HP Limit of stock exhaust

[TType85]

My car is a 2013 GT Premium and has a Roush Phase 1 TVS blower with an 82mm pulley and a VMP tune and it runs pretty good but I want more. I am stuck in Southern California so I have to deal with the smog laws around here and can't easily throw on long tubes and an offroad pipe. What point will I hit a wall with the OE exhaust (manifolds, cats, mufflers)?

My eventual goal is to hit 9.99 in the 1/4 on e85 and slicks or drag radials but I want to build up a better long block first so I have less of a worry about the rods turning to spaghetti.

Would shorty headers like the BBK (smog legal) make a difference? I am also thinking L&M intake cams and/or ported heads for the new build but I have a feeling the exhaust is going to be the cork in the system.

 

[RUgoinup?]

Cats are the cork. After discovering cracks in both of my cats I vowed never to run boost/cats again. Some have no issues, I did. I would swap cat deletes in/out if I had emissions checks. I run e85 to reduce possible engine failure due to bad gas/detonation. Nine second goals are lofty and expensive. Good luck and be safe .

 

[TType85]

Cats are the cork. After discovering cracks in both of my cats I vowed never to run boost/cats again. Some have no issues, I did. I would swap cat deletes in/out if I had emissions checks. I run e85 to reduce possible engine failure due to bad gas/detonation. Nine second goals are lofty and expensive. Good luck and be safe .

Was thinking of cat deletes, just have to swap them on every other year and get the monitors set to smog it, that should be easier than all the stuff I had to do to my Turbo Buick to get it ready for smog. Ideally I would find a stock set and gut them so visually it looks like they are there. I know it is a lofty goal but I know it is doable, just not cheap. It still might be cheaper and more reliable than it would have been doing it with my Turbo Buick.

 

[biminiLX]

You can buy a set of headers and mid pipes that come with both cats and cat deletes. At least my Stainless Works set was like this, with both. I sold the cats, but you may be able to call one of the companies and ask for a set of cat deletes that look like the high flow cats. Or weld a cat shell over a straight pipe. Not that I’d advocate getting around state or federal emission law
Good luck.
-J

 

[TType85]

You can buy a set of headers and mid pipes that come with both cats and cat deletes. At least my Stainless Works set was like this, with both. I sold the cats, but you may be able to call one of the companies and ask for a set of cat deletes that look like the high flow cats. Or weld a cat shell over a straight pipe. Not that I’d advocate getting around state or federal emission law
Good luck.
-J

Unfortunately I cant get away with LT headers here due to visual inspection, maybe I can find someone who did do LT and buy the stock cats and gut them like I did on my buicks, you know, for "off road use" . I wish I could get out of this state but it's not happening for a few more years at least.

 

[biminiLX]

Sounds like you need to find the right people to help with that problem
The inspection I mean.
-J

 

[RUgoinup?]

Just looked at your screen name. Grand Nationals/Regal T Types are some of my favorite cars of all time. I’ll never forget test driving a new one back in 1987...thankfully I bought a mustang because I ran it into a tree, showing off lol.

 

[kingcobra323]

Def some cat deletes and e85 and will need to pulley down to like 69. I'm in Cali to on e85 with kooks on 69 pulley. I'll most likely run Fontana on 3/31

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