Exhaust sizing and sound for Super Charged M42....

[JiXer]

I am building what I am calling an M43SC.
Its part M42, part M44, and will be running a modified DASC system on 12 psi.
My best calculations say that I should come up with about 230-250 HP at the crank.

I have read a lot of info pulling me toward a 3" exhaust and a 2.5" exhaust and I am on the verge of splitting the difference and making a 2.75".

So where are the exhaust tuning experts and what do you know about Twin Screw exhaust systems? I know a turbo running 12 lbs. would definitely justify a 3", but I am not as certain about a belt driven blower.

And that brings me to sound. I have absolutely NO CLUE what this things is going to sound like or where to even begin muffler choice, resonator combos, etc.

I do know that I want it to be deep and rasp free. If I could make it sound like a high compression V8 or Dinan Super Charged M5, I would be a happy boy.

Thanks in advance for your suggestions.

Peace & Speed

[msp13]

Great Calculator

http://dairally.net/daihard/chas/MiscCalculators/DaiPipes.htm?Cam=1&Pots=4&RPM=7100&fld2=1867&Boost=1&fld3=0&VPC=2&fld5=input&fld6=input&fld7=input&fld5a=input&fld6a=input&fld7a=input&fld8=0&fld9=0&fld20=0&fld8a=0&fld9a=0&fld20a=0&fld21=0&fld22=0&IC=0&VEE=1&EXH=0&fld42=Input&fld100=835&fld101=900&fld102=80&fld150=1&fld100a=667&fld101a=687&fld102a=377&fld23=109&fld24=0&fld25=0&fld26=NaN&fld27=NaN&fld28a=Cannot+Calc+Centreline&fld28=NaN&fld110=NaN&fld110a=NaN&fld112=NaN&fld113=NaN&fld10=1516&fld10a=1053&fld114=44&fld115=37&fld11=48&fld11a=40&fld116=N%2FA&fld29=0.1289&fld29a=0.0483&Keep=2&fld12=109&fld12a=151&fld30=1.00&fld300=cannot+calc&fld301=cannot+calc&fld302=NaN&fld303=146&fld304=986&fld305=More+data&Button=Reset&fld306=168&fld307=Satisfactory&fld197=66&fld198=59&fld199=NaN&fld199a=NaN&fld151=NaN&fld605=1&fld200=output&fld201=output&fld202=59&fld203=NaN&fld204=NaN&fld206=NaN&fld207=NaN&fld209=NaN&fld210=NaN&fld220=NaN&fld221=NaN&fld212=496&fld213=372&fld214=298&fld215=NaN&fld216=NaN&fld217=NaN

[JiXer]

Damn! Thats pretty deep stuff. Not sure I know all that data or would know how to interpret the results, but that is pretty sick. If the math behind it is correct, it would sure help dial things in. Definitely going to study it and see if I can come up with all of the data.

[msp13]

The hardest part...which is still easy, would be converting everything to SI units. You could probably get ahold of the engine specs (valve lift, cam duration, valve diameter, etc...) somewhere. In fact, the very first thread I looked at on this site like two hours ago was all that same type of info for the m20's.

[gearheadE30]

SCing the motor will make it quite a bit louder, so you will want all of the muffling capacity you can get for the street.

[Justin B]

Great Calculator

http://dairally.net/daihard/chas/Mis...NaN&fld217=NaN

:bow::bow::bow:

Ive found PDF's of how to properly size the intake with all that math, but nothing like that!