Some previous informative threads here (circa 2012), for the 200 cell group buys.
https://www.pistonheads.com/gassing/topic.asp?t=1215335
http://www.911uk.com/viewtopic.php?t=73887&postdays=0&postorder=asc&start=0
Sharing an update of my own recent experience, having done the same.
For clarity, the job involves cutting the old cat cans, removing the original 400 cell inserts, replace with new free flowing 200 cell inserts and rewelding the cans.
If you also wanted a shiny new look under the rear apron, a whole new cat offering from the reputable guys like Fabspeed, Cargraphic and Scart currently cost almost double the money.
Why did I need to change?
My car has Europipe made back boxes(mufflers) and LWF, so together they made for a nice raspy driving experience.
Guess with time, I got used to it and was looking for the next fix.
Those of you living in the south east, the guys at Powerspeed in Ashford still offer the best value for money with their sport cat inserts.
When I enquired, they said they were using inserts from Magnaflow.
They are very experienced with this sort of work, so less of a gamble for things to go wrong and the whole job completed within the same day.
For me, after factoring the cost of taking a day off + fuel for a 450 mile return journey, it made more sense for my local indie to remove/ refit and send the cans to Cargraphic or Carnewal to make the change.
At the time of writing, both these companies use HJS trimetal inserts.
I chose Carnewal as they were marginally cheaper than Cargraphic and Gert's a nice chap to speak with.
Gert's turnaround time is 1-2days. Fedex did the best they could under the current climate, transporting my rusty can to and from Belgium.
So job done and first impression on starting up outside my indie was disappointment, as it sounded quieter.
On the plus side, it definitely feels stronger to pull, the difference being similar to the extra torque felt when engaging the sport/sport plus button an a later water cooled car.
Still disappointed with the sound, I speak to Gert and he says drive it for 100miles, allowing the ECU to readjust and it will improve.
Done 200 miles now.
Windows down, its approximately 20% louder, sounds more metallic and slightly bassy. Some of this perceptibly filters into the cabin under load from about 4000rpm. I like this.
Windows up at lower engine speeds, I found it remains quieter than my original cat.
My very subjective conclusion:
1) The car feels more torquey.
2) The higher gas flow is existing from the rear, hence why sound increment more noticeable with windows down.
3) The old inserts may have been loose inside the cans and added to the incabin sound drama, its absence now being perceived as a quieter system.
4) Should have gone for the 100 cell ?
https://www.pistonheads.com/gassing/topic.asp?t=1215335
http://www.911uk.com/viewtopic.php?t=73887&postdays=0&postorder=asc&start=0
Sharing an update of my own recent experience, having done the same.
For clarity, the job involves cutting the old cat cans, removing the original 400 cell inserts, replace with new free flowing 200 cell inserts and rewelding the cans.
If you also wanted a shiny new look under the rear apron, a whole new cat offering from the reputable guys like Fabspeed, Cargraphic and Scart currently cost almost double the money.
Why did I need to change?
My car has Europipe made back boxes(mufflers) and LWF, so together they made for a nice raspy driving experience.
Guess with time, I got used to it and was looking for the next fix.
Those of you living in the south east, the guys at Powerspeed in Ashford still offer the best value for money with their sport cat inserts.
When I enquired, they said they were using inserts from Magnaflow.
They are very experienced with this sort of work, so less of a gamble for things to go wrong and the whole job completed within the same day.
For me, after factoring the cost of taking a day off + fuel for a 450 mile return journey, it made more sense for my local indie to remove/ refit and send the cans to Cargraphic or Carnewal to make the change.
At the time of writing, both these companies use HJS trimetal inserts.
I chose Carnewal as they were marginally cheaper than Cargraphic and Gert's a nice chap to speak with.
Gert's turnaround time is 1-2days. Fedex did the best they could under the current climate, transporting my rusty can to and from Belgium.
So job done and first impression on starting up outside my indie was disappointment, as it sounded quieter.
On the plus side, it definitely feels stronger to pull, the difference being similar to the extra torque felt when engaging the sport/sport plus button an a later water cooled car.
Still disappointed with the sound, I speak to Gert and he says drive it for 100miles, allowing the ECU to readjust and it will improve.
Done 200 miles now.
Windows down, its approximately 20% louder, sounds more metallic and slightly bassy. Some of this perceptibly filters into the cabin under load from about 4000rpm. I like this.
Windows up at lower engine speeds, I found it remains quieter than my original cat.
My very subjective conclusion:
1) The car feels more torquey.
2) The higher gas flow is existing from the rear, hence why sound increment more noticeable with windows down.
3) The old inserts may have been loose inside the cans and added to the incabin sound drama, its absence now being perceived as a quieter system.
4) Should have gone for the 100 cell ?
