Cracked turbo housing, pics inside
 

I pulled the turbos off yesterday to do the full non-sequential mod and found the housing is cracked. Now, I heard this is common and some cracks are OK and can still run. I am brand new to the turbo world so I don't know if a crack is OK or if the housing should be replaced or what. Below are close up pictures I just took.

http://www.blackgto.com/RX7/crack1.jpg

http://www.blackgto.com/RX7/crack2.jpg

http://www.blackgto.com/RX7/crack3.jpg

Internal cracks are normal and totally OK. Cracks that get into the surface that the gasket seals to are bad - exhaust gasses can build up under the gasket and blow it out.

Fortunately, used turbos are plentiful and cheap - usually about $150 for an average set of twins. If the turbine housing is bad, swap it out with another.

Dale

To expound on that advice, I see one crack that isn't too far from getting past the gasket.

However, I've seen that same crack pattern develop and erode a whole lot more and still not develop a problem leak. You could probably bolt these back on and use them some more.

Dave

That manifold is wasted...pitch it for another with less wear and the "worry meter" will be on the lower end of the scale

Looks like the vote is split 50/50. Maybe I should have made this a poll.

What side effects can this cause if I reinstalled it?

you spent the time to putt it apart, isn't a "quick" job.... switch it before you have to do it when it's really bad....

I have to change my radiator, and the way my car boosts I'm suspecting a cracked mani or turbo housing..... so i think while I wait for the radiator to come I'll pull the turbos off... and check.....

DO THE POSTING TOO!!!!!!!! (wastegate)

It wasn't super easy to remove but not terrible either. I just hate the thought of installing bad parts. The costs of acquiring a good casting and then the rebuild and balance by a pro is almost halfway towards a single turbo kit. Decisions, decisions.........

I would pick up a good used set of twins. Good sets with very little, if any, cracks can be had for under $300. If your goal is to eventually go single, you could just slap those back on and just deal with what you have until you install your single turbo kit.

However, more often than not, those plans get pushed back and you end up waiting longer than you thought. So I still recommend picking up a good used set. There are several sets for sale now on the forum.

replace them.

Time to go SINGLE!

So it a complete failure? If I re-installed it can anyone guess how long it might hold? Could this be the cause of my cold startup smoke? It only smokes for less then a minute and only on the first start of the day. After that all is great even at WOT.

It is not a failed manifold at all. I also don't think it's related to your cold startup smoke. racks in the turbo manifold result in exhaust leaks. Oil smoke from bad turbos comes from the seals inside the turbo - separate issues. In fact, the 'smoke' you describe sound smore like condensation. C

If you use this car on a regular basis, and you don't mind the labor of pulling these turbos again later, then put them back on, and begin planning your next step. They are not going to fall apart. Or, if your engine has 80k original miles, it's likely these turbos will outlast the motor - just keep in mind to replace the turbos when the motor goes.

Would I put these on a car to replace bad turbos - no. For $500-800 you can get some really really clean low mileage turbos that will last a lot longer. So if you won't be need the car for a few weeks then another option is to buy a new set and put them on.

Dave

sorry that was supposed to say
"do the porting too!!!!!(wastegate)" not posting

The crack at the bridge piece will have no detriment to non-seq operation. The cracks out to the gasket surface are completely normal on twins with any mileage on them. They could last quite a while, but then again, once the crack gets into the gasket, you're going to have to pull them out again.

I guarantee you that any used set of twins you find with over 50k miles on them will look pretty close to that. Even lower mileage turbos will have cracking.

I repair those cracks as part of the rich mans non seq .All the prespool area gets welded closed .

PM sent!