free hit
counters
catalytic converter on V-8 - Induction/Turbo/Manifold/Exhaust - The Lotus Forums Jump to content
Sign in to follow this  
buck's esprit

catalytic converter on V-8

Recommended Posts

Next week I am having another catalytic converter replaced on my ’03 Esprit. I had the other side replaced last week at Lotus of Denver, too bad they didn’t notice that both had failed. So now I have gone through 6 Catalytic converters, all replaced under the emissions warranty. I only have another year left on my warranty. Can anyone tell me why is my car blowing apart the cats? Where can i get cats for less than the $2200 each that the dealer wants?

Colorado Buck

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

you can find various catalytic converters within the *e-bay* world. Most of them even in the more practicable 200cell/in^2 metal-base version.

If you source out the right 'round' diameter you even could fit them within the original Lotus-OEM converter casing. Or otherwise, fit them between the original Lotus pipe ends.. .

As for the failed converters: . ..check out your fuel-injection system, and the 'oil-fumes'crankase breather system for unwanted mixtures in the combustion process. This could cause irritations in the engine running & ECM control process and can enrich the combustion. The Lotus OEM catalytic converters are made with a fine mesh, that can block up by carbon deposits really fast. Other point is that together with those temperatures and blokades in the converter and with the steady vibrations from the engine/exhaust system in the car the converter core breaks and dismantels easylie -what's left in those cases is white powder and pieces who look like coal from a BBQ clogged up in the remnaining core parts... .

Share this post


Link to post
Share on other sites

Hi Guntner,

I would like to obtain some of the 200 cpi catalyic inserts which will fit inside the stock OEM Lotus converters, but I can't find them anywhere on e-bay. Can you send me a link?

Thanks,

Wayne

Share this post


Link to post
Share on other sites

I have a pair of 200 sports cats in stock, polished and ready to go if you get stuck? I can post today via DHL or UPS and it can be in US in 48 hours. www.espritperformance.com

e099bf97a9eb0138ce71f0c7b322a8df.jpg

Regards,

David Walters

Share this post


Link to post
Share on other sites

Thanks this is just the kind of information I wanted, thank you. However, the dealer has installed the left side cat under the warranty and is waiting for the other cat to arrive so I don’t need them now. But they seem to last less than 10,000 miles so i will be looking for my cats in about a year.

Buck Wenger

[email protected]

Share this post


Link to post
Share on other sites

Wayne, use this as an example: e-bay

-it is not the product/dealer I've used for my rework in the past ,and i would gues it is possible to find similar ones in *e-bay US* ?! ..so measure/ compare the lenght of the main-core [the one that is actually the metal-mesh, not the additional casing or the conical adaptor ends -sounds logical :thumbsup: ] on any given reference drawing from the sellers page first. But all in all ,think it should fit into the Lotus casing and all will look like stock on the MOT inspection.. (depends on your welding skills..) :dizzy:

Other way is if you type in 120mm-race catalyst on *google*or *e-bay* and search for the bigger catalyst that fits in the rear end: other e-bay

Edited by Günter

Share this post


Link to post
Share on other sites

Hey Gunter,

Did you ever measure the inside diameter and length of the starter CAT space inside OEM shell?

I need to completly hide the replacement substrate inside the OEM CAT shell.

Wayne

Share this post


Link to post
Share on other sites

the OEM casing is over 98mm (would say around 100mm) in internal diameter -so most of the available *98mm aftermarkets do fit .

The distance between the two black metal rings who hold the OEM ceramic internals in place was not to measure on mine ..as at least one of those rings was completely gone -so it would just be a guess, based on the weld-marks from the fabrication (as you can see on the outside of your parts -there are three marks who show where the metal ring sits in his place).

If you have already opened the OEM casing on both ends ('on both'...in case you want to fit both sizes into place , like in the OEM version..) you can measure the distance between 'ellbow connector face & O2-probe' on one end, and for the rear section between the internal casing-step and the conical connector as this has to be fitted back on like OEM. Just keep in mind that the seperate parts of the OEM casing are fitted 'on in the other' ,so there is always a little reserve in lenghth. Use the angle grinder only to 'weaken' and cut the weld until you scratch onto the other part of the casing. Thius also means you can simply do a 'test fit' ..as it all hold together like *LEGO* , the ellbow connector is a little wider that the small catalyst section, the conical rrear section sits inside the big section. It is a thight fit, and means you have to calculate around 5mm loss of lenght for every weldline on your measurements... .

I've just cut off the additional ends on the aftermarket replacements and shortened the catalyst casing as far as possible -with noticing on 'keep it in a save distance to the metal mesh' ...as the heat on the welding proces (only spot-welding , this is enough to hold the in place internally..) means you have to do it with at least 8mm -10mm additional metall left from the aftermarket casings.

Share this post


Link to post
Share on other sites

Gunter,

I intend to use only the starter CAT section and fit an aftermarket 98 m/m 200 CPI metal substrate. I have not removed the OEM CATs yet and once I cut them apart, I am committed to the replacement substrate. I need to determine the internal length of the starter CAT area before I destroy the OEM CAT, use be sure I can purchase a correct substrate.

Thanks Gunter.

Share this post


Link to post
Share on other sites

go on your catalyst , use a wire-brush or simmilar , clean out the front section on those and if you spot closely you will find the mentioned welding points (around 3mm diameter) for the metal rings who hold the ceramic substrate-piece in place.

The L-profile shaped metal rings are around 8mm wide, the weld-spot is in the middle of this distance. So you can actually measure the distance between those lines of weld spots , and therefore determine the original lenghth of the internals from outside on your catalyst (add the 8mm, for two times 4mm on each ring of course..) . This should give you an impression on how short the OEM ceramic substrate block really is.

There is more room in the front section than that by the way... would say up to 95mm (from inner edge of the front section [this is covered by the ellbow on the outside!] and just up to the o2-sensor as far as I can see it on the outside of mine)

My first experiments on catalyst replacements suffered from the Ethanol fueling experiments... as the starter cat on one bank was running with really lean [hot] emission rates ..there is now an sign of 'overheating' in the centre section on this starter catalyst mesh. But it was also a good sign, as the centralised and nearly globular orientation means the catalyst was still converting emission gasses in his reactive renter.

I still have one as an replacement (you can see on the picture what I mean with 'cut the ends off on the replacements along the weldings..' ) ..for now both front sections run without internals and I just use the bigger and colder operating rear parts with the 120mm inserts for my still existing 'fuel creativity' :)

Edited by Günter

Share this post


Link to post
Share on other sites

Hi Gunter,

Your pictures and explaination are very clear. I also can see the welding marks on the outside of my CATs.

You are using only replacements for the main CAT where I would like to use only the starter CAT location as the Lotus post CAT O2 sensor is after the starter CAT. This must look stock and meet California smog performance levels to work for me! This project is in support of my soon to be replacement for my high torque ECU, which is based on a variant on the Lotus RED ECU. I am willing to swap out the ECU every two years to pass the smog tests, but don't want to have to swap the CATs. I am concerned that the OEM CATs will have to much back pressure, for the boost level I intend to run, and force the wastegates to open early. Stronger springs in the wastegate is not the correct way to go.

I have a source for the substrate and another to provide the washcoat, but this is an expensive way to go. Using off the shelf CATs are cheaper but it is difficult to get performance information from the manufacterer, especially if you live in California.

Thank you for the information.

Wayne

Share this post


Link to post
Share on other sites

Wayne, it's just as I said -first time all four internal were fitted in place ...but as you can see in the forums archive in this time I was also testing different set-ups for my fueling experiments.

The heat up cycle for the Euro2 emission rating does only require an reaction time in the rate of the rear internals. What means my rears are placed far enough from the engine to have an compensation for slightly 'to lean' or 'overheated' emission mixtures. On the other hand those rears are big enough to convert in an sufficient rate to pass emission test by the German TÜV.

I can understand that you need to have an catalyst placed between both O2-sensors, and as far as I know it there is an steady 'monitoring' of conversion rate programed into the 'California calibration' ECU.

From my impressions those small aftermarket catalyst can heat up as fast as it needs to pass the emission tests . It works in the same way as in OEM fitment - just keep in mind not to manipulate the fuel mapping in the same way as I have done it :) (but I think this would kill nearly every type of catalyst under this circumstances, OEM or aftermarket..)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  


×