[Biostockman]

I installed SSTT a week ago... I'm meticulous with my car and it's always clean, within the last couple of weeks the inside of my tailpipes went from being clean to as dark as coal. Granted I've always had some carbon build up at the tailpipe exits but I don't think I've ever had this much.. Do any of you you believe that there is some sort of connection to the SSTT and increased carbon output? Is this something I should even be worrying about? BTW, not that it matters a whole lot but I do only run Shell's V-Power.

[midlife]

Originally Posted by Biostockman

I installed SSTT a week ago... I'm meticulous with my car and it's always clean, within the last couple of weeks the inside of my tailpipes went from being clean to as dark as coal. Granted I've always had some carbon build up at the tailpipe exits but I don't think I've ever had this much.. Do any of you you believe that there is some sort of connection to the SSTT and increased carbon output? Is this something I should even be worrying about? BTW, not that it matters a whole lot but I do only run Shell's V-Power.

good question, was anyone else noticed this on their other tunes ? (like aa, JB or procede) ?

[Icedog_16]

TADTS - They All Do That, Sir! Every car I've ever had (turbos and NA) has had carbon deposits inside the tailpipe.

The SSTT doesn't have anything to do with it. My guess is that, if anything, that would make your car run lean. How long have you had your car? I'd say probably not very long.

[Biostockman]

Originally Posted by Icedog_16

TADTS - They All Do That, Sir! Every car I've ever had (turbos and NA) has had carbon deposits inside the tailpipe.

The SSTT doesn't have anything to do with it. My guess is that, if anything, that would make your car run lean. How long have you had your car? I'd say probably not very long.

I've had it since December. I know that ALL cars have carbon deposits inside the tailpipes, but there is more now than there was before the SSTT install.

[DrewKo]

Figment of imagination in my opinion.

[Biostockman]

Originally Posted by DrewKo

Figment of imagination in my opinion.

It's possible.. Although I could swear that more carbon exists now...

[leftcoastman]

I know for a fact that PROcede runs richer than stock.

Look at any of the AFR ratios. Shiv richened it up to protect the engine. Fine by me.

[e.n335]

I saw dark black and wet tailpipes ( inside ) already as well. My car does not do that. I used the PROcede for quite a long time and use currently a JB2H. Everything dry and dark grey after 12500 miles.

[tek818]

Originally Posted by Icedog_16

TADTS - They All Do That, Sir! Every car I've ever had (turbos and NA) has had carbon deposits inside the tailpipe.

The SSTT doesn't have anything to do with it. My guess is that, if anything, that would make your car run lean. How long have you had your car? I'd say probably not very long.

+1... you are running leaner than stock!

[5soko]

more psi, more build up.

[XS4]

-if only 1 week's time has elapsed your ecu may still be adapting/optimizing the fuel trims.
- as mentioned, more boost (air in) means more air out so carbon deposits will accumulate faster.
-it's common for tunes to specify a richer mixture as also mentioned.

[Biostockman]

Originally Posted by XS4

-if only 1 week's time has elapsed your ecu may still be adapting/optimizing the fuel trims.
- as mentioned, more boost (air in) means more air out so carbon deposits will accumulate faster.
-it's common for tunes to specify a richer mixture as also mentioned.

Excellent points!!! Thanks!

[BoostedBMW]

Well, my guess would be that more boost means more fuel so you have more buildup in your exhaust. I don't run a SSTT though.

[Chowbow]

SSTT doesn't change timing and fuel maps. It runs off the stock maps still so if it is richer, it's because the stock ECU map is adding more fuel... which could be but sounds unlikely.

Only way to really get a good idea is to get an AFR reading on the dyno.

[5soko]

the ecu will add more fuel if it feels the need to. the more "black stuff" showing up is from the higher psi and power being produced.

[2e9x's]

An earlier poster suggested that you are running leaner. That is untrue. The SSTT keeps the afr at the stock ratios until close to redline. At that point the deviation is minimal. However I have never seen an afr reading taken with a wideband 02 sensor welded in before the cats so IMHO all of the readings are relatively irrelevant.

Here's what I would do...make a note of your mileage for 3 days. Then take the SSTT out and make a note of your mileage for 3 more days. If it changes you have your answer.

FWIW I have to 335i's, one with SSTT and one without. The tail pipes of both cars contain the same amount of black stuff.

[Steve335i]

Another thing to consider is that you are running the car harder, enjoying the new tune.

[Malek@MRF]

Yes there is a direct connection with you are seeing and you are not halucinating.

An Air Fuel Ratio, is exactly what it is, its a Ratio. Meaning its proportional. Given the AFR remains constant from 8PSI to 12PSI and so on, that means with your SSTT there is more boost pressure, meaning more fresh air entering the combustion chamber, and fuel is added in accordance to maintain that Air Fuel Ratio. Yes, that means there is more coming out from your tail pipes and yes that means they will get more dirty in less time.

Plus, I am sure there is a direct correlation with you driving it harder since you got your SSTT.

[bucktown]

Originally Posted by Steve335i

Another thing to consider is that you are running the car harder, enjoying the new tune.

bingo