07-14-2008, 04:13 PM
Hi there
As I had some time today I made one of my many old ideas come true; I built my own exhaust. I was never very pleased by the original or Cargraphic twin-pipe design as I was sure it would prefer the higher frequencies. So this morning I went to a friends garage where I could do all the work.
I made a 2 1/2-monotube-design with a resonator and a main-muffler fitted to the original 4-2-1-header and the stock catalytic converter. I could also have used my RSbarn header and 100-cell-cat but as I got to know over the last 15 years I didnt want to lower backpressure too much; even this will give great gains under 3000rpm it could lead to loosing significantly above 5000rpm. Also - and even I made some good power using the RSbarn header - I found it would make the sound of the car a bit noisy / ricey (or how do you say?) and I hoped I would get a nice deep and not too loud tune. So it all was a bit of a compromise... The resonator and muffler are Magnaflow universal parts.
It all took me some 4 hous to manufacture the exhaust, but in the end I was under great pressure (remember that befor criticise the welding as well as the fact that I am a doc and not a mechanic) and I didnt have the time to make pics of the system on the floor nor could I take the weight (which is about half of the stock system). Still I tried to get you some impressions...
Also I made several GTech Pro RR-runs befor and after which gave me consistent results. After was a bit heavier than befor due to my little son assisting me on the testdrive and some 10l more of fuel. Unfortunatelly I didnt have My laptop to pull the runs, so I got the datas in EXCEL-form. Still - as you can see - I was able to make some gains; a lot under 3000rpm and significant from 4000rpm up to redline...
The sound is as I wanted it deep, not too loud, not ricey at all. If I manage I will take some clips and post them here.
OK, that's all for today!
Kunz
As I had some time today I made one of my many old ideas come true; I built my own exhaust. I was never very pleased by the original or Cargraphic twin-pipe design as I was sure it would prefer the higher frequencies. So this morning I went to a friends garage where I could do all the work.
I made a 2 1/2-monotube-design with a resonator and a main-muffler fitted to the original 4-2-1-header and the stock catalytic converter. I could also have used my RSbarn header and 100-cell-cat but as I got to know over the last 15 years I didnt want to lower backpressure too much; even this will give great gains under 3000rpm it could lead to loosing significantly above 5000rpm. Also - and even I made some good power using the RSbarn header - I found it would make the sound of the car a bit noisy / ricey (or how do you say?) and I hoped I would get a nice deep and not too loud tune. So it all was a bit of a compromise... The resonator and muffler are Magnaflow universal parts.
It all took me some 4 hous to manufacture the exhaust, but in the end I was under great pressure (remember that befor criticise the welding as well as the fact that I am a doc and not a mechanic) and I didnt have the time to make pics of the system on the floor nor could I take the weight (which is about half of the stock system). Still I tried to get you some impressions...
Also I made several GTech Pro RR-runs befor and after which gave me consistent results. After was a bit heavier than befor due to my little son assisting me on the testdrive and some 10l more of fuel. Unfortunatelly I didnt have My laptop to pull the runs, so I got the datas in EXCEL-form. Still - as you can see - I was able to make some gains; a lot under 3000rpm and significant from 4000rpm up to redline...
The sound is as I wanted it deep, not too loud, not ricey at all. If I manage I will take some clips and post them here.
OK, that's all for today!
Kunz
