What's the real story on headers
02-12-2015, 11:20 AM
#16
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I don't have the hard empirical data you are looking for, but went through this exercise a few years ago and looked at it all. My objectives were improved sound, weight reduction, heat reduction and power gains. Probably in that order. This was primarily for a street application.
I considered everything from starting from scratch (headers and all) to simply changing the center muffler. My recollection is that power gains from swapping headers was pretty small and I could get most of what I wanted by leaving the OEM header intact.
In the end, I decided to dump the side mufflers and replace the center muffler. I used M&Ms system. Saved a bunch of weight and helped a lot with heat in the rear quarters. The side mufflers are ovens.
Definitely a discernible pickup in torque and HP. Not huge, but I knew before I got into second gear. I should clarify that this was a 4.0 car, so the gains to be leveraged were probably less than those in 3.6 or 3.8 applications.
I considered everything from starting from scratch (headers and all) to simply changing the center muffler. My recollection is that power gains from swapping headers was pretty small and I could get most of what I wanted by leaving the OEM header intact.
In the end, I decided to dump the side mufflers and replace the center muffler. I used M&Ms system. Saved a bunch of weight and helped a lot with heat in the rear quarters. The side mufflers are ovens.
Definitely a discernible pickup in torque and HP. Not huge, but I knew before I got into second gear. I should clarify that this was a 4.0 car, so the gains to be leveraged were probably less than those in 3.6 or 3.8 applications.
02-12-2015, 12:01 PM
#18
So the back story is this. I have GMG headers on my RS, side muffler delete and M&M exhaust. The bung broke and I pulled the header off to have it welded back on. In doing this I realized the packing from the cats is falling completely out. So I emailed GMG. I didn't get much help. They want to charge me $1200 per side to rebuild. Car only has 13,000 miles. They blame it on abuse.
I've heard that the power gains are not found in the headers, but the side muffler delete and a high flow center exhaust. Others claim they come from the headers.
I started looking at the factory headers. There really isn't that much difference and it makes sense that Porsche would put the most powerful, lightest and highest flowing header they can get to make emissions and last. They went as far as to make the center out of titanium!
So my real question is who has done actual testing and has data on the factory headers versus after market with side muffler delete and high flow center exhaust? What does the data show?
I really don't want to hear from anyone that is guessing or someone trying to sell there product. I want the whole truth and nothing but the truth so help me God!
I've heard that the power gains are not found in the headers, but the side muffler delete and a high flow center exhaust. Others claim they come from the headers.
I started looking at the factory headers. There really isn't that much difference and it makes sense that Porsche would put the most powerful, lightest and highest flowing header they can get to make emissions and last. They went as far as to make the center out of titanium!
So my real question is who has done actual testing and has data on the factory headers versus after market with side muffler delete and high flow center exhaust? What does the data show?
I really don't want to hear from anyone that is guessing or someone trying to sell there product. I want the whole truth and nothing but the truth so help me God!
02-12-2015, 12:13 PM
#19
So the back story is this. I have GMG headers on my RS, side muffler delete and M&M exhaust. The bung broke and I pulled the header off to have it welded back on. In doing this I realized the packing from the cats is falling completely out. So I emailed GMG. I didn't get much help. They want to charge me $1200 per side to rebuild. Car only has 13,000 miles. They blame it on abuse.
I've heard that the power gains are not found in the headers, but the side muffler delete and a high flow center exhaust. Others claim they come from the headers.
I started looking at the factory headers. There really isn't that much difference and it makes sense that Porsche would put the most powerful, lightest and highest flowing header they can get to make emissions and last. They went as far as to make the center out of titanium!
So my real question is who has done actual testing and has data on the factory headers versus after market with side muffler delete and high flow center exhaust? What does the data show?
I really don't want to hear from anyone that is guessing or someone trying to sell there product. I want the whole truth and nothing but the truth so help me God!
I've heard that the power gains are not found in the headers, but the side muffler delete and a high flow center exhaust. Others claim they come from the headers.
I started looking at the factory headers. There really isn't that much difference and it makes sense that Porsche would put the most powerful, lightest and highest flowing header they can get to make emissions and last. They went as far as to make the center out of titanium!
So my real question is who has done actual testing and has data on the factory headers versus after market with side muffler delete and high flow center exhaust? What does the data show?
I really don't want to hear from anyone that is guessing or someone trying to sell there product. I want the whole truth and nothing but the truth so help me God!
As far as a replacement header, lots of options. I am not a big dyno sheet guy. Choose what your trusted dealer recommends.
I went with a set of PMNA headers.
02-12-2015, 12:20 PM
#20
Rennlist Member
Yes sounds better. And when I went to the setup I mentioned I could tell a difference in every day driving across the range. So I would say the right header setup is worth the money
02-12-2015, 12:40 PM
#21
Rennlist Member
full custom set up from someone that knows what they are doing and you get power - catless, side muffler delete, and decent weight loss (IIRC from 70 lbs to 28)... just what's pictured below bolted on was 25+ hp without tune... since then the car has morphed into quite a bit more... but I had a similar experience on my previous 996 gt3 by just changing headers back.
is it all worth it?
I think so... car has noticeable power gains and sounds great
If I was forced to run CATs I am not sure I would do anything but a bypass pipe or the side delete... Cats seem to the be culprit in most of the exhaust disappointment scenarios -- failed cats, cats throwing check engine, costly etc....
is it all worth it?
I think so... car has noticeable power gains and sounds great
If I was forced to run CATs I am not sure I would do anything but a bypass pipe or the side delete... Cats seem to the be culprit in most of the exhaust disappointment scenarios -- failed cats, cats throwing check engine, costly etc....
02-12-2015, 02:06 PM
#22
Rennlist Member
02-12-2015, 07:49 PM
#23
02-12-2015, 07:56 PM
#24
02-12-2015, 08:27 PM
#25
That was enlightening.
Here is some light reading on GMG, headers, and cats. Looks like they are back to their old tricks.
As far as a replacement header, lots of options. I am not a big dyno sheet guy. Choose what your trusted dealer recommends.
I went with a set of PMNA headers.
As far as a replacement header, lots of options. I am not a big dyno sheet guy. Choose what your trusted dealer recommends.
I went with a set of PMNA headers.
02-12-2015, 10:19 PM
#28
Drifting
02-13-2015, 10:47 AM
#30
Drifting
I have been running GMG headers on my 2010 GT3 for 3 years. The cats went bad after a time so I just got rid of the internal elements and put them back on. Of course it will not pass emissions anymore but who cares. FWIW, I deleted the side mufflers and used stock rear until it cracked then welded it back together. Last year I removed the rear stock muffler and now run little coffee can mini mufflers. It is LOUD.