Which catless downpipes..?

[john-e89]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Now that....THAT is the answer.....why the chuffing hell didn’t I think of it...I’ve got the tools, and not to....well actually yes I am, blowing my own trumpet I’m an awesome welder.... :lol:

Light bulb moment....Owe you a pint good sir...!

That should work, twin turbo did the same thing on his 28i
Rob

Good memory there big B....did he report his findings do you know..?

 

[keving1]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Can this be done on the 35i? How easy is it to do this?

I'd love to do this if it is possible

 

[mcbutler]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Can this be done on the 35i? How easy is it to do this?

I'd love to do this if it is possible

No idea, it was just a thought

 

[john-e89]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Can this be done on the 35i? How easy is it to do this?

I'd love to do this if it is possible

Take the pipes off, neatly cut open, remove contents, weld back up, replace pipes. OEM pipes, no need to chuff about with coding out dash lights. Easy to do if you have the facility.

 

[sunnydays]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

He would potentially be missing out on the increased diameter, and optimised flow of after market DP's, which also affects the noise and tone of the exhaust.

 

[Smartbear]

Now that....THAT is the answer.....why the chuffing hell didn’t I think of it...I’ve got the tools, and not to....well actually yes I am, blowing my own trumpet I’m an awesome welder.... :lol:

Light bulb moment....Owe you a pint good sir...!

That should work, twin turbo did the same thing on his 28i
Rob

Good memory there big B....did he report his findings do you know..?

I don’t think he said how much vava voom the decat added on its own, but combined with his tuning box thingamajig it allegedly made 311bhp. I’ve heard rumours of an extra 15/20bhp on the 2litres & I’d guess more than that on a 35iS? :?
Rob

 

[R.E92]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Can this be done on the 35i? How easy is it to do this?

I'd love to do this if it is possible

Take the pipes off, neatly cut open, remove contents, weld back up, replace pipes. OEM pipes, no need to chuff about with coding out dash lights. Easy to do if you have the facility.

You will still get an error code and a dash light. The light is not caused by the aftermarket pipes, rather the lack of catalytic converters.

Another issue is that the flow characteristics of the stock pipes without the cats are going to be poor. You also won't be able to go back to stock if the need arises without spending £1500 on a couple of new OEM downpipes.

The VRSF downpipes only cost me £340 so hardly worth the hassle of messing around with the OEM pipes.

 

[john-e89]

Can this be done on the 35i? How easy is it to do this?

I'd love to do this if it is possible

Take the pipes off, neatly cut open, remove contents, weld back up, replace pipes. OEM pipes, no need to chuff about with coding out dash lights. Easy to do if you have the facility.

You will still get an error code and a dash light. The light is not caused by the aftermarket pipes, rather the lack of catalytic converters.

Another issue is that the flow characteristics of the stock pipes without the cats are going to be poor. You also won't be able to go back to stock if the need arises without spending £1500 on a couple of new OEM downpipes.

The VRSF downpipes only cost me £340 so hardly worth the hassle of messing around with the OEM pipes.

Point taken and very good advice thanks R:E92, as I said this is the first foray into this mod so this is the route I’ll take.

 

[keving1]

The VRSF downpipes only cost me £340 so hardly worth the hassle of messing around with the OEM pipes.

Where did you get your VRSF downpipe for £340 from?

 

[Z4M-2006]

Decatted downpipes sound crap,the bulge where the monolith sat acts an expansion chamber and reverbs the exhaust note..

You will also get a EML on do to the rear lambda readings.. Map should sort it if you go down this route.

I have used JP exhausts in Macc for one off stuff,the quality of the stainless and welding was top notch.

 

[R.E92]

Where did you get your VRSF downpipe for £340 from?

https://www.n54tuning.com/vrsf-3-cast-stainless-steel-catless-downpipes-v2-n54-2010-e89-bmw-z4-35i-/-35is.html

I contacted Mike directly and he sorted out a deal for me. I think the website calculates shipping incorrectly. He also declared the item at wholesale value for customs so the duty was around £20. They come with the fitting kit included and also a replacement engine mount bolt to help with clearance during fitting.

Took less than a week to arrive too. Ordered on the Friday, they arrived the next Wednesday.

 

[stijohnny]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Good idea. however the decatted downpipes from VRSF l bought dont look at all like the OEMs, so not sure how the gas flows in comparison - anyone?

 

[sunnydays]

Why n ot remove the current pipes and hack out the contents of the cat so you have a straight through pipe, that'll cost you nowt

Good idea. however the decatted downpipes from VRSF l bought dont look at all like the OEMs, so not sure how the gas flows in comparison - anyone?

Pretty sure the VRSF have a wider diameter, and more optimised flow through the entirety of the pipe.

 

[Miyli]

The original empty downpipes are enough up to 450hp and no problems with emissions

 

[mcbutler]

The original empty downpipes are enough up to 450hp and no problems with emissions

Thanks for the info, your car looks fabulous, what spec is it?
I can see red calipers, Brembo??

 

[Miyli]

The original empty downpipes are enough up to 450hp and no problems with emissions
Thanks for the info, your car looks fabulous, what spec is it?
I can see red calipers, Brembo??

Engine Spec is MHD stage 2+ E85 software, 3” blank downpipe, DCI air system, aluminum chargerpipe and oil cats can. These changes have 460 hp.
Other spec, BC racing suspension, fronr spoiler and rear spoiler. Wheels 19” Monaco cockpit black, also m performance side skirt stripe.
Brembo front brakes and rear orginal. Color now orange.

 

[mcbutler]

She is a beauty, honestly.
I note you are in Finland, how do you find it when it snows

 

[keving1]

The original empty downpipes are enough up to 450hp and no problems with emissions

How did you get the cat material out of your downpipes and was it easy or hard work?

 

[Smartbear]

The original empty downpipes are enough up to 450hp and no problems with emissions

How did you get the cat material out of your downpipes and was it easy or hard work?

You could just put some mice at the end of the pipe & see if it comes out?
Rob

 

[Miyli]

She is a beauty, honestly.
I note you are in Finland, how do you find it when it snows

I'm not driving in winter with this