Stock Down pipes? Decat / Removal

[Quepps]

Hi,

I'm thinking of gutting my stock downpipes.

Has anyone got any advice? I have a few questions.

How much more power will it give me? Currently running 720DMS Map and Eisenann mid pipe, with stock rear mufflers.

Can I delete the cold start with no issues?

What happens with the sensor?

Is it much more beneficial buying new Down pipes?

Will it be ridiculous loud even with running the mid pipe and stock rear mufflers?

I want the crackle and bang from the de-cat, but want to tame it a little.

Any experiences and advice ??? Would be grateful

Thanks.

[TheHouseWon]

What is 720DMS?

[Quepps]

My tuning company Ecu map

[Vonhaas]

As long as you still have the stock mufflers it won't be crazy loud.

[R3dn3k Flyby]

Gutted stock downpipes are much quieter than aftermarket ones due to design and fitment. I had the Armytrix downpipes on my car with the full Armytrix. Very loud and aggressive. I put stock gutted downpipes back on the car with the Armytrix, and it was much, much quieter. Also, the wastegate rattle I had pretty much went away or is far, far less noticeable now.

-James

[Quepps]

Brilliant. Thanks for the info

Much power difference? Response?

[Quepps]

Did you isolate the cold start? My neighbour are Not impressed with my noise at 6:30 am every morning 😊

[mike@x-ph.com]

No point in doing so for couple reasons.

1- More labor with a risk of ruining the downpipes

2- Does not make sense financially. It is against the law to sell your car without emission legal downpipes. So eventually you will need to buy a set of OE downpipes which will end up costing you more than aftermarket ones.

[DenverF10M5]

Originally Posted by mike@x-ph.com

No point in doing so for couple reasons.

1- More labor with a risk of ruining the downpipes

2- Does not make sense financially. It is against the law to sell your car without emission legal downpipes. So eventually you will need to buy a set of OE downpipes which will end up costing you more than aftermarket ones.

It only takes a few minutes to gut each downpipe once they are removed.

You can buy a used set of OEM downpipes on here for $400-$500. It makes more financial sense to go this route, as you'll save yourself at least $400.

Fitment is spot-on and they're double-walled. Installation is a breeze.

[mike@x-ph.com]

Originally Posted by DenverF10M5

It only takes a few minutes to gut each downpipe once they are removed.

You can buy a used set of OEM downpipes on here for $400-$500. It makes more financial sense to go this route, as you'll save yourself at least $400.

Fitment is spot-on and they're double-walled. Installation is a breeze.

You can get VRSF downpipe for that price with free shipping and better air flow

[DenverF10M5]

Originally Posted by mike@x-ph.com

You can get VRSF downpipe for that price with free shipping and better air flow

You're still paying $200 more. I haven't read any reviews on fitment. Then you'll need to have them wrapped or coated due to the excessive heat.

[mike@x-ph.com]

Originally Posted by DenverF10M5

You're still paying $200 more. I haven't read any reviews on fitment. Then you'll need to have them wrapped or coated due to the excessive heat.

you dont need to have them wrapped.

[DenverF10M5]

Originally Posted by mike@x-ph.com

you dont need to have them wrapped.

Why wouldn't you need them wrapped?

[mike@x-ph.com]

Originally Posted by DenverF10M5

Why wouldn't you need them wrapped?

Same reason why would not need to coat or wrap any other catless downpipe

[DenverF10M5]

Originally Posted by mike@x-ph.com

Same reason why would not need to coat or wrap any other catless downpipe

What reason is that?

[mike@x-ph.com]

Originally Posted by DenverF10M5

What reason is that?

There is no benefit in doing so for daily drivers

[DenverF10M5]

Originally Posted by mike@x-ph.com

There is no benefit in doing so for daily drivers

These downpipes run directly behind the rear cylinders. Do you want the excessive heat transfer? I sure don't. Anyone who has experience with this engine will certainly advise you to wrap or coat the downpipes on this platform.

[m5james]

This ^ and it's been proven on here that they need to be wrapped or coated if they're not stock. Mine doesn't make money telling us otherwise.

[mike@x-ph.com]

Can someone post a link of the thread where they did these tests?

[DenverF10M5]

Originally Posted by mike@x-ph.com

Can someone post a link of the thread where they did these tests?

Oh, so now you're going to pull THAT card? Two guys on here have disagreed with your logic, so you're going to resort to asking for test results? Come on Mike, think about the location of these downpipes. We're not installing downpipes on a 335 where they aren't located directly next to the block. The downpipes on the S63TU run directly behind the engine and within inches of the rear cylinders. Do you have tests that prove me wrong? No, you don't.

Wrapping or coating the downpipes is also going to keep that excess heat out of the engine bay, while slightly reducing heat soak. It will also retain heat in the exhaust. Hotter gas flow faster than cold gas.

This is all common sense. How about you do some tests yourself and prove my theory wrong. It makes more sense to wrap or coat the downpipes given their location. I can't imagine that heat doing anything to help the engine run more efficiently. Some of the more experienced owners can chime in, but I'm sure the top guys will agree that you will need to wrap or coat the downpipes. You're giving bad advice. I would stick to selling parts.

[DenverF10M5]

By the way, I'm sure you can find plenty of test results of before and after temps through the companies that manufacture the wrap or coating. A test on this platform is going to give you similar temperature results.

[TheHouseWon]

"We also offer ceramic coating services on these utilizing Cerakotes High Temperature Ceramic coating, made to withstand temperatures up to 1800F. Please note that while we do offer a lifetime warranty on the downpipes, we only offer a 1 year warranty on the ceramic coating services due to the nature of the product."

https://www.x-ph.com/vrsf-3-stainles...-11-bmw-m5-m6/