how can i make my SC roar - Page 2

emcon5 · emcon5's Garage

I like the sound of Chris Striet's car, Headers into Supertraps I think. You can hear it in his racing vids on his web page:

http://homepage.interaccess.com/~erolflyn/racing/streit-racing.html

Tom

frz · frz's Garage

Quote:

Originally posted by widebody911
I have a dual-in/dual-out B&B muffler for sale, and I know someone who has the headers FS. That will get you some roar!

Break it to me gently how much?

etip · 01-30-2002, 02:33 PM

hey,
i just got SSI for my sc. I need a 2 in/2 out muffler. how much for your B&B?? sounds like just what I need.

TargaEuro · 01-30-2002, 04:45 PM

I have a Mille Miglia 2 in 2 out that is basically new that Im willing to sell if anyones is interested. Im looking for $ 600 plus shipping from Massachusetts. It is not currently on the car but there is nothing wrong with it ....TargaEuro

jbripps · jbripps's Garage

I've got a Borla dual out. My PO put it in.......he spent something like $2500 bucks for it. Anyone with a P-car ALWAYS comments on the sound. I must say it's not too loud, and gives the car a rumbling aggressive sound at low RPM's and ROARS at high rpm's.

Here's a shot for you (the chips have been resprayed!!)

regards,

Clark Griswald · Clark Griswald's Garage

You can open up the muffler and re-arrange the the baffles to convert to dual out. Warren posted a link to instructions on how to do this some time back.

If you don't do any internal mods, the muffler will be very loud if you just cut and add the new tailpipe. One way to deal with this is to drill a small hole where you want the new tailpipe, then fire it up and see how it sounds.

Keep enlarging the hole until it gets as loud as you want it. Then weld the new tailpipe on.

trak ratt · 01-31-2002, 07:30 AM

I have a test pipe on the SC & like the way it sounds if nothing else. It wasn't until I added the Borla (1 in, 1 out) muffler that the car really seemed to have a power increase. The sound is sweet! Just remember that the pipe replaces the cat & so will probably have to be switched back for emission testing. With the pipe/muffler/K&N filter combination the SC pulled 170hp at the rear wheels last year so there definitely is a slight power gain. The car has about 140K miles, lots of track time, but stock US inside. I wouldn’t have the Borla but my wife found it new on the internet for $1.89 + shipping. The supplier honored the price even though obviously a typo so…
Anderson commented that he thought the SSI tubes were two small for the 3.2. We have SSIs on our ’71 & definitely think they make a difference & are worth it if you need to replace the stock heat exchangers.
I have heard that there is a relatively inexpensive mod for the standard SC heat exchangers that allows the use of two in two out mufflers? Anybody have details?

rscupper · 01-31-2002, 08:18 AM

"...how can I make the SC sound great? What improvements can I make...?"

You could transplant a carb'd 2.7

911nut · 911nut's Garage

Jon,
Nice license plate.
GO BUCKS!

pbs911 · pbs911's Garage

I wouldn’t have the Borla but my wife found it new on the internet for $1.89 + shipping. [/QUOTE]

I'll tripple your money and give you $5.67. Heck I'll even pay fro the shipping.

etip · 01-31-2002, 10:48 AM

you want a nice license plate!!!

SK · 01-31-2002, 12:34 PM

There was a post many months ago showing the details involved in adding a second outlet to a stock muffler. I searched for it but could not find it. Does anyone remember that post.......Please help me find it.

StuttgartDavid · 01-31-2002, 02:00 PM

That is what you need to do to "squeeze a little more performance out of her" - you need to outsmart the engineers, which is pretty tough.

As you live in England, I assume you already have the good euro-spec equal length exhaust that the SSIs are attempting to replicate for us poor B******s in the US with unequal length design, so you already have picked all the low-hanging fruit.

Perhaps the second pipe mod described above will give extra power, perhaps not. I know the dual pipe sport muffler on my '68S does, but it is a factory approved design. It is also loud as hell and raspy-sounding (all engineering is a trade-off between optimized variables). It gets its extra power primarily by providing a more direct, and equal length, route from the terminous of each heat exchanger to the atmosphere, rather than from simply from having another random exit tube (i.e., placement of the outlet piping is key, along with internal mods to allow the most direct exhaust flow path - in other words, it is a "non-muffling muffler").

Note that the total cross section area of the exhaust pipes on the early sport mufflers (again, factory developed as part of the "sport tuning" kits) is no larger than the stock muffler - key for keeping up gas flow velocity, and therefore torque.

If you just cut another exit on the side without narrowing the cross-section of each outlet, you have just vastly increased outlet cross-section area and reduced exhaust flow velocity through the system at all but the highest rpms, which may kill significant torque in the midrange. Poor midrange torque is the downfall of most BS aftermarket mufflers, and rarely worth the tradeoff!

Bottom line, don't assume the engineers "left money on the table." Think carefully, or you might leave more than you pickup.

etip · 01-31-2002, 02:06 PM

are all euro cars equiped with equal length exhaust tubes?? I have a 79 sc and thought I was cursed with the unequal length tubes. I just bought some SSI, was that a waste?

Bill Verburg · Bill Verburg's Garage

All oem exhausts from '75 911/930 thru '94 964/964T are junk wrt performance and should be updated to SSI, B&B, FVD, Bursch, Cargraphic etc. Take your choice, choose your primary tube diameter and length wisely and the performance minded owner will be rewarded. Usually a free flowing (and loud) muffler accompanies the headers and will enhance their performance.

The problem with the oems is not so much volume as poor exhaust extraction qualities due to their unequal length primary pipes. One cylinder may be in good resonance while adjacent firing ones are actually in reversion.

etip · 01-31-2002, 02:37 PM

thanks Bill,
that's what i thought, but the previous post sounded like all euro exhaust was equal length.

DANNOV · 01-31-2002, 03:09 PM

Quote:

Originally posted by Clark Griswald
You can open up the muffler and re-arrange the the baffles to convert to dual out. Warren posted a link to instructions on how to do this some time back.

If you don't do any internal mods, the muffler will be very loud if you just cut and add the new tailpipe. One way to deal with this is to drill a small hole where you want the new tailpipe, then fire it up and see how it sounds.

Keep enlarging the hole until it gets as loud as you want it. Then weld the new tailpipe on.

I remember a tech note in Pano a long time ago about this. This may be true on the earlier 911's. But I don't think it applies to the Carrera muffler because mine just has a new pipe welded on, same diameter as stock, with no internal mods. The diameter of the pipe and hole are the same. It sounds fine, it is not at all loud. With all that said, it can't hurt to be careful so a little experimentation is ok.