factory exhaust: which material are the tubes made of?
09-01-2015, 08:42 AM
#1
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Thread Starter
factory exhaust: which material are the tubes made of?
Does anyone know the exact material specs for the later (S4/GT) exhausts, especially the tubes?
I need some welding to be done and the guy who does it needs to know ...
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
I need some welding to be done and the guy who does it needs to know ...
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
09-01-2015, 04:40 PM
#2
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Porsche used to advertise that the exhaust on the GT's was stainless. I don't know if that applies to the S4's though.
09-01-2015, 05:01 PM
#3
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09-01-2015, 09:29 PM
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From a little research, I see that the common alloy for exhaust systems is 409. A better grade used for catalytic converters is 439.
I would tell the guy "400 series, you know, ferritic." If that doesn't satisfy him, you might then have to speculate on 409, or for a very expensive, over-engineered German car, perhaps 439. Test in an inconspicuous area?
I've often wondered whether stainless exhaust systems came about when improved melting processes made ferritic alloys more workable, or if it had to do with emissions regulations. (Ferritic means little or no nickel, and therefore cheaper but not as easily formed into shapes, or welded. The 300 series alloys are the other type, with lots of $ nickel - austenitic. They have different crystal structures at the atomic level. Now you know.)
I would tell the guy "400 series, you know, ferritic." If that doesn't satisfy him, you might then have to speculate on 409, or for a very expensive, over-engineered German car, perhaps 439. Test in an inconspicuous area?
I've often wondered whether stainless exhaust systems came about when improved melting processes made ferritic alloys more workable, or if it had to do with emissions regulations. (Ferritic means little or no nickel, and therefore cheaper but not as easily formed into shapes, or welded. The 300 series alloys are the other type, with lots of $ nickel - austenitic. They have different crystal structures at the atomic level. Now you know.)
09-02-2015, 03:50 AM
#6
Instructor
Thread Starter
From a little research, I see that the common alloy for exhaust systems is 409. A better grade used for catalytic converters is 439.
I would tell the guy "400 series, you know, ferritic." If that doesn't satisfy him, you might then have to speculate on 409, or for a very expensive, over-engineered German car, perhaps 439. Test in an inconspicuous area?
I've often wondered whether stainless exhaust systems came about when improved melting processes made ferritic alloys more workable, or if it had to do with emissions regulations. (Ferritic means little or no nickel, and therefore cheaper but not as easily formed into shapes, or welded. The 300 series alloys are the other type, with lots of $ nickel - austenitic. They have different crystal structures at the atomic level. Now you know.)
I would tell the guy "400 series, you know, ferritic." If that doesn't satisfy him, you might then have to speculate on 409, or for a very expensive, over-engineered German car, perhaps 439. Test in an inconspicuous area?
I've often wondered whether stainless exhaust systems came about when improved melting processes made ferritic alloys more workable, or if it had to do with emissions regulations. (Ferritic means little or no nickel, and therefore cheaper but not as easily formed into shapes, or welded. The 300 series alloys are the other type, with lots of $ nickel - austenitic. They have different crystal structures at the atomic level. Now you know.)
I suspected a ferritic steel since the tubes are quite magnetic.
409 seems a good bet. I hope it doesn't make too much of a difference for the welder whether it is 409 or 439. Maybe I find out more details before he starts working on it.
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
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09-02-2015, 08:23 AM
#8
Instructor
Thread Starter
good thought, I'll shoot them an email and see what I get back.
EDIT: nothing useful came back, it was the wrong "Bischoff" company. I cannot find any reference to the real Bischoff company in Stuttgart. I'll have to look further into it.
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
EDIT: nothing useful came back, it was the wrong "Bischoff" company. I cannot find any reference to the real Bischoff company in Stuttgart. I'll have to look further into it.
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
Last edited by kurt_1; 09-02-2015 at 09:04 AM.
09-02-2015, 09:43 AM
#10
good thought, I'll shoot them an email and see what I get back.
EDIT: nothing useful came back, it was the wrong "Bischoff" company. I cannot find any reference to the real Bischoff company in Stuttgart. I'll have to look further into it.
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
EDIT: nothing useful came back, it was the wrong "Bischoff" company. I cannot find any reference to the real Bischoff company in Stuttgart. I'll have to look further into it.
Kurt
____
90 S4 satin black metallic
928 OC Charter Member
09-02-2015, 10:27 AM
#11
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Thread Starter
Kurt
____
90 S4 satin black metallic
928 OC Charter Member