new exhaust makes big power

[falcon fanatic]

Hi,
For those of you who haven't been following the progress on my Falcon restoration, here's a little update. I've done all sorts of repairs on it which are detailed on the videos in my blog, or which will be when I get around to editing the rest of the footage. One thing I will tell you about here, as it relates to small six performance, is my new exhaust system. After reading several articles and a book by David Vizard I built the exhaust you can see in this post here:

http://falconfanatic.blogspot.com/2012/ ... ng-in.html

And in this video here:

http://falconfanatic.blogspot.com/2012/ ... ision.html

Well, I took it out for a drive today (Finally! car has been on stands since February 18, 2011) and the results are stunning. I had this engine built a year before, and I've been sorely dissapointed with the performance ever since. No surprise give the exhaust I was running, but little did I know what a big difference this would make. Now, it just takes off from 4000 to 6000 rpm, and makes much better torque below that. It's a screamer. I do need shorter gearing, though. Video forthcoming, before I install the mufflers...

 

[turbo2256b]

Looks good. couple things that might be a bit better a smoother longer Y my last one was about 16" long. Having th dual outlet that distance from the header exh gases are cooling and smaller dia tubing helps to keep the exhaust velosity up.

The anireverson thing is a good idea usally do them at the street hookup.

 

[falcon fanatic]

Actually, the Y is about 18" and very smooth both inside and out. Here is a link to a better picture:
http://www.mandrelbendingsolutions.com/ ... %2C/Detail

I compared several products before choosing this one. You're right about the length, though. Those pipes probably should be more like 40" given that my primaries average out to 20". It's just that it looked so darn cool as it was coming together that I couldn't bring myself to cut them down. If I was building for max power at a certain rpm I would determine pipe length and diameter on a dyno. I this case, I just did some math and came up with the most practicable solution, and then winged it from there.

The question of pipe diameter is a tough one, though, because it affects the size of the header reducers, which will also have an impact on power output. Since I have 2.5" collectors, dropping to a 2"pipe at the collector would create a big pressure increase at the collector which will pulse back to the exhaust valve at different frequencies than the one created by the end of the pipe. I sacrificed velocity for smoother header reducers more predictable pulse tuning, leaning towards data that indicates that pipes between 36" to 60" will give the fattest torque band, and anything I did was going to make better high rpm power what I was running before.

 

[CoupeBoy]

Looking good, can't wait to see videos of it under its own power and hear your 'seat of pants' impression of the changes you made to the cars structure.

-ron

 

[falcon fanatic]

Made a drive around the hood today and a little stretch of rolling road and it certainly feels much more solid. This with no sound deadening or carpet or anything, just one seat, so if it feels solid now, it'll feel awesome with all the interior and some dynamat in. . I also upgraded to braided brake lines and a '67 mustang master cylinder so I had to make some panic stops to adjust the brake bias valve as the rears where locking before the fronts. In addition I did one good standing start full throttle run up to about 50 or so. All together I was left with very favorable impressions.

The car feels stable and nimble, is much quicker, and the brakes stop straight and true. This without even doing an alignment after changing the lower control arms to opentracker spherical bearing units and dissassembling and reconditioning the strut rods. Good, good, good...

 

[CoupeBoy]

The LCA spherical bearing swap has had me wondering if there is any more vibration transmitted up into the unibody, have you notice any additional noises? On the other hand the upper control arm has always been metal on metal so maybe there wouldn't be any additional vibration/noise by changing out the lower half of the system...

Did you buy the parts and make your own? Or did you buy them pre-assembled?

You kept the rubber bushed strut rods? No spherical bearing or Heim jointed ones yet? Interesting, very interesting...

Deep Thoughts, by Jack Handy....
-ron

 

[falcon fanatic]

No, I have TCP strut rods. That was one of my first mods as the stock ones were deflecting under hard braking and I'd already been through a similar modification with a Supra I used to have. The spherical LCA, which I bought assembled from Opentracker, are surprisingly smooth. I was expecting more NVH, but actually the ride is smoother, even on these nasty DC streets. Weird, because my experience with urethane bushings is quite the opposite. However, these have dramatically less friction that even the best lubed urethane installation, so maybe that's why. I now have spherical joint strut rods, LCA, roller spring perches, and the upper arms are metal on metal, as you say. So my whole front suspension is metal on metal, with lowering springs and bilstein shocks, and is smoother than ever. Go figure.

 

[CoupeBoy]

Well they do say iron (FE) is good for you....

Happy to hear the results, keep emailing coming,
-ron

 

[falcon fanatic]

finished system:

http://falconfanatic.blogspot.com/2012/ ... -demo.html

 

[wsa111]

Very nice job done.
Quality workmanship & the exhaust sounds great. Bill

 

[dshorton]

Excellent!!! Love the sound you have been able to achieve. 8) I will have to get back through all of your old posts, so I can get some better info for the calculations for my own cars.

 

[falcon fanatic]

Thanks, I do think it sounds great. I think a lot of the buziness I'm experienceing from the driver's seat is because I have no interior and no sound insulation, so the whole body is buzzing a little when I drive. And thanks for the comment on the worksmanship. I really spent a lot of time designing and carefully welding all those mandrel bends together. I'll post pictures of the rear sections later today.

 

[don65stang]

I watched your vids and really like what you've done. It sounds good too! I don't know much about exhaust and am trying to plan out an exhaust for mine. What made you decide on the dual headers setup instead of the 6 into 1 header? Again, I know very little about exhaust theory so I appreciate your posts and videos.

 

[falcon fanatic]

I bought the header years ago, so that's just what I had. However, it is pretty well established that a 4-2-1 design, or in our case a 6-2-1 design, makes for a broader torque band than a 6 into 1. 6 into 1 (and 4 into 1) headers tend to have higher peak torque and hp numbers, but with a much narrower torque band (sweet spot). That's why you'll see that type of header on race cars that spend most of their time at a certain rpm such as dragsters and road race cars, whereas you'll see the 6-2-1 (and 4-2-1) design on street cars and slalom cars more often. Since this is a street car which spends most of it's time between 2000 and 4000 rpm, then I'm using this exhaust design: It has the low end torque but still retains a substantial boost in hi-rev power.