Exhaust Question - interesting

[firefox]

Hi

Have an r33 gts-t with about 3" dump pipe, straight through catalytic converter, and 3.5" - 4" straight through Apexi exhaust. Gt30 turbo, microtech ltx-12, standard injecors, Making about 198rwkw at about 15psi.

Car use: daily drive, 1/4 mile, cruise, high speed driving, and want to do 'track days' in the future.

It’s VERY LOUD not your standard 3.5' loud, I mean loud est. 110+db. Also when I kill it there is a 'flame' after burn from the exhaust, reduced this a little with some tuning but its still happening.

I want to get a quieter exhaust.

This is what I though, and was ratted at 89-90db (EPA compliant t00!).

- Install catalytic converter

- 3" mantel (or whatever it’s called) bend piping

- Hotdog/Straight through resonator

- 3 flow muffler.

"The guy at the exhaust place" said the catalytic converter will help protect my engine, because it will provide back presser and at the moment the straight through cat does not have any back pressure. Also should stop the after bun/flame from the exhaust.

Is a cat a good idea and how will it affect performance????

Does anyone know about 3 flow mufflers?

How will the suggested system affect my performance???????????????????????

Was told it would give me more power down low while only losing 3-4rwkw on the top end.

And finally how much tuning do you thing will be required once the new system is installed?? eg. Timing change...

[firefox]

Also it was suggested that i could take off the 3 flow muffler and bolt on the 4'' apexi cannon for track work

[someonestolecc]

You don't need backpressure.

A cat is a legal requirement and if you get caught not having one EPA are going to slap you a fine.

I have a similar settings to what you're saying stainless eximani>dump>front pipe>cat>resonator (hot dog)> cannon muffler and the thing isn't quiet.. it was measured at 96db. Probably a lot quieter than yours though.

I don't think performance is an issue.