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Today I had the car up on the rack on post to check a drive shaft vibration that just started. I need a new guibo. In doing this I had to remove the exhaust system. When I pulled the section with the catalytic converter on it, I noticed a lot of stuff rattling around in the pipe on the engine side of the converter. So I dump all of this crap out on the floor.

Sorry, phone camera

Well, sometime in early October when I started hearing this "detonation" noise the converter broke apart.

So I had 6-8 charcoal size chunks of ceramic material that would rattle around under boost and high rpm. It sounded EXACTLY like detonation. I have spent the last two months pulling my hair out trying to tune this apparent "detonation" out of my engine. Needless to say, I AM A VERY HAPPY GUY to have finally found the problem.

I went ahead and gutted the converter. I now have a truly "free-flow" KAT.

So, its back to programing a new timing table again. This time it should be a kick in the butt.

And yes Todd.........................you were right 8), it was not detonation. You would have thought it was if you had heard it though.

I had the same problem a year ago and took the cat out completely. It sounds even better without it.

The insides of the cat on my former 535i went.. *cough* missing.

You wouldn't believe the extra kick you get above 4500rpm with that thing cleaned out, pulls so much stronger!

Awesome to hear. Im interested to see how far you can push it now.

Was that a Magnaflow cat?

Do you guys think your Cats Broke from being over heated by un-burned fuel hitting it?

Im thinking my Cat might be partially melted or broken, because earlier I had an Intermittent Spark issue, and because of that it dumped Alot of unburnt fuel into the exhaust and fuel actually shot out the end of my exhaust onto the driveway.

UPDATE - Just loaded new timing table.

Hit I24 and did some data logging. Had some detonation, the real kind, on the way out. Pulled over and looked at at my 12 and 20 psi readings. Pulled 2 degrees here and 3 degrees there. Now I am flat out WOT with no detonation and a lot more timing.

I'll tell you this. At 19-20 psi my car is as fast as the 500 crank HP corvette I rode in GA. My car has entered the "STUPID FAST" category and I am loving it. I don't like the rear tires breaking loose at 70 mph though

The guibo is giving me problems so I will have to cool my jets until I get another installed. What a great day!

The KAT failed probably due to the first head gasket failure and flushing lots of water through it. I also has some issues when I was running extremely rich.

Hummmmmmmmmmmm......may just have to take it to 25 psi. Need dyno.

all right Duke M535ti the car sounds strong.

How many maps are you creating?

are you going to record and copie your maps so when one day I get my m30 up and running agean and want to go with tec3 I will be talking with you and todd.

Big Q were do you think you are at 20psi innercooled pump fuel nothing more?

were would you like to be? what # are you shooting for?

How many maps are you creating?

Dozens so far.

are you going to record and copie your maps so when one day I get my m30 up and running agean and want to go with tec3 I will be talking with you and todd.

I can send you any number of BIN files that you will load into the ECU , start your car and drive. You will not have to go thru the pain and expense of creating them yourself.

Big Q were do you think you are at 20psi innercooled pump fuel nothing more?

With water injection.........I would say in the 400 RWHP area.

were would you like to be? what # are you shooting for?

520 RWHP.

Thanks Duke M535ti Next time I will not ask so many Q all at once.

But latter down the road I would like any help you would be willing to give with the tec3 That is something I would not be able to do my self

Duke M535ti wrote:

Big Q were do you think you are at 20psi innercooled pump fuel nothing more?

With water injection.........I would say in the 400 RWHP area.

were would you like to be? what # are you shooting for?

520 RWHP.

Yes. People in Hell want ice water, too. Let's see. Nitromethane and water.$. 25 psi lift. $$ One each guibo per week. $$$ Heh. Heheheh. Heheheheh. Snark (Beavis accent)

Duke M535ti wrote:
So I had 6-8 charcoal size chunks of ceramic material that would rattle around under boost and high rpm.

LOL

this is why you're supposed to use metal core cats on setups like yours. Much more durable and more suited for a setup like yours.

Flip_Side_the_Pint wrote: LOL

this is why you're supposed to use metal core cats on setups like yours. Much more durable and more suited for a setup like yours.

No, this is why tuning is the most important part of the equation. Improper tuning can kill just about everything!

T_C_D wrote: No, this is why tuning is the most important part of the equation. Improper tuning can kill just about everything!

+1, Amen brother.

Nice to see you found your problem.

I bet 20psi is sweet. I haven't even drove mine in 4 weeks. This E34 is a super nice car. But I do miss the boost, just not the manual.

Looking forward to the dyno #s.

RussC

russc wrote:Nice to see you found your problem.

I bet 20psi is sweet. I haven't even drove mine in 4 weeks. This E34 is a super nice car. But I do miss the boost, just not the manual.

Looking forward to the dyno #s.

RussC

Simple way to fix that.

Auto + Turbo =

Skeen wrote:

russc wrote: I bet 20psi is sweet. I haven't even drove mine in 4 weeks. This E34 is a super nice car. But I do miss the boost, just not the manual.

RussC

Simple way to fix that.

Auto + Turbo =

Im working on it. Should be in the near future. The tuning is a bit tough, as the auto tranny adds complexity with a turbo and aftermarket tuning products arent designed with a auto trans in mind.

RussC

Congrats Duke


Going for 520rwhp....go for it man...


*thumbs up....arsenio hall pumping fist*

From Random Technologys' website;

In theory, a catalytic converter should last the life of a vehicle; it has no moving parts, the bricks are not consumed by the catalytic reaction and the cases of all original equipment converters are made of stainless steel, so rust isn’t a problem. In the real world, an excessively rich air/fuel ratio, oil or antifreeze in the exhaust system or physical damage can send a catalytic converter off to the great recycling yard in the sky.

Physical damage is the easiest to diagnose. If a converter is bounced off a curb or speed bump, or is struck by freeway flotsam, the ceramic bricks can be fractured. Once that happens, it’s just a matter of time before the bricks start rattling around inside the case, beating themselves into oblivion.

"Extremely high temperatures can result in destruction..."

Fuel, oil and antifreeze cause a different type of brick destruction. Under normal operating conditions, the catalytic process doesn’t begin until temperatures inside a converter reach 500 to 600 degrees (F). If air/fuel ratio is on target, and the exhaust is free of contaminants, internal converter temperature stays at about 1200 degrees. But when unburned fuel enters the picture, temperatures can reach 2200 degrees and either burn the precious metals out of the washcoat, or literally cause a melt down of the bricks. Extremely high temperatures can also result in destruction of the mat that's wedged between the bricks to the converter case.

Oil and antifreeze also cause elevated temperatures, but as the converter tries to burn (oxidize) these compounds, a residue, which plugs up the bricks is formed. At this point, the converter not only loses its effectiveness, it also becomes very restrictive to exhaust flow, which kills horsepower.