my camaro 402 has pushed 457rwhp true a 3" loundmouth and 1 3/4 pacesseters headers and cathed y pipe, i have done all the intake systeme over since then(fast 102intake and t/b, 100maf and 104 lide) and tuned properly, i would like to go to 4" exhaust later(enough spent for now), but i am wondering how mutch would i gain going to a 4 exaust and is it worth it , what is the hp you have seen true a 3" systeme?

 

Do you mean to say 'through'?

Anyways... I don't think you'll get a big enough gain to be worth the work for it. Plus, will it even fit over the axle?

 

should get tsp or hooker 1-7/8 if you want an even bigger ypipe and HP gains...then sell your pacesetters

 

x2


You are at the power level where stepping up to 1 7/8" Headers and a better Y Pipe would be beneficial. Then you can run a cutout after the Y Pipe, and keep your 3" catback.

 

the law is getting severe on noise, for now i added a cherry bomb 3"inlet and 33" of tube glass packed tube muffler, but when you look inside there is 3/8" fins inside every 1" all around and all the way down in a spiral , there must be at least 300 to 400 fins, it leave's you with about 2 1/2 of inside pipe unrestricted, yes it did quiet my car to a reasonable sound level but holly **** i also noticed a diference in power level, i will leave it like that to finish the year but i will be asking Santa Clause for an 4" exhaust this Christmas, what is out there that i can have a muffler out back and have a tail pipe on both side , i would also have to get a panhard bar relocatore braket wouln't i ? i kno the 4 " will performe enough for me but is it to loud?

 

A few brands make a 4'' catback style system for our cars, try searching around for them. Here is one made by mufflex, nice unit and would go really well with their ypipe as it has a FM merge with a 4'' outlet that would mate right up to this guy. http://www.mufflex-performance.com/m...tegory_Code=FZ

And no you shouldnt have to relocate your PHR but everyones car is a little different depending on what kind of PHR you have, if car is lowered at all and what brand catback as they all run a little different over the rear axle.

Some info from the sticky that can help as well...

David Vizard stated that CFM is a great way to help develop a zero loss exhaust system. For zero loss a exhaust must flow 2.2 CFM per horsepower(This means less than 1% of total power produced by the engine is lost due to back pressure.). From reading the article I think that a lot of people that see gains when going from a 2.5” exhaust system to a 3” dual system see them because the muffler on the 2.5” system didn’t flow enough for their application. David stated that per square inch of exhaust tubing there is 115 CFM of flow. So plugging some numbers into the good ole TI-89….. ((3.14 * radius^2)*115[*2 for a dual exhaust system])/2.2 = Max hp supported with zero loss

A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…

Now these numbers are assuming that everything else is set up perfectly. The muffler must flow as much as the open pipe or more to get zero loss at the listed hp levels. He also states that using a muffler with a larger inlet/outlet diameter than your exhaust pipe is a great way to get more out of a smaller diameter system since the muffler flow will be able to match the straight pipe flow.

 

i wonder how that mufflex system sounds, looks like the only 4" available with the 2 outlets. and my car is lowered and has a dana 60.

 

Holy crap a ti-89... I still got mine.. From '89 lol

 

what???