PorscheFanatic202

I'm looking for a solution to my cracked exhaust manifold. It's leaking from under the shielded part (soot all over the head) from the 2/3 manifold.

How high are the chances that the following will fail in the next 5 years? Buying a used set vs having mine welded or brazed. Or a used set below 100k miles. Obviously buying a new set (original Porsche) will set one back upwards of 1500 and a decent aftermarket set will be about a grand.

Your thoughts...

moalaska

You can weld if cracks aren't too bad, but the exhaust is a nichel chromium alloy make sure welder knows that but they will just act like they know everything. That would be cheap solution but risk cracking again. With pain of removing headers if they haven't been taken off in 30 years, next best solution would be to jump on the obx bandwagen. For just a replacement solution ive heard they aren't bad and for 350 to 400 bucks price is the main selling point there. After that you are looking at 2 main vendors I believe, which would run you probably 800 to 1300 depending on options or even higher if you decide to do crossover etc which might not be a bad idea not knowing condition of rest of your exhaust, you may fix one problem area just to expose another. But im not nearly as knowledgeable as other members on here and apparently I ask stupid questions about spark plugs.

moalaska

If you are considering Welding, take heat shielding off if you haven't already, you may find more cracks and may not be best option depending on how bad it is. I had the same scenario as you, when i remove heat shielding i found my 2-3 header had completely broken. I found another for less then 100 had welder weld it for 30 installed new gaskets and wrapped headers. But I seriously considered the obx for a budget solution. Depends on what you want to do and current mods to car.

PorscheFanatic202

The headers won't be hard to remove. I rebuilt the motor 2k miles ago. The most tempting one is the one that includes the crossover pipe, but I haven't heard many reviews of the obx ones. My crossover is fine and I don't want to remove intake again. Do people usually insulate the obx headers?

moalaska

Insulating/wrapping has two different camps. Keeps heat down holds heat to help turbo spool. Porsche insulated theirs. Obx is stainless, do you care about bling or function? Wrapping runs risk of soaking oil if oil filter oring blows, or if fuel leak. Are you tracking car or daily driving? What climate are you in? If you are in arizona desert wrapping might not be bad, if you are in colder climate might not be needed as far as underhood tempuratures are concerned. There are many different opinions on this subject and all dependant on goals. If you just rebuilt motor you probably aren't fighting oil leaks as much.

PorscheFanatic202

Trying to keep the hoses near the manifold from heating up too much or heating the body near the metal fuel lines.

moalaska

This is what i did someone Will probably find reason not to like it. Factory exhaust manifolds with the factory shielding removed and wrapped. Heat protecting loom around fuel lines, insulation around injector harness fuel rail and heat shielding from volkswagen recall program to direct heat away from pressure reg.

PorscheFanatic202

I'm trying to go with the OBX headers, but they say that it is for 88-91. Why do they exclude 86 and 87?

moalaska

As far as I know the flanges and everything is the same, I believe there is a difference with that expansion section on the 1-4 on some of the factory manifolds and maybe something with the wastegate piece but as far as I know nothing to prevent you installing it. Think their listing is just wrong. I have been known to be wrong though.
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PorscheFanatic202

Well, for $250 I cannot really complain if it doesn't fit.