I'm running down a boost problem in my stock fd using the two troubleshooting threads on the board. Both say check the 1" hoses going into the y pipe. The short 90 degree hose was petrified and split.
I replaced it with a molded reinforced heater hose from advance auto.
No help. Now I'm wondering if my new hose could be collapsing.
Is that hose under enough stress to collapse, and is the original Mazda hose a special super stiff hose that i should order or is the heater hose sufficent?

 

You wouldn't have problems collapsing, you'd need vacuum at the hose to collapse and the only way you have a strong vacuum in front of the throttle plates.

That hose won't last long most likely, you'll probably see it split and fail from heat in short order.

Either get the stock part from Mazda or get silicone replacements. I posted up a while back about replacements for those 90 degree and straight sections for a reasonable price, search around on that.

Also, if you have the stock rubber Y-pipe coupler, go ahead and get a 2.75" silicone coupler to replace it. If it hasn't failed, it will at some point.

Dale

 

Will do. Thanks Dale.