Hi,
today we had an SC36 billet that didn't spool until 5500 RPM.
This particular turbo was supplied by us and fitted by someone else, we noticed some nasty headers on the car, equal length but with a woven steel flexy in the middle of them, as a suspect we swapped them out for a set of ported standard oe unequal length ones, spool improved by 500 RPM but still poor, time to take the turbo off and inspect.
Inside the exhaust housing we found this.
You can clearly see the woven steel flexy sat inside the snail.
Once removed it looked like one of the village people had lost his tash.
Turbo survived, spool is back to normal now we can map the car properly.
Lesson here is avoid cheap headers, stick with a known good quality brand, this could have been very expensive for the customer, luckily its cost a few hours labour and a few gaskets, could have been another new turbo.
cheers
Kev