[AlexTampabay]

Any Advice on downpipes prefer Catless. I heard its a must for Tunning for E85 and unlocking ECU.

[Bostro]

Originally Posted by AlexTampabay

Any Advice on downpipes prefer Catless. I heard its a must for Tunning for E85 and unlocking ECU.

I will not go down the rabbit hole on the subject is it really must as my opinion it will not heart but do not expect mirracles around HP/TQ gains. On other side catless DPs are quite cheap.

If you want to go catless any brand will work but I can say MAD and AA demonstarted to me their quality. Great quality!

MAD i believe released catless resonated DP !!! Maybe worth to consider by you!

[markoz28]

For Catless, MAD has excellent construction and prices is great. I went MAD 200 cell just to decrease smell. E85 is not a problem.

[ChrisM4]

MAD resonated catless would be great to try out as they’d reduce rasp with virtually no flow restriction. That and their resonated mid pipe would be a great setup to the stock back section/muffler. Then have the SST valve controller to give you the ability to open, close valves, run them at 50% open.

The above setup would support a ton of power on E and sound great without being too expensive.

[mike@x-ph.com]

Originally Posted by AlexTampabay

Any Advice on downpipes prefer Catless. I heard its a must for Tunning for E85 and unlocking ECU.

It's not a must to have downpipes for E85 or DME unlocking.

It will improve air flow and sound.
Catless is louder but also raspier and generates a fuel smell
resonated fixes reduce the raspiness but still have a fuel smell
Catted is quieter than catless, and louder than stock, but it fixes the fuel smell and raspiness of the catless option

[AlexTampabay]

Great advice , and i am happy to see honest support from experienced members

thank you

[GrannyShiftG80]

Originally Posted by mike@x-ph.com

It's not a must to have downpipes for E85 or DME unlocking.

It will improve air flow and sound.
Catless is louder but also raspier and generates a fuel smell
resonated fixes reduce the raspiness but still have a fuel smell
Catted is quieter than catless, and louder than stock, but it fixes the fuel smell and raspiness of the catless option

does it smell if ur catless dp but still have secondary cats

[AlexTampabay]

MAD resonated catless would be great

Any deals on these for black Friday?

From whom?

[mike@x-ph.com]

Originally Posted by GrannyShiftG80

does it smell if ur catless dp but still have secondary cats

its not terrible but certainly noticeable

[Info@mad-us.com]

Originally Posted by AlexTampabay

MAD resonated catless would be great

Any deals on these for black Friday?

From whom?

Our black Friday sales are active till the end of the month.

Click below to join the pre-order

https://mad-us.com/mad-bmw-m2c-m3-m4...-flex-section/