3.0L exhaust options, and small rant

I have been looking at various threads on the topic of exhaust systems in the archives, and weighing the cost of some of the aftermarket replacement parts and the hassle of keeping a smog legal car in California.

In this thread:
http://www.pelicanparts.com/ultimate/Forum3/HTML/007881.html
Doug Zielke mentions getting from his mechanic "6 dyno print-outs of 3.0l motors he had done, and gave them to me to study. Typically, a quality sport muffler, and the SSI's had about 16 hp more than stock. A quality sport muffler and a cat test pipe, yielded about 13 more hp than stock."

I also saw Jack's recent post, showing Black Beauty's exhaust setup. For those that missed it, here it is (shamelessly lifted from Jack's post):



With Doug's dyno numbers, it looks like this may be a good option for my SC. I wouldn't get as much of a HP boost as from SSI's, but it should help a little, and make it sound better as an added bonus. From a smog legality standpoint, it is easier to swap out the cat test pipe every 2 years than essentially the entire exhaust system, and no oil line to move. Another option would be to get a used cat and hollow it out. It would pass visual inspection this way, and still pass smog if it is running properly.

Any thoughts?

Rant mode on:
I have a bit of a problem with the prices of some Porsche parts, and aftermarket mufflers is a good example of what looks to me as price gouging.

GHL, $775.00
Borla: $1125.40
B & B $1152.90
Flowmaster, about $80-100, plus fabrication costs of the pipes, probably $250-300 total at any competent muffler shop.

I realize small runs make things cost more, but this looks like a Porsche surcharge to me. Doing a simple web search, most Borla SS mufflers range from $100 to $200. Very few of the complete cat-back systems they sell go for over $600 (Vette-$800 and Viper $1200). What makes the 3 bent pipes and 1 muffler for a 911 cost over twice as much as the 6 bent pipes and 2 mufflers for a Mustang?
I know it is a fact of Porsche ownership, and I knew it when I bought the car, but I still think it is a load of BS.

So I ask, what do you get with a $1100+ Borla or B & B that you don't with a system like Jacks?

Tom
82 91 SC coupe

"Doug Zielke mentions getting from his mechanic "6 dyno print-outs of 3.0l motors he had done, and gave them to me to study. Typically, a quality sport muffler, and the SSI's had about 16 hp more than stock. A quality sport muffler and a cat test pipe, yielded about 13 more hp than stock."

That may be true, but I'd certainly like a little more info, dyno, how were the tests run, conditions, etc. Because conventional wisdom (which of course can be wrong) certainly suggests that a cat test pipe and a muffler won't get 13 hp more than stock, at least from what I've always read (Anderson, Woods, etc.) Those same sources also suggest more like 25 hp from SSIs alone (SSI plus stock muffler).

Of those 13 hp, I wonder how much comes from the test pipe. Because I noticed no difference with a test pipe on my SC. But, then again, if it made an 8 hp difference, I probably wouldn't notice it.

Again, I don't know, just what I've heard. Like they say, there are three kinds of lies: "Lies, damn lies, and dyno sheets!" (just kidding!)

On a related note, what is it about the pre-74 heat exchangers (SSI included) that makes them so much better than the later stock ones? Is it the tube size, length of the tubing, the fact that they use a different type of muffler or a combination of these that gives the advantage?

Thanks,

Tom

[This message has been edited by emcon5 (edited 04-24-2001).]

Tom,

I'm not sure that the numbers Doug cited can be taken as gospel, but the 49-state 1975 2.7 CIS engine lost 10 hp over the '74 engine with the 'good' exhaust, and the CA-emissions version lost 15 hp! So, somewhere between those numbers lies the approximate gain you would see for a backdated stock pre-'75 exhaust. The definition of what a 'good sport muffler' is, is so vague that hp claims are virtually useles. The twin, center pipe style from Stoddard or AJ-USA are the only ones that have a documented use by the factory on race/rally cars, and claims of 10-12 hp over the OEM single outlet/dual inlet muffler. Yet, they are NOT the flashy type that 99% of people are talking about when speaking of sport mufflers!

B&B, Borla, FabSpeed, and Tri-Flo designs have nothing to do with the sporterized factory muffler, and I have yet to see any claims of hp gains documented with dyno data!

Sometimes, reality is hard to brag about ... hype is easy, and many that post here have spent money based on advertising hype ... and brag about the great results!

If my $600 Dansk SS dual outlet muffler makes the claimed 10-12 hp gain, fine. If it does no worse than stock, that is fine, too ...

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Warren Hall
1973 911S Targa

well if you look at Jack's pic, you will see that the passenger side exhaust has to cross over to the drivers side, and then into the cat bypass.
The driver's side exhaust just goes to the cat.
this unequal length of travel causes some unneeded back pressure, and essentially chokes the engine.
if you have ever seen the exhuast of a race engine, you see that the tubes are all looped and convoluted. This is to achieve equal length for all cyliders to make the best flowing engine possible.
I just did the 1974 back date on my 1982SC
and I am in California.
I like the upgrade ALOT. low range torque is greatly improved and high RPM hp is greatly improved. I can't imagine that a test pipe would have the same results as a system that truly makes equal length headers.
I am writing a tech articel fro the upgrade, and althougth the project is a bear, it was VERY satisfying.
Also SSI's look nice but are expensive...I picked up a pair of pre-1974 HE's, bursch muffler, and oil lines for 300.00
You may not be able to get such a great deal (this was my friend) but it will easily be half for a SSI setup.
I actually want to upgrade to a Dansk 2 in 2 out muffler later.

As to the emissions. I have heard that the car with my set up can be tuned to pass. But visual is the problem. Many places don't even look under the car. and some people have pointed to the heat exchanger sheet metal and said that was the cat and have passed.

Worse comes to worse, there are places that for 50.00 extra will pass the car. I know this is shady and immoral, but if my car is passing emissions with my set up and it is just the visual that it fails, then my "earth day" soul is not too offended.

search for "heat exchangers" and there are lots of threads about it. I would say 97% of the people are very happy with the upgrade.
I have not heard many rants and raves about the cat by pass...but I could be wrong.

email me if you ahve specific ques...

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=582990185&r=0&t=0&showTutorial=0&ed=988684550&indexURL=0&rd=1

here is a guy I was going to buy my setup from. Really nice guy and selling for cheap.

and don't worry about the look, I figured out a way to make them look great. Takes some elbow grease...but I got all the rust off mine.

MJ

I have the SSIs on a 3.2. I have put it on the "butt" dyno, but never the kind with rollers.

I can tell you this, it is the only engine upgrade I have made that made a truly convincing boost in performance. I previously tried the bypass pipe and my butt testing was non-conclusive.

Consider Warrens comments about the performance drop in '75. You can find "experts" that discount just about every aftermarket bolt on "upgrade" to 911 performance, and that includes the cat bypass. The only upgrade that everyone agrees works is SSI (or BBS, headers, etc).

You can also find the SSIs used. I got mine for $500.

I looked at those on E-Bay. I was concerned that one side looked like it was missing the mounting flange where it mates to the muffler.

82SC, what did you do to yours to make them look better?



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Rob Fix
'78 SC Targa

"there are places that for 50.00 extra will pass the car"

In California? In this day and age?

If they still exist, they are very, very few and far between. Used to be relatively common in the good old days, but not anymore.

The Carrera exhaust on my 3.6 costs me horsepower (I've been told it's about 10), but gives me better torque in the mid and low end of the power band. The chip gives me that back, and a little more. The cat bypass and Camaro muffler probably don't win me a whole lot, but I haven't dyno'd it. I think 260 hp is probably accurate for my current setup.

Here are dyno results for the 3.6 (I know, not what most of you are looking for):

• C2 3.6 with stock chip and exhaust: 247
• C2 3.6 with Cyntex chip 263
• C2 3.6, Cyntex chip, B&B Exhaust 272
• C2 3.6, Cyntex Chip, 1-7/8" headers, Dual in-dual out muffler 282
• C2 3.6, Cyntex Chip, 1-7/8" headers, dual 2.5" stainless Supertrapps 286
• 993 3.6, Varioram, Supertraps 298, 305 with open exhaust

I will probably eventually move to 1-7/8" headers, with a similar dual-in-dual-out muffler. If that gets me an honest 282 hp, I'll be thrilled. If later I can get a Varioram setup and squeeze out 294 hp, that would rock. Importantly, none of these upgrades appear to have any negatives in terms of drivability or reliability (unlike racing cams).

Strictly speaking, none of what you see in that picture was done for performance. When you swap a 3.6 into an early car, you can't use the C2 exhaust or muffler from the donor engine. What you see on my car was basically 'what it took to get it on the road.' That it gets me so many compliments for its sound is an unexpected bonus.

(As a side note, anyone can re-print my pictures anywhere they'd like, providing they attribute them to my car and don't do it for a profit.)

If I can get a decent recording some time, I'll try and post a sound file of my exhaust setup. Opening it up on the front straight at Willow Spring sounds very, very good (and 'the beauty' isn't too slow on that stretch of asphalt, either!).

Here's a new web page for the brakes, coolers and exhaust.

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Jack Olsen
1973 911 T (3.6) sunroof coupe
jackolsen@mediaone.net

[This message has been edited by JackOlsen (edited 04-24-2001).]

Rob,

There IS a missing flange on one side! But, easily purchased replacement can be bought at most autoparts stores. Welding the new flange should only be done with complete exhaust system, including muffler ... installed and tightened down, and with two of the above mentioned gaskets in place, after sandblasting the HEs, of course!

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Warren Hall
1973 911S Targa

I did the pre-75 exhaust upgrade a few months ago. Previosuly the car was equipted with a by-pass tube. I never drove the car with a cat and it passed visual inspection with the bypass. I am hedging my bet that the pre-75 exhaust will also pass. I too am in California.
The increase in power from the by-pass to pre-75 exhaust system wasvery noticable. It is difficult to believe that the by-pass would add 8 hp, considering the power increase the seat of the pants dyno revealed by driving the car with both set ups.
RobFix, I painted mine with aluminum header paint and the look is great. Close to the look of stainless but less than half the cost.
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Paul
78SC Targa

wow...didn't notice the flange.
Ask the seller, he is a really nice guy

I ran across this stuff called Naval Jelly (no pun intended) at Pep Boys.
It is a rust remover.

I put it on...let it soak and then rubbed with a wire brush.

I cycled 5 or six times for every surface and it looked great. I took before and after pics, but then I erased them from my digital camera by accident...damn technology.

but they looked like the ones in the ebay pic. I am going to take pictures of them installed on my car for my article, and compare them with the pic on ebay...they looked really good after the cleaning.
not as shiny as SSI, but just clean metal. But I am afraid they will rust again...I guess taking pics 3 weeks post surgery will show if there is any oxidation...but again...it is the under side of my car...I am more worried about oil...

but this pink jelly was really good.

After claening I guess you could paint with high temp paint, (BBQ grill paint, VHT header paint, etc...) but I got lazy.

but in the ebay auction it sounds like he painted them...but without prep it will look bad very soon...

let me know if there is anything else I can answer

Nick L

Yeah they are hard to find...but having rice boy racers (embaressed) helps find these shady places since many of them hoping to get the 40hp haha increase run with no cat...illegal muffler, etc...

Hey Jack...why aren't you running a SSI or 1974 HE setup? is it emissions?
or are you planning something greater for the car???

MJ



[This message has been edited by 82SC (edited 04-24-2001).]

Hmm, if I could get hooked up with some of those shops (might need more than one, as they each may not be around too long) I'd consider backdating my exhaust. I don't have a problem spending the $$ to do it (just the SOUND and looks alone would probably be worth it), but I won't do it if I have to swap out the exhaust AND the oil lines every 2 years. Too much hassle.

Hmm, I guess I need some ricer friends. Maybe I'll take out a personal ad ("Me: Lonely SWM with cross-over exhaust, Capricorn. You: Pimply-faced kid with a buzz-box muffler and a really bad haircut. I like movies, long walks on the beach, and illegal smog shops . . . ")

MJ, I'm thinking 1-7/8-inch headers and 282 hp. If nothing else, the extra power will compensate for my heavier brakes and roll bar.

As I understand it, SSIs and 74 HEs (like the Carrera HEs) are too small for a 3.6.

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Jack Olsen
1973 911 T (3.6) sunroof coupe
jackolsen@mediaone.net

that's true...how could I forget...
make a recording. I am sending mine of the car without any exhaust system to obin...for his collection

All I can say is that I have an 83SC 3.0
stock engine, K&N flat air filter, Bursch cat by-pass and Bursch muffler.My car dyno'd last month with 200,000 miles on her at 183HP.I have the sheets and will e-mail them privetly, I did multiple runs on a Dynojet Dyno with other PCA members present that were also doing their cars.This set up cost me $100.00 for the cat by-pass (used) and $300.00 for the muffler.

That is interesting Chuck. Did you dyno it before you modified the exhaust?

I will e-mail Doug privately and find out what was meant by a "good sport muffler".

He did mention in his post on the other thread that he ordered a GHL muffler and Cat Test Pipe from Pelican. Maybe we can get him to dyno before and after.

Tom

Seeing as how my initial post is getting batted around here, I thought I should restate the following....

As I wanted to improve the sound and performance of my SC and keep it emmisions test legal, I discussed my options with a Porsche mechanic I trust. It was then we discussed mufflers, SSI's, and cat test pipes etc.
He contends that the cat (especially a 20 year old one) is the biggest factor in the inefficiency of the SC exhaust system. The stock muffler is also somewhat restrictive.
It is his opinion, that decent gains can be achieved by dealing with these two elements of the system.

When I asked about the so-called, pre-74 system, he then showed me the results he had recorded from a dyno at a shop he had once worked for. The pre-74 setup *did* make more power than a cat pipe and less restrictive muffler, but not as much as many people have claimed. Believe who you want to. The claims for this and that are all over the place.
I don't know about the dyno, testing conditions, muffler brands or any other details. What I do know is he helped me decide which setup would give me some benefit and still allow an easy change back to emmisions compliance.



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Doug
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
members.home.net/zielke/911SC.htm