SSI's what years do they stop making a difference
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Instructor
Joined: Aug 2002
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From: Atlanta
SSI's what years do they stop making a difference
In some of the pel-posts it stops at 83. If I have a '84 is it worth doing the SSI's and also what is the difference in brands...I am assuming you can go to a dual in dual out exhaust from there. I do not want to even ask that question "exhaust" I have read most of those and it is very subjective. The only one I did not see, was if Monty Mufflers made a duel in duel out.
Thanks
Thanks
Technical Specialist
Rennlist
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Rennlist
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Joined: May 2001
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From: TX
SSI's can be used on the 3.2 Carrera engines, however, the pipes are on the smallish side so you won't see the benefit you see on the 83's and earlier. I've known two who tried them on their 3.2's and took them off.
In Bruce Anderson's "Porsche 911 Performance Handbook" he cites a case study where someone started with a stock 3.2 engine at 213hp, added SSI's, dual-in muffler, and chip matched to the combination, and recorded 226hp. Adding an Autothority mass air sensor got hp to 236hp. Adding a custom-designed header brought 240.7hp.
In Bruce Anderson's "Porsche 911 Performance Handbook" he cites a case study where someone started with a stock 3.2 engine at 213hp, added SSI's, dual-in muffler, and chip matched to the combination, and recorded 226hp. Adding an Autothority mass air sensor got hp to 236hp. Adding a custom-designed header brought 240.7hp.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
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From: Portland Oregon
If I might add,...........
Its NOT all about power,....its really about usable torque and we call that "area under the curve".
This means the amount of torque (which is what accelerates the car) from low RPM to redline and SSI's do a fine job of that on the 3.2 litre engine.
There is no question that a larger 1 5/8" header will make better PEAK power, but the true measure of overall acceleration is all about average torque and here, the 1.5" SSI's really shines unless you have a 3.6,......
The choice of SSI vs headers is really addressed by considering other modifications one might do such as cams and displacement increases.
IMHO, SSI's and a good sport muffler are a worthwhile upgrade for all street 911's; '75-'89. From extensive dyno testing, they are only a liability on the 3.6 & larger motors.
Its NOT all about power,....its really about usable torque and we call that "area under the curve".
This means the amount of torque (which is what accelerates the car) from low RPM to redline and SSI's do a fine job of that on the 3.2 litre engine.
There is no question that a larger 1 5/8" header will make better PEAK power, but the true measure of overall acceleration is all about average torque and here, the 1.5" SSI's really shines unless you have a 3.6,......
The choice of SSI vs headers is really addressed by considering other modifications one might do such as cams and displacement increases.
IMHO, SSI's and a good sport muffler are a worthwhile upgrade for all street 911's; '75-'89. From extensive dyno testing, they are only a liability on the 3.6 & larger motors.
Racer
Joined: Oct 2001
Posts: 387
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From: PV Estates, CA
Some dyno comparisons from Bruce Anderson done back in the day that may be of interest. Though this data is old the machinery is still the same and should provide some objective data on the differences between the setups. As you can see the results can be mixed depending on the combinations of the exhaust components combined. The Ruf setup is actually a RUF muffler combined with a European style premuffler. SSI's combined with a efficient sport muffler have a slight midrange torque advantage over premuffer/sport muffler combination as Steve stated. Although honestly, when I switched from the premuffler setup to a SSI/Monty setup, I could not notice any appreciable difference in performance or acceleration except extra noise. So YMMV.
Last edited by Steve W; Nov 6, 2012 at 05:05 PM.
Thread Starter
Instructor
Joined: Aug 2002
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From: Atlanta
Where do I find the SSI's that are 1.5" and from my "limited understanding" with this set-up I would be able to go duel in duel out, does Monty have a duel in duel out. I did not see it on their web site.
Thanks
Thanks
