[tennis_pr0]

This was my statement a month ago. I am now all too intrigued at the easy performance gains from tune and am definitely going with the cobb AP. I m very excited. My main concern before was reliability and longevity of my engine as I am out of warranty and plan on keeping my car for long time (07 with 35k miles) but from what I have red the tune is safe and a whole lot of fun.

My only question is, should I have anything done before I do the tune? Spark plugs changed or anything like that? I know this topic as been discussed, but what additional maintenance do I need to do to ensure my car is running reliably and safely? I plan on doing oil every 5k miles, but other than that I'm not sure what else needs to be done...

[n54 xi]

The n54 is the best engine I can think of in the 24 hours of lemans the bm's were all based on that i mean they got forged pistons and rods... I've been thinking about jb and for now I think I wanna just go with the plus I know people who are running stage 5 with just downpipes and air but I mean that sounds pretty rough on stock pumps and pulleys..

[BMJ]

Originally Posted by tennis_pr0

This was my statement a month ago. I am now all too intrigued at the easy performance gains from tune and am definitely going with the cobb AP. I m very excited. My main concern before was reliability and longevity of my engine as I am out of warranty and plan on keeping my car for long time (07 with 35k miles) but from what I have red the tune is safe and a whole lot of fun.

My only question is, should I have anything done before I do the tune? Spark plugs changed or anything like that? I know this topic as been discussed, but what additional maintenance do I need to do to ensure my car is running reliably and safely? I plan on doing oil every 5k miles, but other than that I'm not sure what else needs to be done...

buddy, i used to say this as well, but add COBB FMIC BMW PE and I can now say I have sheer driving pleasure

[tennis_pr0]

That's cool. Yeah I m really looking forward to the cobb tune. I m definitely not going to go all out, but I think the accessport tune is a must at this point as I am getting addicted to the power of this car.

[Ovitrix335]

You should get a cheaper fmic and some catless dps with that cobb
And run e85 if it is available in your area... It's addicting...

[BQTuning]

Originally Posted by tennis_pr0

...My only question is, should I have anything done before I do the tune? Spark plugs changed or anything like that? I know this topic as been discussed, but what additional maintenance do I need to do to ensure my car is running reliably and safely? I plan on doing oil every 5k miles, but other than that I'm not sure what else needs to be done...

Change to NGK spark plugs # ILZKBR7A-8G . Have them gaped to 0.56mm (0.022″)

Make sure your car's DME has the latest software update, of course you will have to pay for this via the dealer but do your best to haggling them. (My personal recommendation)


Edit: As for what FMIC, it is highly recommended to get Helix

[GeorgiaTech335coupe]

Just get a tune to start. Let the mod bug slowly parasite over your body, then you'll be FBO before you know it.

Tune only will not affect longevity.

Oh and the engine doesn't have forged pistons as someone said before, but you'll be fine.

[carlsontheflyer]

Originally Posted by Ovitrix335

You should get a cheaper fmic and some catless dps with that cobb
And run e85 if it is available in your area... It's addicting...

If your car is a daily driver, and not a dedicated track car, I would advise against catless downpipes. First of all, it is illegal, and secondly, your exhaust will smell pretty foul, like raw fuel vapors and rotten eggs. And you will see smoke out of the tailpipes, and black soot buildup on your exhaust tips and bumper.

If you want better downpipes, go with the ones with high flow cats. I know cP-e offers them, and I am sure others do too.

[sickem]

Originally Posted by carlsontheflyer

If your car is a daily driver, and not a dedicated track car, I would advise against catless downpipes. First of all, it is illegal, and secondly, your exhaust will smell pretty foul, like raw fuel vapors and rotten eggs. And you will see smoke out of the tailpipes, and black soot buildup on your exhaust tips and bumper.

If you want better downpipes, go with the ones with high flow cats. I know cP-e offers them, and I am sure others do too.

Does anyone have any data on how catted "high flow" downpipes perform relative to catless on a Cobb or a piggy? I'm skeptical. I'm wondering if there are perceptible differences in the logs, etc. I respectfully disagree with your point of view above...the exhaust fumes, while noticeable, are not that big of a deal and I had significant carbon builup on my tips even bone stock. And the rotten egg smell is actually the result of the catalyst itself if I'm not mistaken...so if you remove them I'm not sure how you're getting that smell. Plus my car still has secondaries...I've never noticed smoke out the tailpipes as a result of being catless. As for being illegal, I couldn't care less.

OP, I agree with others...start with the Cobb AP (excellent tune) and go from there. You don't need to do it all at once, even though I know it's tempting if you've got the cash lying around. There's a lot to learn on this platform and not all products out there are great just because everybody buys them. Good luck!

[secretsquirrel]

Originally Posted by carlsontheflyer

If your car is a daily driver, and not a dedicated track car, I would advise against catless downpipes. First of all, it is illegal, and secondly, your exhaust will smell pretty foul, like raw fuel vapors and rotten eggs. And you will see smoke out of the tailpipes, and black soot buildup on your exhaust tips and bumper.

If you want better downpipes, go with the ones with high flow cats. I know cP-e offers them, and I am sure others do too.

I have a very different opinion.
I would highly recommend catless downpipes. Your exhaust is not going to smell like rotten eggs unless you remove both sets of cats. Dps only remove the primary ones. Catless downpipes have been shown to give 20-25hp on this car and improve throttle response. Not only that, but they remove back pressure from your turbos.

[E90Company]

"Rotten egg" smell is from the cats being overloaded, and can't keep up with demand. Catted downpipes are also "illegal" in the sense that you just altered your cars emissions system.

[BQTuning]

Originally Posted by sickem

Does anyone have any data on how catted "high flow" downpipes perform relative to catless on a Cobb or a piggy?..

I don't have Cobb atm, but I do have highflow catted DPs. From what is understood the data is marginal, or 5-10 whp difference.

[carlsontheflyer]

Originally Posted by sickem

Does anyone have any data on how catted "high flow" downpipes perform relative to catless on a Cobb or a piggy? I'm skeptical. I'm wondering if there are perceptible differences in the logs, etc. I respectfully disagree with your point of view above...the exhaust fumes, while noticeable, are not that big of a deal and I had significant carbon builup on my tips even bone stock. And the rotten egg smell is actually the result of the catalyst itself if I'm not mistaken...so if you remove them I'm not sure how you're getting that smell. Plus my car still has secondaries...I've never noticed smoke out the tailpipes as a result of being catless. As for being illegal, I couldn't care less.

OP, I agree with others...start with the Cobb AP (excellent tune) and go from there. You don't need to do it all at once, even though I know it's tempting if you've got the cash lying around. There's a lot to learn on this platform and not all products out there are great just because everybody buys them. Good luck!

There are sulfur additives in the fuel. When fuel burns, it creates hydrogen sulfide gas, which smells like rotten eggs. This gas burns off inside the primary catalytic converters. Your secondary cats are not good enough to burn off that gas completely because they are downstream from the engine and don't heat up nearly enough to burn those gases. Leaving secondary cats is certainly better than no cats at all, but not good enough. There will be smell, and soot.

As far as you not caring about the legality of removing the catalytic converters, that's between you and your local law enforcement. In Georgia, if you are stopped by the police and they find out you don't have cats on your car, you get a major ticket and your car gets towed. And a rotten egg smell out of your tail pipe is a pretty good sign of being catless, or having failed cats.

[sickem]

Originally Posted by BuraQ

I don't have Cobb atm, but I do have highflow catted DPs. From what is understood the data is marginal, or 5-10 whp difference.

thanks @BuraQ. Good to know. I'm sure there are threads/discussions on this, but I'd be concerned as to how long the catalyst in aftermarket DPs holds up over time...

[sickem]

Originally Posted by carlsontheflyer

There are sulfur additives in the fuel. When fuel burns, it creates hydrogen sulfide gas, which smells like rotten eggs. This gas burns off inside the primary catalytic converters. Your secondary cats are not good enough to burn off that gas completely because they are downstream from the engine and don't heat up nearly enough to burn those gases. Leaving secondary cats is certainly better than no cats at all, but not good enough. There will be smell, and soot.

As far as you not caring about the legality of removing the catalytic converters, that's between you and your local law enforcement. In Georgia, if you are stopped by the police and they find out you don't have cats on your car, you get a major ticket and your car gets towed. And a rotten egg smell out of your tail pipe is a pretty good sign of being catless, or having failed cats.

I'll have to confirm that the generation of H2S is correct, since I know that to be a highly toxic gas, in sufficient concentration of course...Chemically this is unlikely since the combustion of fuel is an oxidation process, rendering something with high oxidation potential like reduced sulfur into oxides/dioxides. Also there must be other sources of sulfur-containing side products otherwise every minivan amd camry I'm behind has catless DPs.

[sickem]

edit: removing incorrect info...

[roadkillrob]

FYI - no one that ever said they were going to leave their car stock ever did!

As for the downpipes, go catless - I did the catted ones and regret it - I did the AR ones so that I didn't have to mess around with the issues of throwing codes and getting my annual inspection, but apparently the AR catted pipes only worked with very early N54 software and later updates make the O2 sensor checks more strict and after about a year and a software upgrade, my car started setting cat codes, so I had to do the BMS downpipe fix. AR claims that the only high flow cats that won't set codes are crazy expensive - they will make downpipes with them, but price is 2k. If I did it again, would just get some $350 catless DP's and BMS downpipe fix.

[BQTuning]

Originally Posted by sickem

thanks @BuraQ. Good to know. I'm sure there are threads/discussions on this, but I'd be concerned as to how long the catalyst in aftermarket DPs holds up over time...

The good part about most aftermarket DP's with highflow catts is they come with lifetime warranty.

Previous tunes, ie piggybacks, from what was understood use to ride the knock sensor which lead to highflow catts failing. However, this was something rare that happened.

[carlsontheflyer]

Originally Posted by sickem

I'll have to confirm that the generation of H2S is correct, since I know that to be a highly toxic gas, in sufficient concentration of course...Chemically this is unlikely since the combustion of fuel is an oxidation process, rendering something with high oxidation potential like reduced sulfur into oxides/dioxides. Also there must be other sources of sulfur-containing side products otherwise every minivan amd camry I'm behind has catless DPs.

Haha, you are right! And yes, the H2S concentration is not high enough to be toxic, unless you put your lips around the tailpipe, and then you'd have bigger issues than that, including burned lips.

It does smell pretty foul though. And all cars with missing cats I've ever seen, and I see them often since I own an emissions testing station, always smell foul and always have a lot of soot on and inside the exhaust tips, and on the bumper around the tailpipes.

[Mayuri Krab]

" I am definitely keeping my car stock"

For at least the next 6 month to 1 year since I'm broke at the moment...

[sickem]

Originally Posted by carlsontheflyer

unless you put your lips around the tailpipe, and then you'd have bigger issues than that, including burned lips.

LMAO, yes I love my car but not THAT much

Originally Posted by carlsontheflyer

It does smell pretty foul though. And all cars with missing cats I've ever seen, and I see them often since I own an emissions testing station, always smell foul and always have a lot of soot on and inside the exhaust tips, and on the bumper around the tailpipes.

yeah I guess it's just sort of subjective. I have a one car garage and if I idle it to warm up in there it will smell worse than stock. But inside the car while moving it doesn't bother me. As "diligent" as the police are around here for tint etc. I've not heard of too many people getting hassled for catless DPs. I have stock exhaust so it is not obnoxiously loud or anything either.

Op, sorry to thread jack. I guess the point here is that there are pros and cons to every mod, and catted or catless DPs are both options without too much performance difference. you will certainly pay more for the catted version, however.

[carlsontheflyer]

Originally Posted by sickem

LMAO, yes I love my car but not THAT much



yeah I guess it's just sort of subjective. I have a one car garage and if I idle it to warm up in there it will smell worse than stock. But inside the car while moving it doesn't bother me. As "diligent" as the police are around here for tint etc. I've not heard of too many people getting hassled for catless DPs. I have stock exhaust so it is not obnoxiously loud or anything either.

Op, sorry to thread jack. I guess the point here is that there are pros and cons to every mod, and catted or catless DPs are both options without too much performance difference. you will certainly pay more for the catted version, however.

Yep, catted downpipes are $300 or more higher than catless.