressive brake bads. I gave that car to my father in 2008 and it still have those rotors.

I had a 79 na (dogleg), only mod were racing tyres, aggressive camber and brake pads. It could do infinit amount of laps without overheating brakes or tyres, it was a great fun track day car!

My recommendation.

std rotors, new
Hawk HP plus, great pads, never faded, reasonable cost, just a couple of brakings to get enough heat in them for great performance.
Rebuilt cailpers (essential for good braking performance, a must do, use only ATE rebuild kit, i fried no name rubber in one track day)
Racing brake fluid, RBF600 motul for example.
Stock rear liners, adjust when hot so you are sure they do not rub (tried racing liners but it didnt make any difference)
New brake lines

If I still had that car i would add brake cooling hoses just to get the temperature down to get better life out of rubber seals, and even longer pad life (still lasted a long time)

The setup above have worked for me and other friends who also tried it. But there are of course many other pads that works great.
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Raceboy  



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PostPosted: Fri Feb 09, 2018 7:58 am    Post subject: Reply with quote

Or you could convert rears to 4lug disc setup using Peugeot 405 rear discs and calipers.
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MikeJinCO  



Joined: 08 Jun 2010
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PostPosted: Fri Feb 09, 2018 11:35 am    Post subject: Reply with quote

Porterfield has both high performance and racing grade rear shoes. I got the high performance ones as I thought they might be at least a little better quality than a typical aftermarket lining. Don't remember the cost, but figured I'd probably only do it once. Had them at HPDE school and had no problems.
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MugenRep  



Joined: 16 Nov 2017
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Location: Watkins Glen, NY

PostPosted: Fri Feb 09, 2018 11:52 pm    Post subject: Reply with quote

Raceboy wrote:
Or you could convert rears to 4lug disc setup using Peugeot 405 rear discs and calipers.


I've been trying to track down on how to do this. Do you have a write up or DIY? Pics of when it had previously been done? Thank you!
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oharris  



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PostPosted: Sat Feb 10, 2018 1:03 am    Post subject: Reply with quote

Raceboy wrote:
Or you could convert rears to 4lug disc setup using Peugeot 405 rear discs and calipers.


Tell me more about this conversion. Is there a writeup somewhere?
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CÚdric  



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PostPosted: Sat Feb 10, 2018 4:46 am    Post subject: Reply with quote

There is a similar conversion kit for vw beetles aswell, but I think you need to buy it with blank rotors and get them drilled to 4/108.

But if you don't get the brake balance spot on you will have worse stopping distance than the drum setup.
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MugenRep  



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PostPosted: Wed Mar 21, 2018 3:24 am    Post subject: Reply with quote

Euro924S2 wrote:
Hi guys. I did this many years ago and was very happy with them.

You need 405 rear rotors and 405 rear calipers. The 924 handbrake cables work without modification (think I re-routed them under the torsion beam instead of above or something). The bracket to mount the calipers needs to be made. I used a piece of 5 or 6mm thick steel sheet and cut it to size and drilled the relevant holes. You remove the drum, remove the 4 bolts that hold bearing cap in place, remove the drum backplate and use that as a template for the caliper bracket. The bracket replaces the back plate. You then need to attack the drum with an angle grinder to reduce its size before putting it in the lathe and turning it down so the 405 disc will fit over it. I.e. You convert the drum into a hub to mount the disc. Then you just need to make a couple of hard brake lines to go to the calipers and you're done. Sounds more complicated than it is!

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Euro924S2  



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PostPosted: Wed Mar 21, 2018 5:30 am    Post subject: Reply with quote

A valid concern regarding the brake balance but I found it was fine/great. I looked into it at the time and found the Peugeot setup was similar with similar sized master cylinder and comparable weight over the rear given the weight distribution of both vehicles.

In fast road use I found them great and much better resistance to fade when using road pads. I didn't want the 'warm up breaking' needed with track pads as after a long motorway cruise they may well be below 'useful' temp and see me in a motorway pile up!! Spirited driving was infrequent given UK roads but I found they worked great.

With the drums I found they worked excellently (would lock on the handbrake on tarmac) until they got hot. Then they couldn't lose their heat and the fronts would be left doing all the work and subsequently cook them too! It's often quoted that stock brakes are fine on track cars so no need to change but I'm not sure that's a comparable use. The track sees better drivers with better tyres who brake hard and fast for short periods. On UK country roads with unknown hidden dangers around every curve there is more trail braking into every bend and potentially much lower speeds to cool them off afterwards. The biggest factor is probably that non-racers (like me!) brake too much and too often and push the brakes past their limit on road pads occasionally - worth noting I think I only saw significant brake fade on a couple of occasions on the road so it's not a common / frequent problem.


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MikesCoupeGT  



Joined: 18 Oct 2006
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PostPosted: Wed Mar 21, 2018 5:40 am    Post subject: Reply with quote

I will throw my two cents of agreement in on this.

My 924 has done multiple track days at WGI and the 21 turn track here in Ottawa. I never ran out of brakes and I am running stock setup. In fact I ran out of pad before brakes, and was able to get a used set of 944 rear pads from a person at the track and finish off the weekend. I still have those used pads as a set of spares.

I have often looked for a way to upgrade in the rear without loosing the 4 lug setup, but at this point it just isn't worth it for me.

Get the best pad you can, keep the stock rotors and go out and have a good time. See you at WGI for the May Long Weekend.

Mike Kirby
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MugenRep  



Joined: 16 Nov 2017
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Location: Watkins Glen, NY

PostPosted: Wed Mar 21, 2018 11:01 pm    Post subject: Reply with quote

Euro924S2 wrote:
A valid concern regarding the brake balance but I found it was fine/great. I looked into it at the time and found the Peugeot setup was similar with similar sized master cylinder and comparable weight over the rear given the weight distribution of both vehicles.

In fast road use I found them great and much better resistance to fade when using road pads. I didn't want the 'warm up breaking' needed with track pads as after a long motorway cruise they may well be below 'useful' temp and see me in a motorway pile up!! Spirited driving was infrequent given UK roads but I found they worked great.

With the drums I found they worked excellently (would lock on the handbrake on tarmac) until they got hot. Then they couldn't lose their heat and the fronts would be left doing all the work and subsequently cook them too! It's often quoted that stock brakes are fine on track cars so no need to change but I'm not sure that's a comparable use. The track sees better drivers with better tyres who brake hard and fast for short periods. On UK country roads with unknown hidden dangers around every curve there is more trail braking into every bend and potentially much lower speeds to cool them off afterwards. The biggest factor is probably that non-racers (like me!) brake too much and too often and push the brakes past their limit on road pads occasionally - worth noting I think I only saw significant brake fade on a couple of occasions on the road so it's not a common / frequent problem.



Did you ever take any pictures of the brake setup?
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