Cats ?

[JBF]

I've taken my car in for the annual assault on the wallet and have been informed that both cats are shot.

What are my options here ? They're quoting 1000 each for the Lotus parts, but from searching around on here other people have suggested 'high flow cats' as being superior to the standard ones.

Any advice welcome - this is an area I know nothing about at all.

Jason.

[Daniel]

The high flow cats are exactly what they say......basically a bigger through flow so theoretically you'd get the benefits of a de-cat and stay legal.

Can you not just de-cat it and find a friendly garage?

[Rob]

Charlie morgan paid 900 quid for a full custom setup from powerspeed (details on LEW) that was a complete turbo-back system to tailpipe including 200 cell metal cats.

Any specialist could make you up something. There are suppliers out there who will sell you just the generic cat ie www.autocats.com . I would only go for a metal cat. You can guy generic hi-flow ceramic cats very cheaply but these will melt with the power/heat of the v8. You could just buy the substrate and have it fitted into your existing lotus pipes if you want to retain the "factory" look.

There are some commercially available "off the shelf" items, e.g. hyperflow. These are ready made to bolt on to your car, and look great in polished stainless, but they are expensive (but still cheaper than lotus). Kev Maier did not give good feedback on his... :-/

[actwon]

Charlie morgan paid 900 quid for a full custom setup from powerspeed (details on LEW) that was a complete turbo-back system to tailpipe including 200 cell metal cats.

Any specialist could make you up something.  There are suppliers out there who will sell you just the generic cat ie www.autocats.com .  I would only go for a metal cat.  You can guy generic hi-flow ceramic cats very cheaply but these will melt with the power/heat of the v8.  You could just buy the substrate and have it fitted into your existing lotus pipes if you want to retain the "factory" look.

There are some commercially available "off the shelf" items, e.g. hyperflow.  These are ready made to bolt on to your car, and look great in polished stainless, but they are expensive (but still cheaper than lotus). Kev Maier did not give good feedback on his... :-/

<{POST_SNAPBACK}>

Personally, I would de-cat and find a friendly garage...

[Rob]

yeah.. but in the uk its a bit of a grey area regarding legality. Ie if your car is not "roadworthy" then your insurance may be invalid if you have an accident. Failure to have cats in place is an mot failure for the later cars so technically it could be argued that the car is not roadworthy without cats..

Personally i would not take the risk (although i know others do) and to get a "friendly" garage.. well, you are asking someone to break the law for you and put their livelyhood at risk. All seems a bit extreme for a couple of extra bhp IMO.

With some hiflow cats you're getting virtually the same benefits as a de-cat without any of the risk.

02p etc.

Rob

[actwon]

yeah.. but in the uk its a bit of a grey area regarding legality.  Ie if your car is not "roadworthy" then your insurance may be invalid if you have an accident.  Failure to have cats in place is an mot failure for the later cars so technically it could be argued that the car is not roadworthy without cats..

Personally i would not take the risk (although i know others do) and to get a "friendly" garage.. well, you are asking someone to break the law for you and put their livelyhood at risk.    All seems a bit extreme for a couple of extra bhp IMO.

With some hiflow cats you're getting virtually the same benefits as a de-cat without any of the risk.

02p etc.

Rob

<{POST_SNAPBACK}>

Ooohhhhh... Wow!! It's a completely different story here in the States... Cats are considered emmissions problems and does not determine road worthiness.. Thus, our insurance cannot be invalidated becuase of catalytic convertors, O2 sensors or anything related to emmissions.

I owned a '98 Mitsubish Eclipse GSX. I gutted the cats thanks to the AWD, it always passed inspection. I may gut the cats to the Esprit as well. Not sure..

[Feffman]

Jason:

How about a pair of off the shelof aftermarket free-flow cats from someone like Magnaflow, etc. Cost is about $100 (US dollars) each. Any good exhaust shop could weld flanges to them for mounting in the system. Will sound a LOT better like mine do.

Mark (Feff) Pfeffer

[Toua]

my civic hatch has a full cat-back with no Cat. converter.. sounds great!.. passes emmissions in the US! 10hp : ) for my little civic..

97hp 97lbs of torque (stock)

2000lbs (love this weight) 400lbs heavier then the elise.

[DJ504]

I'm in the same boat - One cat has totally disintegrated - Garage is advising me to go for the all metal cat which appears to be the best option. I have been quoted

[Rob]

both numbers seem high IMO. I paid 900-ish for a genuine lotus cat a few years back.

[DJ504]

Done a bit more ringing around and looking on the web. Discussed my findings with my garage & they have advised me the following. The guy at the garage is an A1 Lotus mechanic so I take his advice as gospel.

Some of you guys have posted similar comments so I'm assuming it's good advice.

1. Cheap repro ceramic cats will not last even if you have assurances that they're rated for BHP & CPSi.

2. "All-metal" cats are the best option.

3. The cost of all-metal cats vary immensely but you get what you pay for.

4. If you de-cat you car, thre is every possibility you'll blow your turbo - He's seen four de-catted V8's and they all blew turbo's.

5. Fit a metal cat, large bore, at least 200 CPSi and rated for at least 200BHP. There are some out there that are only rated for 180BHP (maybe only 100 cell) - These will not last. 2 x 180 = 360 which is too close to the factory 350BHP output.

6. A company called Blackthorn are linked to the "autocats" website. They no longer deal with cars and put me on to "Jetex" Spoke to a guy called Niel - very helpful.

I spoke to Blueflame - they're listed on LEW and have rave reviews. They quoted me

[mike_sekinger]

Interesting post. Some good advice on replacement CATs. However,

4. If you de-cat you car, thre is every possibility you'll blow your turbo - He's seen four de-catted V8's and they all blew turbo's.

The destruction of the turbos has got nothing to do with CAT removal. This is more likely to do with other modifications (boost upgrades and chipping ECUs) that may have taken the turbos out of their ideal operating range. I bet that in all of these cases the boost will have been increased.

If you

[Rob]

Ditto Mike's comments. Agree all your other points.

My mate Bernard had some hiflow ceramic cats (from D&T in australia). Not sure how long they were on the car, but both had failed last time he took the car for MOT. He luckily managed to find some second hand genuine lotus cats - actually from charlie morgan.

See post #3 above.

Why pay 1300 when charlie only paid 900 inc vat and fitting at powerspeed?? This is for metal cats, 200 cell, full system etc.

N.b. the stock lotus cat has two sections, the first (closest to the turbo) is metal - the later section is ceramic and its this bit that usually fails.

N.b.2. porsche and some other manufacturers of performance cars use only metallic cats.

[bimmabimma]

hey guys, im new but i thought i'd chime in here. You CANNOT blow turbos by doing cat delete. if anything you are making the turbo's job easier becuase it spools up much quicker due to lack of backpressure and make the turbo do its job easier. Some claim you make roughly 15Hp and 30lb feet of torque with cat delete, which sounds about accurate. Removing cats on turbo cars really make a drastic difference especially on old rotted out british cats.

I would suggest just running straight cat bypass and running 4 small resonators and thats all the muffling you'd need. This is what I plan to (run 4 of these, two on each side)

http://www.aero-turbine.com/?flash=1

Those resonators are the highest quality resonators i've ever seen. All the BMW E46 M3 guys run them b/c the stock cars sound like ass and just one of these resonators eliminates 95% of the rasp. I think 4 would be great, two acting as resonators, two acting as mufflers, then coming out to a set of high quality stainless tips, great combo. anyways just a suggestion.

[DJ504]

Had my cats fitted - Exhaust note was good before but now it's superb!

Got talking de-cats with the mechanic. One thing to consider / advise on:

The turbo seals work,and rely on, a certain amount of system back pressure. De-cat the system and the loss in back pressure causes the seals to fail. This was the reason for my original post about "de-catting blowing turbo's".

Worth checking oil levels if you've de-catted.

[Rob]

Paul - how much did you pay in the end and who did the work?

BTW Hangar 111 are now offering cat replacement (and decats) all in for 650 see LEW:

http://www.lotusespritworld.com/news.html

[bimmabimma]

Had my cats fitted - Exhaust note was good before but now it's superb!

Got talking de-cats with the mechanic. One thing to consider / advise on:

The turbo seals work,and rely on, a certain amount of system back pressure. De-cat the system and the loss in back pressure causes the seals to fail. This was the reason for my original post about "de-catting blowing turbo's".

Worth checking oil levels if you've de-catted.

<{POST_SNAPBACK}>

which seals are u referring to? ton of turbo guys run catless and i've never heard of problems on supras or WRX's or etc. why would Esprity be any different. interesting topic to discuss, nonetheless. I hear the gains on catless free flow exhaust turbo car is fantastic so its not just a minor increase in performance, its a pretty huge boost (no pun intended B) )

[DJ504]

I ended up paying

[Kato]

There's some new stuff on the LEW news page about Hangar 111 new CAT/DeCat for the V8.

http://www.lotusespritworld.com/news.html

p.s. Dam! Didn't see the second page of the thread!

[bimmabimma]

How much would these be in US $ ?

[snuffy]

I'm trying to speak with these people cus one of my cats has gone south. It's proving a tad tricky when all you get is an answer phone.

[Rob]

How much would these be in US $ ?

<{POST_SNAPBACK}>

Currency converter here:

http://www.xe.com/ucc/

[snuffy]

About $750, and juding by my trip to NY this week, that's about the same as dinner for two !

[bimmabimma]

About $750, and juding by my trip to NY this week, that's about the same as dinner for two !

<{POST_SNAPBACK}>

oh ok, thats not THAT bad for an exotic supercar, BMW exhaust components are right around that level. do 200CEL cats still provide enough emissions control to pass emissions even in the strictest US cities?

[hovgaard]

The turbo seals work,and rely on, a certain amount of system back pressure. De-cat the system and the loss in back pressure causes the seals to fail. This was the reason for my original post about "de-catting blowing turbo's".

<{POST_SNAPBACK}>

Do not believe that to be the case. Instead, I would support Mike's view that people who de-cat will tend to have done other stuff as well, and may have overstretched their engines somehow.

Is the V8 Turbo unique to both Lotus and the car???

<{POST_SNAPBACK}>

The turbochargers on the Lotus V8 engine are Garrett TB2531. That's pretty much the same turbo as on something as mundane as the Saab 9000 2.3 Turbo. They are most likely not identical, but it is the same model. Could be different wheel trims and that sort of thing. But the bottom line is, the turbos used on the Lotus V8 are nothing out of the ordinary.