[M5OD]

Hi Guys,

I'm planning on buying my new F90 M5 soon and was considering tuning options, I have a couple of questions if any of you guys can help with their input:

1) Have you had any issues tuning the car?
2) If anyone has DPs fitted - do you notice any increased fuel smell / smoke whilst driving or in idle?

Many thanks,

M5OD

[GranitM5]

Originally Posted by M5OD

Hi Guys,

I'm planning on buying my new F90 M5 soon and was considering tuning options, I have a couple of questions if any of you guys can help with their input:

1) Have you had any issues tuning the car?
2) If anyone has DPs fitted - do you notice any increased fuel smell / smoke whilst driving or in idle?

Many thanks,

M5OD

I've been tuned for about 3 months now and no issues.
I am fully catless and my car smells like straight sh*t while idling with windows down. If windows are up, you will never smell it.

[M5OD]

Originally Posted by GranitM5

I've been tuned for about 3 months now and no issues.
I am fully catless and my car smells like straight sh*t while idling with windows down. If windows are up, you will never smell it.

Thanks for your input, do you have an aftermarket exhaust or are you running stock pipes and backbox?

[GranitM5]

Originally Posted by M5OD

Thanks for your input, do you have an aftermarket exhaust or are you running stock pipes and backbox?

Stock exhaust. My decision was between downpipes and full cat back exhaust, so I went with downpipes

[FloridaM5]

If you do downpipes, and are not looking to set records, leave the secondaries in. Replace only the primaries with catless pipes. You'll still make tons of power, hear the turbos in a big way, but with no smell...none.

[LSM]

I would do a piggy tune. ECU flash = voided warranty and BMW seems intent on catching these ecu tunes. They always leave a signature

[GranitM5]

Originally Posted by LSM

I would do a piggy tune. ECU flash = voided warranty and BMW seems intent on catching these ecu tunes. They always leave a signature

This has been covered on the forum numerous times. They all leave a trace. All will void warranty if something happens.

[LSM]

Originally Posted by GranitM5

This has been covered on the forum numerous times. They all leave a trace. All will void warranty if something happens.

How would a piggy leave a trace? Clear codes, it doesn't modify the ecu. I saw it covered on forum and thought the verdict was it's not detectable or very very difficult to detect vs flash

[GranitM5]

Originally Posted by LSM

How would a piggy leave a trace? Clear codes, it doesn't modify the ecu. I saw it covered on forum and thought the verdict was it's not detectable or very very difficult to detect vs flash

Very very very difficult to discover means it's discoverable. If your motor blows, they will discover your tune.

[MWcoupe]

My piggyback was discovered when my shitty local dealer decided they didn't want to fix my evap leak. I had my piggyback taken off before I brought it into dealer. There's way to trace all tunes now. Yes full catless does smell very bad, I hate it. I would not get downpipes again lol

[M5OD]

Originally Posted by FloridaM5

If you do downpipes, and are not looking to set records, leave the secondaries in. Replace only the primaries with catless pipes. You'll still make tons of power, hear the turbos in a big way, but with no smell...none.

Do you have this set up? The downpipes seem very long, are the primaries the upper part of it only or is there another catalytic converter below the downpipe?

[FloridaM5]

Originally Posted by M5OD

Do you have this set up? The downpipes seem very long, are the primaries the upper part of it only or is there another catalytic converter below the downpipe?

I did have that setup, but in addition, I had the full Remus catback. I've since sold the m5, but it was perfect. Exhaust tone was superb, turbo whistle was glorious, and no smell. The downpipes are in two sections on this car (some call the top section downpipes and the next section midpipes). Both sections have cats. If you pull the stock primaries and replace with catless, the secondaries w/ their cats will still be there.

[Genius]

Originally Posted by GranitM5

This has been covered on the forum numerous times. They all leave a trace. All will void warranty if something happens.

TRUE...
If dealer runs spec-actual and data log shows anything outside of factory specifications such as timing, boost etc. it gets flagged automatically. Even your friendly SA will not help you there.
Any tune is discoverable even turned back to stock with piggy removed. I don’t work for bmw but for brand that rhymes with howdy.
Many cars get flagged during routine service if spec actual guided fault finding is ran. Car WILL get flagged and the tech or SA have nothing to do with it. You can ask your SA not to run it, but if there is a warranty claim it will have to be. Claim will be denied and car will be flagged.

[M5OD]

Originally Posted by FloridaM5

I did have that setup, but in addition, I had the full Remus catback. I've since sold the m5, but it was perfect. Exhaust tone was superb, turbo whistle was glorious, and no smell. The downpipes are in two sections on this car (some call the top section downpipes and the next section midpipes). Both sections have cats. If you pull the stock primaries and replace with catless, the secondaries w/ their cats will still be there.

It sounds like you had a very nice set up, the Remus sounds great even without downpipes