Dundon GT4/Spyder Race Header Group Buy
#437
will hopefully get to go for a drive tomorrow or Thursday, i'll let ya know, double demerits will probably start Friday, this nanny state country so pretty keen to give it a squirt before the fun police come out in force
Mechanic said the quality and fitment were excellent, O2 sensor a little tight
Mechanic said the quality and fitment were excellent, O2 sensor a little tight
#438
#439
Creates a bit more of a "vacuum" by emptying the exhaust completely. Essentially goes along with their "tuned header" description.
#440
This creates scavenging? How does it evacuate if sealed at the end? I am intrigued.
#442
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From: Gig Harbor, Wa
This is why we call all of our designs "tuned length", not long tube as longer isn't always better. It's the tuning that creates power throughout the entire powerband.
The 4th tube is a patent pending design that aids in a number of parameters that enhance our ability to tune the headers...
Can't say too much as not just customers watch this thread...
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#443
Not so much fluid dynamics as it is pulsed gas flow. The gasses leaving a cylinder when an exhaust valve opens creates a pressure wave (imagine the picture of a bullet leaving a gun...) That pressure wave expands, reflects and is redirected back to the head. If the timing is correct you get the reflected expansion wave (now a "suction wave") back to the cylinder head when the exhaust and intake valve are both open. This allows more air to be removed from the cylinder and also pulls fresh air into the cylinder through the intake valve. Some headers get this right by accident, some of them get this right by design.
This is why we call all of our designs "tuned length", not long tube as longer isn't always better. It's the tuning that creates power throughout the entire powerband.
The 4th tube is a patent pending design that aids in a number of parameters that enhance our ability to tune the headers...
Can't say too much as not just customers watch this thread...
This is why we call all of our designs "tuned length", not long tube as longer isn't always better. It's the tuning that creates power throughout the entire powerband.
The 4th tube is a patent pending design that aids in a number of parameters that enhance our ability to tune the headers...
Can't say too much as not just customers watch this thread...
#444
I understood that tuned headers only work over a certain RPM range (due to the fixed length of the headers combined with variable engine speeds leading to the rebound timing only "working" in certain ranges). Is this what you mean by working over the entire "powerband" - ie a certain rev range. If so, what range have you targeted?
#445
Hey Mike, I will be there (if my schedule holds) with MVP for the 3 days. My only engine mods will be the headers/filters / and tune. Hopefully we are in the same run group. Than we can run tests the whole 3 days if we desire.......
#446
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From: On a pygmy pony over by the dental floss bush
I think where the fourth tube ties in to the collector it is sharing sonic/pressure pulses with all 3 cylinders, not just one, but that's based purely on what I can see from the few photos I've seen on this thread.
#448
Nice! There will be several other GT4s there as well, so I'm sure we can do some experimental drag racing for comparison.
#449
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From: Fort Washington, Pa
PA is so boring, wishing we were located in TX so I could get in on this haha
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155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com