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Anybody ever tried doing away with the cat and muffler and running a straight through system on an na6. good idea or not, its on a race only car.
olboy

I think it would sound absolutely crap.

don't beat around the bush give it to me straight

No back pressure. Not sure if that's real good. Yes it will probably give you a slightly better Dyno reading But I feel Patchy likes a little back pressure. Mine was almost like what you describe. It idles better with some extra back pressure. As well my transient throttle seems to be less obvious with a little extra backpressure

olboy wrote:Anybody ever tried doing away with the cat and muffler and running a straight through system on an na6. good idea or not, its on a race only car.
olboy

I have no cat on my NA6 racer. The system goes 4-2-1 extractors>2.5" press bent pipe>hot dog resonator>2.5" press bent pipe>straight through muffler>2.5" press bent pipe tip.

The sound is raspy but you can tell there isn't much restriction to breathing. Much better than stock. Comes in at 98db at Lakeside.

No power figures as the car came with a side exit muffler that was bashed and rooted (being so low, it's no surprise). I replaced it straight away.

Oh, another thing. There used to be a flexy bend at the end of the extractors. That busted after a short detour on the grass at a race meeting so we ran without any rear section for the rest of the day.

NO top end power due to car pinging its head off. I'm guessing that had a lot to do with the O2 sensor being so close to the outside world. Maybe a bit of back pressure helps the sensor work properly. Your Miles May Vary.

Boags

I've seen one NB running with just a hotdog to a side exhaust. Blackflagged for noise. I don't think it gave it any gains anyway.

i just got rid of an exhaust that had an empty cat and muffler. more power but less torque. and it was very very noisy and annoying. don't do it.

It would just sound like a huge raspy fart at nearly 100db. Cop magnet.

very raspy and much louder then 100db. mine was 101 at 5krpm. would have got to 110 easy.

here's mine.

http://www.youtube.com/watch?v=Gn_UEYWNrX4

in a tunnel though.

Boags wrote:Maybe a bit of back pressure helps the engine work properly.
Boags

rectified & quoted for historical purposes

maybe I should quote your comments in mIRC for hysterical purposes Boags???...........no???

AJ wrote:

Boags wrote:Maybe a bit of back pressure helps the engine work properly.
Boags

rectified & quoted for historical purposes

maybe I should quote your comments in mIRC for hysterical purposes Boags???...........no???

Bite me.

PS: you are wrong.

bruce wrote:It would just sound like a huge raspy fart at nearly 100db. Cop magnet.

olboy wrote:its on a race only car.
olboy

didnt know there were any cops on the track

MXHEVN wrote:

bruce wrote:It would just sound like a huge raspy fart at nearly 100db. Cop magnet.

didnt know there were any cops on the track

Well there is the sound police! Can't exceed 95db at most tracks otherwise you get booted off. (At least you dont get a ticket, but you also cant race again till you quieten it down..)

ah touche!