Being i have a low hood clearance i have to run an elbow from the manifold over to the wastegate. At first i was using class 8.8 bolts(m8x1.25) to hold the elbow on the manifold and they kept breaking so i went up to class 10.9 bolts of the same size. After a few days they broke off as well. So out of frustration I drilled and tapped the manifold and flange to accomodate 7/16-14 Grade 8 bolts Now after 3 days they have broke.


Any ideas on what to do now? Or things to look for?

 

heat expansion is your problem. bolts are not going to be able to handle the stress of the expanding metal. your going to have to weld the elbow onto the manifold. make sure you use thick tubing like schedule 10 pipe to ensure there will be no cracks. if you use thin metal it will crack.

 

My elbow is schedule 10 304SS. I already found out the hard way that thin pipe will crack and snap off. No thanks to my fabricator who is complety incapable of making a decent weld as well.

 

aaahhh the infamous "finding out the hard way" routine. been there, done that!!!!!!!!