Mitsubishi Repair: Hello, cast iron manifolds, tubular exhaust

Question
Hey,

I've got the 1991 Eclipse 2.0 GSX pretty much identical to yours.  Were you focused on performance for those cars?  if yes, are the tubular exhaust manifolds superior an any way to the cast iron ones?

thanks

do you still have your DSM?

Answer
Rob,
I do still have my DSM.  Though I only drive it on nice days in the summer.  With 180,000 miles on it, it's purely a summer car for me now, but I drive it whenever I get a chance.

I've done quite a few mods to my Eclipse, along with lots of maintenance so the increased power added does not hurt anything else on the car.  Tubular exhaust manifolds have their pros and cons.  Their pros are that they can allow for increased air flow and give your engine a nice look.  However, their cons can outweigh those pros.  The tubular manifolds are quite expensive; around $400 for the ones I've seen.  Also, being that they are made from thinner metal than the cast iron manifolds, they have a tendency to crack under the intense pressure and heat.  It's connected to the cylinder head and the turbocharger.  The head is made of aluminum and the turbo is iron.  The tubular manifold may not be made of either material, so that can cause warping and leaks over time.

If you want to upgrade your exhaust manifold, I would recommend a stock manifold from a 2G turbo Eclipse, and you can get it ported for additional flow.  Even if you just get a stock 2G turbo manifold, it is still much stronger and allows for greater air flow than the 1G manifold your car came with.
Good luck!