JBrady

Kyle, actually, that is NOT what I am saying. You currently have a 60mm (2.36") center resonator. Removing it by itself will not help as it is a straight through design. What I was saying was the GS resonator and splitter (the section that splits it back into duals after the center resonator) on the GS cars is the main reason (plus the silencer's) for the 10hp/10tq diff in the GS vs the SC400 and LS400/430 cars.

If you put on larger pipes you MAY or MAY NOT gain power in fact you may loose power if not designed correctly. You could get lucky and then again...

Now, Roenick has a custom exhaust that gained him 30hp on his supercharged and modified GS. I haven't seen any pictures of his system (I would like to) but he does say he used 2" piping which is SLIGHTLY larger than the stock 50mm (1.96") pipes. He deleted the stock Y pipe, center resonator and splitter. All of which are better than the SC and LS parts. He used an H design which is proven to make more torque than just duals without a crossover. Now, a properly designed Y pipe or X pipe is proven to make more torque than an H pipe. So, IMO, an H design is not the way to go if you are going to the trouble of re-working your system. I am also going to use 2.25" piping which has more peak flow potential but by going with a larger pipe it becomes critical to keep the velocity high so as to preserve and enhance torque accross the range.

When my Y pipe is done and tested I may offer copies for sale. We shall see. It is an art and a science to design a system that will keep as much of the exhaust energy intact at all RPMs. This will enhance power accross the range.

nudderGS400

I also lost the two center resonators. I did it because a speed bump crushed a center section of the exhaust on one side and instead of buying the new sections (only sold in pairs for $485) I thought I'd try it with straight pipes instead for 50$ and see how it was. They slid 2.5 inch piping over the 2.25 (I think) and welded them keeping the flanges on both sides so i can go back.

Results were: a little louder, not much (still have stock exhaust) and no noticable change in power. I am putting Borlas on next week. Remind me and I will let you know how loud it is then.

Also, losing the resonators would allow me to put the full boxed version of the lower chassis brace on. But I deceided to stop after the 6 pc kit anyway.

Either way, I think you need to consider an intake with ECU or SAFC to eliminate the bottleneck up front for performance.

Used SRT for sale anyone?

JBrady

nudder, if I understand your post you had damaged one side of the dual system AFTER the center resonator... correct? If this is the case, and you had them just splice a piece in place, I would not expect any noticeable gain as that is not the restriction area. Notice that Roenick kept that part intact and replaced the front Y section and center resonator with an H pipe arrangement made from 2" pipe.

Another observation, one that I see VERY frequently at muffler shops... when they splice a larger diameter pipe (2.25 over the 50mm stock) you end up with a very poor flowing section where it goes back to 50mm. The inside "see's" the sharp edge and flow is turbulent and poor. It may phyisically fit on the car but that does NOT make a good section. Sorry. Transitions should always be smooth and gradual with the downstream side NEVER protruding into the gas flow.