I've got an 2001 LS1 Z28 and I'm going to be purchasing an exhaust system from the engine back... My questions are these...

#1 Can I run true duals? I was looking at the underside of our cars and it looks like it would be difficult put up a true dual system... If I can run true duals, whats the maximum diameter of pipe I can use without running into clearence issues? (That goes for over the Rear Axle aswell)

#2 This sounds a bit dumb but on the 01 Model are the Cats on the Y-Pipe or directly on the headers? Will ANY High Flow Cat system work on our cars or is there particular OBDII compliant ones I need to look for? (or is it just the 02 Sensors that monitor our cats?)

#3 I was looking at the Corsa and Borla Corvette Exhaust system and I was wondering if I got these Cat Backs, could I use them apart of my True Dual setup to go over my rear axle without modification? If it needs to be modified then I'm best of just fabbing up an True Dual system with Bullet Mufflers right?...

 

yes you can run true duals...runing it past the axle is not easy or cheap. best bet is side-by-side 2.5" pipes over the stock routing location.

one cat bolts directly to the manifold (driver side i think) and the other is back a little ways.

no a corvette exhaust would not be an easy mock up. your best bet is a set of the "universal" true dual setups in the jegs or summit catalog and ahve a decent shop do the fabbing

 

Thanks alot man! Much appreciated

 

#2) No aftermarket system that moves the cats would pass visual in the strictest sense. Yes it is the rear O2's that monitor cat efficiency. You can have them tuned out or just run some high flow cats and O2 extensions or if they're close enough to the bend there is enough play that the stock wires will reach. Would have to use mid length headers for this. LT's will require extensions.

 

Would Headers come with Cats or will cats have to be purchased seperately?

 

Seperate unless you buy a catted Y. They still won't be legal. Not saying your state won't allow them, just by federal laws.

 

headers themselves will most likely not come with cats.

now if you get a Ypipe designed for the headers...it may be a "catted" ypipe

but since you want duals...you wouldn't be purchasing that.


however

going back to my suggestion of side by side duals. you can use a typical header Ypipe and cut the union and turn it into a side-by-side by adding 2 elbows instead of joining into one pipe.

here is an example of a setup like i mentioned. this is the exhaust from mrr23's car (do a search if you want to talk to him). i show you it to give you and idea of what i mean on the Ypipe setup. the rest of the exhaust is badass...but also bad$$$$$$$.

with the BMR panhard relocation setup, you can run two 3" pipes, side-by-side over the stock routing location (instead of snaking it around like the bassani).

just some food for thought

 

Or you could get the Summit X pipe that has the inlets in an open Y and the outlets side by side straight. Then you put the center of the X right where it goes over the g-load brace.

 

yeah, but the angles that the inlet/outlet of the X are not all that easy to fab up to a Ypipe

the better bet is to get the magnaflow X ...which has 3" inlets that are parallel. that way you can just run the proper bend off the Y pipe...side by side...and into the crossover...then out side by side

like this


as opposed to this


sorry the links won't work for long...

 

I did some cut and weld on a Jegs X so that it looks like the first one going out and the second one going in. Then I fabbed up the rest.

 

Okay just to get the jist of this, how do these exhaust systems sound?

Exhaust 1
- Short Tube / Mid Tube Headers
- 2 High Flow Cats
- 2 Electric Cutouts (If 2 are nessicary, 1 if not.)
- 2 Resonators (Just incase the Borla's are OBNOXIOUSLY loud.)
- Fabbed Pipes to Center and Over Rear Axel
- 2 Borla Mufflers
- Center Exit Quad Tips

Exhaust 2
- Long Tube Headers
- Catted Y-Pipe cut at the ends for true duals
- O2 Exstensions
- 2 Cutouts (Wielded into the Y-Pipe.)
- 2 Resonators (Wielded into the Y-Pipe.)
- Fabbed Pipe from Y-Pipe to Rear Axel
- 2 Borla Mufflers
- Center Exit Quad Tips


Where would I use the X-Pipe? In place of the Y-Pipe and which would have the better advantage? Also are there any particular Y or X Pipes I should be looking for?

Thanks in advanced...

 

I wouldn't mess with buying a Y only to cut it. Just get a dual system if thats the route you're taking.

 

You can buy an X pipe easy, dont buy an expensive Y and cut it, like he said.

Now the cutouts will give maybe a 2 hp increase over true duals. Its not worth the extra 300 bucks, give me the 300 and i'll give your car a push when you launch at the drags, same performance increase, i could just use the money more.

The borla mufflers will be loud, no boubt, but with cats it'll be a little quieter than usual. We cant really acurately say what it will sounds like, becasue 1: All exhaust combinations sound a littel different, and 2: Sound is really hard to describe lol.

 

I see, I'm just curious would I need to find an X-Pipe for my make and model to fit correctly or would ANY X-Pipe work? Also while I'm at it I may aswell ask a few questions about these pipes...

How do they work and how will I use it?

- Do they crossflow or do they form an X and just V Bend at the center?

- Where exactly will I use it? Will I have Pipe fabbed from the cats to the Exhaust Tunnel and place the X-Pipe right before the exhaust tunnel?

 

#1 yes you can run tru-duals. i have the bassani tru-duals on both cars. dual 2.5" with x-pipe. fits around all stock suspension parts.

#2 look at the pics for my 00 formula. that's what you have. the cats bolt to the manifolds. then, the y-pipe bolts to the cats.