Cracked Ace A350 - anyone else?

[waterpanda]

Anyone else run into similar issue?

The topside O2 bung welds cracked open during a track day @ NJMP Thunderbolt (NASA Summer Sizzle). Had to apply high heat JBweld and safety wire it shut to limp it home.

I bought this unit second hand - the header has been on the car for a little over 2 yrs, ~9,000 miles (50/50 highway, track miles).

Stamping:
NA-421-425063
86-0201

[ArCha]

Haha, yes. I've had had it crack there once, and then again after a washer was melted to reinforce the weld. I've also had cracks at the 4-2 merge and at various flanges. I've lost way too much track time with mine and have given up on repairing it. What's the point having great performance if it leaves you stranded?


I've been running the stock header again while deciding what to do next.

[waterpanda]

Originally Posted by ArCha

Haha, yes. I've had had it crack there once, and then again after a washer was melted to reinforce the weld. I've also had cracks at the 4-2 merge and at various flanges. I've lost way too much track time with mine and have given up on repairing it. What's the point having great performance if it leaves you stranded?


I've been running the stock header again while deciding what to do next.

I too am hugely concerned about losing track time - I considered the JDL header, but it's not free of issues either based on some forum posts. It would also mean having to get a new tune.

Working on getting my hands on a second set of A350 and repairing this one as backup.

[e1_griego]

I've had mine for 7? years now, also purchased use. Autocross use, not track.

Wondering who has upgraded motor mounts? I have STI mounts and have always had. Wondering with a little less movement if that's part of the reason it survives.

[ArCha]

I've been running STI engine and transmission mounts since I installed the header, I don't think that's a contributor here. I am running a Harrop supercharger though so maybe some extra load.

[e1_griego]

I figured, but wanted to ask.

I have expected mine to crack haha.

[waterpanda]

I have Cusco engine mounts and Cusco transmission collar installed ����*♂️

Another theory - the water leaking down onto the header from hood vents potentially cause thermal shocks to the welds

[ArCha]

I don't have hood vents. I'm thinking this is more likely cycle fatigue. The material is too thin to have the strength to survive over a long period of abuse.