LAT

Harvey, did they give you the Dynojet run file, if you have it or can get it I can compare it to my run file with the Cargraphic 100 cell and see how the outlines compare. The ultimate numbers may vary slighlty for a variety of reasons but the curves will be accurate for the respective cars.

My engine has the Cargraphic 100 cell, the Andial 2 deg timing block and Motorsound intake and exhaust.

LAT

993inNC

Those pics look great and all, but the reality is this: guys are griping about spending $650-700 for a set of pipes. Those pics are of a 996 GT3....a completely different motor, and for the kind of money Euro Pipe charges for that last pic's setup ($3500), I don't think there are to many 993 guys willing to spend 10% of the car's value on their exhaust. Maybe I'm wrong, but.......if I am, I'll GLADLY mimic those for that kinda cake. If not, we're still giving 20 hp out of a cool looking bolt on.

Bill Verburg

Once again use your eyes, the motor is not completely different as far as the exhaust needs are. Look at the broad strokes, the general layout, not the details, not the pretty bends or hardware, not the cats. Look at the design used for a flat, even fire 6.

yes, you would do well to mimic those pipes, in layout, that is what Joe did.

Some simple ss tube, left bank goes to right muffler, right bank goes to left muffler, never the twain shall meet. Use existing stock connectors.

I think it should cost less than $500.

Harvey Yancey

Hey Bill,

Thanks for the post. Those installations are pretty impressive and if I was going to use my car exclusively for the track that is the direction that I would take. But my goal has been to build-up a car that was as track-able as possible but still be able to drive it on the street too. Budget also dictates how far I can go on some projects.

Once I get the new flash I will post the updated results.

993inNC

Well, here's the way I see it. Your saying Joe mimicked those pipes ( in theory), yet his claimed output is LESS than what mine put out. Secondly, and Harvey correct me if I'm wrong, that "system" (including new cut out filter box) was used on a friend of his 993, which actually resulted in a LOSS of power and torque. I have yet to read what the gain is on those "systems" you have pictured. Mine are providing GAIN, so I'm confused as to why you are so against what we are doing? They look great, offer power gains and are only minimally more expensive than stuff that has been plenty well documented here not to fit well or look right. Whats the deal? There are different ways to do everything. Is mine the best? maybe not, but its also not the most expensive and considering they were intended for noise only, the fact that they put out 8% +/- of the cars power at the rear wheels I would say is one hell of a PLUS....no?
And yes a couple of pipes that never meet can be done for $500 (hence this discussion), but why? We have created a functional piece of art for your car for a reasonable price. No slip joints or hanging down below the bumper, just precission fit, one piece art! If you don't care for it, cool but please, like the old saying "if you don't have anything good to say......."

Thanks

Bill Verburg

And that is relevent, how?

Secondly, and Harvey correct me if I'm wrong, that "system" (including new cut out filter box) was used on a friend of his 993, which actually resulted in a LOSS of power and torque.

That's not what I see on mine

I have yet to read what the gain is on those "systems" you have pictured.

possibly because you haven't looked?

Mine are providing GAIN,

I have yet to see a before and after comparison

so I'm confused as to why you are so against what we are doing?
I believe that you are making a good faith effort to make a better mouse trap, but that effort is not based on sound engineering. The workmanship may be great but w/o a good design it is wasted. I am sorry that you feel that my posts are an attack on you ir your product, they are not. I merely feel the need to point out that the factory engineers w/ all of their knowledge and money came up w/ a system based on a totally different design from yours, I put my money on the factory design, it is based on sound engineering principles which I have tried to lay out for you, but apparantly you are confident enough in your gut feeling that the factory has it all wrong.

Bull

It seems to me that the test conducted and the results is interesting but don't really give any insight to me regarding the questions that have been raised several times about differing designs for pipes that eliminate the cat on a 993. I'm not surprised that a car (even with a sick engine) shows a gain in power with the cat removed, although I'm surprised with the small gain in torque with this test, which is more important to me.

I thought that most of the questions revolved around the amount of gain experienced with different designs for eliminating the cat. Until the different designs are tested on the same car, same day, same equipment, I don't see how this discussion will ever be resolved. If the test ever happens, i would hope it will be on a healthy, normal running 993 engine.

993inNC

I just think you are to stuck on the whole "factory engineered" thing, and won't conceed that although its not factory that it can't be right. The factory parts are great and I'm not claiming to be better than the factory engineered parts. But what I am saying is that without spending millions on engineers, we came up with a bolt-on that looks great, gives nice power gains (of course I would like to work on getting bigger torque #'s) and is within a budget that most guys can deal with on their 10 year old cars. IIRC that euro pipe setup (your last pic) doesn't give much more in the way of power but costs $3500.00. I don't see most 993 owners spending that kind of $$. I'm offering a piece that they can be proud to sport on their car and apparently does give a power benefit as well (something we never claimed in selling these).
I've told you before that I don't see your posts as a personal attack, just a general "diss" on what we have done. Yet you stand behind someone else's product, that has fitment issues and is $100 less for simply to slightly bent peices of pipe. Who's lack of engineering is ripping who off? Mine should twice the money just based on the time it takes to HAND make them.

Just look at it this way, mine don't hurt the performance and look good. Think of the pipes as a July 4th sparkler.......noise without harm and look great If you don't like my sparkler, don't buy it......simple

Bill Verburg

What I am stuck on is the phusics of of how an exhaust on a flat 6 works. The factory setup shows a clear understanding of the same physice I know, yours does not.

Apparantly you can not get over the superficial details of what you see in the factory set up. The functional parts as far as a 993 exhaust are concerned and emissions are not an issue are "Some simple ss tube, left bank goes to right muffler, right bank goes to left muffler, never the twain shall meet. Use existing stock connectors."

Maybe I have designed machinery too long, but that's what I see, I also see that they went to a lot of design and manufacturing trouble and expense to have it that way.

LAT

Here we compare torque curves and horsepower curves for two different 993's. One after a cat by pass and the other with a Cargraphic 100 cell cat. The absolute numbers may differ for a variety of reasons due to the tester system of tie down etc. The curve however appear fairly parallel, there is a difference in the last 800 rpm or so where the by pass car comes up to meet the other and then drops off at about 6300 for some reason.

These are placed here FYI only, draw your own conclusions.

LAT

Here are the Air Fuel ratios for the two cars as well.

Harvey Yancey

Keep in mind that this is a modified engine (heads, cams, machanical lifters, etc.) that has not had it's ECU optimized. The test was to see if the pipes help or hurt power.

A friend of mine tried the Fabspeed by-pass pipe last year on his RSA and lost 7HP across the board and I wanted to make sure I did not run into the same issue.

Caveman

Sorry to be a bit thick here but are we saying that the by-pass does not give as good results as the Cargraphic sports cats because of this back pressure issue? Where would a normal set up sit on the graph?

Thanks,

David

993inNC

Fine, so they went through a ton of time and trial....so on, so on. Do you know whether the factory has ever tried my way? I believe the #'s Harvey has posted don't lie, the pipes clearly do provide a positive response, maybe not optimum yet, but nun the less.
What bothers me is that you've never seen (other than pics) my pipes, never tried my pipes, yet feel the need to completely discount them because I haven't spent millions in R&D and don't charge 3K for them. I am not arguing that what you know is wrong, and I've told you that before. But you may need to conceed that (going by the numbers from the dyno), I may not be wrong either. There is always more than one way to skin a cat And my way IS working.

There are times when an agreement just won't surface and I believe this ay be one of them. How about we just let sleeping dogs lie, and just let me revel in my accomplishment, right or wrong.

Bill Verburg

This will be by last post on the subject, you are obviously so wrapped in your product and it's promotion that you see what you want to see.

Yes, the factory did investigate every possible exhaust layout, even those that were less than theoretically optimal.

Here is one not chosen for production, the,image comes from a patent appliction.



Here is the one chosen for production, it is more expensive and harder to manufacture but the mixing chamber design proved more efficint. There were a # of others not chosen either and subsequent cars 996 -997 use isolated banks. Again even more expensive but apparantly worth it. Not all aspects of this design were implemented in production


Good luck to all