bdanyluk

I just happen to have a set of over-axle pipes, just the 3" pipes, from a Z06 exhaust that I got for $75.

I just purchased a 2.5" NPP exhaust for $600.

So for the total of $675, I can make my own ZR1 type mufflers by cutting off the 2.5" pipe and welding on the 3" pipe.

Has anyone else tried this?

I will do it next weekend.

I do my own welding and don't care how it looks underneath the car becuase nobody can see it.

I am all for 100% function, and 0% on appearance.

I already have LG Super Pro 1-7/8" headers, 3" X-pipe, high flow cats, and Billy Boat Fusions (2-1/2" pipes). It drones pretty bad in the closed mode, so I am switching to NPPs....I am getting old (33) and the wife needs it quieter or else she won't ride with me. 2006 Coupe.

So my Billy Boat Fusions with 2-1/2" pipes and made for 2005 - 2008 MN6 cars, will be up for sale in the next few weeks...so keep a look out or PM me to let you know when I post them for sale. Looking to get around $1100 shipped to your door or best offer. I did weld them on, so just clamping them to yours won't work well.

RicK T

Just to CLARIFY, you have 3" pipe from a Z06 and you want to mate the 2 1/2" NPP mufflers to the 3" pipe?

If yes, then yes, many have done it.

But, I have to ask, and I'm not arguing with you or challenging in any way, but why not just mate the complete NPP 2 1/2" mufflers and over axle pipes to your 3" X-pipe? Many do it that way too, a little easier and there is argument to be made for the smaller diameter pipe toward the back, in terms of maintaining exhaust gas velocity. Just sayin'.

If I misunderstood your scenario then apologies in advance.

4SELLL

On the over axle pipes to the z06 mufflers it looks like the neck down I thought anyway.

HOXXOH

The NPP mufflers have a 2.5" inlet just like the Z06 and ZR1. If you cut off the 2.5" over-the-axle pipe and replace it with a 3" pipe you'll lose power because the velocity of the exhaust gases will decrease as they cool. Bigger is not always best.

BTW, 33 is old?

madmax4499

this is fact! see it over and over people think they are getting 3" all the way out. if you look right where the over axle pipe goes into the back of the muffler it also necks down there as well. all the factory dual mode equipment flows really well.

haljensen

18" or so inches of pipe it shouldn't make much difference whether it's 2.5" or 3.0".

That far back in the exhaust system the diameter isn't that important for power. Look at a non-NPP LS3, the muffler has a single outlet that is less than 2.0" OD and still manages to make 430HP.

SUB VETTE

I dont get it. You've got a 3" X-pipe that's going into 2.5" Billy Boats, and you want to replace the 2.5" Billy Boats with 2.5" NPP. Why can't you just make the swap. Your X-pipe already must neck down to fit the Billy Boats. I'm missing something here

bdanyluk

Thanks for your input...
I will go with my original plan....
Use the NPP as is...
Weld on ball and socket flange type connectors everywhere...
Use the 3" straight pipes for Track Days only to save 40 lbs of weight off the car...which is the reason for the ball and socket flanges.

SteveDoten

Real market pricing

NPP 2008 up, 600-800
Z06 2006 up, 200-300

just buy the cheaper Z06 mufflers(nobody wants to cut and modify the 2.5 base pipes)

MarkRx

ls3gotcha

I would trade her in then. Lol

bdanyluk

Mocked exhaust up today...no welding yet, just placed things together. Even without welding yet, it sounds great ! Much quieter than Fusions, yet not as raspy as Corsa's. I think it might just be the best overall exhaust.

I'll post video tomorrow night!

I did wind up using my 3 inch pipe, so from 1 and 7/8 headers (LG Super Pro) to 3 inch X-pipe with high-flow cats, to 3 inch over-axle pipes, that yes, neck down to 2.5 inch at the NPP mufflers.

seevi

I put ZO6 Bi-model mufflers on my car. The inlet pipe to the muffler is 2.5" and mates to the 2.5 over the axle pipe. On the drag strip, I get better times with the baffles closed than open.

bdanyluk

That sounds like a traction or driver issue...not mechanical.

Maybe with the 5 less hp, you have less wheel spin off the line or something.

If I want more power, I will get heads and cam.

Not a racer...just drive HPDE's for fun. So 1/4 mile times are useless to me. Along with top speed.

If I hit over 140mph on the back straight at Road Atlanta, I am happy...which you can do in stock form.

Just wanted the easiest installation and best sound.

Yes, it was easier to cut off the 2.5 inch pipes and weld on the 3 inch pipes....it was for me. The 2.5 inch lengths were all different from my current setup....so cutting and using a small adapter was the easiest for me.

Welding it all up tonight.

bdanyluk

INSTALLED...LISTEN AND ENJOY !

http://www.youtube.com/watch?v=sw8UT...ature=youtu.be

DC Z

You just ruined a set of NPP. Even the Z06 pipes neck down to 2.5 at the cans. You are doing a lot of work for nothing.

bdanyluk

I didn't RUIN anything. I PERFECTED the crap that I bought and MADE it perfect for what I wanted.

You do what you want with your stuff...and I'll do what I want.

I was just sharing....negative comments have no place here. You don't like it? Then click that little " X " at the top right of your screen.

HOXXOH

As long as your happy doing what you want to do, and I'm glad you are, but why did you bother starting this thread?

It's pretty easy to change the sound, although most people like to add some power in the process instead of losing some.

bdanyluk

I have no idea why I started this thread....if there was a point to everyone's posting, about 75% of them wouldn't be here.

Like - look, i just washed my car! (really, you're supposed to wash it)

Corvettinator

I think it's cool, ignore the haters, who likely couldn't solder two pennies together.

Would have liked to have seen more pics of what you actually did, and before and after sounds.