What is the difference? What are the Advantages of having a flex over straight or vice versa? And do brands really have a difference?
I have the HKS non-flex for over 40k miles with no problems. I don't believe there is a difference in performance. I don't ever here stories of them breaking on these boards. The stock pipe is not a flex on the Sti and WRX.
What? When I removed my uppipe from my 03 WRX there was no flex what so ever. Even if it was internal, i.e. behind the heatshielding, the heat shielding is one piece and wouldn't allow flex anyways.
the stock units have a small flex in them like the stock header crossover pipe does. I just dont recommend solids since they break when you hit stuff...when you are going offroad...like Colin McRae.
Stock is flex. All the good ones are flex. If Subaru thought you could do it without a flex, they would have left the flex out. For every 1 person that doesn't have a problem with a solid, there are 8 or 9 that have them break, crack, or leak. We have near 100% success with flex UP's and probably 10-20% success with solid UP's... SS
Hmmm seems like a pretty strong consensus in this thread for flex uppipes. In a closely related issue, it seems that all coated (or otherwise heat-protective) UP's are solid. You guys think that stainless steel is good enough or heat wrapping/coating a good idea?
w/e....solid, flex, both, doesnt matter. all of them break eventually. I'm going to install a solid in mine.
the solid ones are fine (IMHO) as long as when its installed you have no issues and dont have to stress or bend it to fit. If you have to do all that then there are stress point on the pipe nad then it will break. The flex joint is there so that if there are a small misalignment it wont be an issue. Even though its cast (engine) there are small misalignments and not all pipes are made the same.