Bilal928S4

The other thing to notice is also that the Porsche unit's teeth are actually above the thicker band of metal. Carl's unit, even though indicates a beefier band has the teeth actually going into that band.
Bilal

NoVector

Jim - Another way to look at it--the yellow ball is the same size in each pic.

Mike Frye

I missed the other thread, so sorry if this was brought up already.

Wow, that's great stuff.

Is that the exact profile of the ribs on the belt?

The 'shoulder' of the belt tooth may be such that it fits better in one and regardless of the shape of the tooth, that one may be the better (or worse) solution.

The design also has to take into consideration the fact that this is a flexible belt that needs to turn and pivot into and out of the cam gear valley (gap between gear teeth?) repeatedly. That action may warrant a shallower leading and trailing edge to the profile even though a tighter fit might seem to be intuitively a better design.

Speedtoys

So...I dont really get it.

If im not saving any real money here, and there's a lack of a significant breakthrough in longevity/performance, why would I not buy the Porsche gears?

Lizard928

Mike,

Having the tooth be held at the bottom of the gear is not the best idea because it will twist the tooth sideways to load it up against the edge of the tooth. This will cause premature failure IMHO.

Imo000

Where is Carl in all this?

hans14914

From just a pure theory standpoint, the hard-anodizing process should be a superior process to whatever Porsche is using at this time. 6061-T6 is also a very strong allow, with good machinability and corrosion resistant properties. Tooth profile differences aside, the materials used in Carl's gear should be better than the new Porsche part. That in no way is an endorsement, as I have no way of verifying the accuracy of the tooth pattern, keyway.... etc, but from a pure materials standpoint, it would appear to me as though that portion of the project is well selected. It is the material and treatment process I would have used for the wear portion of the gears if I was making them.

PorKen

As well, air has to have a pathway to escape at high rpm.

AFAIK, this is the reason for the tooth with two nubs instead of the full round profile. (Not for performance, but for reduced noise.)

Mike Simard

That's something few understand. A wider belt can be noticably noisier than a narrower one because of that.

Lizard928

I think I would rather take a noisier belt, over one that doesn't load the tooth properly for the load.

hacker-pschorr

To answer the initial question - Carl requested to have the thread removed. Any further questions related to that topic should be directed privately to Carl via PM, E-mail etc....

Back to the topic......Are good gears with a worn coating that hard to find? I have a few that will be hard anodized and installed on my cars.

I would think a return / exchange program to have OEM gears coated would be a good option. Or am I missing some obvious issue with doing this?

Carl Fausett

Eric is right. I asked for the thread to be closed, then about an hour later, thought the better of it and asked the moderators to get involved instead. I welcome appropriate questions and comments. Not everyone is going to agree with me, and that is understood. But there were suggestions of trickery and fish eye lenses and just such outlandish crap that it blew my mind. It demeans the whole purpose and value of a forum when this happens.

Thats all I'll say about that. Lets talk about the part.

I will restate what I said earlier because it was deleted. We purchased the latest sprocket from Porsche when it was released, version 04" and sent it off to be laser-profiled. I have had poor results working from Gates tooth profile specifications before on other pulleys I make and have learned not to trust them alone.

The laser profile gave us an absolute pattern of the brand new part to the thousandth. 0.001
You cannot take low resolution pictures from an internet site and hope to see this kind of detail.

Suffice it to say, given the claims that are possible if the cam sprocket was wrong IN ANY WAY we were exceedingly careful to make sure they are perfect. Not close. Perfect. They are.

We also recognised certain wear patterns on the used sprockets that we had and added material to help
control/prevent the flex at the crown that we beleive is happening. Then we klightened them in the webbing area to lower the load on the belt.

Of course, it is difficult to compete with Porsche prices when they make hundreds of whatever at a time, and a small manufacturer like myself produces a much smaller batch. Cost per piece increases when the production run is 20, not 200, for example.

Still, I was able to bring these to market at $365 each. A call to Porsche today told me that the retail from the dealer for this part is $413.68 each. This means a savings of $100 to the owner replacing both sprockets at the same time (like you should).

They also showed an inventory of "1" in stock, like the did on Friday when I asked. Thats doesn't include private parties that have a few on hand, of course.

I hope this information is helpful.

If you want more info about the part, please visit our link here:
http://www.928motorsports.com/parts/...t_sprocket.php

ALKada

I wonder at what point the pitting on the teeth is beyond re-anodizing? Mine are ready for replacement and would love to re-coat vs buying new ones.

Carl Fausett

Anodizing will not replace metal that is lost.

Also, be aware that there are two processes, anodizing and hard-coating. The common term is anodizing and it is broadly over-used. These sprockets are hard-coated, not anodized.

You will find anodizing in colorful red and blue aluminum key chain rings. It is easilly scratched, not very deep, and has poor wear properties. Just an FYI.

ALKada

Thanks Carl!