[Moonshine Bandit]

Hi. I am a future M5 owner. I hope to get my car delivered by end of October. I have started to gather information about exhaust modifications and hopefully have the parts just in time when I take delivery of my car. The first two mods that I plan to buy now are the exhaust and down pipe.

I have selected the F.I. exhaust. Based on videos I watched, I liked this one over the others. I have Remus on my F80 and I like it a lot. However, the Remus for the F90 seems to be tamed a little bit as compared to the F.I. exhaust. The question is do I have to buy the separate remote controller to open or close the exhaust flaps? The Remus in my F80, the flaps open when I select Sport+ mode. No separate remote controller is needed.

I am still undecided about catless downpipes. VRSF seems to be the popular brand on the F80 platform. I am not sure about it in the F90 platform. So here are some questions I hope everyone can answer.

1.) What is the recommended downpipe brand for the F90?
2.) I understand that installing catless downpipes would produce CEL, foul odor in the interior and drone while the car is running. Is this true when it comes to all catless downpipes or is there a specific brand that eliminates all of these concerns?
3.) Would a high-flow cat downpipe be the best alternative to eliminating the CEL, foul odor, and drone?

Thanks.

[will0621]

Originally Posted by Moonshine Bandit

Hi. I am a future M5 owner. I hope to get my car delivered by end of October. I have started to gather information about exhaust modifications and hopefully have the parts just in time when I take delivery of my car. The first two mods that I plan to buy now are the exhaust and down pipe.

I have selected the F.I. exhaust. Based on videos I watched, I liked this one over the others. I have Remus on my F80 and I like it a lot. However, the Remus for the F90 seems to be tamed a little bit as compared to the F.I. exhaust. The question is do I have to buy the separate remote controller to open or close the exhaust flaps? The Remus in my F80, the flaps open when I select Sport+ mode. No separate remote controller is needed.

I am still undecided about catless downpipes. VRSF seems to be the popular brand on the F80 platform. I am not sure about it in the F90 platform. So here are some questions I hope everyone can answer.

1.) What is the recommended downpipe brand for the F90?
2.) I understand that installing catless downpipes would produce CEL, foul odor in the interior and drone while the car is running. Is this true when it comes to all catless downpipes or is there a specific brand that eliminates all of these concerns?
3.) Would a high-flow cat downpipe be the best alternative to eliminating the CEL, foul odor, and drone?

Thanks.

1) all brands that have been mentioned frequently here can probably fit with some hassle but I would recommend a quality brand and avoid the hassle. I had issues with fitment with a lesser known brand and switched to Keller which fit just fine with some maneuvering. Other brand i considered was lusso. Eisenmann too but they’re way too expensive.

2) the smell is absolutely prominent if you’re doing primary and secondaries. I was catless on my F80cs and the smell was maybe 50% of what the F90 is, since you retained secondary cats with the F8x.

3) yes that, or just doing catless secondaries. I don’t have drone with mine though, just the CEL and odor

[pbonsalb]

Fabspeed or Redstar with 200 cell HJS cats in the upper downpipes and catless lower downpipes for the best quality and compromise on power over catless.

Since removing cats or changing to less restrictive ones increases the sound, do this first. Then think about a mid or rear exhaust. The downpipes add power; the mid and rear do not or add comparatively little.

There are cheap catted downpipes like CTS Turbo but the cat is much lower quality. Don’t know how long they will hold up and they admit they aren’t effective enough to stop a CEL, unlike the HJS cats.

Catless downpipes without a tune for catless will smell. With a tune, not so much. I would tune out the cold start function that heats up the cats and makes a lot of noise. The sound will be worse with high flow or no cats if you do not.

[mike@x-ph.com]

Originally Posted by Moonshine Bandit

Hi. I am a future M5 owner. I hope to get my car delivered by end of October. I have started to gather information about exhaust modifications and hopefully have the parts just in time when I take delivery of my car. The first two mods that I plan to buy now are the exhaust and down pipe.

I have selected the F.I. exhaust. Based on videos I watched, I liked this one over the others. I have Remus on my F80 and I like it a lot. However, the Remus for the F90 seems to be tamed a little bit as compared to the F.I. exhaust. The question is do I have to buy the separate remote controller to open or close the exhaust flaps? The Remus in my F80, the flaps open when I select Sport+ mode. No separate remote controller is needed.

I am still undecided about catless downpipes. VRSF seems to be the popular brand on the F80 platform. I am not sure about it in the F90 platform. So here are some questions I hope everyone can answer.

1.) What is the recommended downpipe brand for the F90?
2.) I understand that installing catless downpipes would produce CEL, foul odor in the interior and drone while the car is running. Is this true when it comes to all catless downpipes or is there a specific brand that eliminates all of these concerns?
3.) Would a high-flow cat downpipe be the best alternative to eliminating the CEL, foul odor, and drone?

Thanks.

1) Evolution Racewerks is the most popular for us. CTS Turbo just released their downpipes. Check it out.

2)all catless will throw a code , and fuel odor

3) you'll still get a check engine light with catted (unless you get the active autowerke), just no odor