SSI Heat exchanger/Muffler help

[dsisco]

Hey Guys,

Just picked up another 1978/79 SC, after selling my 996 & 987,

Looking to order some SSI heat exchangers, just not sure which ones to order as they have different flanges?

I think I have the 930/06 motor according to my engine no: 6590388?

Also can anyone recommend a good muffler at a reasonable price? I looked for Danks but seem to be discontinued,

how much performance is the gain also?

[Reiver]

Dansk is still there. US models use the thick flange SSI and I do believe the 06 is a California market 930 so the thick flange. My 930/10 ROW uses the thin flange. You will also need some rerouted oil tubing.
For the best performance on a stock motor get a Dansk 2 in / 1 out in normal or sport version.

[Flat6pac]

The 78/79 uses thin flange heat boxes.
Bruce

[boyt911sc]

Originally Posted by Flat6pac

The 78/79 uses thin flange heat boxes.
Bruce

Bruce,

That's the problem getting information in an open forum like this. You have to use some logic and prudence who you listen too. People are well read from all the information you get in the Internet or reading materials. Nothing could replace hands-on experience like yours. I have a '78 targa and it has thin flange exhaust with shorter exhaust studs.

Tony

[RarlyL8]

Generally speaking the early '78/9 SC used thin flange and the late SC thick flange. To be sure what you have on your 35+ year old engine take a look down below and measure the thickness of the existing flanges. If 3/8" they are thin flange.

For the best performance on a stock motor get a Dansk 2 in / 1 out in normal or sport version.

I respectfully object to this statement. Free flowing is free flowing which results in most performance mufflers being similar in returns on a stock engine. At around 13 pounds our mufflers offer a greater weight savings than any other. We also are the only manufacturer using 321 stainless which will last the life of your car. The price is also very competitive ...

[Reiver]

Originally Posted by RarlyL8

Generally speaking the early '78/9 SC used thin flange and the late SC thick flange. To be sure what you have on your 35+ year old engine take a look down below and measure the thickness of the existing flanges. If 3/8" they are thin flange.



I respectfully object to this statement. Free flowing is free flowing which results in most performance mufflers being similar in returns on a stock engine. At around 13 pounds our mufflers offer a greater weight savings than any other. We also are the only manufacturer using 321 stainless which will last the life of your car. The price is also very competitive ...

Lol, beware of merchants they are cunning and persistent.....
I apologize for the initial bad poop...thought all US were thick flange.

[JohnJL]

Brian may be a merchant, and he knows his stuff too.

[Spumato]

I can attest personally to the difference of stock vs. M&K mufflers. My 911 went from the stock 2.7L in a MY1974 to a rebuilt 1983 SC 3.0L that uses the same SSI's out to a 2in 2out M&K. The sound is amazing, and Rarely L8, a.k.a Brian, is not a trolling merchant. He is the real deal and should be valued for his knowledge.

[RarlyL8]

Appreciate the props, but I didn't read anything negative into it. Yes I suppose I am a merchant but that is secondary, first an foremost I am an enthusiast. If my stuff won't work for your application I'll tell you so. Exhaust systems are not one size fits all, they should be designed for specific applications. Mufflers generally can cover a more broad range than headers. A good example is the 3.0L SC. The SSI/M&K combo works really well with the port sizing on the SC but is less effective on the larger port 3.2L Carrera. The premuffler/muffler combo produce similar results for that application. Weight, sound, and quality are also considerations as well as appearance. Our products are raw hotrod old school, if you want heavy bling you'll need to look elsewhere.

[dsisco]

also how do the SSI compare vs headers? in terms of performance

They are 25% of the price of SSI?

[gtc]

Originally Posted by dsisco

also how do the SSI compare vs headers? in terms of performance

They are 25% of the price of SSI?

SSIs are equal length headers, but with heater boxes around them, so you retain (or improve) heater performance. SSIs are all stainless steel, and most cheap headers are mild steel, hence the price difference.
I would suggest some SSIs and a single out muffler from Dansk (1974 non-sport).

[gliding_serpent]

Originally Posted by dsisco

also how do the SSI compare vs headers? in terms of performance

They are 25% of the price of SSI?

Depends on how much you need your engine to breath. For a mostly stock 2.7 or 3.0 with stock redline, SSI's are a no brainer. For a strong midrange and bottom end, they are the easy choice. Where things get more grey is for a 3.2 or high rpm high hp engines with less displacement, that will be pulling in more air at very high rpm's. The setup could be restrictive. Steve Wong figures I will be down ~10 or so hp with SSI's on my 3.4. Mind you, my bottom end performance is killer.

Here is an old chart Steve Wong shared a number of years back for the 3.2. Even in the 3.2, the SSIs have an advantage over the cat bypass/sport muffler with stock heat exchangers, but more around 3.5K rpm (perfect for the street). You can see that a proper set of performance headers can give you more top end power, but what you do not see is the loss below 3.5K.


The trick seems to be in getting it "right", and not going too large or small for primary diameter based on the breathing needs f your particular engine. But then it becomes more complex when you have high rpm power and high overlap cams... then things like primary length and merge design become more important. In short, longer headers tend to favor more midrange torque, and shorter headers tend to promote top end power, but in the extremes this can come as a hit to low and midrange. To me, the holy grail is large diameter long headers which fabspeed and B&B make, but came with proprietary muffler spacing which was annoying. M&K was reported to be deigning a set... which would be great as their build quality is great.

That being said, it I had a 3.0 I would get SSI's hands down. No question. I now have a 3.4 however, and I am looking at an interesting solution from Patrick Motorsports... B&B long headers with heat and spacing to utalize our very common "two in" SSI style mufflers.

I would chat with folks like Bill Vielburg (spelling?), Steve Wong, or Steve Weiner.

[Reiver]

I'm going to disagree with the pro's on this thru practical experience.
I've a 930-10 stock with 204 HP so 24 more HP than your 930-06.
With SSI's and an M&K 2 out/in I lost some mid range but gained at WOT. I drive mostly on the street so like the mid range more...on the track ok for WOT.
It is too open flow to be a good mid range and a WOT gain.
A Dansk 2 in 1 out gave me great mid range and good WOT.
It is a heavier unit than the M&K and not made of the same SS, altho the old Dansk I took off was 30 years old and in fine shape so I don't think the wear out to be much of an issue.
That's my experience...many like the noise over performance so go where your heart dictates.

[dsisco]

thanks for the input guys, I have ordered the Dansk 2in 1 out muffler,

would using the dansk pre 74 heat exchangers be an option instead of ssi?

1973 Porsche 911 S Coupe/Targa - Heat Exchangers and Hoses - Page 1

or the SSI best way to go?

[Reiver]

I can't honestly say about the earlier ones on an SC. You need to find someone that can answer these two things: the flange mating /bolt line up and the diameter of the tubing that was designed for a smaller cubic in. motor and output.
Would it fit properly and would it hinder performance?

[sp_cs]

Supersprint are now offering heat exchangers and headers for the SC and 3.2

http://www.supersprint.com/ww-en/porsche-911-930-series-30-sc-77--83.aspx

[dsisco]

does anyone know if there is Is there a performance difference between the SSI & the Dansk heat exchangers?

Exhaust & Heat Exchangers Package Porsche 911 1974-83 - EXHAUSTKIT05, Porsche | Design 911
VS
Porsche 911 Exhaust Package Straight threw SSI - EXHAUSTKIT55 | Design 911

They said SSI is owned by Dansk? is it just one is stainless steel & other is mild steel?

[Spumato]

And the SSIs that are 1974 & older vintage are some of the best equipment that you can get. They are better than a regular set of headers and are expertly designed for their application. Yes, it's true that they are equal length headers, but the heater box surrounds are just additional brilliant engineering for providing fantastic heating as or when needed.

[Josh D]

Originally Posted by dsisco

does anyone know if there is Is there a performance difference between the SSI & the Dansk heat exchangers?

Exhaust & Heat Exchangers Package Porsche 911 1974-83 - EXHAUSTKIT05, Porsche | Design 911
VS
Porsche 911 Exhaust Package Straight threw SSI - EXHAUSTKIT55 | Design 911

They said SSI is owned by Dansk? is it just one is stainless steel & other is mild steel?

Performance would be the same, as would using factory or aftermarket mild steel '74 or earlier heat exchangers. The design is the same. The difference is in the materials and quality of construction of which the SSI's are at the top of the list.

[cary]

[/QUOTE]

Brian, what muffler is this ?

Winter project is SSI's, sport muffler and a 91 octane chip on my AX car. I really like the GT3 look. But not really appropriate on my 3.0 RS clone. This muffler looks like somewhere between the sport and the GT3 ?