Custom mild steel exhaust vs stainless

[GTI6R]

Alright guys I'm just trying to justify the cost of buying a milltek turbo back exhaust.. $2200 vs $1200 of the custom turbo back exhaust. Will there be any differences..? Would the stainless give more power? What do you guys reckon

I really don't want to fork out the 2k plus on the stainless when it could do towards handling of the car.

[jimmjumbo]

I usually go custom in mild steel for various reasons. Price is a major one. Yes stainless steel has better longevity than mild but I will change cars long before it rusts out. I like custom as it also allows me to choose how loud/quiet I want it.

However, products such as Milltek are tested and researched and may be tuned to resonance. But as you said, having an extra $1000 towards coilovers etc. will put a bigger smile on my face then shiny pipe under my car

[Hillbilly]

When I was putting a 3in custom exhaust in my Land cruiser I asked for a stainless one and the guy laughed and said that I had too much money. It was double the price of the mild steel one I put in. He also said it was harder to mandrel bend the stainless one as they didn't stretch so easily

[gavs]

When I was putting a 3in custom exhaust in my Land cruiser I asked for a stainless one and the guy laughed and said that I had too much money. It was double the price of the mild steel one I put in. He also said it was harder to mandrel bend the stainless one as they didn't stretch so easily

Don't know about stretch but stainless work hardens which can make things difficult. Stainless due to its density can hold heat longer, helping to keep exhaust gas velocity up but in all honesty, for the cost saving its not really worth it for a custom system. What you will find is that off-the-shelf pipe work will not only be "tuned" for performance and sound, but will also be mandrel bent (a must especially at the really hot end) and will be built to meet certain quality controls, specifically regarding emissions. Try getting an independent workshop building custom pipes to give you a docent that says your car complies to emissions regulations

[bradsm87]

I've built about 6 custom full exhaust systems using tube and mandrel bent sections. The last one I did was stainless. NEVER AGAIN. It's so much harder to work with, so much harder on cutting wheels and costs heaps in gas because you need to back purge it and tig it to get a good weld because stainless reacts with oxygen a hell of a lot worse than mild when at welding temp. Also if you make an identical system in mild steel, the mild steel system will be quieter because the metal itself can absorb the sound a bit because it's got a bit of give in it. Stainless mufflers are definitely worth getting though.