i was looking and thingin about instead of TD get the mufflex 4" cat back and dump it befor the axle so i dont have torque arm issues. but if i did that itd seem stupid to hav headers with a 3" collector is there a way around that does anyone make anything?

 

Are you talking about where the headers both y together is 3"? If that is the case, have an exhaust shop make something up for you.

 

Just curies but why in the $%#@ to you need a 4 inch exhaust. Let me try to get a better idea. I am assuming you are trying to run a Y pipe off your 3 inch collector and are concerned that it might hinder flow so you want the exhaust to be 4 inches coming out of the Y pipe into a 4 inch muffler and dump 2 or so feet behind it right before the rear axle correct [>:].

 

no i figured it out lol i was talkin bout the 3" collectors on the headers. but they wont restrict it because only 4 of the cylinders r going into that 1 3" collector so opening it up to 4" where the exhaust from all 8 cylinders meet will help the flow over a 3". make sense? i know its confusing

 

yea your correct cbr and i no it makes no sense to anyone wen u read my sig and see 13.1 u think y the f*** would he need that much flow? well the answer is cuz the 383 were buildin were gonna spray the **** out of and hope to see a few 9 second passes.my concern for flowmake a bit more sense now?

 

If I did my math correctly, the volume of one 4" pipe is slightly less than the combined volume of the two 3" pipes that would be Y'd into it. So that would be a good way to go.

 

Lol yes as soon as i looked at your sig i figured it out. You can make a 4 inch pipe work its going to be a little tight around the middle of the car but as long as you are not slammed and dont plan on driving over speed bumps it will work. The bigger issue is going to be your muffler finding one that isnt too big and placing it right might take a little thinking[>:].

It may be easyer to run cut outs.

 

am i able to do cut outs b4 the Y lik right after the headers? if you've read any of my stuff on ls1tech ive been talkin and askin a million ?s because i wanna do it right the first time. dont wanna leave anything on the table.

 

Whoa Whoa Whoa...slow down chap...

If you're looking for 9 second passes my bet would be you're not going to be running a street legal tire as it is, meaning you're probably going to have to trailer it to the track or jack the car up and replace the tires when you get to the track. That said, why not just run a 3 inch X-pipe with axle dumps. You can use band clamps to connect it to your collectors and remove it when you get to the track and run open headers. The flow of a single 4 inch exhaust is going to be less than that of a dual 3 inch anyway because not only do you have less cross sectional area, but you also have an increased surface area to volume ratio which is going to cause more internal friction.

Edit: This post was full of stupid math errors, refer to here to get the correct calculations

As you can see, the single four inch system adds much more surface area with a decrease in volume, overall I'd say it wouldn't be the best decision.

 

true but here's my reason for lookin at other options over true duals. running an X pipe will not allow me to use a chassis mount torque arm. so i thought id use an H pipe but i just realized using the lpp stainless long tubes that the Y pipe just slips over the collectors and clamps to it. so i think i will cut the Y pipe a bit smaller and put in 2 3" cut outs right off the headers. good idea? o and you r correct the car will be trailered to the track but the car will be driven alot more then any other 9 second car.