Stainless exhaust?
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Guest
New member
Depends on your car I think. If you have a foreign car with a CAT then you could gain about that much by getting rid of it. Some say fitting a whole SSi system (heat exchangers aswell) will give better performance but it would cost you about £1400ish to do.
Try fellow PCGB forum poster Bert Gear for prices at Berlyn Services.
Try fellow PCGB forum poster Bert Gear for prices at Berlyn Services.
Guest
New member
I think you also have to backdate the heating - which is neither easy or cheap. Unless you know a very good cheap workshop, you may exceed £1400.
I have posted before that the SSI conversion was found by Autofarm to produce no more power on the dyno but recently on the Titanic List we were made aware of a Clubsport that gained 10hp and 5nm of torque.
Simply adding a dual outlet backbox is unlikely to gain power and some have experienced loss of torque. Claims of 15-20hp are highly unlikely.
For prices, give Bert a call or try any of the main Porsche aftermarket people - Design 911, Porscheshop etc.
Richard
ClubSport 911
New member
Interesting to hear about your new exhaust David. Have you had the car Dyno' d before and after... All i seek is one 3.2 carrera in a reasonable condition, dyno' d before and after having the SSI' s
Im particularly intererested in the point around 4000rpm when the cam timing hits the sweet spot...
Rgds
Im particularly intererested in the point around 4000rpm when the cam timing hits the sweet spot...
Rgds
Guest
New member
Hi Steve,
Not sure if Dave H means an SSI or an OE pattern stainless system - no doubt he will clarify.
In your search for info you could do worse than call Jack at Autofarm. I have mentioned my chat with him above, but I can flesh it out. His comment specifically was that, compared with OE, once they installed the SSIs they couldn' t get them to make *any* more horsepower. I asked if they tried different mufflers and he confirmed they did. I suspect that maybe they then called it quits. With SSIs being a little freer breathing they may need a mixture tweak towards the rich side to realise any gains.
I guess what you are driving at though is whether there is any increase in midrange torque(?). One piece of info I can add with this in mind is that the SSIs were specifically designed to maximise torque rather than hp - hence the slightly smaller than optimal primary pipe diameter. More often than not, people who have SSIs claim an increase in torque rather than big changes in peak hp.
Hope this is of some help.
Richard
Not sure if Dave H means an SSI or an OE pattern stainless system - no doubt he will clarify.
In your search for info you could do worse than call Jack at Autofarm. I have mentioned my chat with him above, but I can flesh it out. His comment specifically was that, compared with OE, once they installed the SSIs they couldn' t get them to make *any* more horsepower. I asked if they tried different mufflers and he confirmed they did. I suspect that maybe they then called it quits. With SSIs being a little freer breathing they may need a mixture tweak towards the rich side to realise any gains.
I guess what you are driving at though is whether there is any increase in midrange torque(?). One piece of info I can add with this in mind is that the SSIs were specifically designed to maximise torque rather than hp - hence the slightly smaller than optimal primary pipe diameter. More often than not, people who have SSIs claim an increase in torque rather than big changes in peak hp.
Hope this is of some help.
Richard
Simon Davidson
New member
Hi, My thought on exhausts are:
From tests and discussions with specialists on the subject of 3.2 exhausts i have the following opinions:-
Nearly all aftermarket exhausts will not add power, if you have a catalyst just get a de-cat section as that may help but I dont know anyone that has tested this, before and after, on a rolling road but some european customers swear it feels faster with it removed, makes sense to me.
BACK PRESSURE - this seems a key element within the 3.2 exhaust set up, JZ and another specialist I have worked with have both said that replacing the pre-silencer with a straight thru version and then using a big bore sport exhaust or twin exhaust will usually lose you upto 10% torque because of reduced back pressure.
When I put my twin 84mm sports exhaust on it felt and sounded great I kept the original spec pre-silencer, although it was a new stainless version. I cant say I noticed any real difference in performance, any small sacrifice in power/torque was well worth it for the great flat six burble and roar, also very good on backoff where you get sound great effects at high speed.
The bottom line is with that noise you will drive faster, you must have sand in your veins not to be inspired to push it more than you used to.
The SSI systems sound wonderful and some folks say they feel its faster and I have seen quotes of about 10-12BHP I would love to see a before and after test, i personally think its another case of " noise inspired speed" but would love to be proved wrong.
Noise levels
Note that for track days a std car will be around the 92 to 95dba level so almost any mod that increases noise will go over the limits for most courses, this is a pain but I believe much of the noise detected is engine/induction so the exhaust is not all to blame.
On my 965 conversion we put a very tight bend/weld into the pipes and then used twin 100mm resonated tailpipes to take out some more of the noise as well. This has certainly quietened things down and the first passenger, Hugh Smith, reckons it sounded better beforehand with the twin 84mm dansk. I agree, but I wanted something quieter so it worked out as we designed it to and its still better than standard.
Resonated pipes also look great. See below.
My conclusions are - there arent many ways to get easy power from a 3.2 engine but you can make them sound great without gaining or sacrificing power to the point where you notice it. Better sounds always inspire you to drive faster so there is the power gain.
If I was advising I would say go for a loud back box if you like some noise and keep the rest std unless someone can show you a rolling road power gain. Using a sports pre-silencer will improve the sound even further but make it louder and I personally havent tried one yet so cant comment about noticing the 10% loss of torque that has been measured by the likes of JZ Machtech.
Best regards Simon
www.essentialstyling.com
From tests and discussions with specialists on the subject of 3.2 exhausts i have the following opinions:-
Nearly all aftermarket exhausts will not add power, if you have a catalyst just get a de-cat section as that may help but I dont know anyone that has tested this, before and after, on a rolling road but some european customers swear it feels faster with it removed, makes sense to me.
BACK PRESSURE - this seems a key element within the 3.2 exhaust set up, JZ and another specialist I have worked with have both said that replacing the pre-silencer with a straight thru version and then using a big bore sport exhaust or twin exhaust will usually lose you upto 10% torque because of reduced back pressure.
When I put my twin 84mm sports exhaust on it felt and sounded great I kept the original spec pre-silencer, although it was a new stainless version. I cant say I noticed any real difference in performance, any small sacrifice in power/torque was well worth it for the great flat six burble and roar, also very good on backoff where you get sound great effects at high speed.
The bottom line is with that noise you will drive faster, you must have sand in your veins not to be inspired to push it more than you used to.
The SSI systems sound wonderful and some folks say they feel its faster and I have seen quotes of about 10-12BHP I would love to see a before and after test, i personally think its another case of " noise inspired speed" but would love to be proved wrong.
Noise levels
Note that for track days a std car will be around the 92 to 95dba level so almost any mod that increases noise will go over the limits for most courses, this is a pain but I believe much of the noise detected is engine/induction so the exhaust is not all to blame.
On my 965 conversion we put a very tight bend/weld into the pipes and then used twin 100mm resonated tailpipes to take out some more of the noise as well. This has certainly quietened things down and the first passenger, Hugh Smith, reckons it sounded better beforehand with the twin 84mm dansk. I agree, but I wanted something quieter so it worked out as we designed it to and its still better than standard.
Resonated pipes also look great. See below.
My conclusions are - there arent many ways to get easy power from a 3.2 engine but you can make them sound great without gaining or sacrificing power to the point where you notice it. Better sounds always inspire you to drive faster so there is the power gain.
If I was advising I would say go for a loud back box if you like some noise and keep the rest std unless someone can show you a rolling road power gain. Using a sports pre-silencer will improve the sound even further but make it louder and I personally havent tried one yet so cant comment about noticing the 10% loss of torque that has been measured by the likes of JZ Machtech.
Best regards Simon
www.essentialstyling.com
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