Any problem w/ 3" exhaust and 2.5" inlet?

[GAdriver]

As the title says... would it make a difference if i had 3inch exhaust going to a 2.5 inlet?

 

[L2RTSiAWD]

I'm confused when you say 3 inch exhaust going into a 2.5 inch inlet?

 

[c5chris]

Sounds like a 2.5" downpipe to a 3" catback. For a small to medium turbo, it would be good since there will be less boostcreep. For a big turbo, it might be a little restrictive and a 3" all-the-way might be a better choice.

 

[GAdriver]

2.5" inlet on a muffler.

 

[L2RTSiAWD]

Sounds like a 2.5" downpipe to a 3" catback.

In that case it's fine, I used to have a 2.5 inch dp and a 3inch cat-back.

 

[98spydert]

2.5" inlet on a muffler.

There's no problem with it, it's just a bottle neck you'd probably be better off without. It won't creat any negative side effects though if that's what you're asking.

 

[L2RTSiAWD]

2.5" inlet on a muffler.

It's ok, but why in the world would want to do that?

 

[Generation1JeY]

just get 3" all around dude

 

[GAdriver]

Because im getting 3" exhaust made and I already have the muffler w/ the 2.5" inlet on my car? But would my dual canister muffler sound alright? Or should i buy a apexi style muffler w/ a 3" inlet off ebay?

 

[InferiorWang]

there's no point in running 3 inch piping if you're going to choke it off to 2.5 inches at the muffler. Get bigger as you go away from the motor, not smaller. It won't hurt your engine, but you could spend less money and get the 2.5 or keep the 3 and do it correctly with the right size muffler.

 

[BoredOutaMyMind]

While we are on this topic, i need to ask a complete newb question, when you say 3" exhaust, is that the size of the pipes inlet, or the thickness of the pipe, like 3 inch diameter outside to outside (if measuring across inlet) if so, whats the avg size of the inlet on a 3" exhaust?... this dp i got for free is 2.25 inches inlet, isnt that like stock?

 

[98spydert]

That's close to stock, I'm not sure what the exhaust stock measurement is. As for inside or outside measurements, it depends on how the vender measures it and advertises it really. They might use a 3" flange but a 3" outside diameter pipe. My extreme motorsports down pipe is advertised as 2.5" and actually measures 2.5 inches from inside to inside. I don't think there's a standard.