Exhaust part advice.......NOISE !!!!
Exhaust part advice.......NOISE !!!!
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Discussion

K13 WJD

Original Poster:

275 posts

221 months

Wednesday 22nd August 2007
quotequote all
hi guys, newbie here.....

I Run a 2.0 16v corsa as a trackcar, and a roadcar......Which as you can understand has its issues....its a fairly well built engine, some mega cams, lightened bottom end/flywheel...Fully rebuilt coscast head....regal motorsports 8000RPM limit chip..and a stainless exhaust....with 2 silencers ( mid and backbox) amongst other things....

im runnig a f16 gearbox, so on track its always well up the rev range ( ie 6000RPM+ )

I was contemplating building a new exhaust system, comprising of a flanged downpipe, and a 2 inch dia Stainless side exit pipe. no silencers.

Now, i couldnt use that on the road due to it being too noisy - but it would be fine for the motorsports i do.....Plus it would sound awesome at full chat. im well aware it would cause a lack of low end power/torque due to low back-pressure/no scavange effect...but at 6000RPM it'll sing just nicely.


NOW, to the point. i want both. Where can i find a exhaust diverter...ie a y peice with a butterfly in it .....one end of the y would be my std exhaust, the other a straight pipe.........quick pull on a cable in the cockpit, and hey presto, it goes from std to race.........

ANY ideas welcome..im sure some ferrari's are fitted with these.....but thats not in my budget !!!!!

BB-Q

1,697 posts

231 months

Wednesday 22nd August 2007
quotequote all

stevieturbo

17,916 posts

268 months

Wednesday 22nd August 2007
quotequote all
Nothing new about it...

Quicktime Performance in the US offer electric cutouts.

Although IMO, most cars with open exhausts like these really sound crap.

as for performance ?? I doubt it would offer any gains over a well sorted full length system.

http://www.quicktimeperformance.com/QTEC/index.php

BB-Q

1,697 posts

231 months

Wednesday 22nd August 2007
quotequote all
stevieturbo said:
Nothing new about it...

Quicktime Performance in the US offer electric cutouts.

Although IMO, most cars with open exhausts like these really sound crap.

as for performance ?? I doubt it would offer any gains over a well sorted full length system.

http://www.quicktimeperformance.com/QTEC/index.php
I have to agree.

There's a performance benefit for turbo cars, but for N/A there's really no point, and you may well fall foul of some tracks noise limits too.

wildoliver

9,199 posts

237 months

Thursday 23rd August 2007
quotequote all
Yep you will probably lose power over a proper exhaust, it will not sound nice at all, and will be far too loud.

Depends whether your track car is for show or not I suppose.

love machine

7,609 posts

256 months

Thursday 23rd August 2007
quotequote all
What duration/timing are the cams, what's the compression ratio and that's a guide.

An open exhaust can help in some cases but I expect that yours will not benefit from it.

Also, what length are your primaries/bore and what comes out of them size wise?

K13 WJD

Original Poster:

275 posts

221 months

Thursday 23rd August 2007
quotequote all
293 degrees duration
13.75mm lift

cam timing was set using verniers at plus and minus 1 degree.....but only as there was some concern as to valve contact....

comp ratio should be 10.9 : 1

as for manifold....its a 4 to one mandrel bent mild steel number, with matched ports. full length, approx 45 cm before collector.

If anything perhaps a straight pipe with a resonator fitted?