4" 034 turbo inlet install question

**WAF** · 10-10-2022 01:14 PM

Hello, Can anyone confirm that if installing a 034 4" turbo inlet pipe (2018 rs3) requires you to upgrade the waste gate line to the unitronic waste gate line upgrade kit? Or will the oem line fit? I've heard new wastegate line is required on 4" inlets and 3" inlets are compatible with the oem line. Thanks in advance.

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**DrMerl** · 10-10-2022 02:14 PM

Hmm. I'm emailing my 034 rep if it's required or not, or a good idea to do. I'll be installing their part soon.

**01CamaroSS** · 10-10-2022 02:47 PM

When I installed the 034 4" inlet I did replace the metal line that bolts to the inlet and just ran similar sized vacuum line over to the firewall and up around the inlet toward the fuel lines. Then ran it across under the engine cover and reconnected to where the metal line transitions to rubber. Essentially replaced one section of metal/rubber line with an all rubber single piece vacuum line that runs around a safer/cooler location.

I did try to bend the metal OE vacuum line to try to make it work, but ended up too mangled to use and just looked bad.

I'm not familiar with the Uni upgrade kit to know if it offers any other advantages. I only spent a few bucks on 3' of vacuum line and 2 screw clamps.

**tegxsi** · 10-10-2022 02:54 PM

I don't think it's necessary but with like most 4" inlets, you lose the hard line attachment point.

**CavEsk1337** · 10-10-2022 02:56 PM

I did not upgrade my line and it runs fine. '18 RS3

**mtwallace85** · 10-10-2022 03:38 PM

With the 4” line it’s definitely necessary because the stock metal hardline is bent to fit fairly tightly around the stock elbow and it doesn’t fit around the bigger inlet.

https://www.audizine.com/forum/showpost.php?p=14002286

**DrMerl** · 10-10-2022 03:52 PM

Can concur, 034 replied and said a custom waste gate line will be needed to work properly with the 4" elbow, needs to be routed above.

What's diameter and general length of the silicone hose?

**WAF** · 10-10-2022 05:40 PM

Originally Posted by DrMerl

Can concur, 034 replied and said a custom waste gate line will be needed to work properly with the 4" elbow, needs to be routed above.

What's diameter and general length of the silicone hose?

Thanks for conquering that. Sorry which silicone pipe are you referring to?

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**Hollingsworth** · 10-11-2022 05:25 PM

I recently installed the 034 4" inlet. Prior to installation, I ordered in a Unitronic wastegate line upgrade ($38) because I'd been hearing how difficult it was to get the oem metal line to bend and fit around the larger 4" inlet. Anyway, the inlet installation was a piece of cake, As far as the wastegate line goes, I ended up not bothering to replace the entire oem line with the Unitronic upgrade. Instead, as 01CamaroSS did, I simply trimmed the Unitronic hose to size and replaced just the metal section of the oem line that connects to the inlet. That seemed the easiest way to do it.

**adam044** · 01-27-2024 12:50 PM

Old thread, but no where in 034’s write does it say the line needs to be replaced or changed. Have they made changes?

https://www.034motorsport.com/docs/0...structions.pdf

**CavEsk1337** · 01-27-2024 02:28 PM

Originally Posted by CavEsk1337

I did not upgrade my line and it runs fine. '18 RS3

Glad this thread was resurrected.

Update: My OEM wastegate ended up failing about 1 1/2 yrs ago. I upgraded to the Unitronic line and have had zero issues since.

**Hollingsworth** · 01-27-2024 05:06 PM

The issue is that the increased diameter/size of the 034 4" inlet, as compared to the OM inlet, makes it difficult for the oem wastegate line to stretch around the inlet to reach the wastgate. The oem line is composed of like an alternating series of metal and silicone tubing segments. There is a metal section of the line near the inlet that interferes with the line fully reaching the wastegate. The Unitronic replacement line is just a solid silicone hose with enough length to reach the wastegate. As I mentioned in my earlier post, I left the entire oem line in place, except for removing just the metal section near the inlet, and replacing that section with a piece of the Unitronic line long enough to reach the wastegate. That seemed the easiest way to do it, rather than yanking out the entirety of the oem line. the inside diameter of the Unitronic line fits up perfectly the metal sections of the oem line. Hope this helps!

**adam044** · 01-27-2024 06:09 PM

Originally Posted by Hollingsworth

The issue is that the increased diameter/size of the 034 4" inlet, as compared to the OM inlet, makes it difficult for the oem wastegate line to stretch around the inlet to reach the wastgate. The oem line is composed of like an alternating series of metal and silicone tubing segments. There is a metal section of the line near the inlet that interferes with the line fully reaching the wastegate. The Unitronic replacement line is just a solid silicone hose with enough length to reach the wastegate. As I mentioned in my earlier post, I left the entire oem line in place, except for removing just the metal section near the inlet, and replacing that section with a piece of the Unitronic line long enough to reach the wastegate. That seemed the easiest way to do it, rather than yanking out the entirety of the oem line. the inside diameter of the Unitronic line fits up perfectly the metal sections of the oem line. Hope this helps!

Good to know. It’s just strange that 034 does not mention this at all.

Also, why is the Unitronic 4” inlet $200+ more than the 034 one. Seems a bit ridiculous.

**integroid** · 01-28-2024 07:12 AM

Yeah, it doesnt matter which 4" inlet you go with, you will want to replace the wastegate line from about cylinder 3 to the wastegate. Not sure why 034 doesnt supply you with the $2 hose? Even the basement bargain CTS kit comes with it.

**DrMerl** · 01-28-2024 08:05 AM

034 sent me a silicone hose from WG to the metal pipe across the head. I got an early production unit which had a casting defect, they sent a new one in a few days. It added a bit more to the mid-top on S2 E85 over the 3" 034 elbow. I also left the OEM piping, except for the hose, what is it about 10-12"? Works great so far, no problems with the hose getting close or touching heat items.

**adam044** · 02-05-2024 11:54 AM

Emailed 034 today and was told "We have not found the need to upgrade/change the wastegate line when using our inlet pipe. There should be no issues installing our upgraded inlet on your RS3."

Looks like I'll just order the Unitronic line.

**adam044** · 02-05-2024 11:55 AM

Originally Posted by DrMerl

Can concur, 034 replied and said a custom waste gate line will be needed to work properly with the 4" elbow, needs to be routed above.

What's diameter and general length of the silicone hose?

......

**CavEsk1337** · 02-05-2024 12:31 PM

Originally Posted by adam044

Emailed 034 today and was told "We have not found the need to upgrade/change the wastegate line when using our inlet pipe. There should be no issues installing our upgraded inlet on your RS3."

Looks like I'll just order the Unitronic line.

I'd probably do it for piece of mind.

Here is my OEM hose. Snagged a Uni line and have been good since.

**integroid** · 02-05-2024 01:22 PM

Originally Posted by adam044

Emailed 034 today and was told "We have not found the need to upgrade/change the wastegate line when using our inlet pipe. There should be no issues installing our upgraded inlet on your RS3."

Looks like I'll just order the Unitronic line.

It is an internal diameter of 4mm. You can get the silicone line on Amazon for like $10