BamBam

you guys have a clever sense of humor

buck

jc_rotor

Hey guys just posting an update. Got the 1.8 flange design finalized and the first set is supposed to be cut out and machined this week. Here is what it looks like rendered in 3D CAD software:

MiataTurboFlangeFinal.jpg

Notice the transition from the oval port shape to the circular shape of the manifold tubing.

MiataTurboFlangeTopView.jpg

Heres the face view, just for another look at the details.

More details, and pictures of the actual flanges later this week.

JKav

iTrader: (1)

That oval-to-round transition in the flange is way too abrupt. You're better off just oversizing the ports in the flange. That way you can form a nice gradual transition in the primary tubes themselves (just squish the ends of them gently in a vise). Then slip the primary tubes into the oversized ports in the flange and weld them on the inside and out.

This way, the flange can easily be lasered or water-jetted and will be cheaper, and the joints from flange to primary tubes will be stronger and less likely to warp during fab.

patsmx5

iTrader: (16)

+1

jc_rotor

The ports are slightly oversized, and the counterbore of the circular holes is actually sized to the OD of the primary tubing, so that they will actually sit down in them about 1/8". That should keep the warpage to a min I hope. Ive used a similar design in a manifold for a 1.8 acura integra and had no problems. The flow will be out of the port opening and into the primary directly.

I agree that it doesnt look that smooth, but once all the pieces are in place it makes for a very nice fit and smooth transition. See integra manifold below:

09-18-08_1035.jpg

09-18-08_1034.jpg

Thanks for the advice though, Pat mentioned a smoother port opening so I may play around with that too, and see which one works better.

And youre right, the main thing is keeping it economical, so the feature may be deleted altogether. Wont know until I get my hands on one later this week.

jc_rotor

Also, the ports on the B18 honda manifold are more towards the top of the counterbore and the bottom only has the transition, may try something similar to this as well. It is only a few clicks of the mouse after all.

y8s

iTrader: (8)

squeeze the tubes! I'm sure you can make a fancy fixture that sits in a hydraulic press to do it. then you can make the counterbores ovalized like the ports and the tubes will be your transition.

jc_rotor

so you want me to crush (basically) the Tubing on a Stainless Tubular manifold? this is not some cheap mild steel manifold. Please tell me why I would want to press the tubing? thats just going to give it a weak area for future failure. That doesnt make sense.

TurboTim

iTrader: (9)

Don't ovalize/squeeze/crush the primaries at the head flange.

muhahhaa

y8s

iTrader: (8)

what does absurdness do?

JKav

iTrader: (1)

If you're using tubing (16ga) then you should swedge the tubes over a form. Use a vise / fixture if sch10 pipe. It's a non issue.

TurboTim

iTrader: (9)

I ovalize the primaries. If the fabricator of the OP's (Jason?) manifold uses this flange and tries to market them to this audience, and I decide to get off my **** too, then the absurdness would have another benefit.

elesjuan

iTrader: (11)

I've been thinking lately of bugging you to build me some Absurdness... Dooo et!!

patsmx5

iTrader: (16)

Here's why:

• Simpler
• Cheaper
• Faster
• Prettier
• Less transitioning
• Flows better

Doing it any other way doesn't make sense to me. You say you had "no problems" before. I'm not saying it's a problem, but for all you know that transition costed you 10 HP. You won't know unless you test it. Don't ASSume it's better when it goes against common wisdom. My presumption is crushing pipes to match the ports will make more power, and just so happens to be easier, cheaper, and simpler to build.

jc_rotor

Well, honestly i dont think it makes that much difference in flow. You have to remember which way the gases are flowing here. They are coming out of a relatively small diameter port compared to the 1 1/2 ID of the SS piping.

Plus like i said, ovalizing the primaries will create stress points in the form. If you take this O and turn it into () this, then the sides that have a smaller radius will have pre stress from the pressing, forming, and whatnot. And which form do you think is better for flow? Crush a drinking straw and blow through it and youll see what i mean. The ID of the tubing is very close to the extents of the ports and after its welded on the outside, the inside can be ported to match the size and you have no restriction, plus you have the knowledge that its not going to crack on the first heat cycle. This has to be a reliable manifold.

patsmx5

iTrader: (16)

Well I don't think crushing the pipe a little bit is gonna hurt it, at least not mild steel. I've never seen or heard of one cracking from it being crushed, have you? Heat cycle it afterwards if you are worried about it. If for some reason I could not crush the pipes, I would just weld them right to a regular flange. It would flow about the same as your tapered one and be a lot faster and cheaper to produce.

Somebody with time, fab skills, and some common sense needs to man up and start making decent affordable manifolds. There's not much market for a $700 manifold. That's all I'm saying. It's not like their are a slew of $600 heavy duty tubular manifolds available from 14 different vendors and yours for 700 is worth the jump in price. Not like they all use steel crushed pipes and the manifolds break in half within an week, or the inferior mild steel welds are just cracking left and right. Not like your 700 dollar one is gonna corner some market. If you made ANYTHING that was a mild steel regular length 4:1 turbo manifold that accepted a t25 or t3 turbo for 500ish bucks you would sell the hell out of them. Who's gonna buy an ETD shorty manifold for 500 when they can get the full length one that flows better and makes more power for the same price? ETD claims they've sold hundreds of their shorty manifolds...

JayL

iTrader: (12)

JC, what's your background? Most of your posts sound very intelligent and well thought out. But, at times I feel like I'm reading a book on how to build a manifold from someone that has lots of book smarts, but lacks real world experience.

samnavy

iTrader: (7)

^Absofuckinglutely.
FM/BEGi/ETD/HKS/JGS... is anybody else making production manifolds?

So that's 5 total and HKS really does't count and Greddy isn't a factor? Competition is good for the consumer... but 4 real options just aren't enough. Tim might be #5 someday...

Within the next 6months, I'll be building an NB turbo in some form or another... right now it looks like I'm back to the cast BEGi unit for absolute reliability and ease of install. I wish I had more choices.

jc_rotor

Read the whole post for background info.

I do not do this for a living. I work in the field of Mechanical Design but not always with turbocharging. I design things like this for my job all the time but most of the time I have a team of designers that I collaborate with.

So I dont have extensive experience with designing turbo manifolds but the people at Top Speed that do this 6 days a week, 48 weeks a year do. Im taking my knowledge and applying it to the real world with the help of the guys there at the shop. It was per their suggestion all the design changes in the flange.

I know it doesnt always pan out exactly how its planned on paper but in my experience it gets pretty damn close.

jc_rotor

whoops read the whole thread for background info!