Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Incredible Exhaust System (repost)

Ok someone please post a summary of all findings...it is very confusing

Thanks
Derek

Has anyone here ever heard of Laminar flow? How about sonic waves? and the part these 2 items play in your exhaust system.

No I doubt it because everyone here looks at the face value of the diameter and the word meaning (crush) instead of the physics behind it. Laminar air flow "smooth flow" does take an effect in this area and also Poiseuille's Law also effects the given output. Thus the given output would exceed the given flow if the rate of pressure is constant which in this case it is not. Therefore there would NOT be a sufficient loss between the Mandrel and Crush bent pipes based on the fact that the open corners in a mandrel bend in effect "slow" down the where the crush bends actually "speed up" the airflow through the bends by the pressure differential acting as a doubler. No this is not backpressure persay - But a given physics force that drives the air out.

I've read this whole post and from what I've read - It all comes down to who created it. It has nothing to do with the crush or mandrel bends. This is a very poor example to make of someone who did improve on a factory design and also offers it at a decent price. Whine whine whine - And DemonSVT, what else would anyone else want besides performance for their SVT? You are truly the king of idiots for you contributory ramblings.

John

Maybe you didn't read the whole thread then.

Is there any dyno proof of before and after with cardoc's system vs stock SVT yet? (same car, same dyno)

As I said then. I am willing to bet the stock system will out perform it with less than $100 worth of changes... (resonator & rear Y-split)

...and as for me just rambling. I'll let my dyno speak for my tuning and fabrication abilities...

Something cardoc never could or would own up too...

I don't know why you folks come over here just to stir up trouble when you always get shot down the same way. With cold hard facts...

If you could see through your own arrogance Demon I believe the Doc was after sound and performance. Something that is a little bit of a fine line in these cars. Obviously you've overlooked that fact that was presented almost two years ago - Ohh... I guess that his research with using over 8 brands of mufflers and 8 hours of pipe bending and trials to get the right sound and fit goes without mention and consequence to you.

Nobody asked if the stock setup could be improved with a $100.00 in modifications. It would still not sound like his system no matter what you throw on it. As far as dyno's are concerned - I don't see you trying to win any poles in the Contour NASCAR so please take your dyno bs and give it a rest. Youd dyno sheets showing a precious extra hp will not make you faster in an autocross ... You merely waste your time and keystrokes. Your highest # of what???? Gee - Didn't someone who actually has his exhaust already present dyno data? You just have a hard time believing that something could actually be good about that system - Don't you. Give the whole thing a rest - It's terribly obvious you don't like the guy so you shoot down anything he has, Pity that he has something to offer that is pretty good and all you can do is badmouth him about it when he's not even here to defend himself.

John

I'm just voicing my opinion that his setup is far from optimal and adding that extra weight is a double negative.

I don't argue in the least it is a great sounding exhaust. It does sound very nice. However I personally don't buy an exhaust on sound alone. Peformance normally drives my choices and it is noticably lacking in this department versus numerous other options.

As for cardoc. There are many reason not to like him. None of which I will get into, nor change the hard facts against his exhaust.

I do notice that any time hard facts are brought up against cardocs "views" his groupies come out of the wood work and attack the "nay-sayers" A far too common practice I must say.

You do realize this is far from the first time any of this has come up & likely far from the last time as well unfortunately.

As for ragging on my car. Whatever makes you feel better. :rolleyes: Seems a little silly since we all own a version of the same thing.
I find it performs quite nicely in all aspects thank you.

Demon - This addresses you and the other CEG nay-sayers as you call "the followers".

I have no idea why you have a beef with Cardoctor. The stone cold facts are these - Thanks to your great "search" system I was able to find all the answers I needed.

#1. When Doc originally posted about his exhaust system he never touted that it actually created more horsepower - Only that it sounded better than factory and gave him a better performance feel. IIRC he was the FIRST person to do dual pipes around the tank (owner wise) not racing. This paved the way for the current dual exhausts knowing that it could be done and that using it on a daily basis instead of just racing was feasible. He gave everyone the idea - Posted pics, helped people that wanted the system and were trying to get them done at their local shops.

Ask anyone who has his setup or who has reproduced his setup about the actual system - You will not find one dissatisfied person. That should speak for something right there. Just because he has a difference in opinion does not mean he should be the "black sheep" of the CEG. Do you not realize that he has contributed more than just the exhaust system? He has also helped many many people in the time he was a member here. I remember when everyone was asking him questions (before I ever signed up) back when I remember he was an active member. When I signed up I never posted much because of people like you who make people out like they are truly below you. Did he screw your dog or something, because how you and others treat his name like a bad omen are only the root of all the animosity between the sites and him. I guess it's hard for you to see that because you seem like a "yes man". I had the opportunity to meet this Cardoctor last year and I learned more about my SVT in 4 hours than I ever read in 2 years of owning it. You should be sorry to lose someone of his obvious knowledge and expertise. The only reason he started his own site was to break away from this "clique" started here by a few moderators and people like you. Frankly I see why he did it and with his intelligence and resources I would be really concerned about the impact of his site will have on this one as time goes on. He is obviously trying to make a great site - You never see people getting ripped down for their ideas and the atmosphere seems pleasant instead of timid and tense.

From all this info I've collected from the many pages and pages of bs that I've sifted through on my spare time - All the guy ever did was defend himself... You all had an axe to grind with him anytime he stepped into a conversation so I don't see why him having his own site makes members here feel like he is belittling you. When even is the last time he posted here???? He is no threat to you if you have nothing to worry about right? But obviously you are worried and maybe you have a right to acting with the attitude you do.

You see my member #, you see my join date and you see my number of posts. That is directly because of posts like this. I'd rather read and move on instead of answer to posts that have no more meaning but to rip a fellow enthusiast down.

What a sad affair here - Really and truly is.

John

I just bought a '98 GL 2.0 (K&N air filter isall I've done so far). I want to improve the exhaust first, but my limited knowledge and budget plus the different views I read on this forum cause me to be confused. Is the biggest bang for the buck gotten with a slightly modified single? What exactly should be done to a single? Or should I be looking at a single to dual, and, again, what are the recommended mods in this scenario? What is this CarDoc's system, and what is the address of his web site? I'll have a lot more questions in the future, so be patient with me.

Originally posted by trapps
demon, I'm no physicyist, but when a a diameter decreases, doesn't flow speed increse? A simple question from a guy who took High School physics a long time ago in a galaxy far far away......... It may be true that the flow speed may increase after the point of restriction, however pressure will also increase behind the point of restriction, more backpressure= less hp. Does that sound right?

All of you are not seeing the complete picture. This is something that has already been posted in this forum by other members and completely overlooked.

#1. RoxRocket says "The overall pipe diameter between both pipes is enough to feed a small block.

#2. Others have pointed out the same.

Here, Let me show you school children (DemonSVT) what I'm talking about.

Take your crush bent exhaust. 2 pipes at 2.25 inches. On crush bends only the inside of the pipe is actually crushed - And true mandrel bends lose diameter on the inside of the bend also - Just not as noticable. Say the the crush in the bend reduces pipe diameter to 2". That's a 1/4" in pipe deflection. So in the worst case scenario you have two full length 2" pipes considering the defelction. Do you realize the overall total exhaust cross size is 4"?

2.0 + 2.0 = 4.0 inches. The system has more than enough capacity - The factory system has one single 2.25 pipe and a 2" neckdown at the factory Y. Using basic mathematical calculations 4" cross section is a HELL of alot bigger than the factory 2.25". Losing power from backpressure? Where in this system could you get backpressure from? You effectively doubled your factory flow right off the bat running the system at it's worst point.

Crush vs Mandrel is a very old topic. In a single 2" pipe coming from the engine back this could be a critical point. But for this setup - Using mandrel bends would NOT make any benefit.

Geez - And it didn't take a genius to figure this out, just a brain that some people seem to forget they have.

John