Stainless Exhaust System
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Guest
New member
Hi Dave,
If you have not already you should check out the discussions on 3.2 exhaust upgrades on Rennlist and Pelican Parts BBS - there are some relatively recent ones that should be easy to find.
As Bert confirms, it is not straightforward doing the SSI installation. There is, in addition to the heater changes, an oil line that must be replaced. You also need to run a two-in muffler, so nothing is usable from your existing system. That said, the SSIs are a thing of beauty and last forever.
Whether or not SSIs provide any great performance advantage is also questionable. The threads I have followed on the above BBS lead me to conclude that there is very little gain to be had from SSIs alone. There are lots of claims of an extra 20hp, but these are usually in the contaxt of US motors which have a restrictive catalytic converter rather than a premuffler. Dyno runs suggest that the standard exhaust with a premuffler and a sport muffler (ie standard UK exhaust but with a twin outlet muffler) gives virtually the same horsepower. The only advantage that the SSIs have is in the midrange - and the difference is very small. Top end is virtually identical. I think an SSI system is also a little lighter as you dispense with the crossover pipe and premuffler, so maybe 20-30lbs(?) weight saving.
You may be interested to know that the standard rear muffler can be converted to sport spec by adding a second pipe to the RH side. No internal modifications are required, just cut a hole with a hole saw and weld on a pipe. Rear valence must also be modified.
If your heat exchangers are in good shape, I would simply replace any of the other bits that need replacing, however, I wouldn' t blame you if you decided to do SSIs, as, like I said, they are beautiful! With an earlier rally style muffler they will also sound fantastic.
One other thing to note, if you remove the heat exchangers yourself, is to be very careful, as it is easy to break exhaust studs. Soaking with a penetrating spray and repeated applications of heat with a torch should break the rust and ease things out. SSIs come with a special tool that helps in the removal.
HTH
Richard
If you have not already you should check out the discussions on 3.2 exhaust upgrades on Rennlist and Pelican Parts BBS - there are some relatively recent ones that should be easy to find.
As Bert confirms, it is not straightforward doing the SSI installation. There is, in addition to the heater changes, an oil line that must be replaced. You also need to run a two-in muffler, so nothing is usable from your existing system. That said, the SSIs are a thing of beauty and last forever.
Whether or not SSIs provide any great performance advantage is also questionable. The threads I have followed on the above BBS lead me to conclude that there is very little gain to be had from SSIs alone. There are lots of claims of an extra 20hp, but these are usually in the contaxt of US motors which have a restrictive catalytic converter rather than a premuffler. Dyno runs suggest that the standard exhaust with a premuffler and a sport muffler (ie standard UK exhaust but with a twin outlet muffler) gives virtually the same horsepower. The only advantage that the SSIs have is in the midrange - and the difference is very small. Top end is virtually identical. I think an SSI system is also a little lighter as you dispense with the crossover pipe and premuffler, so maybe 20-30lbs(?) weight saving.
You may be interested to know that the standard rear muffler can be converted to sport spec by adding a second pipe to the RH side. No internal modifications are required, just cut a hole with a hole saw and weld on a pipe. Rear valence must also be modified.
If your heat exchangers are in good shape, I would simply replace any of the other bits that need replacing, however, I wouldn' t blame you if you decided to do SSIs, as, like I said, they are beautiful! With an earlier rally style muffler they will also sound fantastic.
One other thing to note, if you remove the heat exchangers yourself, is to be very careful, as it is easy to break exhaust studs. Soaking with a penetrating spray and repeated applications of heat with a torch should break the rust and ease things out. SSIs come with a special tool that helps in the removal.
HTH
Richard
Guest
New member
Dave,
Hi there, the previous owner of my 3.2 spent a small fortune on this rocket, amongst many things, including a complete Stainless Steel exhaust system. The system is a " Billy Boat" Tri-flow exhaust, from the states.
Web page http://www.bbexhaust.com/
The BB was fitted in 1995, and the car has done some 70k (miles) since fitting, and at this point looks all but brand new. Heat exchangers are in-corporated, with neat SS boxes, complete with SS air tubes up to heater control boxes. As my car has a C2 (964) body kit, the muffler is plumbed to exit on right side, with a 75mm tail pipe from single SS muffler. The note from this baby is too die for.......
Malcolm has seen and heard the rig, if any one wants a 2nd opinion. I think BB have actual exhaust sound files on web page plus heaps of other stuff. If you want further info I have all the original invoices.
all the best,
peter
Hi there, the previous owner of my 3.2 spent a small fortune on this rocket, amongst many things, including a complete Stainless Steel exhaust system. The system is a " Billy Boat" Tri-flow exhaust, from the states.
Web page http://www.bbexhaust.com/
The BB was fitted in 1995, and the car has done some 70k (miles) since fitting, and at this point looks all but brand new. Heat exchangers are in-corporated, with neat SS boxes, complete with SS air tubes up to heater control boxes. As my car has a C2 (964) body kit, the muffler is plumbed to exit on right side, with a 75mm tail pipe from single SS muffler. The note from this baby is too die for.......
Malcolm has seen and heard the rig, if any one wants a 2nd opinion. I think BB have actual exhaust sound files on web page plus heaps of other stuff. If you want further info I have all the original invoices.
all the best,
peter
Guest
New member
If anyone is thinking of getting a B&B tri-flo muffler I suggest they look at Fabspeed' s website where a B&B is cut open and exposed. Not nearly as free flow as Billy Boat would have you believe.
Look under " Mufflers Exposed" :
http://www.fabspeed.com
The headers/heat exchangers, on the other hand, I have heard nothing bad about.
Richard
Look under " Mufflers Exposed" :
http://www.fabspeed.com
The headers/heat exchangers, on the other hand, I have heard nothing bad about.
Richard
Guest
New member
I have a Dansk pre pipe and a 84mm stainless steel back box.
I fitted the back box first then replaced the pre silencer. The pre pipe didn' t make much difference to the sound (the 84mm box had already made it a deeper note)
I do however get occasional small backfire/popping when lifting of the revs.
I' m told this is normal for the pre pipe, your hearing the sounds the pre silencer used to remove.
I' m not so sure - I recon I might have a small leak.
Richard
PS - I got the distributor cap and rotor thanks Burt - it fixed my problem - Cheers.
I fitted the back box first then replaced the pre silencer. The pre pipe didn' t make much difference to the sound (the 84mm box had already made it a deeper note)
I do however get occasional small backfire/popping when lifting of the revs.
I' m told this is normal for the pre pipe, your hearing the sounds the pre silencer used to remove.
I' m not so sure - I recon I might have a small leak.
Richard
PS - I got the distributor cap and rotor thanks Burt - it fixed my problem - Cheers.
Simon Davidson
New member
If anyone has an interest in exhausts they should get along to the 3.2 registers first event of the year at JZ machtech (herts) on April 5th, so far we have a variety of 3.2s attending which between them have systems from.
Dansk
hayward & Scott
B&B
SSI (hopefully)
should be a good chance to see, hear, ride in a some cars to compare.
Regards, Simon
Dansk
hayward & Scott
B&B
SSI (hopefully)
should be a good chance to see, hear, ride in a some cars to compare.
Regards, Simon
Guest
New member
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Ok, OK, OK, I' ve checked my exhaust (Billy Boat) and yes the outlet from the muffler is 75mm right through.
I checked out the web site Richard has suggested (fabspeed) and while some of this may be true, including the resonating (my does a little at around 2k rpm), but then the gurgle/burp you get on a down change (performed just right) is to die for...... I' ve had VW air cooled beetles with open extractors and this is better than that.
Whilst the muffler itself may not be perfect (construction), the headers are a work of art. On the down side here - the Heat exchangers are only Ssteel boxes around the 3 pipes; there are no fins inside for extra heat shedding, therefore the cabin heating can be a little cooler. But hey: wear a wooly hat, or as us Ozzies call em; a " Beanie" . (sorry I digressed!). Oh and by the way.... when you play cricket you hold the bat by the handle....[&o]
see ya,
]Ok, OK, OK, I' ve checked my exhaust (Billy Boat) and yes the outlet from the muffler is 75mm right through.
I checked out the web site Richard has suggested (fabspeed) and while some of this may be true, including the resonating (my does a little at around 2k rpm), but then the gurgle/burp you get on a down change (performed just right) is to die for...... I' ve had VW air cooled beetles with open extractors and this is better than that.
Whilst the muffler itself may not be perfect (construction), the headers are a work of art. On the down side here - the Heat exchangers are only Ssteel boxes around the 3 pipes; there are no fins inside for extra heat shedding, therefore the cabin heating can be a little cooler. But hey: wear a wooly hat, or as us Ozzies call em; a " Beanie" . (sorry I digressed!). Oh and by the way.... when you play cricket you hold the bat by the handle....[&o]
see ya,
ClubSport 911
New member
My ten pence worth.
The major power gain that people talk about (+20bhp etc) were only on the SC 3litre versions where the exhaust (SSI) removed a load of restrictions that can occur mating exhaust and head design, and of course, improving flow.
The major improvement on the 3.2' s is less noticeable, (Porsche did a reasonable amount of work on these cars) but measurable and this is down to the system as standard having unequal length primary resonance. SSI' s and all other " power" exhausts have equal length systems for both cylinder banks. This allows the exhaust resonant pulse to improve the charge filling of the inlet system @ high rpm, improving power.
As many people have mentioned however, you' re going to need new oil transfer pipes, some mods to heaters and a new back box.
Sounds good though...
Steve
The major power gain that people talk about (+20bhp etc) were only on the SC 3litre versions where the exhaust (SSI) removed a load of restrictions that can occur mating exhaust and head design, and of course, improving flow.
The major improvement on the 3.2' s is less noticeable, (Porsche did a reasonable amount of work on these cars) but measurable and this is down to the system as standard having unequal length primary resonance. SSI' s and all other " power" exhausts have equal length systems for both cylinder banks. This allows the exhaust resonant pulse to improve the charge filling of the inlet system @ high rpm, improving power.
As many people have mentioned however, you' re going to need new oil transfer pipes, some mods to heaters and a new back box.
Sounds good though...
Steve
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