Custom exhaust

[laborsmith]

If going w/o a resonator there would be room for an electronic exhaust diverter, I have used NoWeeds version with satisfaction and QTP reportedly has a good product also.

Laborsmith

 

[rdss]

Laborsmith, that might be an option to replace the resonator and keep the muffler.

 

[laborsmith]

And either hook up directly to 2.5 inch pipe. Don't know about QTP, but NoWeeds allows you to adjust how loud or quiet you want the exhaust to be on the fly. I need a resonator as it cancels out noise that disturbs me but others often do not perceive otherwise I would have the diverter instead of the cat back system.

Laborsmith

 

[jpierro79]

Here are some pics of secondary cat delete please dont mind the piping after the flange its only temporary till I get the stainless steal mandrel bent. Also a pic of the muffler delete. Once again please note the piping after the flange I installed is only temporary until I get my stainless piping.

 

[rdss]

Here are some pics of secondary cat delete please dont mind the piping after the flange its only temporary till I get the stainless steal mandrel bent. Also a pic of the muffler delete. Once again please note the piping after the flange I installed is only temporary until I get my stainless piping.

Are you essentially down to one cat and straight factory pipe? Your muffler delete is something that I would consider but think I would rather go with DDM's test pipe (mid pipe with no cat) so that I could throw the factory secondary cat back in if I needed to bring the car in to Chevy. Or have you removed the factory cat and built from there?

 

[jpierro79]

Are you essentially down to one cat and straight factory pipe? Your muffler delete is something that I would consider but think I would rather go with DDM's test pipe (mid pipe with no cat) so that I could throw the factory secondary cat back in if I needed to bring the car in to Chevy. Or have you removed the factory cat and built from there?

I removed secondary factory cat and built from there but still have some factory piping from the resonator to axle pipe including resonator. I know I voided my exhaust warranty but I really dont care about that. There is no O2 sensor after secondary cat so it will not set check engine light. I did also put a stainless 2.5 inch flange there so the rest of the piping can go right on when I get it and so I can remove it easily if needs be for service. I am building this car with the ability to service it in mind. I work on cars for a living so I don't want to make mine a pain in the rear. I did notice small power improvement even though the factory piping is still on there. I am waiting for my next pay check or maybe the one after I found a stainless mandrel bent universal kit which I am going to build the exhaust out of. Its also 2.5 inch piping. It will cost me considerably less to do it myself and I have pipe expanders and have a metal table saw on order. I dont know if you noticed but at the end of your second cat before the flange it reduces to 1.75 inches. I dont think it would be smart to buy a whole cat back exhaust unless you remove that kink. When all is said and done I will post pics.

 

[laborsmith]

Yeah, we noticed. That is why the 2.25 starts there and continues to the tip in the Solo Performance system I am using as developed by DDMWorks.

Laborsmith

 

[dvn]

Wait, so the secondary CAT has a 1.75" outlet? Isn't going to a larger pipe after that point senseless? It's like having a fire hose with a section of garden hose in the middle. It's only going to flow what the garden hose diameter will allow. This is just me thinking out loud. Correct me if I'm wrong.

 

[Preloader]

That logic is rational, but the reality is not as bad as you might think. Hydronics is a good analogy. 20 gallons of water per minute can flow from a 3" pipe through a small length of 2" pipe and back to 3" pipe. The velocity of 20 gpm through the 2" pipe will be much greater and require more pressure (the downside), but the shorter the length of the bottleneck 2" pipe, the less affected the 20 gpm will be when it returns to 3" pipe.

 

[Eric Smit]

Just rip the whole thing off. ;P


-Eric Smit

 

[laborsmith]

dvn, this is what Dave Michel posted back in February:

"1.4L has the following dimensions -

The front of the secondary cat is 2.125" OD
The back of the secondary cat is 2" OD
The rest of the exhaust behind the secondary cat is 1.75"

So the stock 1.75" has an internal area of 2.07 sq/inch (with wall thickness taken into account) and our 2.25" system has an internal area of 3.54 sq/inch or about 70% larger."

Hope that helps.

Labosmith

 

[rdss]

I removed secondary factory cat and built from there but still have some factory piping from the resonator to axle pipe including resonator. I know I voided my exhaust warranty but I really dont care about that. There is no O2 sensor after secondary cat so it will not set check engine light. I did also put a stainless 2.5 inch flange there so the rest of the piping can go right on when I get it and so I can remove it easily if needs be for service. I am building this car with the ability to service it in mind. I work on cars for a living so I don't want to make mine a pain in the rear. I did notice small power improvement even though the factory piping is still on there. I am waiting for my next pay check or maybe the one after I found a stainless mandrel bent universal kit which I am going to build the exhaust out of. Its also 2.5 inch piping. It will cost me considerably less to do it myself and I have pipe expanders and have a metal table saw on order. I dont know if you noticed but at the end of your second cat before the flange it reduces to 1.75 inches. I dont think it would be smart to buy a whole cat back exhaust unless you remove that kink. When all is said and done I will post pics.

Sounds good, I do look forward to your finished custom exhaust. That pipe reduction is why I am buying the DDM test pipe which is just replacement pipe for that second cat so I wont have that problem as well. Good luck and let us know what you think of your custom kit and hear/see what your finished product.

 

[Frizodanizzo]

Since I work in a shop and have a welder I was thinking of using Jegs Universal kit to make my own exhaust. It is all mendrel bent and its only a matter of making the correct cuts. I have exhaust hangers the only thing I would need is another 2.5 flange to replace the one at the rear of the second cat. I dont know why but it is reduced to 1.75 just before that flange. JEGS Performance Products 30671 JEGS Street Rod/Muscle Car Exhaust Kits Also my girlfriend has a sedan and the only difference from the cat back to the hatchback is the length of the tail pipe. I cant understand why people can't just make the kits for sedans already. Its literally adding a few inches of tail pipe.

Actually I was thinking of buying a cat back for a hatch and modding it by adding another 14 inches approx of straight piping somewhere to make this work... If i try this at all and do have success I'll let you know. I'm sure it's as easy as adding at least 12-14 inches of pipe at the end somewhere to where the tip is still located in the same region but it reaches the end of the cars bumper at least. They said its 14 inches longer somewhere I read the car.

 

[redsonic]

i got my exhaust done at a exhaust shop for 125 bucks 2.5 inch pipe no resonater and a straight through thrush muffler sounds awesome looks great too btw this is on a 1.4 turbo

 

[Eric Smit]

i got my exhaust done at a exhaust shop for 125 bucks 2.5 inch pipe no resonater and a straight through thrush muffler sounds awesome looks great too btw this is on a 1.4 turbo

That's a great price, assuming its high quality mandrel bent stuff. I did similar, but no muffler.


-Eric Smit

 

[redsonic]

yup stainless pipe and the muff no res

 

[slitzell]

yup stainless pipe and the muff no res

but is it mandrel bent? like 99 percent of exhaust shops do crush bending bc the machine to do mandral bent stuff costs an insane amount of money

 

[redsonic]

yes as stated before mandrel bent guy liked the car alot gave me a stellar deal on the exhaust work

 

[Eric Smit]

I paid 180 for mandrel bent stainless steel from the first cat back, but I kept the second cat, resonator, and muffler.


-Eric Smit

 

[redsonic]

i kept everything too just incase you know although i did mine from the second cat thought about it after then took it out and had a test pipe made too be just the same size as the cat pipe just 2.5 inch