This is my first post on this board. I have done quite a bit of
reading and researching up to this point. Although I am not
in the Chevrolet family, I am in the "F" body family with my
1997 WS6 TA.

I have been researching the hell out of true-dual exhaust
systems. After many theoretical calculations and reading
hundreds of posts on the topic I pulled the trigger on a 2.5"
true-dual system. Special thanks to Brent94Z for the links on
his home page.

I did a base line dyno run with the original 3" cat back system
w/ Flowmaster crossflow muffler and managed 298 rwhp and
316 rwtq. I just had the true-dual system installed and should
be doing a follow-up dyno run in the next two weeks.

The true-dual system has a noticeable power improvement
over the 3" cat-back. The system includes cats and tailpipes
and exits in the stock location. I am using Flowmaster 2.5"
race mufflers (5.5" case) so it's pretty loud. There is also a
custom crossover chamber (not an "x" or an "h") that
is a window in the siamesed pipes.

Just wanted to introduce myself and will present more info if
there is interest in my true-dual quest. I can't wait to make the
next dyno run.

 

Welcome to the board.Please let us know your dyno results.

 

welcome to the board

 

I'd be interested to see the layout of it. Throw some pictures up if you have any. Thanks!

 

yes, pictures please.

 

Welcome,

What headers did u use for your true dual setup?

 

Hi...Welcome to the Club Youll love these boards!!

 

Welcome to the board!

Please do post the pics and if you need, I'll host them for you... just email me and I'll stick them up for ya.

 

Edited to add that I don't have headers on the car. I know
they make lots of power, but I don't like them and don't need
the potential hassles being in CA. The true dual system should
be completely CA legal. I even used the OBD II compliant
converters (which cost 3x as much as a regular one).

Thanks for the welcome. I will definately provide some pictures.
I think I'll take Brent94Z up on his offer to host them. I need to
go through them and send him a few. I will also follow up with
the dyno results with the new exhaust system.

I have spent a lot of time on a fishing board and know how to
get around, but this board is a little different. I hope this reply
gets to the right place. I could not see how to reply to the
individual responses to the original post. I'll get the hang of it.

 

At the lower right of each individual reply is a "Quote" button. That is how I just did the above

Here are your pics...

http://www.bfranker.badz28.com/misc/td02.jpg
http://www.bfranker.badz28.com/misc/td03.jpg
http://www.bfranker.badz28.com/misc/td04.jpg
http://www.bfranker.badz28.com/misc/td05.jpg
http://www.bfranker.badz28.com/misc/td06.jpg
http://www.bfranker.badz28.com/misc/td07.jpg
http://www.bfranker.badz28.com/misc/td08.jpg
http://www.bfranker.badz28.com/misc/td09.jpg

Looks nice!

 

nice job! How much ground clearance did you lose?

 

Well... the main reason lots of headers aren't legal in CA is that they move the cats downstream. Your setup moves the cats, and is not CA legal as a result. I think I would have done the headers while I was in there... Sure looks like a nice exhaust setup though!

Dave

 

I probably only lost about 1". The lowest point is at the
ball/socket connections just ahead of the rear end.

 

The inlet to the stock exhaust system from the exhaust manifolds
was roughly 2", even though the outlet of the exhaust manifolds
was 2.2" on the driver side and 2.3" on the pass side. I used a
die grinder and made a smooth transition from the mainfolds to
the 2.5" system.

If you just bolted up a set of CARB approved headers to the
stock exhaust system you would not resolve the issue with the
small pipes.

As for legality, it would be difficult for a referee to argue that my
CA approved OBD II cats are illegal, especially since I had
replaced an original that failed. I just have no desire to fight
with headers any more. Especially since my target HP is only
in the 350 range.

 

I think those look badass. Nice job!