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OT: Poster & Posts Disappeared + Continued Discusion on Boxter Big Brake Conversion.

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OT: Poster & Posts Disappeared + Continued Discusion on Boxter Big Brake Conversion.

 
Old 06-04-2009, 02:16 PM
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MAGK944
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Default OT: Poster & Posts Disappeared + Continued Discusion on Boxter Big Brake Conversion.

[/COLOR]Not a paid member but "xschop" was the one trying to design an alternative big brake kit for our cars using the Boxter discs and Lexus 4-pot monoblock calipers.

I don't think he was posting anything for sale yet, just getting some input on the design and some feedback. I was posting a reply and it's been pulled, together with a bunch of his other posts - what gives?

Last edited by MAGK944; 06-05-2009 at 09:04 AM.
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Old 06-04-2009, 02:38 PM
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IB Mod Squad?
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Old 06-04-2009, 02:44 PM
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yea he was selling the adapter block. good idea. he should just pay membership and get the whole thing into production
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Old 06-04-2009, 03:23 PM
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Someone possibly saved all the information from that thread in a folder.... Including a image print of the entire thread....

http://thedge.info/index.php?d=rennl...eap_big_brakes
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Old 06-04-2009, 03:39 PM
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that someone must be a pretty nice guy

And if they deleted the OP, then what a bunch of BS ... It's not like it will be a mass production item...WTF??
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Old 06-04-2009, 03:42 PM
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Originally Posted by theedge View Post
Someone possibly saved all the information from that thread in a folder.... Including a image print of the entire thread....

http://thedge.info/index.php?d=rennl...eap_big_brakes
Good Man

I am still not convinced that this is a safe solution for the early offset cars, but they would work well on the 87+. Hope he pays his membership and opens the thread up again without trying to sell anything. Here was my last post that did not make it through:

Originally Posted by xschop View Post
"""""The early hubs are already a known weak spot """""
Where was the weak spot originally?
The early spindles are smaller in diameter both at the larger rear and smaller front bearing, the hubs are proportionally smaller. Porsche improved the design to a thicker spindle when they had to change the design for the abs option (87+). The early hubs are prone to breaking, it's a known weakness, especially on tracked cars and cars running larger wheel and brake combos.

Here's some older threads on the subject:
https://rennlist.com/forums/showthre...ferrerid=54590
https://rennlist.com/forums/showthre...ferrerid=54590
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Old 06-04-2009, 03:55 PM
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Default show of hands

I was only guaging interest. I will be making another run of them for the Hybriders soon.
For the Gestapo, I am not a business. I am a hobbyist that likes fast cars and bikes. I am a Biochemist in the real world. I just happen to have a full blown machine shop at my disposal and own 2 Hurco CNC machines. All I have to do is fire it up.
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Old 06-04-2009, 03:56 PM
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I don't think he was posting anything for sale yet, just getting some input on the design and some feedback.
+1

He wasn't selling anything yet. Just getting an estimated number for a production run since he doesn't own a business. He's doing this for us as a favor basically......

http://www.porschehybrids.com/php/vi...2193&start=315

Here's the link to his original posts about his design. Since RL seems to have a problem with it, we can deal with xschop on a different site.
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Old 06-04-2009, 04:32 PM
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Default Early hubs

Has anyone ever snapped their early spindle?
Anything will snap if put under enough severe stress.
I have thought about machining out custom hubs that fit the Porsche spindle and mount Corvette wheels. Billet T-6061 nothing but the finest.
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Old 06-04-2009, 04:37 PM
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Has anyone ever snapped their early spindle?
There's a whole other thread about that, that I started a few days ago. I just want to upgrade to the Lexus brakes, but I've been told that the early spindles won't support the added force of the LS2 engine on a track..... however, I cannot find any thread, or have heard of anyone actually breaking a spindle on an early car.

Billet T-6061
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Old 06-04-2009, 04:42 PM
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Default early spindle strength

I believe with the swap, the torsional vectors are removed from the back side of the 944 early spindle and applied to the 14mm wheel studs that have 3 X the beef in material support around the studs.
Where's that thread of snapped spindles?
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Old 06-04-2009, 04:55 PM
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I bumped my "early or late offset" thread for you.
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Old 06-04-2009, 05:18 PM
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Default early spindles

I have not heard about an early spindle snapping either. I am getting ready to Cryotreat my spindles along with the 5/8" bump-steer studs I am machining to adapt 5/8" heim joints for maximum strength.
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Old 06-05-2009, 12:07 AM
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Welcome back!

Originally Posted by xschop View Post
I have not heard about an early spindle snapping either. I am getting ready to Cryotreat my spindles along with the 5/8" bump-steer studs I am machining to adapt 5/8" heim joints for maximum strength.
It's not the spindles that break, it's the hubs. The hubs are the weakest link, but the early spindles contribute to their failure due to the shafts being smaller in diameter and therefore smaller bearings supporting the hubs. The early hubs are weaker than the late hubs, but even the late hubs have been known to fail. It's not a worry for road cars, both hubs can do the job. You were talking about LS1 conversions, big brakes and track use, now you are putting extra stresses on the hub and the early ones just won't be as safe. See the links in my last post ^^ for hub failures on track cars plus I have had personal experience with a hub failure on an early car.

Here are some pictures to explain further:

Late (L) and early (R) turbo spindles - I just happen to have lying around:



Early spindle inner bearing 32mm (Late spindle is 35mm):



Early spindle outer bearing 19mm (Late spindle is 22mm):



Late (L) and early (R) hubs - I just happen to have lying around:



Early hub outer bearing 45mm:



Late hub outer bearing 50mm:



Now we know that the early spindles are thinner and run smaller bearings.

The late brake discs fit to the wheel studs at the front of the hub, the early to the back of the hub flange (early shown below):





Now my point is we now know for certain that the early spindles/hubs are weaker than the late. Where the brake disc is located on the early hubs (back of the hub flange) puts the brake forces more towards the center of the hub. If you move the brake forces to the outer edge of the hub you will put more stress on the hub outer bearing.

Porsche engineers designed the later hub/spindle combination with bigger bearings and thicker spindles at the same time as they moved the brake discs outboard. Now I can only assume that this was required to support the extra forces from moving the brake disc, but if you disagree you have to ask yourself why they did it.

So, early hubs are weaker, they are prone to breaking, you want to move one of the largest forces acting on the hub to a place that will induce more stress on the hub outer bearing. Then you will induce even bigger forces by using larger brakes, and finally you are moving the wheel further out, which causes even more stress through leverage on that poor small outer bearing. IMO it's a recipe for disaster.

It's a great idea, I especially like having the discs outboard of the hub and the fact that they are more securly located using the wheel studs. Now, doing this on a late offset car is another matter, I can only see positives, especially the price! But for early offset, I would recommend fitting late spindles and hubs before fitting this set-up.

Originally Posted by xschop View Post
I believe with the swap, the torsional vectors are removed from the back side of the 944 early spindle and applied to the 14mm wheel studs that have 3 X the beef in material support around the studs.
Where's that thread of snapped spindles?
Yes, agreed, those larger studs would secure the disc better than the smaller bolts at the rear, but as explained above, you are directing the braking forces even closer to the smallest bearing in the weakest hub.

Good thread.

Last edited by MAGK944; 06-05-2009 at 08:50 AM.
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Old 06-05-2009, 01:24 AM
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I don't think there is any disputing the earlier hubs/spindles are weaker than the late. They are smaller..... The question I have is... How weak? Just because they are smaller doesn't mean they can't support a 2800lb car.

The advantage to bigger bearings in the later spindles is they don't get as hot. They spin slower due to the larger diameter. But with the new synthetic grease now days, I don't think a 5mm smaller bearing will get hot enough to do any harm on a few occasional track days.

(I'm just responding to xschop's post..... I haven't read Mike's post yet, so don't yell at me yet if I've said something he already did lol)

Also, if the hub is the actual weak spot, then why will no one make a billet hub?
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