[CarAbuser]

Hi,

I decided I wanted another E92 again so I picked up a low mileage 335i with the DCT box. It's been well maintained with a far chunk of the usual N54 issues already dealt with.

One of my first priorities it getting catless downpipes fitted as the exhaust note is very muted at the moment. I already have an N54 engined Z4 which I've fitted catless downpipes to so I'm happy enough doing the fitting myself and know what to expect regarding emissions, smell, noise and tuning requirements.

I went with VRSF downpipes on the Z4 and they fit quite well. On the 335i there seems to be more choice out there. Most reviews are centred around LHD cars so not useful for our cars with the rogue steering column. What are the go-to catless downpipes for our RHD vehicles?

[Smokey33]

Evolve are good quality and you know there going to fit perfect.

https://www.mlperformance.co.uk/prod...t-day-delivery

There 399 from evolve themselves, so thats not a bad price.

I have them on mine.

If your tuning make sure you get a decent map for the DCT box line pressures.

[CarAbuser]

Thanks for the heads up on those DPs.

I'll do the engine tuning myself, just need to get some new coils and plugs fitted this week then I'll start pushing things. I use xHP on my Z4 which really makes the DCT shine, probably do the same with the 335i, brings the line pressure up to a max of 19bar instead of the normal 17.

[Ruster82]

How do you get it through the MOT with catless down pipes?

Do you swap them back or is the secondary cat enough?

Or secret option do you have a friendly tester?

[CarAbuser]

They pass as long as secondary cats are in place. A little closer to the limit but not been a problem so far on the Z4.

[Chapperss]

I was gonna go VRSF delivered from USA, but going to have to double check now as hadn`t heard of LHD/RHD fitting oddities...

[CarAbuser]

I actually just ordered the VRSF downpipes, BMS intercooler and BMS chargepipe from n54tuning.com.

I got my Z4 downpipes from him previously and the price was better than anyone I could find in the UK and the shipping was really fast. I think he's a vendor on here Mike@N54Tuning.com

I did look at the ones recommended here from ML performance but I wasn't keen on their rebranded AliExpress intercooler options or their pricing so decided to go with Mike again and just get everything in one shipment.

I'll let you know how the shipping goes (last time they arrived in 1 week!) and if the downpipes fit.

[Chapperss]

An update would be great @carabuser

Can i ask why you went BMS for the Intercooler over, say, the VRSF equivalents??

[CarAbuser]

The stock couplings were the main reason. I think the silicon tube and jubilee clips that the VRSF intercooler uses look shoddy. There's an argument that at higher boost levels those couplings may start to become a restriction but I don't buy that until you're running bigger turbos.

[Smokey33]

Originally Posted by Ruster82

How do you get it through the MOT with catless down pipes?

Do you swap them back or is the secondary cat enough?

Or secret option do you have a friendly tester?

Mine passes ok. Just take the car out for a good blast before, make sure its hot and get them to test it first. Theres a second pair of cats as well.

[Chapperss]

Originally Posted by CarAbuser

The stock couplings were the main reason. I think the silicon tube and jubilee clips that the VRSF intercooler uses look shoddy. There's an argument that at higher boost levels those couplings may start to become a restriction but I don't buy that until you're running bigger turbos.

Cheers dude - More stuff to consider