[XutvJet]

As we all know, the stock charge pipes on these cars break fairly often. The break happens at the rigid plastic pipe lip where it attaches to the throttle body. The break typically happens at the gap where the pipe snap ring slides in.

My opinion of the issue
The front of the charge pipe is mounted to the intercooler which doesn't move. The other end of the pipe is mounted to the throttle body/motor which is always moving, especially on hard acceleration and shifts. The accordion section of the charge pipe is designed to offer some movement between the pipe ends, and the pipe mount on the engine which helps reduce pipe movement/load as well. However, there is still some tugging/lifting load on the lip of the charge pipe (at the throttle body) as the motor rocks around, especially on the portion of the pipe lip facing the front of the engine. If you look at where most of the charge pipes break, it's in this area.

I think what happens is a small hairline crack starts to form in the lip after lots of heat cycles and the constant stressing of the lip. It continues to get worse over time, probably quite rapidly once the crack forms. Then one day you hammer the gas, you downshift, the motor rocks violently in the mounts, boost hits very hard a split second after the shift, the crack says "Enough!" due to the violet rocking teamed with a big gush of boost/air and POP, the pipe lip breaks completely and the pipe is pushed off the throttle body. This is likely why so many believe the pipe breaks because of boost.

Adding some level of additional support at the pipe lip may help combat this issue. With all that said though, the OEM charge pipe should be considered a wear item and owners should expect to replace them at least every 5 years (or only once if you buy a quality aftermarket one) because they will eventually break.

Possible mod to help make the OEM charge pipe live longer
My M235 has 25k miles and is 2.5 years old. The motor is pushing betwen +2 to +4 psi depending on my mood. It's been that way for about 5 months. I have a 6MT and routinely punch it in 2nd and 3rd with lots of fairly hard 2-3 shifts. I also punch it pretty hard in 4th, 5th, and 6th from around 2800-3200rpms which can create quite a bit of load and heavy boost quite rapidly. The charge pipe hasn't broken.

After some consideration and studying of the issue, I took a $2.50 3.5" hose clamp and put it just under the charge pipe clip in an effort to support the charge pipe lip. Between the hose clamp and pipe is an approximate 1/2" wide by 1/8" thick rubber seal to keep the clamp from creating direct pressure points on the rigid portion of the charge pipe. I've been running this for about 6 months now. It's definitely an experiment and I'm making no claims that it's a fix. I'm hopeful the clamp helps reinforce the charge pipe rigid plastic lip and may help take the load off. I've been running this for about 4 months now.

I did make sure to not overtighten the clamp. People tend to over torque band clamps. The bolt on the clamp is a 6 or 7 mm. That means max torque is somewhere in the order of 3 to 5 ft/lbs. I tightened the clamp using a flat head screwdriver so that I couldn't over torque it. I just wanted enough pressure to help offer support to the pipe lip without putting excessive pressure on it. It's rigid afterall and didn't want the clamp to create a pressure point and crack the lip.

[wntrsnowg]

Call me pessimistic but I don't think this will solve the main issue here - the material is hard plastic. I'm thinking that reinforcing the one area will just move the stress to the next weakest location, right outside of the clamp, and break there. Thoughts?