For all you techs out there.

I am in the process of making a y-pipe and have a question. First I went to an exhaust shop and we looked at how much flex the exhaust had and we decided that I would still need the flex pipe in the exhaust.

My question is: Would here be any problems if i used one flex pipe and locate it near the mid pipe connectoin instead of the two flex pipes, one at each cat connections?

I was just asking because I see all the aftermarket pipes and they use two flex pipes..

 

I think they use 2 flex sections (when their used at all, some Y pipe don't use them) because of how the engine is mounted as opposed to a transversly mounted engine to handle side to side motion. I ordered a pair of flex section's to add into my custom header back system. But as soon as I saw the ugly flow robbing corrugations inside them, I but them back in the box they came in and never looked back. Their is a company that is supposed to offer lined flex sections, you might want to look into it. http://www.warpspeedperformance.com/retrofit.htm

Since your in charge of what you create. Make sure the bends off the cats in nice and smooth all the way to the collector. Word to the wise buy prebend mandrel sections to do this. Don't have the shop create the collector, flowmaster makes a excellent collector. You'll of course want to decide if your going to go with 2 1/2" piping off the cats into a 3" collector or 2 1/4" to a 2 1/2" collector. If you go with the 3" collector you'll have to install a transition piece to step down to the 2 1/2" oem down pipe. Unless you'll install a custom 3" system to the tail pipe. Done right, you can have yourself a sweet Y-pipe at a reasonable price.

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

Thanks, that really helps.
Are you having any bad experience with the welds breaking?
What I am having the shop do is like a v-shape pipe with no bends. The size pipe will be 2 1/4.
I took apart the stock y-pipe and notice the differnet size pipes they used and how the bends made the tube even smaller.

Thanks again for the info..

Hope it works.