SSI installation

maui44 · 07-31-2012, 07:49 PM

I am thinking of doing a SSI installation on my 1977 911S.

First, let me say I am a novice at knowledge of working on the car. I have started doing small things (enjoyable) and slowly moving up on the projects.

The TR have been removed and replaced with "candle stick" pipes. If I go to SSI will I use the candle sticks or have to replace them. Also, should I be replacing the muffler and if so, what type to consider. If read some about 2 in 2 out vs 2 in 1 out.

Lastly, on s scale of 1 to 10, how hard is it to do this install myself. The last thing I want to do is take on too much and break something. I heard the stories about breaking off head bolts etc.

My goal is to replace my old dented exchangers and try and to add 20 to 25 HP if that is possible.

Thanks in advance for any comments.

wildcat077 · wildcat077's Garage

You're going to gets lots of different replies on this one ... lol
Read up on the proper way to loosen the exaust nuts as you don't wan't to snap off any studs and as far as mufflers go,there are many theories ...

Many poeple have done SSI's so you'll get some good advice !

Cheers !
Phil

tirwin · tirwin's Garage

I haven't done this myself, BUT it is definitely on my to-do list.

There are many threads out there on different exhaust sounds complete with clips. Conventional wisdom is that you want to avoid "drone". Along those lines SSI + M&K seem like a popular choice but that's certainly not the only option. I would also look at RarlyL8 Motorsports in Huntsville, AL. You could probably even give Brian a call and get some great advice.

Definitely read up on the numerous threads about how to remove the exhaust nuts. It can be done with patience, heat and a good penetrating oil. Follow the words of wisdom from John Walker.

will hung · 08-01-2012, 04:26 AM

First, I'll start off by saying congratulations. I've performed many modifications to my car, but installing SSI's was by far the greatest mod yet. When you start the car for the first time, it is such an instant gratification for your hard work. Just keep that in mind.

When I was getting ready to swap out exhausts, I followed these two links.

Pelican Technical Article: Installing SSI Heat Exchangers on your 911

Pelican Technical Article: 911 Heat Exchanger Retrofit

There were a few challenges I found in installing SSI's.
1. The exhaust stud issue.

I was fortunate. The previous owner had rebuilt the engine right before I bought the car, so the heat exchangers hadn't been installed for very long. As a result, I soaked the nuts each night for a week with PB Blaster and they pretty much came right off. One nut was seized to the stud, so the stud and nut came out together. I just replaced the stud and nut.

If you stay patient and follow the guides as far as heating the nuts, you should be ok.

2. Getting the old oil lines off without stripping the threads on the external oil thermostat.

For this, I knew I was replacing the lines with squeaky clean, new oil lines, so I just got the Dremel out and carefully cut the old lines off.

If your car doesn't have a front oil cooler or trombone oil cooler, you shouldn't have an external thermostat, so this shouldn't be a concern.

3. Unbolting the crossover oil line from the engine.

I had problems getting the old one off. I finally removed the middle oil return line. Luckily, mine are the collapsible type, so I could just reinstall them with new o-rings. If yours aren't the collapsible type, this is probably a good time to replace them with the collapsible ones because they'll be very easy to access when the exhaust is removed.

4. Finally, I found getting all the exhaust nuts fully tightened was challenging.

SSI sends a tool for tightening the nuts that don't have an access hole through the SSI itself. The problem is, Pelican lists a nut that is 1mm bigger than the tool. So be smart, search through the BB and you'll find the proper size nut for the tool. If you mess up like me, get lots of universal joints, extensions, really short sockets, and some creativity to get the nuts tight.

Muffler
When it comes to a muffler, I thought about all kinds of exotic, lightweight options from off the shelf to custom. After doing lots of homework and talking to some local wrenches, I decided to get a Dansk 2in-1out oem replacement muffler. It is quiet when you need it to be quiet, yet when you get on it, it sounds like a 911 is supposed to sound. There are no fitment issues when using them. Plus it's the muffler Porsche engineers intended for the engine.

On a scale of 1 to 10, I'd probably place this at a 5 and that's only because the items are heavy and there are so many things to remove and replace. But it's a project that has been done thousands of times and is very well documented. As long as you keep a reference nearby to follow and diligently keep track of completed steps, you shouldn't have a problem. And if you do end up having a problem, you aren't alone. Somebody most likely made the same mistake, you can search it out here and find the solution.

Luckily for you, SSI's are based on the original equal length exhaust manifolds Porsche intended for the 2.7, so the highest gains possible will be experienced by your engine. The hp jump was definitely noticeable on the top end of my 3.0, but the biggest jump I noticed was the mid-range torque. There used to be a very prominent step in power around 3-3.5k. But now it just pulls, and pulls hard, from idle to redline. All the while making the sweetest music you've ever heard.

maui44 · 08-01-2012, 10:14 AM

When you install SSI's, will I connect them directly to the exhaust or will I connect them to the candle sticks that replaced the thermal reactors?

will hung · 08-01-2012, 11:29 AM

The SSI's bolt directly to the head.

maui44 · 08-01-2012, 04:51 PM

Like I said, the thermal reactors have been removed and I am using candles sticks in their place. The car in Ca. smogs fine.

If I do place SSI's will they have any impact on passing smog testing? Also, does the muffler have anything to do with SSI's passing smog.

Thanks you

will hung · 08-02-2012, 04:49 AM

Does your car have catalytic converters now? I don't know what candle sticks are. Can you provide a pic of your complete exhaust system.

This has been covered several times. SSI's are stainless steel copies of the steel pre-1975 heat exchangers. As a result, the complete exhaust system has no emissions equipment. Some people have played around with different muffler systems that incorporate cats. They use the cat/muffler setup to pass smog and then swap over to a plain Jane muffler.

calling911 · 04:59 AM

San Diego? I'd go with early exchangers and use your money elsewhere.. unless you like looking under your car a lot. $300 vs $1000...

Just be careful of the stud length issues.. read up on that.. and cherry red each one before you even attempt to take the nuts off.. MUST MUST MUST be cherry red. Did I mention MUST or the risk is quite high to break a stud?

If I were in san diego, Id consider real headers.. save weight, run cooler.

Also, I cut the "divider" inside my stock muffler.. no drone, no rasp, throaty.. but not as throaty as some aftermarket mufflers.. cost? $5 in welding materials? Effectively, look up sport muffler mod or something like that.. I even have a thread on it somewhere.. The only REAL way to get a great sound is to go to carbs... but you cant do that in CA I bet..