Any cat experts out there...?
Discussion
Don't have an answer for you.
May be worth asking a similar question on the engines forum as there are many turbo experts over there.
I believe a cat needs to be close to the engine to get to the right temperature so down near the back box may not work. Further forwards will be a problem due to space constraints. So make sure the engine guys know these issues when you post your question.
Steve
May be worth asking a similar question on the engines forum as there are many turbo experts over there.
I believe a cat needs to be close to the engine to get to the right temperature so down near the back box may not work. Further forwards will be a problem due to space constraints. So make sure the engine guys know these issues when you post your question.
Steve
Just a thought...
I've just had to replace the cat in my ACT Y-piece (high flow 100-cell), and was told that the high flow 100-cell version would need getting up to temp before the MOT, with a good blast to get it hot rather than just warm. (Not enough 'friction' in the 100-cell density to do it itself, if you see what I mean?)
It was suggested that unless a reasonable blast happened, it would probably be running around the 150C mark rather than the 250C mark it needed to be at to work properly.
Given that that's in the standard Y-piece location, locating it further aft would most likely exacerbate this problem...
Therefore perhaps it might be worth thinking about using a removable NON-high-flow cat (400-cell?) to counter this effect, and remove it after MOT?
Disclaimer: cannot vouch that the figures are exactly right, this is just what I was told today (by chance) by the chap who has just recatted the y-piece...
HTH,
Dom
I've just had to replace the cat in my ACT Y-piece (high flow 100-cell), and was told that the high flow 100-cell version would need getting up to temp before the MOT, with a good blast to get it hot rather than just warm. (Not enough 'friction' in the 100-cell density to do it itself, if you see what I mean?)
It was suggested that unless a reasonable blast happened, it would probably be running around the 150C mark rather than the 250C mark it needed to be at to work properly.
Given that that's in the standard Y-piece location, locating it further aft would most likely exacerbate this problem...
Therefore perhaps it might be worth thinking about using a removable NON-high-flow cat (400-cell?) to counter this effect, and remove it after MOT?
Disclaimer: cannot vouch that the figures are exactly right, this is just what I was told today (by chance) by the chap who has just recatted the y-piece...
HTH,
Dom
Dominic TVRetto said:
Just a thought...
I've just had to replace the cat in my ACT Y-piece (high flow 100-cell), and was told that the high flow 100-cell version would need getting up to temp before the MOT, with a good blast to get it hot rather than just warm. (Not enough 'friction' in the 100-cell density to do it itself, if you see what I mean?)
It was suggested that unless a reasonable blast happened, it would probably be running around the 150C mark rather than the 250C mark it needed to be at to work properly.
Given that that's in the standard Y-piece location, locating it further aft would most likely exacerbate this problem...
Therefore perhaps it might be worth thinking about using a removable NON-high-flow cat (400-cell?) to counter this effect, and remove it after MOT?
Disclaimer: cannot vouch that the figures are exactly right, this is just what I was told today (by chance) by the chap who has just recatted the y-piece...
HTH,
Dom
This is correct I've just had to replace the cat in my ACT Y-piece (high flow 100-cell), and was told that the high flow 100-cell version would need getting up to temp before the MOT, with a good blast to get it hot rather than just warm. (Not enough 'friction' in the 100-cell density to do it itself, if you see what I mean?)
It was suggested that unless a reasonable blast happened, it would probably be running around the 150C mark rather than the 250C mark it needed to be at to work properly.
Given that that's in the standard Y-piece location, locating it further aft would most likely exacerbate this problem...
Therefore perhaps it might be worth thinking about using a removable NON-high-flow cat (400-cell?) to counter this effect, and remove it after MOT?
Disclaimer: cannot vouch that the figures are exactly right, this is just what I was told today (by chance) by the chap who has just recatted the y-piece...
HTH,
Dom
hence why over the years manufacturers have moved them closer to the engine to light off the cat sooner and keep it up to temp , the courser core/monolith of the high flow cat like you say will be harder to heat and keep up to optimum temp whist stationary , however replying to the title of this thread i'm no expert 
Edited by Sardonicus on Thursday 22 November 09:48
ThommoHawk said:
1st Cat on my Sapphire Cosworth was about 14” downstream of the turbo as standard.
Just proposing that the use of a HIGH-FLOW cat in this location, as proposed in the OP, may cause the problem as detailed above - worst of both worlds compounding each other...Either one in isolation - fine (probably!) - but add them together and could be an issue...
Mr Plow said:
Hi
I have two after market cats in place of the silencer in the middle of the car and a custom silencer before the diff. Only just fits but means I don't nee to mess about at MOT time.
Liam
Hi Liam which cats did you use, I have custom silenced tailpipes so if I could remove the catted y piece and fit them where the original silencer was without any mot issues that would be a bonus.I have two after market cats in place of the silencer in the middle of the car and a custom silencer before the diff. Only just fits but means I don't nee to mess about at MOT time.
Liam
Thanks Trevor
I looked into this a while back and am still considering replacing my TVR silencer box with a catalytic converter system, my research lead me to these people in Sweden:
http://www.redbackconverters.com/
Red Back Converters are a respected company producing quality products, they specialise in free flowing and so less restrictive than OEM catalytic converter systems for classic and performance cars, I am considering this model:
http://www.redbackconverters.com/twin-in-twin-out-...
The reality is as I present my TVR for MoT on LPG I am only required by law to pass a pre-cat test, LPG being a fuel that already considerably lowers emissions over petrol this becomes a comically easy pass.... even given the fact I haven't run any cats for years!
However, and for fear of being ejected from the TVR gang for being too dolphin friendly I often think it would be nice to lower my emissions even further with a free flowing cat system, and really just to see how clean I can make an old Rover V8 engine without strangling it's performance.
The way to do this of course is to make the cat system do two jobs:
1. To further reduce my already very low (& low carbon) LPG emissions
2. To provide the silencing function of my TVR silencer, thus allowing me to completely delete my standard central box replacing it with the new performance free flowing cat system
Having listened to many TVR exhaust arrangements I still feel my no cats with the standard TVR silencer box retained setup gives the perfect compromise between the full fat V8 sound without being too 'hooligan' around town or annoyingly loud on the motorway.
My theory is by replacing my central box with the right catalytic converter setup will ensure I retain my performance and the great V8 sound I love, while still keeping the car civilized and making my LPG TVR the lowest emission Chimaera ever to turn a wheel.
It's all part of keeping my 45-50mpg TVR up to date and a credible alternative to a modern sports car while retaining it's old school analogue driving experience and character, just another enhancement in my pursuit to create the best enhanced classic car for the modern world.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
http://www.redbackconverters.com/
Red Back Converters are a respected company producing quality products, they specialise in free flowing and so less restrictive than OEM catalytic converter systems for classic and performance cars, I am considering this model:
http://www.redbackconverters.com/twin-in-twin-out-...
The reality is as I present my TVR for MoT on LPG I am only required by law to pass a pre-cat test, LPG being a fuel that already considerably lowers emissions over petrol this becomes a comically easy pass.... even given the fact I haven't run any cats for years!
However, and for fear of being ejected from the TVR gang for being too dolphin friendly I often think it would be nice to lower my emissions even further with a free flowing cat system, and really just to see how clean I can make an old Rover V8 engine without strangling it's performance.
The way to do this of course is to make the cat system do two jobs:
1. To further reduce my already very low (& low carbon) LPG emissions
2. To provide the silencing function of my TVR silencer, thus allowing me to completely delete my standard central box replacing it with the new performance free flowing cat system
Having listened to many TVR exhaust arrangements I still feel my no cats with the standard TVR silencer box retained setup gives the perfect compromise between the full fat V8 sound without being too 'hooligan' around town or annoyingly loud on the motorway.
My theory is by replacing my central box with the right catalytic converter setup will ensure I retain my performance and the great V8 sound I love, while still keeping the car civilized and making my LPG TVR the lowest emission Chimaera ever to turn a wheel.
It's all part of keeping my 45-50mpg TVR up to date and a credible alternative to a modern sports car while retaining it's old school analogue driving experience and character, just another enhancement in my pursuit to create the best enhanced classic car for the modern world.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
COG have you tried Eurocats http://www.eurocats.co.uk/products/sports-catalyti...
They are in Hampshire and will make anything you want. Very nice people.
I turned up there asking about fitting lambda bosses in an exhaust (before I had access to welding kit). Guy said fine follow me and before I had a chance to ask how much it would be it was done. He took me into the office to pay the man.
Two bosses fitted, customer supplied the bosses in that case it will be two quid......result.
Steve
They are in Hampshire and will make anything you want. Very nice people.
I turned up there asking about fitting lambda bosses in an exhaust (before I had access to welding kit). Guy said fine follow me and before I had a chance to ask how much it would be it was done. He took me into the office to pay the man.
Two bosses fitted, customer supplied the bosses in that case it will be two quid......result.
Steve
Steve_D said:
COG have you tried Eurocats http://www.eurocats.co.uk/products/sports-catalyti...
They are in Hampshire and will make anything you want. Very nice people.
I turned up there asking about fitting lambda bosses in an exhaust (before I had access to welding kit). Guy said fine follow me and before I had a chance to ask how much it would be it was done. He took me into the office to pay the man.
Two bosses fitted, customer supplied the bosses in that case it will be two quid......result.
Steve
Looks good, tanks for that Steve. They are in Hampshire and will make anything you want. Very nice people.
I turned up there asking about fitting lambda bosses in an exhaust (before I had access to welding kit). Guy said fine follow me and before I had a chance to ask how much it would be it was done. He took me into the office to pay the man.
Two bosses fitted, customer supplied the bosses in that case it will be two quid......result.
Steve
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