How much HP from upgrading catback?

[oplix]

i have a evo3 16g running 20psi on a stock exhaust system. (all supporting mods done). I also have a stock SMIC. I'm wondering if I upgrade JUST the catback (i dont want turboback right now), will I gain a significant amount of HP?

Mind you, I still have a cat converter.

 

[Redfwdsm]

let that bi*** breath bro you'll feel the diffrence cat back with a 3 inch high flow cat is the way to go

 

[Dsmj89]

Why wouldn't you want to upgrade the downpipe ? That's one of the biggest restrictions on our cars. I'd say ge ta full turboback system and be done with it for once. As for your stock smic, i hope you aren't boosting those 20 lbs daily as your smic is most likely heat soaking like hell right now. I would get a fmic or upgrade to a supra smic. I'm sure you don't want melted pistons..

 

[toofast82]

i have a evo3 16g running 20psi on a stock exhaust system. (all supporting mods done). I also have a stock SMIC. I'm wondering if I upgrade JUST the catback (i dont want turboback right now), will I gain a significant amount of HP?

Mind you, I still have a cat converter.

This is an example of how you mess your motor up and than blame it on being a "7-bolt"
"all supporting mods" would include full exhaust and upgraded intercooler or e85/meth/water injection for 16g at 20psi

 

[wvturbo2]

I'm not sure that I would say E85 is needed a bit of overkill. There isn't much point in just buying the catback it won't make much difference except for noise. I would wait and get one of the catback and downpipe combos for a bit cheaper.

 

[oplix]

This is an example of how you mess your motor up and than blame it on being a "7-bolt"
"all supporting mods" would include full exhaust and upgraded intercooler or e85/meth/water injection for 16g at 20psi

intercooler i can see, exhaust irrelavent.

 

[Boost92awd]

Either way, bench racing FTL!

 

[nuclearr]

E85 what a joke I can buy/build a flex fuel vehicle but I can't even get E85 and there is a plant just a few hours away .

 

[94Jettameowpsst]

when you half a$$ something you get half the power.

Do a full turbo back if you want to make a gain. Doing a catback isnt going to net you too much of a gain since you have a small downpipe and a cat....thats about 6/7ft of pipe right there thats the majority of your power right there.

Think of it as blowing through a straw. The volume of air you can fit into a LARGE hole tapering down to a smaller one is going to be greater than visa versa.
However it could work in reverse too since the hot air leaving the turbo can only expand as it cools so the 3 inch after cat could help a little.

Point being, just swap the whole thing while you have it off.

 

[Defiant]

We can't guess how much you'll gain, but a ballpark for improvements through exhaust mods is 15~25hp, varying throughout the rev range.

The only way to know is to dyno it.