Headers.
02-10-2003, 12:49 AM
#1
Nordschleife Master
Thread Starter
Headers.
This recent hit of the bottem insident as reminded me that I need to replace my motor mounts, and soon. (As if the viberation wasn't enough...)
I would like to think that I've got a very free flowing exaust. However, one thing could use some improvement, I could use a set of headers. This is on my list of things to do while I'm replaceing the motor mounts. Might as well think about it while I'm thinking about Ford vs Porsche mounts.
As far as I can tell, there are two fairly common brands. MNDS, and Devek. Are there any others for a 928?
I know haveing a free flowing exaust will reduce backpressure on the engine. This should reduce the density of the exaust in the pipes, and that changes the speed of the pulse that the headers are tuned to. If it's enough of a diffrence, the pulse will be changed to the point that the header won't do it's job so good.
Now my question, does anyone make a header that will work well with a free flowing exauste, on a 928S?
Btw, I have no cat, or center muffler, the final, and only, muffler is a ANSA, which I am not fimiler with. At least I think it's a ANSA muffler. It's a boxy looking thing with the letter ANSA punched in the bottem of it. The PO thought it was a Borla.
Thanks
I would like to think that I've got a very free flowing exaust. However, one thing could use some improvement, I could use a set of headers. This is on my list of things to do while I'm replaceing the motor mounts. Might as well think about it while I'm thinking about Ford vs Porsche mounts.
As far as I can tell, there are two fairly common brands. MNDS, and Devek. Are there any others for a 928?
I know haveing a free flowing exaust will reduce backpressure on the engine. This should reduce the density of the exaust in the pipes, and that changes the speed of the pulse that the headers are tuned to. If it's enough of a diffrence, the pulse will be changed to the point that the header won't do it's job so good.
Now my question, does anyone make a header that will work well with a free flowing exauste, on a 928S?
Btw, I have no cat, or center muffler, the final, and only, muffler is a ANSA, which I am not fimiler with. At least I think it's a ANSA muffler. It's a boxy looking thing with the letter ANSA punched in the bottem of it. The PO thought it was a Borla.
Thanks
02-10-2003, 04:09 PM
#2
Rennlist Member
I tested the DEVEK MSDS headers and the devek stage 2 headers. on the 2 valve, they were very effective. the ENTIRE hp curve was shifted higher. (ie no loss of torque at the bottom at ALL!!!!) free flow (or race) exhaust gave almost as much. (ie straight pipe, with only a borla tip) flow master cost about 4hp in addition to the borla tip on the part euro 5 liter when it was dynoing about 285 at the rear wheels.
I have a set of S4 headers that will work on the 4.7 l block. (small mods needed) I also have the cat bypass Y pipe., so you could install a cat on smog years. It would be a bolt on affair with probably as good as MSDS headers with the addition of the Y pipe to drive down costs.(that y pipe can be expensive as well, and you would need a custom cat to replace it during smog years)
Let me know if you are interested.
MK
I have a set of S4 headers that will work on the 4.7 l block. (small mods needed) I also have the cat bypass Y pipe., so you could install a cat on smog years. It would be a bolt on affair with probably as good as MSDS headers with the addition of the Y pipe to drive down costs.(that y pipe can be expensive as well, and you would need a custom cat to replace it during smog years)
Let me know if you are interested.
MK