[Liquidpaper]

Originally Posted by zipphreak

http://www.bmwe34.net/E34main/Trouble/Catalyticconv.htm


Most likely too rich, raw fuel hits the hot cat and ignites making it hotter and melts

Thanks, but I haven't had any of these problems. No engine misfires, or any engine malfunctions at all.

[zipphreak]

Are you running a Jb4 or other tune ? Might be masking the issue.

I would imagine these things dont just melt for no reason. The cause is too much heat. The cats melt because you get raw fuel into them. Raw fuel + hot cat = combustion = extreme temps & melted cat.

I would replace your cat and see what happens, might melt again though

Is the stock OEM cat Ceramic or Metallic core ? I wonder if the added AFR from a tune just cant keep up with the stock cat.


http://store.uucmotorwerks.com/articles/catless.htm

[Liquidpaper]

Originally Posted by zipphreak

Are you running a Jb4 or other tune ? Might be masking the issue.

I would imagine these things dont just melt for no reason. The cause is too much heat. The cats melt because you get raw fuel into them. Raw fuel + hot cat = combustion = extreme temps & melted cat.

I would replace your cat and see what happens, might melt again though

Is the stock OEM cat Ceramic or Metallic core ? I wonder if the added AFR from a tune just cant keep up with the stock cat.

http://store.uucmotorwerks.com/articles/catless.htm

Engine is bone stock. No tune. Cat core is/was OEM ceramic.

[zipphreak]

Very interesting, I'm going to start tracking my car as well. I'll let you know if I run into the same issue, bone stock as well.

-Paul

[Pparana]

Originally Posted by Liquidpaper

Engine is bone stock. No tune. Cat core is/was OEM ceramic.

It's fuel, car is stock. When you run without intercooler upgrade the turbo heats up intake temp heat soaks and car pulls timing and dumps fuel to cool turbo.

I only ran my car stock for one or two track days, car would heat soak in 4-6 minutes, so that does not surprise me. If your running hard.

[Liquidpaper]

Originally Posted by Pparana

It's fuel, car is stock. When you run without intercooler upgrade the turbo heats up intake temp heat soaks and car pulls timing and dumps fuel to cool turbo.

I only ran my car stock for one or two track days, car would heat soak in 4-6 minutes, so that does not surprise me. If your running hard.

Huh. Well yeah, running it very hard. Oil temps are fine. Thanks for the tip. I'll add upgraded intercooler to my list of crap to do.

[evanescent03]

Originally Posted by Pparana

It's fuel, car is stock. When you run without intercooler upgrade the turbo heats up intake temp heat soaks and car pulls timing and dumps fuel to cool turbo.

I only ran my car stock for one or two track days, car would heat soak in 4-6 minutes, so that does not surprise me. If your running hard.

what (specific parts) have you done to fix the issue?

[evanescent03]

this thread kinda bums me out. I am looking for a car that can handle done track time stock and this (the result or the suspected cause(s)) doesn't sound good.

OP - you said you aren't having any of these issues, but how do you know your car isn't running a bit rich? melting your car = driving like you stole it. congrats! and I'm also sorry and hope it's isolated

[Liquidpaper]

Originally Posted by evanescent03

this thread kinda bums me out. I am looking for a car that can handle done track time stock and this (the result or the suspected cause(s)) doesn't sound good.

OP - you said you aren't having any of these issues, but how do you know your car isn't running a bit rich? melting your car = driving like you stole it. congrats! and I'm also sorry and hope it's isolated

To be fair, I have 14 days on track and this is my only real issue other than tires/alignment.

Don't let this bum you out. Almost every street car needs some TLC to do serious track work -- it's not isolated to this car. Yeah, if you run a Miata its going to be less of a hassle than this car, but then, you're in a Miata...

Seriously, this car is a major blast and I've loved it every day I've had it on track, melted catalytic converter or not.

I don't know if I'm running rich or not, but considering how badly the converter was melted (seriously, it was a goddamn horror show), I can't believe running a little rich would do that. I would be more inclined to say BMW has a design defect considering what I saw.

[pikcachu]

If you keep melting cats you will be reported for animal cruelty

[LDSM]

Originally Posted by Pparana

It's fuel, car is stock. When you run without intercooler upgrade the turbo heats up intake temp heat soaks and car pulls timing and dumps fuel to cool turbo.

I only ran my car stock for one or two track days, car would heat soak in 4-6 minutes, so that does not surprise me. If your running hard.

Interesting, did you upgrade your intercooler?

[Liquidpaper]

Originally Posted by LDSM

Interesting, did you upgrade your intercooler?

No. It's stock. But I haven't ever gone into limp mode or anything, so I don't think that's the culprit. Not saying I don't get some heat soak on hot days, but its never that bad.

[ketema]

Is there any way to "trick" the engine and not get a CEL code if you don't run a CAT?

[Pparana]

Originally Posted by ketema

Is there any way to "trick" the engine and not get a CEL code if you don't run a CAT?

JB4.

[ketema]

Originally Posted by Pparana

JB4.

I knew about that one, but Boo. I didn't buy JB4.

[Pparana]

Originally Posted by ketema

I knew about that one, but Boo. I didn't buy JB4.

you could try different spacers, but no one knows which size is needed to fool the cat, or you could just go with a sports cat like the OP.

[Fabspeed Motorsport]

Originally Posted by Pparana

you could try different spacers, but no one knows which size is needed to fool the cat, or you could just go with a sports cat like the OP.

We are currently experiencing around a 70% M235I success rate with no check engine lights on our Catbypass pipes + our o2 spacers.



Fabspeed Sportcat downpipe

[G-Mann]

Originally Posted by Fabspeed Motorsport

We are currently experiencing around a 70% M235I success rate with no check engine lights on our Catbypass pipes + our o2 spacers.



Fabspeed Sportcat downpipe

70% success rate for the two options or just the non-catted option? What is the success rate for no cel with Catted Down pipe only?

[Fabspeed Motorsport]

Originally Posted by G-Mann

70% success rate for the two options or just the non-catted option? What is the success rate for no cel with Catted Down pipe only?

70% was with the Non catted option and spacers. We have had 100% success rate with our Sport cat down pipe. Not one CEL has been reported. Everyone seems to love our SportCat Downpipe.

[G-Mann]

Originally Posted by Fabspeed Motorsport

70% was with the Non catted option and spacers. We have had 100% success rate with our Sport cat down pipe. Not one CEL has been reported. Everyone seems to love our SportCat Downpipe.

Good to know and order placed. Nice working with you John.

[Bee Pee]

Originally Posted by alz0rz

Longstanding bugaboo with many cars, aftermarket 'sport' cats just do not seem to have the durability as an OEM cat used within its limits.

HJS supply most of Alpina and AMG road cars fitted with freer flowing or sports cats. No issues with durability.

[KAY-OS]

Does anyone know at what temperature will the stock cat melt?
I have the P3 gauge and it allows exhaust temp monitoring.

Is a sport cat more durable than the stock cat? I mean, if OP's stock cat has melted, won't the sport cat also has a chance of melting?