Just bought a used M2 dual tip and installed it. First off, the install was harder than I planned. Maybe I am just an idiot but I had trouble getting all the hangers on and the flange bolted up. I found that I had to put the front hanger on first, then the right rear, then the left rear and then bolt up the flange. After that it was piece of cake. I did have the same trouble others have mentioned in that the exhaust tips hang too far to the driver's side. Some rearrangement of the spacers on the hangers helped out. Build quality is excellent.

All descriptions I have heard have been accurate. At idle it is a little louder than stock with a lower, more mellow tone. As soon as you come off idle it quiets a little until the second turbo comes on and then it just howls if you are pulling hard. Not ricey at all, still bassy and mellow but you can hear a shreik mixed in there too when on it hard. Highway speeds are only slightly louder than stock and are not intrusive; everything I wanted.

All that said, my stock exhaust was definately toast. Three different spots on the can where the soot showed small exhaust leaks. When removing a rear hanger I grasped one of the tips for leverage and broke it clean off just inside the chrome surround. Oops! So much for trying to sell off the stocker!

I am now getting 15 psi spikes in second gear though with nothing but a downpipe. My stock exhaust must have been clogged becuase I notice a much bigger difference in acceleration with the catback than I did with the downpipe. When the second turbo comes on it just squats and rushes. I spend a lot of time in the top of second autoxing and I am worried of the spike at this point. Pattern before catback was 10.5-9-spike to 12-10.5 and now it is about 11.5-10-spike to 15-11.5. Can I cure the spike with pill size in the prespool? Any boost controller is illegal in my racing class.

 

Here is the fuel boost cut chart:

RPM       &nbsp ;  ABS. CUT OFF(PSI)         SEA LEVEL CUT OFF(PSI)
1000       &nbs p;              26.5  &nbs p;                 &n bsp;       &nbs p;    11.8
1500       &nbs p;              26.5  &nbs p;                 &n bsp;       &nbs p;    11.8
2000       &nbs p;              26.5  &nbs p;                 &n bsp;       &nbs p;    11.8
2500       &nbs p;              26.5  &nbs p;                 &n bsp;       &nbs p;    11.8
3000       &nbs p;              26.9  &nbs p;                 &n bsp;       &nbs p;    12.2
3500       &nbs p;              27.1  &nbs p;                 &n bsp;       &nbs p;    12.4
4000       &nbs p;              27.5  &nbs p;                 &n bsp;       &nbs p;    12.8
4500       &nbs p;              28.0  &nbs p;                 &n bsp;       &nbs p;    13.3
5000       &nbs p;              26.9  &nbs p;                 &n bsp;       &nbs p;    12.2
5500       &nbs p;              26.0  &nbs p;                 &n bsp;       &nbs p;    11.3
6000       &nbs p;              25.8  &nbs p;                 &n bsp;       &nbs p;    11.1
6500       &nbs p;              25.4  &nbs p;                 &n bsp;       &nbs p;    10.7
7000       &nbs p;              25.4  &nbs p;                 &n bsp;       &nbs p;    10.7

Am I telling you it's ok to spike? No. So many variables can cause the spike to be larger. There are 2 things you can do to reduce prespool up. Either manually adjust the prespool rod or install a restrictor pill.

 

post some good pics. of it intalled for us.