Machined/cast turbo inlet pipe - gauging interest

[Rig]

Gauging interest for a machined part: Turbo Inlet Pipe - Part# 1h0-129-654

Best pictures of it are here: https://www.shopdap.com/1h0-129-654-r.html

The plastic flange is a common part to break and disconnect fron the turbo, causing your car to feel like driving a Walmart scooter. I think mine had a small leak for a long time before it totally busted as now that I've jury rigged a hose to it and sealed the intake, my TDI seems to run quite a bit better.

No new parts for this exist online that I can find and why spend good money on more plastic doomed to fail? Sure I could live with a jury rigged silicone hose here, but I like things to be clean and fancy. I'm also skeptical that the upper plastic piece will last much longer.

I'm envisioning an aluminum flange bolted to the turbo which has a receiver for a silicone pipe going up to the connection for the air box intake, which ideally could be replicated with machined or cast aluminum.

If a suitable performance swap in doesn't already exist, I would like to ask @thechoochlyman if he might be interested to making a replacement. If so DOES ANYONE HAVE ONE OF THESE LYING AROUND TO SEND HIM? mine is sawed in half and I threw one half in the trash.

What should such a part look like? What can be improved on the stock design? Can we flow more air through a larger intake?

How do you handle the plug, the vaccum line, the ccv hose? Have other people just blocked/plugged the ccv hose?

Would the aluminum let too much heat into the intake air to be desirable? Should it be insulated or is that not a concern?

The accordian hose coming from the MAF appears to put pressure on the part in question. I think that's another reason this is prone to failure. Between the hose and the part itself (which is rather large) there is decent amount of weight bearing down on that flange. I imagine heat fromthe turbo eventually disintegrates the plastic here.

If this part were machined in two pieces with a silicone hose in between, you would probably need some kind of mount or at least a way to keep the slicone rigid, or maybe just some nice thick silicone that already has an elbow.

 

[Abacus]

I have a spare I‘d send him to use as a pattern, It’s not perfect but is in good shape. I trust him to return it when done, he’s a great guy.

 

[Rig]

I have a spare I‘d send him to use as a pattern, It’s not perfect but is in good shape. I trust him to return it when done, he’s a great guy.

Awesome! Do you think it would be sufficient to just machine the flange that bolts to the turbo, or replicate the upper piece with the hose connections as well? What about the ccv hose? Did you keep yours stock or plug it?

 

[Abacus]

The piece I have is all stock. As to how to machine it, I’ll leave that up to Charlie since he’s the expert. I’m not.

 

[Rig]

Well, I know you are pretty familar with these cars. If he's going to make a part, we should take the opportunity to make it superior if possible. It may not be desirable to copy the part exactly.

The electrical plug is a heater which from what I've heard is basically useless unless you drive in very cold climates. This plug receiver would most likely be impossible to duplicate with aluminum anyway.

I'm thinking the easiest and most functional solution here is to just machine the flange and forget about the upper section of the part. The plastic can be cut and a silicone connector hose-clamped to tie the two pieces together. That way the factory functionality can be maintained if desired and the problem is solved with very little investment.

 

[thechoochlyman]

Judging strictly from the photos, I think this will have to be a combination venture with a good tig welder. The flange that bolts to the turbo is the most critical part, the rest isn't all that important I don't think.

Someone with a good mandrel bender could shape a pipe with all the curves you need to get it from the flange to the filter tube. The only other things on that pipe are some line holders, the CCV hookup tube and heater (no idea if this is even removable or not), and a barb for the ECU to measure boost pressure.

Too bad VW didn't use something like a V-band flange down there, it would make the whole process a lot easier. As it stands it looks like I'll have to start with a square block and mill everything away, and put in an internal O-ring groove. Won't be a difficult project on my part, but it's gonna get costly with proper madrel bends and welding.

 

[burpod]

it's a neat idea, but i think would be too costly for what it is. honestly you'd be much better off putting that money towards a vnt conversion which isn't really all that hard. i don't know how anyone can live with a tdi with the power output of a tiny gt15. as far as mpg's, can have your cake and eat it too with a good size turbo + injectors.... it's also just too easy to just make your own turbo inlet pipe from stock silicone/pre-bent pipes. in my mk1 i have one 90deg reducer elbow to a 12" 2.5 pre-bent (mandrel) to another 2.5->3" reducer coupler to my jaguar airbox. mk3 is the same deal, but i use the stock airbox, so it just needs an extra length of pipe/silicone hose. easy, cheap, effective.

 

[thechoochlyman]

i don't know how anyone can live with a tdi with the power output of a tiny gt15. as far as mpg's, can have your cake and eat it too with a good size turbo + injectors.

I guess I'm just used to it, but I've been running a Malone stage III for like the last 5 years, everything is stock otherwise. Plenty of bottom-end power for sure, enough to slip my VR6 clutch if I'm not careful. Would be nice to eventually get a turbo with more top-end power someday.

 

[Rig]

This is the turbo I have: https://kermatdi.com/i-198-k03-k04-...html#!model=JETTA||make=VOLKSWAGEN||year=1998

 

[burpod]

the k03/04 hybrid is really only worth it as a drop-in/no-fuss replacement that has potential for slightly more boost. the exhaust side though is still the same size, tiny.

 

[Rig]

Too bad VW didn't use something like a V-band flange down there, it would make the whole process a lot easier. As it stands it looks like I'll have to start with a square block and mill everything away, and put in an internal O-ring groove. Won't be a difficult project on my part, but it's gonna get costly with proper madrel bends and welding.

I meant to ask, any idea what you would charge for just the flange connecting to the turbo? I think a simiple straight metal flange could be connected to a silicone hose with an elbow to go up to the remaining section of the part, depending on how bad the damage was.If I recall there just wasn't that much metal to attach the hose to on the turbo itself. The connection could be more secure.

 

[xLazybuttx]

I definitely be interested in probably buying one depending on the cost because I need one for my vw as well. Maybe as a idea probably going off a couple peoples idea as well but like making it to fit the original fitment on the turbo than doing like a 2 in flange( i think that’s what it’s called) or a bit bigger on the side that the turbo inlet pipe would go on then can just use the old turbo inlet pipe or that person making a new one them self using the silicone tubing to clamp on too. Honestly it be easier to draw out but it would look something like a a blow off value spacer but of course it be more open for my air flow and be different but I’ll attach a picture for reference just so everyone can have an idea if any of this makes since lol.

 

[pwachs0603]

It's a good idea and I'm interested - mine cracked into shards and shreds at the bottom, as they do. I had to cut it back almost to where it lips out below the bend and was able to cobble it back together from there with a Fernco 1-1/2" flexible coupling, cut down to about 2" long. Which seems to be working just fine, at least for now. I agree with the concern that a custom designed/machined part may be cost prohibitive for what it is. So yes, maybe just the flange, but then the next challenge would be where/how to connect securely to the inlet pipe, which tapers. Maybe above the bend? Mine doesn't have a whole lot left below the bend....

 

[Rig]

It's a good idea and I'm interested - mine cracked into shards and shreds at the bottom, as they do.

Cool, I think we've got 3-4 people interested in at least the flange part. As far as connecting the flange to the remainder of the inlet pipe, I think the right size reducing silicone elbow would be perfect that can just be cut to whatever is left of the plastic part.

 

[ToddA1]

With a new o-ring at the bottom of the TIP, I doubt you’d need the flange bolts. It’s an amazingly tight fit and I’d bet just the upper bolt at the intake would be enough. I’d bet most o-rings are shot and in need of replacement.

I bought a small bag of these and will never go through them all. I’ve got extras if people want to give it a shot. I’m not going to start a FS thread… send me a message if interested.

-Todd

 

[Truckeratlarge]

Count me in as prospective buyer

 

[gboss]

Interested in buying one as well.

 

[thechoochlyman]

Currently revisiting this, as I now have a spare inlet pipe to dimension.



It would be just the flange that bolts to the compressor housing with the internal O-ring, made in aluminum, with an opening to accept an aluminum mandrel bend. I just need to figure out the right size for it, maybe you guys who expressed interest could help me out. I'd shoot for selling these at $100 shipped per item.

 

[volksguy]

Would you be able to put the vent pipe heater in with it and the stock hose to the MAF

 

[thechoochlyman]

Would you be able to put the vent pipe heater in with it and the stock hose to the MAF

That would be up the buyer to figure out - all I'll be making is the flange to bolt to your turbo, the rest can be fabricated however you like. Plastic tubing, aluminum mandrels, etc.

 

[thechoochlyman]

So this is what I have so far. It's essentially an exact copy of the original part, just with a 2.05" diameter hole on the outlet side so a 2" mandrel can be inserted and welded on. It would also be easy enough to make the rear OD the right size for clamping on a fernco or pipe. Just depends on how the customer wants to build it.

This is the turbo side with the stepped ears and O-ring groove



And the backside with a cleared ID. The only change I've made was to leave the right-hand ear a little thicker to cut machining costs, but that can be remedied with a slightly longer bolt.

 

[Rig]

Awesome! I'm sold!

Any questions I have will be newb, but are you sure it will seal itself to the turbo? do we need a copper seal or a rubber seal of some kind?

Any idea if these will fit the VNT turbos also?

 

[ToddA1]

If the OE design is the model, I’d imagine an o-ring will be needed.

-Todd

 

[thechoochlyman]

If the OE design is the model, I’d imagine an o-ring will be needed.

-Todd

Correct. Only way to do it without a V-band clamp I suppose.

 

[thechoochlyman]

Any idea if these will fit the VNT turbos also?

No idea. If the VNT is a direct swap with no mods to the intake horn I'd imagine it will work.

 

[Rig]

Any purpose for the four indents on the turbo side of the part? I notice the oem part has those as well. Possibly unnecessary machining given the fact so many people just hose clamp a pipe directly to the turbo

I'll take a look at my old turbo to see if I can come up with any reason for this.

 

[thechoochlyman]

Any purpose for the four indents on the turbo side of the part? I notice the oem part has those as well. Possibly unnecessary machining given the fact so many people just hose clamp a pipe directly to the turbo

I'll take a look at my old turbo to see if I can come up with any reason for this.

It's just for facilitating the O-ring as far as I can tell. And it probably makes it easier to slide over the turbo inlet.

 

[TDIDaveNH]

Looks nice Charlie...why not make the left side padeye thick as well?

 

[thechoochlyman]

Looks nice Charlie...why not make the left side padeye thick as well?

No reason I couldn't! It would just take a longer bolt. Either way, one side will be thicker than the other to reduce machining time.

 

[thechoochlyman]

Got the prototype done today. Just need to go home with it and see how it fits on the engine in my basement.





I accidentally fudged a number and made the mounting tabs thinner than they should have been. Oops. Guess that's what prototypes are for! The good news is that it's still plenty robust, even at that thickness. These won't be breaking off like the stock part did.



And that's with a 2.25" OD and 2.030" ID so you can insert a 2" OD pipe and weld it on.