I agree with the others. My '94 (57k miles) still looks VERY NICE, oddly my '92 with 140k miles looks WAY better than my '95 with 108k miles... The '95 is being changed out right now infact and with a little luck will be back on the road in about 30 min... It will be the crazy but beautiful lime green and purple that has been pictured in other threads.

The way these late cars finish just flakes off in HUGE slivers is crazy... My '88 didn't come off like that at all, but it looks like all the GTS intakes flake off in huge chunks.

 

Looks stock to me to. I was trying to find a picture of mine when it had 60k miles on. As everyone else found out the slivers eventually came off in chunks.

Tell him not to worry about the color and that I will take it off his hands for $5k and he will then be able to sleep at night

 

Looks stock to me, but IMHO that's not a plus. I believe Porsche coated the GTS intakes with a different coating than the earlier S4 manifolds. This coating, while very durable, breaks away from the manifold in large chunks. The coating is inside the manifold runners, as well as on the outside and although I have no anecdotal evidence to support this thought, it seems to me that if a large piece came loose at 6000 RPM and entered a piston, it could be a potential problem, and one very hard to trace.
I have blasted and powder coated both GTS and S4 manifolds , and there is a marked difference in the coating. While an S4 manifold can be blasted down to the bare metal in a half hour to 45 minutes, the GTS manifolds will take hours to strip. I even rented time on a large commercial blaster, thinking my setup wasn't powerful enough. An hour and a half later, the GTS manifold still wasn't giving up all of it's coating.

 

Yeah but if you drove it long enough it would probably all just fall off... Seems its an adhesion issue and maybe a temperature coefficient issue that causes it to crack like it does...

Since it doesn't happen for quite a while - maybe it needs to heat harden first, then temperature cycles crack & delaminate it... sure is ugly and agree with the interior thoughts...

However it seems quite brittle so I imagine it would get pulverized - however still not something I'd want in my cylinders.

Alan

 

Actually when the magnesium alloy that the intake is made of is allowed to oxidize due to a nick or scratch, the exoxy coating loses adhesion and you end up with the egg shell effect. It is actually surface corrosion of the intake that detaches the coating. On GTS's the coating is much thicker, probably to dress up the intake and make it appear smoother. Due to the thickness it usually doesn't flake off, it comes off in large pieces.

And yes, stripping a GTS intake is a real bear. We have tried many different procedures trying to make it easier but haven't found the right one yet.

 

My intake had no damage at all until the large cracks formed - long open cracks - and at the time it cracked large areas were already loose. These are not restricted to the edges - some are in the center cuved trumpet area.

Whatever the mechanism it appears suddenly - I suspect whole areas were loose before the cracks formed.

Clearly there is a significant difference in the coating method on these later intakes - not sure what Porsche was trying to fix with this change - but they created a new long term issue.

Alan