Thinking of running a decat downpipe for the 364 days of the year the car isn't being MOT'd.
Regarding the o2 sensor in the existing cat, do I simply swap this into the new decat downpipe?
I read somewhere on here something about an "o2 conditioner" but couldn't find much more info on it. Can anyone enlighten my novice mind?
Most of the downpipes I'm looking at come with gaskets but not sensors afaik.
Lambda fooler, google it. Its just a long extension to make the sensor sit further away from the pipe. I have ons fitted, no engine light on with it. The smell is rly bad tho.
Quote from: househead on October 7, 2019, 20:15Thinking of running a decat downpipe for the 364 days of the year the car isn't being MOT'd.
Regarding the o2 sensor in the existing cat, do I simply swap this into the new decat downpipe?
I read somewhere on here something about an "o2 conditioner" but couldn't find much more info on it. Can anyone enlighten my novice mind?
Most of the downpipes I'm looking at come with gaskets but not sensors afaik.
Why would you not want to produce clean emissions?
Thanks
@Nvy I have a feeling that will be a more forthcoming search term!
So a bit like the maf mod ... fool the sensor by pushing it further away. Gotta love a good hack
Quote from: Carolyn on October 7, 2019, 20:25Quote from: househead on October 7, 2019, 20:15Thinking of running a decat downpipe for the 364 days of the year the car isn't being MOT'd.
Regarding the o2 sensor in the existing cat, do I simply swap this into the new decat downpipe?
I read somewhere on here something about an "o2 conditioner" but couldn't find much more info on it. Can anyone enlighten my novice mind?
Most of the downpipes I'm looking at come with gaskets but not sensors afaik.
Why would you not want to produce clean emissions?
Simply for a little more power. I do take your point though, and if this was a daily car then I would not entertain running a decat pipe.
C'mon go easy on me, I've already had a lecture from the missus for even thinking about it :'(
Quote from: househead on October 7, 2019, 20:29Quote from: Carolyn on October 7, 2019, 20:25Quote from: househead on October 7, 2019, 20:15Thinking of running a decat downpipe for the 364 days of the year the car isn't being MOT'd.
Regarding the o2 sensor in the existing cat, do I simply swap this into the new decat downpipe?
I read somewhere on here something about an "o2 conditioner" but couldn't find much more info on it. Can anyone enlighten my novice mind?
Most of the downpipes I'm looking at come with gaskets but not sensors afaik.
Why would you not want to produce clean emissions?
Simply for a little more power. I do take your point though, and if this was a daily car then I would not entertain running a decat pipe.
C'mon go easy on me, I've already had a lecture from the missus for even thinking about it :'(
Now you've got one from me too. Look after our planet, please?
Bit of middle ground....
What about a 200 cell sports cat?
Also, can we really call our emissions clean *with* a cat? I was also mulling over the sports cat option but it does seem a fair bit more expensive and less available.
Does anyone have numbers for how much difference this makes to actual tested emissions? I'm the first to admit I am a little uninformed in these matters.
Legend has it, if you get it warm enough it will still pass the mot. Never happened for me though.
Edit: I was referencing a sports cat with this comment
Quote from: wotugonado on October 7, 2019, 20:39Bit of middle ground....
What about a 200 cell sports cat?
Yea that's on the menu too. Can you name drop any companies that supply a decent one without any fabrication or hassling? It would get me a back in few peoples good books O:-) (maybe)
Quote from: wotugonado on October 7, 2019, 20:42Legend has it, if you get it warm enough it will still pass the mot. Never happened for me though.
I'd colloquially trusted such legend for both the aftermarket decat manifolds (of which I'm running the toyosport) and/or the expensive 200 cell sport cats but I wouldn't trust it for a full decat.
Not really one off the shelf I can think of. I spoke to an exhaust fabricator and he quoted me around £150 iirc (was a while back though) to weld one into my original pipe in place of my cat.
Unless your mot tester is a good mate ;) you've got no chance of passing with a decat pipe and toyo manifold.
Fair play
@Carolyn In my defence I've spent a lot of my adult life living in cities without a car at all and using a cycle and public transport to get around.
Ok it's not a blank cheque but I think my account is probably well in credit compared to many on here!
We all have to do our bit which is fair enough.
It's a lot of money, is a 200 cell. But, it certainly adds thr necessary oomph and when hot you're still passing emissions.
Or, accept that a big bowel movement has about as much effect on your power to weight ratio :)
I shit you not. My car, zero manifold, 200 cell cat, versus Helen's bone stock beautifully maintained 2....id challenge anybody to REALLY notice the difference on public roads at legal speeds.
I do like a bit of oomph >:D
And if I forego the decat/ sports cat and just eat more beans and cabbage instead, I'll have much more than just a lecture from Niamh to contend with!
Sports cat might cost a bit up front, but surely just for the easy life of not swapping it out every year for mot, it'd pay for itself. Do you have to change gaskets everytime you swap the decat in and out? because they aren't cheap.
I also very much like an easy life!
I'll get some quotes and whatnot and weigh up my options. I'm not sure I'd look to use fresh gaskets every time unless that's an absolute must, but I wouldn't use the same set of gaskets with 2 cat pipes
In all honestly I'm probably more bothered about my own time swapping it over than the extra 20 quid a year or whatever the gaskets will set me back.
There is a Malian sports cat + downpipe for 175 on their site.
Does that get any love around here? Not sure many on this forum are using Malian generally.
The emission issue is a tricky one.
On the one hand anyone with common sense wants to mess up the earth as little as possible.
On the other hand we are grossly misinformed and manipulated with the only goal to extort more money from us with the resulting pollution being secondary at best.
Doing longer with a car; reducing production, does more to reduce the eco-burden than reducing exhaust emissions.
That however does not generate business nor emplyment nor taxes so the public is not educated on that.
Mind, doing longer with a cleaner car is better still, but that is not my point.
Furthermore it´s all relative.
Also, going quicker through a corner pollutes more than a more moderate pace.
Sporty rubber lasting 20K miles pollutes three times as much as eco stuff lasting 60k miles.
I try run the farm eco-friendly and practice eco-tourism; see exotic destinations on the tele instead of going on a plane, cruise or ferry.
Oh and the average age of the cars we drive is 21 years/ two are on recycled tyres.
Sadly modern diesels are more tricky to run on veggie oil. The previous ones ran 50% recycled veggie oil for 15 years. This is illegal btw. Although a lót cleaner and reducing waste oil, the State considers revenue from taxes on fuel more important.
Lastly a question; what is the ecological footprint of a new cat?
And no you do not always need new gaskets.
Quote from: shnazzle on October 7, 2019, 20:54Or, accept that a big bowel movement has about as much effect on your power to weight ratio :)
Given that the circumstances on the public road set the boundaries of how you drive, reducing the car´s weight improves fuel economy, reduces emissions and tyre wear. It´s safer too.
De cat is a waste of time as is sports cat on stock ecu the tiny bit extra hp you make will be unnoticeable. Imho.
Keep the money save for turbo or more powerful engine.
A friend at work still runs his old Land Rover on 50% veggie oil. Fair play to him I say!
I'm surrounded in London by drivers with huge engined SUV things often driven by a single person. I wonder often if they just hate speed bumps and figured it would be an answer. Then also 20mph zones and speed cameras. Limits which if followed by everyone it could be argued leaves more emissions in residential areas than is necessary.
It's a funny old world. I try to do my bit where I can, generally, whilst also allowing myself a few vices.
Quote from: 1979scotte on October 7, 2019, 21:41De cat is a waste of time as is sports cat on stock ecu the tiny bit extra hp you make will be unnoticeable. Imho.
Keep the money save for turbo or more powerful engine.
Such things are also on the cards eventually, but not until this time next year I reckon. It will take me that long to decide which option, probably!
With regards to emissions and saving the planet, myself and wife decided not to have kids, so in my mind we have made the ultimate sacrifice to save the planet. I can run decat guilt free :) brap brap
As a cynic I would like to know how much effort is put into making a catalytic converter, do the companies that supply and make the cats actually pump out more No2, CO & hydrocarbons then these things save? The precious metals in cats have to be dug out of the ground, processed and then shipped to a factory. The factory will burn energy like no tomorrow putting together these pieces of kit and then transport them to a car manufacturer.
For electric cars please replace 'catalytic converter' in the paragraph above with 'battery'.
In answer the original question, you can use a spacer to have the sensor mounted just outside the gas flow or you can use a something to alter the volts going through it, which is what I have but I cannot remember the £0.30 part I bought from CPC. I will have a look under the bonnet when it stops raining.
I shall setup another weekly meet and you can have a go in my setup. There is a significant difference going full decat, with sound being one of the factors you should bear in mind.
Can you make it out to sort of towards Slough maybe South of that?
Quote from: househead on October 7, 2019, 21:43It's a funny old world. I try to do my bit where I can, generally, whilst also allowing myself a few vices.
Ok a quick but fairly accurate one on a new cat:
The welding contributes about 200 gram of CO2.
The steel 1.8 kilo of CO2 per kilo. This does not take into account the environmental cost of iron mining.
Platinum is ... horrific and quite a relief that there is only a minute quantity in the cat.
Aluminium btw, even considering 50 % recycling rate, has a footprint of 8,96 kg CO2 per kg. Glass is 25 times eco friendlier.
To put that in perspective; every gallon of gasoline burned gives about 8,887 grams of CO2.
So a thousand gallons results in 8.887 kilos of CO2.
Without a cat at 30 mpg that is 30.000 miles for 8.887 kilos.
15% weight reduction giving 5% improved fuel economy saves 0.444 kilo of CO2; the welding of two cats.
Right, now have a beer or what to unboggle the mind.
Quote from: jvanzyl on October 7, 2019, 21:54I shall setup another weekly meet and you can have a go in my setup. There is a significant difference going full decat, with sound being one of the factors you should bear in mind.
Can you make it out to sort of towards Slough maybe South of that?
That would be sweet mate, thanks. Definitely can make it out that way. Just over an hour away, which is basically about how long it takes me to get to a decent road anyway ;D
Quote from: MannyUK on October 7, 2019, 21:48As a cynic I would like to know how much effort is put into making a catalytic converter, do the companies that supply and make the cats actually pump out more No2, CO & hydrocarbons then these things save? The precious metals in cats have to be dug out of the ground, processed and then shipped to a factory. The factory will burn energy like no tomorrow putting together these pieces of kit and then transport them to a car manufacturer.
Short answer; yes.
See the values I gave above.
Haha
@Petrus already one step ahead on the beer! Thanks for the figures, they definitely had me heading for the fridge (again) too O:-)
I love the theory of saving mass, but I love my speakers, sub and storage more! I might test her without power steering some time soon though. I actually run with the spare wheel in the frunk because I'm hesitant to drop weight in the front without balancing it in the back somehow. I think the toyosports is quite a bit lighter than the stock manifold but it's somewhat offset by the TTE dual exhaust which is by my reading "pretty. Damn. Heavy"
Quote from: househead on October 7, 2019, 22:12Haha @Petrus already one step ahead on the beer! Thanks for the figures, they definitely had me heading for the fridge (again) too O:-)
I love the theory of saving mass, but I love my speakers, sub and storage more! I might test her without power steering some time soon though. I actually run with the spare wheel in the frunk because I'm hesitant to drop weight in the front without balancing it in the back somehow. I think the toyosports is quite a bit lighter than the stock manifold but it's somewhat offset by the TTE dual exhaust which is by my reading "pretty. Damn. Heavy"
The mass reduction is only an example to show the relativity of the cleaner cat.
The rest of the numbers you can crucch to see that doing just a few months longer with a 10 y.o. car ´saves´ more carbon footprint than the gasoline over the average 1o year distance driven produced uncatted.
So although there is no discussion that less footprint is better, we are totally misinformed/manipulated about the whole picture.
Back to the weight distribution.
Have a look at the Spyder´s versus the Elise´s.
Don´t worry about chucking any weight anywhere with respect to the belance. Simple aero mods do a power of greater good ;-)
That written; a decat manifold, decat pipe and lighweight muffler easily save 20 kilos.
As observed by others, be aware that a decat midpipe is a lot louder.
Having swapped about the lot in mine I´d say that (starting from a decat header) the muffler is 2/3 of sound reduction and the cat 1/3.
A sports exhaust with decat midpipe will be LOUD.
The increase in noise bear noooo relation to the extra oompf.
You can easily go 18 or more dB = being 600% louder whereas you get at best 10% or so hp extra?
I am currently back to OEM and mán it´s silent. If anything I drive faster in silent mode because of the relative ´stealth´ so the extra oompf is useless; just attracts attention.
About the noise, decat + OEM muffler is perfectly fine for daily driving. I wonder what would happen if I fit a cat at the moment. Id imagine that I wont be able to hear anything but wind noise. I have a heat wrap - the cheapo one - on the header and down pipe and no drone is present. With the previously fitted TTE, the exhaust was loud, like on 6k rpms it would scream so much that my head would start hurting in 10 mins or so.
Quote from: Nvy on October 8, 2019, 09:39on 6k rpms it would scream so much that my head would start hurting in 10 mins or so.
10 minutes at 6000 rpm the engine´s head might start to hurt too ;-)
No, seriously, my decat header, decat midpipe and superbike no-muffler combi is seventies Kawa 900 open 4-1 level of noise.
The only thing coming close nowadays are ´kids´ on larger capacity quads with unbaffled pots.
Still not found an alternative :-(
TBF The noise is a concern as I'm running the TTE exhaust and it's already pretty loud. It's a level of loudness I'm happy with but I don't think I'd want *much* more.
Am tempted by the Malian 200 cell sports cat. Comes as part of a downpipe so no fabrication and it's only £175. It would also allow me to keep the old pipe and cat intact so if there are MOT issues (notwithstanding a good, hard ragging before handing over for the test) it could always be swapped back.
Quote from: househead on October 8, 2019, 11:07TBF The noise is a concern as I'm running the TTE exhaust and it's already pretty loud. It's a level of loudness I'm happy with but I don't think I'd want *much* more.
Am tempted by the Malian 200 cell sports cat. Comes as part of a downpipe so no fabrication and it's only £175. It would also allow me to keep the old pipe and cat intact so if there are MOT issues (notwithstanding a good, hard ragging before handing over for the test) it could always be swapped back.
One of the ideas I was working on was to take a decat pipe and cut out the section where the cat should be and have v-band flanges put on. This would enable swapping in and out of your desired cat level or no cat quickly and easily.
i.e. off to track day or off to the MOT etc..
Nice idea that
@jvanzyl did you get a price on having a pipe modified in this way?
Quote from: househead on October 8, 2019, 11:11Nice idea that @jvanzyl did you get a price on having a pipe modified in this way?
Not yet... basically it's a max 2 hour job to swap over a cat pipe without the v-band idea... the current plan is to schedule in 4 hours a year for this work :-)
Quote from: jvanzyl on October 8, 2019, 11:18Not yet... basically it's a max 2 hour job to swap over a cat pipe without the v-band idea... the current plan is to schedule in 4 hours a year for this work :-)
I found that with the car on the bridge I can quite easily get the cat and/or the muffler in out from underneath. Only need to take the nappy off.
As to the sound level househead you will hear it at jvanzyl but imo you will be unpleasantly surprised if you think the TTE is loud enough. The cat really muffles.
For mé a sports cat is not a route I go as maybe yes maybe no on the MoT emission means I would drop in the OEM cat anyway for MoT and I réally do not like the heat radiation of the cat.
The set up on our MR2 is enclosed ín the engine room, not like front engine cars in the cool air underfloor.
The heat behind the car at a road side restaurant is shocking:
With the OEM set up the lid gets pretty hot and the hot air really hits you. It also takes a lóng time for the rising air to get noticebly cooler.
The cat gets HÓT and the rising heat, heats up the hot muffler even more.
Whatever the muffler set up, deleting the cat will significantly lower the temp. because there will be 5 kilo less heatsink ánd the exhaust gasses have less time heating up the rear.
That observed I am at the moment a bit stumped as the decat & bike muffler combo I had is simply too loud and I´d rather fit the cat and bike pot than no cat and OEM muffler.
Quote from: Petrus on October 8, 2019, 12:09Only need to take the nappy off
That's about 30mins (25%) of the job! I'm actually thinking of leaving mine off the next time it comes off. Which will probably be really soon if I'm going to commit to oil changes every 3k miles. Feels like I only just changed the oil, but a trip up to Scotland and back added some serious mileage!
Yeah if I had car lift it would be nice and quick... but I don't unfortunately! Oh well..
My setup is fully heat wrapped from exhaust header till the exhaust muffler.
On a plus side, I got 39mpg as an average on the last tank, and that's with country laning and motorways and stop start etc... so I reckon there a slight economy to it.
But yeah noise can be dealt with my turning the music up louder as well..
Quote from: jvanzyl on October 8, 2019, 12:18But yeah noise can be dealt with my turning the music up louder as well..
:))
My neighbours are gonna LOVE me!
Quote from: jvanzyl on October 8, 2019, 12:18But yeah noise can be dealt with my turning the music up louder as well..
I did a delete on the sound system as I mostly drive top down which very effectively drowns all sound quality so why bother?!
Opening up the exhaust indeed increases fuel economy. The say 10% power gain is the engine not using power in pushing the gasses out. Using the same engine power to drive it means less fuel burned to flush the gasses. It also means less CO2 produced.
There is a direct link to fuel burned and CO2 pumped out.
Btw. the complete exhaust system; manifold w. cats, cat, muffler, shields, assorted hardware, weighs a whiff over 30 kilos.
Muffler is 12.5 kg.
Cat is 7.6 kg.
Quote from: Petrus on October 8, 2019, 11:0210 minutes at 6000 rpm the engine´s head might start to hurt too ;-)
Its my head/ears that hurts, it really does. I used to drive a 500mile trip to work once a week and I used a noise cancelling headset designed for a helicopter to make it bearable. On short fun trips no problem but the drone on a motorway for 6 hours is horrific. Bear that in mind before you do it or maybe be a passenger in someone elses with a similar setup.
Quote from: MannyUK on October 9, 2019, 08:21Quote from: Petrus on October 8, 2019, 11:0210 minutes at 6000 rpm the engine´s head might start to hurt too ;-)
Its my head/ears that hurts, it really does. I used to drive a 500mile trip to work once a week and I used a noise cancelling headset designed for a helicopter to make it bearable. On short fun trips no problem but the drone on a motorway for 6 hours is horrific. Bear that in mind before you do it or maybe be a passenger in someone elses with a similar setup.
I meant some spirited driving but not constantly being on 6k rpms :D We have speed limit, if we were in Germany that would be another story :) Now I have OEM muffler and im happy.
Quote from: househead on October 7, 2019, 22:12I might test her without power steering some time soon though.
The ´00 tech info doc. on the new MR2 mentions that in case of failure the electric assitance is switched off and the steering functions as manual. Imo this means the power assist is designed to not hamper manual function.
QuoteI actually run with the spare wheel in the frunk because I'm hesitant to drop weight in the front without balancing it in the back somehow.
I´ve started a thread on that.
You will reduce understeer.
Mind; I have seriously lightened the front, upped tyre pressure a whiff, gone 195 and at lower speeds it will still understeer on sharp turn ins into tighter corners even on AD08Rs.
Stabilty at speed is an aero issue. Weight up front is only massaging the symptom.
Though not addressing the real cause either, deleting power steering has the side effect that the car appears more stable at speed because it respons less twitchy on driver input.
That's good to know
@Petrus understeer is indeed the work of the devil!
For me, removing the power steering will be more about improving the road feel, with the added benefit of losing some mass if I went the whole hog and ripped it physically out. Also need to check on the legality of that too. It's just an idea at this stage rather than something I'll definitely do.
Quote from: househead on October 10, 2019, 12:08That's good to know @Petrus understeer is indeed the work of the devil!
For me, removing the power steering will be more about improving the road feel, with the added benefit of losing some mass if I went the whole hog and ripped it physically out. Also need to check on the legality of that too. It's just an idea at this stage rather than something I'll definitely do.
No need to: It is not allowed unless you have a declaration of the manufacturer and a certificate of the work from a registered garage.
Still more than is possible for a decat manifold a decat midpipe of a non homologated muffler. The létter of the rules do even not permit the so called ´cool air inlets´ replacing the OEM filter housing.
Quote from: Petrus on October 10, 2019, 15:01Quote from: househead on October 10, 2019, 12:08That's good to know @Petrus understeer is indeed the work of the devil!
For me, removing the power steering will be more about improving the road feel, with the added benefit of losing some mass if I went the whole hog and ripped it physically out. Also need to check on the legality of that too. It's just an idea at this stage rather than something I'll definitely do.
No need to: It is not allowed unless you have a declaration of the manufacturer and a certificate of the work from a registered garage.
Still more than is possible for a decat manifold a decat midpipe of a non homologated muffler. The létter of the rules do even not permit the so called ´cool air inlets´ replacing the OEM filter housing.
Is the universal joint (joints) up to the task of running without assistance? Particularly considering that some may well have endured many years of use already.
Quote from: McMr2 on October 10, 2019, 18:39Is the universal joint (joints) up to the task of running without assistance? Particularly considering that some may well have endured many years of use already.
Dunno. If it has/develops play then replace it. Should be easy to check/replace if you have the vanity cover out.
Now I have easy talking as I hardly do any slow traffic nor parking manouvring and at the farm the parking is hardpack crushed gravel.