Ron Pope Motorsports                California Custom Roadsters               

Header Design & Build

I promised a video with sound so here is a couple I put together and edited with the free
editor called "VSDC Video Editor". I had to run Video Stabilization on the video mainly
for the 2nd segment, there was so much wind buffeting my head where the GoPro was.
Will try to do another video from outside the car soon, but the video below was obviously
more FUN to make !!!

During the 1st pass I bumped the shifter into 3rd gear from Drive, this took my attention
away from driving and the reason why the car changes lanes, I was looking down briefly!
I'm trying to leave it in Drive and see where the new transmission governor shifts. If you
watch thru the steering wheel, the Tach is on the left and straight up is 6000 rpm, I finally
had to lift so the trans would shift, I think it was about 6300-6500 rpm. I'm wanting it to
shift at 6000 rpm. On the right of the Tach is the Speedometer and straight up is 70 mph.
Not sure home much you can tell with the camera bouncing around.

On launch you hear some tire spin, but then it goes away because I am feathering the
throttle. I'm trying not to over rev the engine and bend another intake valve which has
already happened once.

.
 
Good stuff
 
Sounds great! Not too loud or tinny!
As I have more time to experience the sound, it's definitely louder than the old headers, but
like you said "not too loud". I'm still wanting to experiment some and record the sound
pressure with my iPhone with some different setups.
 
For your listening pleasure . . .
Damn did you see his front wheels about 1/2 way down the track !!!

Curious, what did he need the radiator shell for ?
 
Not as much fun testing in the driveway, but still interesting.

I did the sound level measurement first and then I had an idea to video the different configurations
and then splice 5 second segments together so you could hear the difference. Thought this might
be a better way to convey the differences.

Below is my test setup with the iPhone or GoPro at 15 feet from the source.

FP01_SoundLevelTestSetup_02028.jpg

I tested 3 different configurations:

- No Baffle or restriction of any type, open header
- Auger style baffle only
- Baffle wrapped in SS wool

Next 2 photos show how I wrapped the auger style baffle (muffler) with stainless steel wool.

FP01_SoundLevel_BaffleWrappedSSWool_02032.jpg
FP01_SoundLevel_BaffleWrappedSSWool_02034.jpg

Sound pressure level measurements below, next 3 photos.
I thought it was interesting what frequency component had the biggest impact on the sound level. On the graphs you will see 213 Hz, 141 Hz and 124 Hz respectively.

FP01_SoundLevelMeasurement_NoBaffle_02030.jpg
FP01_SoundLevelMeasurement_OnlyBaffle_02026.jpg
FP01_SoundLevelMeasurement_BaffleAndPacking_02040.jpg

 

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