New Product: 928 clutch short shafts
12-11-2013, 09:21 PM
#76
300M is harder rockwell, right? So it will not be grooved in the wear areas as easily?
12-11-2013, 11:13 PM
#77
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No, if you truely understand the forces, this is NOT true at all. Ill give you a hint. can you break the tires free by dumping the clutch shifting into 3rd on race rubber in a car with 300-400rwhp?? another hint: no you cant.
other much greater forces are at work here. thats my point about the short shaft and driveline forces . Very relevant to the discussion here on this part.
other much greater forces are at work here. thats my point about the short shaft and driveline forces . Very relevant to the discussion here on this part.
It depends on the time you need to do this. 
I think you might know this, but at the higher gears, the reverse forces are even greater than if you are in first. (it works opposite to what you Plus we are talking about instantaneous forces, which can be tremendous. (with out getting the crayons out)
I think you might know this, but at the higher gears, the reverse forces are even greater than if you are in first. (it works opposite to what you Plus we are talking about instantaneous forces, which can be tremendous. (with out getting the crayons out)
If the factory part is 4130 then all of the factors are included which are hardness, toughness, lubrication and surface finish factor in.I can tell you that the surface finish on those cut splines are not very good. If they are indeed heat treated harder than the factory, then your clutch splines will wear out faster.
12-11-2013, 11:58 PM
#78
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If it makes a difference, I'm actually "cool" (unlike CSC) with people getting off on tangents and talking about other topics, on my threads. I think that Rennlist should be an open Forum where people can exchange ideas, with each other. And, realistically, after about the first page, the product introduction stuff (if the product is worth a crap) should be all over....
However, nobody is stopping any conversations here. Just a suggestion to start new threads for side subjects so the original goal of this (or any other) thread isn't lost.
I've seen way too many excellent threads nose dive into oblivion thanks to a few people who have to be king dig-a-ling every time they start posting.
I cannot attend the two excellent Chicago Region PCA DE events at Road America with a Chevy motor in m 79.
12-12-2013, 06:04 AM
#80
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I think the biggest point of this story,is that Greg has produced a replacement part that if it is still available from Porsche it is unrealistically expensive, will eventually be NLA in the future and reasonably priced in comparison to a good used one if you can find it. Seems like a huge win with a side benefit of handling large amounts of power if you so decide to need it. Thanks Greg!
12-12-2013, 06:18 AM
#81
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Having been down this road myself I will offer the following.
Parts for the 928 are simply going away and those that Porsche will make in the future will come with a Porsche price tag. They also have a two (2) year warranty in most cases and that's it.
So all this talk about how long these new shafts will last doesn't really matter. I'm sure Greg will provide a certain warranty with them and it will then be up to the buyer on what they want to buy.
If you think you can do better, then put your money, and time, where your mouth is and do it.
And I do wish we could keep on point in these threads.
Parts for the 928 are simply going away and those that Porsche will make in the future will come with a Porsche price tag. They also have a two (2) year warranty in most cases and that's it.
So all this talk about how long these new shafts will last doesn't really matter. I'm sure Greg will provide a certain warranty with them and it will then be up to the buyer on what they want to buy.
If you think you can do better, then put your money, and time, where your mouth is and do it.
And I do wish we could keep on point in these threads.
12-12-2013, 08:01 AM
#82
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Why the big hard on for this shaft? You've been drop kicking it, since your very first post.
It's made out of a better material, machined to very close tolerances, heat treated to the proper requirements
And exactly where did I say that it was harder than the factory shaft?
Actually, the factory shaft is 46.5C to 48C, depending on where you measure it and what shaft you measure. This shaft is slightly less that that. I have my own Rockwell tester, right in my own shop!
It's a very nice fricking part....very well researched, very well thought out.....like everything I make.
What the hell do you want me to do?
Build 20 shafts with rolled splines for $2,000 each?
Yeah, those are going sell to the 928 crowd....they are lining up outside my door, right now!
If you think that people would do better to pay almost 2X as much, for a factory part....just say so....everyone is entitled to an opinion. If you think people would be better off just using a shaft like one of those I pictured....just say so.....I've got a whole box of those worn out shafts.
It's made out of a better material, machined to very close tolerances, heat treated to the proper requirements
And exactly where did I say that it was harder than the factory shaft?
Actually, the factory shaft is 46.5C to 48C, depending on where you measure it and what shaft you measure. This shaft is slightly less that that. I have my own Rockwell tester, right in my own shop!
It's a very nice fricking part....very well researched, very well thought out.....like everything I make.
What the hell do you want me to do?
Build 20 shafts with rolled splines for $2,000 each?
Yeah, those are going sell to the 928 crowd....they are lining up outside my door, right now!
If you think that people would do better to pay almost 2X as much, for a factory part....just say so....everyone is entitled to an opinion. If you think people would be better off just using a shaft like one of those I pictured....just say so.....I've got a whole box of those worn out shafts.
12-12-2013, 10:30 AM
#83
No hard on for this shaft. Any one who claims that it is better than thefactory shaft had better have proof or sound engineering data to back it up. I have a great deal of respect for you Greg, don't get me wrong. But if there is something that is claimed to be better and there is no proof that it is, I will call you out on it. Call it what it is. A cheaper version of the factory shaft, with inferior manufacturing processes and maybe better material that is softer. Your work speakes for you. You claim that you have more work than you can handle.. you are starting to sound like Carl and Jake Ruby. Once you cannot defend you attack personally. Please don't turn into that person.
Greg, keep up the good work buddy, most of us know where you are coming from on this project and appreciate the time you've put in to it.
12-12-2013, 12:19 PM
#84
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Why the Fuuck did you pull me into this? Go back circlejerking the Moderator in OP.
12-12-2013, 12:21 PM
#85
12-12-2013, 12:30 PM
#86
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No problem Sean. If I give bad advice, I would hope people would be all over me about it. I will certainly listen if there is logical reason and/or proof. But 'Do it because I say so' NEVER flew with me. Here or anywhere in my life.
12-12-2013, 12:34 PM
#88
12-12-2013, 03:08 PM
#90
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Put another couple hundred miles on the old very brown 1980, son in law Jeff Allen and Meggan of The car Chasers TV show used it to get into the Pomona swap meet early to scope it out before the 5 am opening. And if you watch the show you know how he drives
So the testing continues !! Geez I forget to tell him to RPM match on downshifts and he LOVES rowing the gears up to a stoplight ! Me I just use the brakes.
So the testing continues !! Geez I forget to tell him to RPM match on downshifts and he LOVES rowing the gears up to a stoplight ! Me I just use the brakes.