Custom Exhaust Advice Please!

[scsi]

I'm looking to build a custom catback for my 99 STR car and I think I'm almost ready to go, just hoping for some critique before pulling the trigger...

The goal is to find a good balance between losing weight, keeping the noise levels down and adding power. The most important thing to me is that I don't gain weight or lose power, and that it will at the very least pass the general 92db limit (though we don't have strict sound rules at my location yet) and quieter would be better.

The car is a 99 Sport, so far I've got an AEM intake, Maxim Works header, Greddy eManage Ultimate, the last piece of the puzzle is the catback before I tune.

Right now I'm thinking a 2.25" system with a Magnaflow spun cat (6lbs) within 6" of the stock cat (per ST* rules),
http://www.amazon.com/gp/product/B008W11NHS/ref=ox_sc_sfl_title_3?ie=UTF8&psc=1&smid=A2UUWCCR4G5EFA&tag=5336121873-20

and a Dynomax Race Bullet (6lbs) roughly in place of the OE resonator on the midpipe
http://www.amazon.com/gp/product/B000CIR42C/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER&tag=5336121873-20

and finally a Flowmaster dbx muffler (9lbs) in the rear section.
http://www.amazon.com/gp/product/B004TRXNEA/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER&tag=5336121873-20

I'm guesstimating the proposed system to weigh under 30lbs, I can't imagine it flowing worse than stock, and the dbx seems like it'll keep the noise levels down.

I also want to have the rear section flanged, this way if i want to drop more weight i could replace the whole rear with a turndown right off of the midpipe

Comments? Concerns? Critique?

Thanks in advance!!

[kung fu jesus]

I did something similar on my NA when I had a turbo. I understand the option for a turndown/flanged rear section, but it is an opportunity for a leak.

My only other recommendation is a flexpipe section between the header and cat (can't remember if the Maxim already has one). It will take a bit of stress off the header manifold flange and possibly a lot of vibration from the car.

[scsi]

Thanks for the response! The maxim header does have a flex section in it. As for the flanges, I want to keep the modularity in the system but a leak doesn't sound good. I never thought about any gasketing on a custom system. Actually my original idea was a slip joint which seems to simplest and lightest, a shop I went to told me to do a v-band, and the last shop told me to do a 2bolt flange.. Idk :[

[MX5RACER]

The proven CSP set-up has been 2.5" pipe with a hushpower 18" muffler. Add in a high-flow cat and your car should not be loud or too restrictive.