Ok, being a newb to muscling up a car, as my TB R/T is my first musclecar, I have some questions on redoing the exhaust system. Keep in mind that I want to keep it all legal.

1) Is it better to do it all at once?
2) If not, or it doesn't matter, then what stages should I do it in?
3) Where in the Daytona R/T's exhaust does the bottleneck occur?
4) What brands are good for what parts?
5) What brand should I stay away from if i don't want any drone?


Thanks for da Hep!

 

Rugby - Stay away from the Magnaflow fulll cat back exhaust. It is the one with, I believe, the worst drone. Others will chime in here, but I think either the Borla or Corsa have no drone at all.

I did mine all at once, i.e., full cat back system (I got the Magnaflow, that's how I know about the drone). However, I have the regular R/T, and I'm not sure, other than a better sound, that an after market exhaust will help you that much. The Daytona exhaust is different than the R/T exhaust. Maybe the one thing I would look at would be the mufflers/resonators at the tails. If they are like the R/T's, then they are big, heavy and probably really restrictive. The Daytona's "suitcase" section (kind of in the middle of the exhaust system - look underneath) is straight through (you cansee straight through the Daytona's) , whereas the standard R/T's is not.

Hope this helps.

dave

 

Thanks Dave that helps alot!

So it sounds like the money would be better spent from the cats to the engine then?

Ok, could someone give me a quick synopsis of what each part does between the cats and the engine or point me to a reference?

thanks

 

Basically, the cats attach to the collectors at the end of the exhaust manifolds. You can get headers that the stock/factory cats will bolt directly to once the headers are installed. You can also get "high flow" cats to replace the factory units, and maybe even headers with high flow cats already attached. There are others here who have installed headers, etc., and they can give you more info as far as where to look for them, etc. JBA is supposed to make a really good set of headers. MP (Mopar Performance) also has some. If you go the header route, remember, you still have the units at the end of the exhaust pipes that should probably be dealt with to get the full potential out of the exhaust flow the headers will give you. Again, hope this helps.

dave

 

Again thanks Dave that helps alot! So it sounds like with the Daytona R/T what I need to look at in the complete exhaust system are
1) The mufflers at the end(not a whole cat-back exhaust which I assume means replacing everything from the cat back... hence the name right?)
2) The headers and
3) Changing out the factory cats for some high flow cats

Now as for the headers some are referred to as "shortys" and the some headers are "long tube".. what's the difference? I've also read about mid-pipes and Y-pipes. Do you need mid pipes with shortys and not with long tube or am I missing the boat here? Since I've only heard about the car having one "suitcase" I'm assuming that the Y-pipe brings the two exhaust paths from either side of the engine and combines them going into the suitcase. Is this right?

Thanks for the help!!

 

a great article that should be read at least twice:

http://www.superchevy.com/technical/...exh/index.html

another good article that kills a 'common internet myth'

as info to your question about backpressure always being a horsepower robber -
here is a quote from page 139 of the Austrailan book "21st Century
Performance"

begin quote

"Few tests have been done that clearly show the effect of changing back
pressure. Most muffler and exhaust comparison tests change more than one
parameter simultaneously, making the identification of exhaust back pressure
as a culprit difficult. However, Wollongong (Austraila) mechanic Kevin Davis
has done extensive testing of varying back-pressure on a number of performance
engines. These range from turbocharged Subaru Liberty (Legacy) RS flat fours
to full-house traditional pushrod V8s. In not one case has he found any
improvement in any engine performance parameter with increased exhaust back
pressure.

The tests came about because Kevin has developed a patented variable-flow
exhaust that uses a butterfly within the exhaust pipe. He initially expected
to use the system to cause some back pressure at low loads 'to help torque.'
However, he soon changed his mind when any increase in back pressure proved to
decrease torque on a properly tuned engine. What increasing the back pressure
does do is dramatically quieten the exhaust.

One of the engine dyno tests carried out by Kevin was on a modified 351 4V
Cleveland V8. Following the extractors he fitted a huge exhaust that gave a
measured zero back pressure. Torque peaked at 573Nm (423 ft-lbs) at 4700 rpm,
with power a rousing 329 kW (441 hp) at 6300 rpm. He then dialed-in 1.5 psi
(10.4 kpa) back pressure. As you'll see later, very few exhausts are capable
of delivering such a low back pressure on a road car. Even with this small
amount of back pressure, peak torque dropped by 4 per cent and peak power by 5
per cent. He then cahnged the exhaust to give 2.5 psi back pressure. Torque
and power decreased again, both dropping by 7 per cent over having zero back
pressure.

Figure 6.1 {which is a graph with three lines showing HP against rpm} shows
the power curves gained in the tests. These results were achieved on a large
engine with a large overlap cam - one of the type some people suggest is
'supposed' to like back pressure.

If, in fact, power does increase with increased exhaust back pressure, it is
most likely the air/fuel ratio and/or ignition timing that are no longer
optimal for the altered state of engine tune."

end quote

 

Rugby - The shorties are what you would use if you were going to utilize the existing cats. The long tube headers, I believe, have high flow cats already integrated into them. Mid pipe would be, again I believe, the pipe from the suit case on back. You are correct concerning the X-pipe. It is incorporated into the "suitcase".

davew

 

Yep, shorty headers bolt up to the stock CATs & midpipes. Long tube will extend beyond stock so the CAT/midpipe will be pushed back. Most long tube headers will come with everything needed to complete the install.

Here's a pic of the stock exhaust for reference.


[IMG]local://upfiles/33009/6B6DE6655D674660A7BB92D53074C533.jpg[/IMG]

And another pic:

 

What's the bonus of choosing long or short tube headers?

 

1. Either will allow the engine to breathe better than the stock exhaust manifold.

2. State emission compliancy. In some states LT headers are not legal.

3. End result wanted by the modder: ST will enhance low end torque. LT’s will not produce as much low end torque as ST but there’s torque enhancement throughout the whole RPM range.