I got bored and tired of thinking about it, so I just dove in. Im converting the stock plastic janky TB to SC tube to a large, free flowing metal tube. I started with a stock tube, made a jig, cut a bunch, then used some ducting to make a new tube.

Been using some rivets to hold the most of it together. Sill have to do some finishing work and seal it up. Think I'll use metal / aluminum tape for the main seal on the outside, then some high temp silicone paint, heat wrap, more paint.

I hoping this thing will bolt right up with minimal adjustments, hence the use of the jig. The BPV is going to be hard, as its in. Goofy **** position. Suggestions for this are welcome. Think I could use a 90 degree bit on the side, then some long silicone hose? I dunno. I was also thinking of grafting the original BPV piece on as my current option....

There's still a lot of porting to do as you can see in the pics. You can also see the restrictiveness of the OEM tube vs the ducting. Hoping this will be bad A :-)

 

Did some "porting" on the plastic bits. Still working in filling the gaps in the metal parts. I'm afraid to use RTV or similar, for fear of it coming apart and flying into the engine.

Suggestions?

 

I would't trust any filler type material on that sheet metal, possibly some solder or brazing but I'd imagine it to be fairly flexible and over time even small flexes will shake any fillers off.

 

Yes, my friend and I came to the same conclusion.

More headway. The basic shaping and porting is done. Now on to the BPV. I cut the original off. Need to shape it, then somehow mount the bastard in the correct position. I worried about this bc I don't have another OEM piece to get its position 100%. Anyone care to temporarily donate? Lol

 

Little more progress. Did final sanding on the plastic ends. Has to melt in some plastic to fill cracks, so that took some time, but the end pieces are now acceptable.

I've attached the TB side to the metal pieces. Did more internal metal trimming to attempt optimum airflow.

I've also started with the aluminum tape. Neat stuff, pricey tho @ $8 a roll. After the RTV cures I'll somehow make the final attachment to the SC side, then when I get my loaner tube, I'll fix the jig to include the BPV placement.

 

Got the SC side on.

 

More work. Wrapped and sealed in aluminum tape.
Fellow Nammer is sending me a loaner unit so I can fab up final placement of the BPV.

Also ordered a 40mm inner diameter silicone piece of tube. Hoping that will give me any final flexibility I need during install.

Heres a pic of the stock tube for reference.

 

I have the OEM parts on a shelf in Ft. Lauderdale if you still need them.

 

i would interested to see how this effects the engine

 

I will be welding one from aluminum soon.

As nice as your idea is, I do not think it will hold up.

Thin gauge metal like that is fine for a mock up to get shape and OD size, but it needs to hold up to a vacuum.
on overrun at 6000 RPM we pull quite a nice vacuum as well (lower than 20 in.)
maybe the tube will last one cycle, but fatigue is prevalent, as well as heat cycling, and you will be throwing codes if it ever develops a small leak.

Then there is the clearance between the tube and the fan/shroud.

If they touch they will rub as the tube is on the engine which vibrates / moves relative to the rest of the car, while the radiator fan / shroud is bolted to the frame and does not move with the engine.

best of luck! (it is quite a tight space. Largest tube my 3d scans and mock up show me being able to fit is a 2" Sch 40 tube (I think that is it.. maybe it is 2.25"...) still...

(remember, for schedule piped the higher the number the thicker the wall. And they are sized with a constant OD, with the nominal size corresponding to the ID on SCH 80 pipe)

 

Yup, rubbing will def. be something to watch out for. I remember seeing pic's of an aluminum Intake Tube that someone had, with a gaping hole rubbed right through it, couldn't imagine the car ran right for all the time it took to create it, not to mention with the vac. created there I guess we all know where all the metal dust & fragments ended up going.....

 

I know this part will have a lot of strain. It is all rivited together, not just taped. The tape is to hold said vacuum.

When it's all done, it will be getting treated to withstand said temps. I also have an engine damper, so that should reduce rubbing. I'll shave the shroud there if I have to... Been wanting to build more of a ram intake there anyway.

 

More work done

Thanks to blown away, I got the OEM tube today. Made the BPV part of the jig. Also did some grinding on the OEM valve I cut off. Not quite sure how to attach the 2 materials securely. Going to stew on that some more, but suggestions are helpful too!

Also including some VS pics to show the diff.

 

Interesting and neat but I see a P0171 for sure. How are you mounting vacuum lines too(most importantly the pre-supercharger MAP)? When you mock it up and put MFE back in place you'll see how tight it's going to be along with mounting BPV to it and the intercooler output duct. I would suggest you get bolts for that and remove the intake manifold studs. Good that you got the good/used spare tube for mock up as that will be your go to tube.

Jeremy

 

Ye all have little faith. Where's the support? How about some answers to go along with these issues and criticisms...

I think some people are making this more complicated than it really is.

Anyway, more progress. Got the vac lines marked out on the jig. Hose barbs will terminate at the points marked, hoses clamped on.
I'm going to keep working the BPV till it seats decent, then work on attachment and sealing.

 

nah, some of us just have engineering degrees and know that the stock pipe while it has a smaller ID was relatively hydraulically smooth on the inside. Yes it is restrictive, BUT!
Every lip, bump, non-smooth profile in a flow system creates vorticies and resistance to flow. Now it is not AS critical in the intake as in the exhaust (where you have 1.2 Mach + flow rates vs flow through our throttle body at ~6000RPM at WOT is ~4.6 M/S

As for how to make this?

If you are persistent on this particular avenue of fabrication I would personally buy a CF, kevlar, fiberglass, or blend sleeve (I would sugest kevlar as it will not mind the metal contact (electrical difference in carbon can cause metal oxidation if not bound properly.).

I would buy a kevlar sleeve,

buy a baloon. One of the long "skinny" ones, but it needs to be able to get to a diameter of your pipe and as long as it. (this is the cheap-o method)

coat the baloon with a silicone spray so it will release.

inflate the baloon slightly (so it is the length, but narrower than the pipe.) and twist-tie it closed. (you will need to inflate it more in a step or two)

Put 2 layers of kevlar sleeve onto the baloon. One layer at a time and apply a vinyl ester or epoxy resin (better).

After you have applied the sleeves and resin, zip-tie or twist tie the two sleeves together at the end they hand off of the baloon (opposite from the inflation end) -> resembles saussage casing. and put the baloon+ sleeves into your tube.

Inflate the baloon until it fits snuggly (very snugly) inside of the tube and then allow the epoxy or vinyl ester to harden.

After cure remove the baloon and then trim out the excess kevlar composite with a dremmel. (for the BPV etc) touch up by hand with some sand paper.

will not be perfect, but most likely better than just the metal alone.



If you have access to more tools than I know, you can do it proper and use a vacuum bag instead of the baloon method. (i do mine via vacuum bag or vacuum resin injection)

 

...

Anyway, back to my project. I know it may look kind of janky, but I think it'll hold up ok.... I used some aluminum brackets to hold the BPV in place after a thorough RTVing. Best I could do for now. If it works, awesome, if not, then V2 will solve the problem.

Also got my silicone hose in the mail today. This should allow some tolerance for install.

 

More.

got some barbs for those 2 side hoses. ground them down so they wouldnt stick out into the tube too much. drilled out some holes measured to be in the same relative area of the oem, and rtv'd the barbs in place. got some hose clamps for those hoses too. i put more aluminum tape around the barbs. all the rtv is protected with several layers now.

i think its about done! going to tape it, clean it, then shoot it with a few layers hi temp silicone paint. still debating using heat wrap also...
after that, i guess ill just need a day and some luck to install it.

 

Painted. Going for a few coats, heat wrap? Then install

 

Good luck....up to 30 psi (difference from vac to full boost) on heating/cooling ducting....will tear in a few days....those rivits in the elbow joint are massive stress points (not to mention not airvtight under psi)...might be good enough for a non pressurized water heater vent... But under load...life will be very short at best. Good luck still....but choice of materials in this first version is not good. I do commend you on trying.....but even if you had welded the elbow joints in place, sheet metal of that thickness will fatigue rapidly.... That is why the sc horns are cast aluminum....

 

well in the TB tube it does not see boost, so he will only have to deal with ambient to vac, but still VAC is much more stressful than boost (compression vs tension).

It may work... but it is not how I would do it.
also, looking at the geometry and knowing how large duct is for vents, I really do not think it will fit.

just look at the profile needed to clear the gearbox!

This is mine that I am making, and it just fits about perfectly.


That damn bolt flange is just in the way.

This one tapers significantly more than mine to that shape, and if it fits there I will be shocked, amazed, and be re-making mine. haha.

there is also the rad. fan clearance.

Between the gearbox and the fan at the stock pipe's path clearance is only 2.154 inches (give or take as the engine moves)

that duct he is using looks to be 2.5-3" OD, plus a little with the mastic and other stuff.

and don't get me started how much a rivet impedes flow in a pipe. smooth is key. Which the factory pipe is.

I would love to see a before and after dyno on this however, and feedback as to how long it lasts through the cold, wet, and heat.

 

looking closer, now the only thing im really worried about is the gearbox flange. it will def suck if / when that is in the way of install.

may have to take a damn hammer or something to this thing, see if i can force fit it :P

will photo document.

 

I think I want V2 to be silicone. I found a company that sells uncured silicone sheets. Have to buy 30 sq ft min, but it's only like $1 a sq ft at that point.

 

I have built wooden kayaks skinned in Kevlar. it is not as easy to work with as you describe. trimming with a dremmel is like cutting a rope. frayed bits everywhere. touching up by hand with sand paper will leave a fuzzy mess.

my degree is in physics, and I agree with much of your advise. just not Kevlar as a material. CF or FRP are much more user friendly for a diy project like this.

OP. like others, I applaud your out of the box thinking, but I am not optimistic on the outcome. press on and prove us wrong.

beaner

 

apologies,

normally when I am cutting kevlar it is bonded to several (4+) layers of carbon, usually in a c-c-k-c-c arrangement. (sometimes with a kevlar skin for metal bonding) and cuts with a dremmel pretty well.

For thin sheets (1-2 ply) a pair of aviation snips has always worked pretty well for me though (as long as they are in good shape)