400 cell catted 3" downpipe

[kai20035]

There’s many exhaust companies that sell 400 cpsi aftermarket cats... The 400 cpsi will pass most 50 State emissions tests over many 200 cpsi cats.

Most of the OEM cats on (insert make/model/year here) come on average of being 700-800 cpsi cores. The more tubes there are in the cat honeycomb core, equals less exhaust pollutants entering the atmosphere.

400 cpsi cats are what *most* exhaust manufacturer vendors offer in the aftermarket, with some offering the 200 or even 100 cpsi versions.

Many of the aftermarket hi-flow cats are stainless steel shells with either a standard ceramic honeycomb core or metal monolith core. Either way you decide to choose, a 400 cpsi core is a 400 cpsi core, regardless of name brand on the shell or in the advertising... so when shopping compare and save some of that $$$ when making a decision to purchase any “hi-flow” cat system.

Usually if producing high horsepower you would go with 200 cpsi (or 100 cpsi) but also want a cat that contains a metal monolith gut as opposed to the traditional ceramic honeycomb gut. The reason being is the metal gut can withstand higher operating temps of modified or tuned engines, they flow up to 40% more efficiently over standard ceramic cores, are more durable and they are resistant to vibration.

Before buying any cat system that is advertised as “hi-flow”, be sure you know what makes a cat “hi-flow”, choose what is best suited for YOUR application (not others) and match it to your vehicle’s performance level (*even if deciding to run catless, know the pros/cons).

Hope you don't mind me reopening this topic as you seem very versed in this CPSI topic! Got a 2016 S550 GT, just bought MAK CAT delete race pipes but didn't like the smell and it was too loud for my taste when adding it to my current Borla S-Type with X pipe setup. "If" I choose to take the route of buying the Magnaflow high flow cats in the link below to reduce the volume "hopefully 50% lesser noise than catless" do you think these high flow cats from Magnaflow with a CPSI of 400 would bring it down approx 40%-50% of the exhaust noise with my MAK race pipes? I'm assuming the smaller the CPSI or CEL these high flow cats are rated is that the smaller the number, the more high flow it becomes and louder it gets correct? I figured 400 CPSI would be something in the middle range of noise level and nothing close to being obnoxious! Your help would be awesome. Thanks

G-Sport by GESI are the #1 premium ones but they aren't cheap and out of my price range! I've already spend approximately $1134CAD for that MAK race pipes and welding fees so this was my last attempt to get some added volume without breaking the bank which will still cost me about $500CAD+ with the welding fees to add these high flow cats! Do you know how much these S550's are as for their CPSI numbers on the GT's?

https://www.ebay.ca/itm/280979349411?_trkparms=aid=1110002&algo=SPLICE.SOI&ao=1&asc=20201210111451&meid=ae5b93c9b4274f979be0621552f8d468&pid=101196&rk=1&rkt=12&mehot=pf&sd=303933421736&itm=280979349411&pmt=1&noa=0&pg=2047675&algv=PromotedSellersOtherItemsV2WithMLRv3&brand=Custom&_trksid=p2047675.c101196.m2219

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[Coyote Chase]

I added my 200 cell catalytic converter onto the end of a non-catted downpipe. I guess you can do the same thing with a 400 cell!??
Didn't see any 3" 400 cell catted downpipes when I was researching aftermarket downpipes.
My downpipe was $100 on eBay and the catalytic converter was $80 on summit.

 

[kai20035]

I added my 200 cell catalytic converter onto the end of a non-catted downpipe. I guess you can do the same thing with a 400 cell!??
Didn't see any 3" 400 cell catted downpipes when I was researching aftermarket downpipes.
My downpipe was $100 on eBay and the catalytic converter was $80 on summit.

Do you recall the percentage of your noise reduction before and after the HFC install? All I can tell you is these MAK race pipes you can wake up the dead with no cats and wished it was 40% less noise and f*ck I'd be happy but that's not the case, plus smelling those fumes was horrible! The Magnaflow's in this posting are 400CPSI Didn't go with Flowmaster as I've heard alot of horrible "rattling" issues with them and Magnaflow no negative reviews but just wanted to see if someone has done anything close to what I'm wanting to do...

 

[kai20035]

I added my 200 cell catalytic converter onto the end of a non-catted downpipe. I guess you can do the same thing with a 400 cell!??
Didn't see any 3" 400 cell catted downpipes when I was researching aftermarket downpipes.
My downpipe was $100 on eBay and the catalytic converter was $80 on summit.

Oh yes sorry about your question! Think your downpipe is 3 inches like the 5.0's so if you look at the link I had put up you can use the same one too! Only 400CEL HFC for the 2.5 inch is this one: https://www.ebay.ca/itm/281224553744?hash=item417a4a2510:g:15kAAOSwd69gjb9W

 

[kai20035]

I added my 200 cell catalytic converter onto the end of a non-catted downpipe. I guess you can do the same thing with a 400 cell!??
Didn't see any 3" 400 cell catted downpipes when I was researching aftermarket downpipes.
My downpipe was $100 on eBay and the catalytic converter was $80 on summit.

https://www.cjponyparts.com/mishimo...s-steel-3-mustang-ecoboost-2015-2021/p/DPMS2/

 

[cvf-jason]

https://www.cjponyparts.com/mishimo...s-steel-3-mustang-ecoboost-2015-2021/p/DPMS2/

You can save yourself a good amount of money compared to that Mishi pipe here:

https://www.cvfab.com/collections/1...el-downpipe-catted-2015-ford-mustang-ecoboost

 

[kai20035]

You can save yourself a good amount of money compared to that Mishi pipe here:

https://www.cvfab.com/collections/1...el-downpipe-catted-2015-ford-mustang-ecoboost

I don't have an EB and it's a GT and already have the MAK race pipes as mentioned!

 

[Coyote Chase]

Do you recall the percentage of your noise reduction before and after the HFC install? All I can tell you is these MAK race pipes you can wake up the dead with no cats and wished it was 40% less noise and f*ck I'd be happy but that's not the case, plus smelling those fumes was horrible! The Magnaflow's in this posting are 400CPSI Didn't go with Flowmaster as I've heard alot of horrible "rattling" issues with them and Magnaflow no negative reviews but just wanted to see if someone has done anything close to what I'm wanting to do...

I don't remember any noise specs listed on the Summit web site.
But it is louder than the system with factory downpipe and factory catalytic converter. But not loud as it was with just the 3" downpipe. Also the car seems to run better with a little back pressure.

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