nex catalytic converter

[Mel_Boss]

-Malcom, when I wrote "issues", I was referring to questionable life span and the reduced max-boost that you cited. There are no extremes to our climate in NorCal , and my m100 is not a racer - both should help with product life. The 36104 remains a viable option for me.

- Steve, you raise a good point - gauge accuracy. I first cited that my max-boost was about .6bar, but later the next morning I made a run. The boost gauge ran-up to .6 initially and as I approached max engine speed, it creep up to .75/.8bar. This is "new" and is higher than I've ever seen it go. I'm inclined to go the "shell-option" (remove,clean,replace) for the meantime and enjoy the extra performance. In two yrs time, I can pre-test for smog and replace with a legit-cat if necessary. I still want to get an oem cat if that's possible since they might not be available in time.

Update - my mechnic-buddy just phoned and I've scheduled the m100 for next Thursday morning for the "shell-option". It won't cost much (1hr labor) and no significant parts. We'll call this - "an experiment". In the mean time, I'll collect some performance data as a reference. Something simple for me to measure like indicated max boost (imperical) , boost behavior (observational data) , 25-60 accelleration in 3rd gear (imperical). Another friend has a pretty sophisticated dyno setup in SJ, but that option would cost me dearly... I'll be in Monterey/Carmel first half next week for an Elan (50th anniversary) concours and meet-up with some friends there. To the races on the following Saturday and hopefully drive my 1972 Elan Sprint there.

[KO6SY]

Steve,
Thanks for the explanation, makes sense. When it cools down here ( presently at 110F) I will take a run with ElanScan logging to see how it compares to a log I took well before the CAT disintegrated.

Malcolm

This is how I believe it works. I'm sure I will be corrected if wrong.
The standard system with 2" pipe "squish" pre-cat and main cat boosted to
.65. If you are getting .5 on the unreliable guage then you may be at .65 which is
stock. When your pre-cat or main cat began to break up the system was able to
flow more volume therefore .8. When you remove or alter the pre-cat or main cat
you achieve .8 to .9 to 1 bar or what is called overboost. Their are many threads on
this subject how to correct and how to use the full potential of our little turbo.
Hope this helps.

Steve

[GoM100Go]

I'll also be waiting on how your cat-Hollowing goes. It may be a solution for my car, if this second cat in 6 monthes craps out as well.

[Brit-Car-Nut]

Thanks for all of your time and help.
This is very kind and generous of you and I appreciate it!

I sent an inquiry to cbrown as you suggested...

Mell Boss:

Just got off the phone with CBrown and, YES they still have stock of the cat.
He suggested dealing with Bibs.
Has he responded to your enquiry?

I can make the arrangements for you through my friendly dealer, but just figured it would be better if you had it shipped directly to you.

If I can help, drop me an EMAIL. I am willing to assist anyone with a problem.

[GeoffSmith]

This is how I believe it works. I'm sure I will be corrected if wrong.
The standard system with 2" pipe "squish" pre-cat and main cat boosted to
.65. If you are getting .5 on the unreliable guage then you may be at .65 which is
stock. When your pre-cat or main cat began to break up the system was able to
flow more volume therefore .8. When you remove or alter the pre-cat or main cat
you achieve .8 to .9 to 1 bar or what is called overboost. Their are many threads on
this subject how to correct and how to use the full potential of our little turbo.
Hope this helps.

Steve

The ECU should be able to control the boost whether the cat is there or not - the wastegate/actuator/boost control frequency valve are the same in the UK SE (no cat) and S2 (both cats).

[Mel_Boss]

I'll be away for a few days to return Wednesday late. Thursday morning the m100 is scheduled for the shell operation - shouldn't take very long. Over the weekend, I confirmed that the boost gauge (that previously read a max of .6) now goes to .8 @rpm max. I agree it is peculiar that the ecu does not better control this boost behavior. I'll be sure to report the results later this week.

[tigerdog]

Magnaflow has the ONLY California-legal replacement cat listed in the BAR database. With current law, it's the only thing that can be installed without your installer having justify the change to the powers that be. California is painfully restrictive these days. That said, I have a Magnaflow on my Elan and it's working fine - as long as the car is properly warm, it passes the rolling-road smog test with ease.

[Mel_Boss]

Back from the weekend Monterey festivities and time to report. Thursday's primary cat R&R took less than 2 hrs with good results. It was filled with broken-up debris (cat guts) that were cleaned out, and the cat was welded back. The rattle is gone and boost response is pretty much as before the R&R, shoots to .6 and creeps to .75/.8 at rpm max. So for now, I am satisfied and plan to pursue obtaining a replacement cat for the future. I will report if I experience any problems like CEL failures.

Thanks to all for sharing their experiences and knowledge. John, I have not heard back from Bibs and will send another inquiry later today

[Brit-Car-Nut]

Back from the weekend Monterey festivities and time to report. Thursday's primary cat R&R took less than 2 hrs with good results. It was filled with broken-up debris (cat guts) that were cleaned out, and the cat was welded back. The rattle is gone and boost response is pretty much as before the R&R, shoots to .6 and creeps to .75/.8 at rpm max. So for now, I am satisfied and plan to pursue obtaining a replacement cat for the future. I will report if I experience any problems like CEL failures.

Thanks to all for sharing their experiences and knowledge. John, I have not heard back from Bibs and will send another inquiry later today

You have an email.

[Mel_Boss]

I wanted to take a couple of minutes to thank everyone to shared information on this topic. Particularly, John Callahan - you are amazing and I owe you. Thank you so much! I now have a genuine Lotus cat wrapped-up and stored away in case I should need it someday to pass our California emissions/smog test. Presently, I'm enjoying the considerable "boost" provided by the freeflowing shell that is welded in place, easily .8 boost. The feel is readily noticeable throughout the rev range. Apparently, the Elan will pass emission testing without the primary cat (marginally) if everything else in in tiptop condition. So with any luck, I will never need to use that cat again. I plan to have a baseline test done as a measure - then, if there is a test failure in a few yrs, I'll know there's perhaps another problem (by then the motor will have about 150k miles on it). Again, thanks to everyone who contributed to this thread!

[GoM100Go]

7 months later I am back here, 1.5 years of ownership and 3 cats. I think my only option is going to be to go the route of hollowing it out as well. I just need to find a shop willing to do the work.

-James

[Brit-Car-Nut]

CATs don't just fail. It sounds like you have some serious fuel or ignition issues that are causing the CAT to overheat and then fail. I wouldn't scrap the condition (CAT), I would fix the cause.

There are many issues that can cause a CAT to overheat. The most common is a misfire at high speed. The other is an excess of fuel which causes the CAT to burn itself to death.

I would look closely at the Fuel Pressure Regulator. I would also find an ElanScan interface, or even better, a real Lotus test system. You have a serious issue that might end up hurting you if the car catches fire.

Factory original CATs were available for a really low price last year. Even with FedEX shipping they were still less than the aftermarket CATs you were looking at. The CATs the guy on eBay UK is selling seem to be absolutely correct. You migfht want to see what it will cost to get one of the originals from him.

[GoM100Go]

My mechanic is on it and thinks to have found the problem, my car is NOT orignally a California car. Therefore to make it California compliant the previous owners simply added a California (ceramic innards) compliant CAT, that's all. It's passes smog fine like that. No new ECU not new oxygen sensors nothing. So my car is eating these cats because its not a CA car but a 49 state car. We changed plugs, wires, O2 sensors. And he eats CA CATS. So an all metal (metal innards) cat, which is originally what was on this car, is my only option. So on to get an all metal cat. I guess. But for now, no turbo boost. I know what a non turbo car is like and I don't like it. I need my turbo.

-James

P.S. apparently, it is illegal for me to purchase or even ship an all-metal CAT to California... :-/ also a visual inspection shows no over heating because the color of the CAT has not changed to a burned CAT color, still pretty and silver?!?! Just over pressure that ceramic is not designed to handle.

[Brit-Car-Nut]

I arranged for a pair of Lotus supplied cats to go to a member in Calif and had no issues with Customs.

Look at these. They appear to be just like the ones I got from Lotus: http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0879455482

You will want to verify they are the correct, original replacement.

We ordered F100S0024F at GBP49.00. Now Lotus wants GBP200.00. Those in the eBay listing look to be identical.

I don't know if he will ship to the US himself, but you can arrange collection via courier using Parcel2Go or Interparcel. The price in the listing includes the 20% VAT which they should knock off as they will have the shipping details when you provide the shipping labels to them (or if they ship it for you).

[GoM100Go]

Thanks for the leads! I will be contacting them.

-James

[GoM100Go]

Quick Update,
I did order the Cat from the UK ebay distributer. I had my shop add a flange to the other end of the Cat, as it came with a flange on the engine end of the cat. Now the new one has flanges on both ends so it can now simply bolt in on both sides. I had the shop then remove the dead cat and empty it, then add a flange to the other end as well. Then add a flange to the down pipe to the muffler. In effect I now have 2 cats that can be swapped without welding. One intact and another empty. I will run the empty one until its Smog time, then simply unbolt the empty and bolt on the intact cat, pass smog then proceed to swap back to the empty for 2 years... So on and so forth. Thanks to everyone's input as I used everyone's input to reach my solution.

-James

http://www.ebay.com/itm/330870578595?ss ... 2295wt_862

[Mel_Boss]

Good solution. My smogdate is next May. I may try as is first since I've heard from a friend that his passed twice with only the precat in place. I'm glad you found a solution that works for you.

[GoM100Go]

Update. I just passed smog today with the UK cat. Now swapping back to the empty... Will do it again in 2 years of cat free fun...

-James