For those wanting to build their own intake manifold... step into my thread.

[myblack98gst]

I have been comtemplating building one for awhile now and finally decided to start it yesterday. I will keep this updated as I make each piece, everything is being made from 18g. sheet metal except the TB and HEAD flanges 3/8".

I got the plenum done yesterday, I do have the TB flange attached but the amera ate the pictures?!?

next step is making a runner, it will have a taper to it which is why I decided to bend them myself instead of buying box stock and cutting to length.


and yes the welds you see are pre-cleanup..

 

[Dirtboarder16]

Cool. Keep us updated.

 

[me612]

Are you incorporating the venturi and velocity stack concepts into this design too? Some things I honestly think should be left to manufacturers to build. I'll build my own intake pipe, turbo back exhaust, heat shield, or fmic piping. But when it comes to designing and manufacturing of a smim, I seriouslly think that is something that should be left to pro's. But I really hope it all works out just peachy for ya!

 

[blcknspo0ln]

jumping on board.. goodluck!!!

 

[Scrymerr]

I would not trust those welds.

 

[myblack98gst]

That was all welded solid on the inside. The stitch welding was just to close the seam on the outside and it was stitched like that not to warp it. It will be ground down and look like it's rounded when it's done. Just throwing up some raw pics to give an idea of what's being done. I will pressure test it when it's done.

 

[MrPikolo]

Looking great! I love to see stuff like this. When done, you should get different dyno runs after you are complete, compair it to stock, then borrow a friends aftermarket. I would be very interesting.

 

[myblack98gst]

I will deff. get before and after as I am going to have to tune my car good before I get this done.


no chance to get one from a friend because no one I know has one available.

 

[Tallen]

Are you incorporating the venturi and velocity stack concepts into this design too? Some things I honestly think should be left to manufacturers to build. I'll build my own intake pipe, turbo back exhaust, heat shield, or fmic piping. But when it comes to designing and manufacturing of a smim, I seriouslly think that is something that should be left to pro's. But I really hope it all works out just peachy for ya!

He seems to be cloning the Magnus, which is a good idea. I do not forsee any problems, but too will be purchasing one.

 

[me612]

I don't want to doubt him, and so I won't pass too much judgment until I see the final results. But if he's trying to clone the magnus, then I want to see some velocity stacks inside the plenum that look like Magnus's. http://www.magnusmotorsports.com/images/intakes/spl4.jpg
And welds that look like magnus's. What kind of welds are those btw? mig? Just don't look like they'd survive a few 30psi passes. But hey I could be totally wrong here and he is infact engineering a damn good piece. But so far it doesn't look like that to me. And like I said earlier, I am all about making my own parts, but an intake manifold sure as hell isn't one of them.

But hey if you feel you can make a great one, then more power to you. Don't let my opinion stop you, just stating my opinion. Good luck man!!

 

[Royalty]

keep em comin

 

[92awdgsx]

just wandering what made you decide to make it out of steel? aluminum disipates heat better and is lighter. do you not have a tig to weld aluminum? i'm not putting down what your doing, just wandering why steel.

 

[Echo5Zulu]

Ive allready had all my parts plas cut based on the same design. All I have to do is bend a few pieces and weld er up. I dont know when thats going to happen but let us know how yours whent when your done (power upgrade, feel, power curve move, ect.) About the ventura and velocity stacks. I know the whole theory around them and how they work but does it really make a huge difference when your blown? I know NA it would but if your forcing air in there would the stacks even make a noticeable difference. With blown engines this intake is just a quick way of getting lots of air shoved into the engine as fast as possible. Good luck.

 

[me612]

Now I have ZERO hands one experience when it comes to this, but this is what I've learned about it from reading. Lets say you have a 2" runner. Now the air is being shoved through that runner since we have a turbo. But the air that is up against the walls is moving significantly slower then the air in the middle of the tube. So in a way it's acting like a 1 3/4" runner, because the air against the walls isn't moving nearly as fast as the air in the center. But with a ventouri design, it will speed up the air on the walls of the runner so that it is traveling nearly the same speed as the rest of the air, using the full 2" runner instead of just 1 3/4". And the Magnus has the designed into it. How big of a difference does it make, hell I don't know. But I would much rather trust someone who does know, to make one much more then I'd trust myself. I don't want to risk blowing a weld at the track because the weld couldn't hold 30psi, or having some of the chunks of slag fly off a not so perfect weld inside there right into my combustion chamber.

 

[ronin807]

I'm sure the welds will be fine, just because he stitched the outside to avoid warpage seems like a good idea to me. and it seems like a professional quality driven mindset. if the internal welds are good with good outward penatration...the welds will hold. stitched welding will probably help keep the steel from becoming brittle from the extra heat also. good luck man, keep us updated.

 

[awddsm95]

First off, you guys are being awful critical of something that you have no idea about. I am a 2nd semester mechanical engineer (honors) at the University of Akron, and am part of the formula sae team here. We design an build our entire car, including the manifold. Plenum volume and runner length/diamater is all determined by math. The size of the velocity stacks inside the plenum are soley determined by equal flow to each cylinder. As you get farther from the throttle body, air velocity decreases, hence the need for progressivly taller stacks or a slanted plenum to keep air velocity equal for each cylinder (You would use a flo-table). As far as the welds, im sure they are fine. I can MIG and TIG. Typically TIG (Tungstan Inert Gas) is prefered for manifold making, but MIG is acceptable. You can only MIG steel. You can TIG aluminum and steel. If you look at the magnus manifold, the plenum is made from thin aluminum. Typically, if your weld has good penetration, the weld is stronger than the actual material, therefore the sheet aluminum would "blow out" before the weld would, of course unless the weld is bad. As far as worrying about, 30psi breaking the welds, any Fluids class would tell you that air, which is a fluid, will take the path of least resistance, which in this case would be th runners to the head to the cylinder, not the welds. This is how manifold manufacturers get away with using such thin material. If you were to take a peice of sheet aluminum that magnus uses on their manifold, you could bend it with your hands, back and forworth until it snapped. When the time comes when i sell my 2g and get my 1g, i will be building my own manifold, with a similar process as he has. Good Luck!

 

[97TSIAWD]

First off, you guys are being awful critical of something that you have no idea about. I am a 2nd semester mechanical engineer (honors) at the University of Akron, and am part of the formula sae team here. We design an build our entire car, including the manifold. Plenum volume and runner length/diamater is all determined by math. The size of the velocity stacks inside the plenum are soley determined by equal flow to each cylinder. As you get farther from the throttle body, air velocity decreases, hence the need for progressivly taller stacks or a slanted plenum to keep air velocity equal for each cylinder (You would use a flo-table). As far as the welds, im sure they are fine. I can MIG and TIG. Typically TIG (Tungstan Inert Gas) is prefered for manifold making, but MIG is acceptable. You can only MIG steel. You can TIG aluminum and steel. If you look at the magnus manifold, the plenum is made from thin aluminum. Typically, if your weld has good penetration, the weld is stronger than the actual material, therefore the sheet aluminum would "blow out" before the weld would, of course unless the weld is bad. As far as worrying about, 30psi breaking the welds, any Fluids class would tell you that air, which is a fluid, will take the path of least resistance, which in this case would be th runners to the head to the cylinder, not the welds. This is how manifold manufacturers get away with using such thin material. If you were to take a peice of sheet aluminum that magnus uses on their manifold, you could bend it with your hands, back and forworth until it snapped. When the time comes when i sell my 2g and get my 1g, i will be building my own manifold, with a similar process as he has. Good Luck!

He actually didn't specify if he used a mig or tig weld. Either way, the thing looks dead solid. I'm sure your inside welds are good, it seems like you know what your doing to take on such a product. Good luck and please post your final product, a write up would be even better as in a vfaq on how you did everything, if you wish to do that sort of thing. Good luck.

 

[pboglio]

A 30 psi spike is like an impact hammer, especially from a fast spooling turbo.

Anybody ever pressure test their intake system. I've seen what 30 psi does to a fiberglass mesh reinforced silicone hose coupling, looks like a ballon. Now imagine a thin ass 18 gauge steel of large unsupported surface area being loaded with 30 lbs of weight for every square inch of surface area. That loading "bows" the metal, levering against the weld line. Now throw in thousands of pressurizeing cycles and thermal cycling. Now include bad welding. Finally, consider alot of these manifolds are made from aluminum which has a limited fatigue life. I'm surprised they don't blow more often.

myblack98gst, Congrats on building your own manifold, should be a good learning process.

 

[CyberEye]

A 30 psi spike is like an impact hammer, especially from a fast spooling turbo.

Anybody ever pressure test their intake system. I've seen what 30 psi does to a fiberglass mesh reinforced silicone hose coupling, looks like a ballon. Now imagine a thin ass 18 gauge steel of large unsupported surface area being loaded with 30 lbs of weight for every square inch of surface area. That loading "bows" the metal, levering against the weld line. Now throw in thousands of pressurizeing cycles and thermal cycling. Now include bad welding. Finally, consider alot of these manifolds are made from aluminum which has a limited fatigue life. I'm surprised they don't blow more often.

myblack98gst, Congrats on building your own manifold, should be a good learning process.

You're quite right, If it were seeing 30psi with the plenum completely blocked off. But the plenum is attatched to the head. So unless for some reason every single intake valve is closed, while the engine is running and producing pressure, the manifold will never see 30psi.
And if thats the case, he's got bigger problems.

 

[92redman]

You're quite right, If it were seeing 30psi with the plenum completely blocked off. But the plenum is attatched to the head. So unless for some reason every single intake valve is closed, while the engine is running and producing pressure, the manifold will never see 30psi.
And if thats the case, he's got bigger problems.

I guess I am baffled at how there can be 30psi in the manifold with out the manifold "seeing it". If your boost gauge reads "30psi", then there is 30psi in the manifold...

 

[greathuskie]

i think what hes trying to say is the manifold isnt like pushing 30psi into a balloon, its more like pushing it through something where the air is going in and out, never 30psi of pressure stacking on top of more pressure in a closed environment

 

[2-0turbo]

i think what hes trying to say is the manifold isnt like pushing 30psi into a balloon, its more like pushing it through something where the air is going in and out, never 30psi of pressure stacking on top of more pressure in a closed environment

Unfortunately, the manifold doesn't know the difference. 30 PSI is 30 PSI, it doesn't matter if it's a static or dynamic reading. If your gauge reads 30 psi, that is what is in your manifold. And others are right, it does get significant. If you run some quick and dirty numbers, if it was 5" diameter and round, on 18 gauge steel that would be about 1600 psi stress at 30 psi. That is not a tremendous amount, but it would be prudent to have a robust design.

I'll have to agree with most other posters. They are pretty shitty welds, but hey, whatever. That is how you get better is by trying new stuff and perfecting the technique. Welding is all technique--you can't tell someone how to do it.

To awddsm95, better re-check your text book. You can MIG carbon steel, stainless and aluminum quite nicely. See Hobart's site.

 

[goofynick6]

It doesn't matter; 30 psi in the intake manifold is the same as 30 psi in the head..etc.

I have built my own manifold from aluminum for my 240sx, and my friend who is excellent at tig welding did the welding for me. At 20psi, I started to slowly develop small crack throughout the welded edges. It turns out the aluminum I used was low-quality and that didn't help.

Anyway, take your time making that manifold and read all of the threads on here. It was found using a specialized program that a 1.5 degree taper and 6-7" runners is best.

Nick

 

[dnhieu]

It doesn't matter; 30 psi in the intake manifold is the same as 30 psi in the head..etc.

I have built my own manifold from aluminum for my 240sx, and my friend who is excellent at tig welding did the welding for me. At 20psi, I started to slowly develop small crack throughout the welded edges. It turns out the aluminum I used was low-quality and that didn't help.

Anyway, take your time making that manifold and read all of the threads on here. It was found using a specialized program that a 1.5 degree taper and 6-7" runners is best.

Nick

why do you have a 240sx on a DSM page?

eclipse talon laser

NISSAN :thumbdown

 

[Gary 420A RS]

I would not trust those welds.

second that. i say practice your welding skills and research the dimensions on the intake manifolds before you apply your final piece