Need some help with overpipe, front pipe, catback combos
 

Okay so I'm pretty sure I want to go with the greddy evo3 cat back which is 2.75 inched.. My question is will a 3 inch overpipe and front pipe seamlessly connect with this cat back or will I need matching 2.75 inch over and front pipe and where do I find them? If I need to go full 3 inch exhaust I will still be sticking with greddy exhaust (maybe perrin) but where can I find more 3 inch over/front pipes. I can't find many and all are rather expensive. I saw a one piece 3 inch over/front pipe but read reviews that it will sag and I would need to add engine mounts which I would like to avoid. Please feel free to air your opinions! Thanks guys!

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I'm pretty sure you want to run a full ACE exhaust.

Disclaimer: I'm not a rep for ACE, just a happy customer.

I only see 1 full ace exhaust and it's only center outlet. I am looking for dual exit cat back and 3 in pipes. Also something that won't scrape when I lower my car.

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Question that should be asked is do you plan to go FI (forced induction aka turbo supercharger)? If not then no reason to run 3".

Yes it will have a turbo in the near future. All mods are purposely being planned ahead.

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We have a CSG Touring86 catback exhaust that is 70mm (2.75"). We have clients with turbo and supercharged applications running it for both performance and improve sound quality over shear noise. Let us know if you have any other questions. Thanks!

I just need to know if 3 inch over pipes and front pipes will seamlessly connect with 2.75 inch or 3 inch catbacks

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It depends on the exact ones as different holes in the flange may align a little different but generally speaking it should be fine. Add some rtv to the gaskets if you are really worried.


You have to think most 2.5" pipes added to smaller diameter stock.pipes end up ok and this is basically the same thing

Depends on who makes it.

Any front pipe utilizing stock donut gasket will neck down to that point.
Any exhaust utilizing stock donut gasket will neck down to that point.

Worrying about exhaust piping without understanding what it bolts up to is not solving your problem.

-alex

I do not understand.

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Kind of the point he was trying to make.:lol:

There is an adapter flange that you can run for the 3". A client is running 3" overpipe/front pipe to a 3" to 2.5" flange mated to the CSG Touring86. The Touring86 flange is designed to mate to a 2.5" front pipe outlet. It has been done. :)

Okay I am asking for help not to point out my lack of knowledge on the subject which was the initial reason for me posting this thread in the first place. Makes sense? Thanks.

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If your exhaust can bolt up to the stock front pipe, it will neck down to the inner diameter of the stock donut gasket.

To say "I have a 2.75" exhaust and will it mate up to this or that front pipe or overpipe" is focusing on the wrong issue, because there will be a bottleneck known as the stock donut gasket.

So, if you want a 2.75" or larger exhaust system (which includes front pipe for purposes of this discussion), you need to consider 1) whether your exhaust of choice reuses the stock donut gasket, and 2) if this singular bottleneck is going to cause you any problems with flow.

If you are running a basic bolt-on FI kit, this is not going to be a bottleneck for you in terms of power. If you are going to do a kit and up it to 10-15PSI or more of boost, then you should consider an exhaust or front pipe with a flat flange.

-alex

Edit: obviously if you don't care about the bottleneck then this is a moot point of discussion.