i work in a fab shop and im planning on making an equal length manifold for my d16, i figure ill feel better about myself when i save a couple hundred bucks, and the more blood sweat and tears under the hood the better! But... i have a few questions, and ill make it as easy as i can for you guys to answer lol.

Runners:
1.) Is the 304 schedule 10 to thin? should i go with the shedule 40?
2.) 1-1/2" piping or 1-1/4"? ive read 1 1/2" is the norm on hondas somewhere, but i just want to make sure because ive read some people using 1 1/4" on this site.

Flanges:
1.) Stainless or mild steel flanges? I've read stainless flanges are not the way to go, but it just seems odd to have stainless runners and mild steel flanges! but yet again, i want to do the norm.

Pricing:
1.) Runner piping, ive checked out acestainless and they seem pretty fair but if there is cheaper i would love to know! at ace its about $11 a foot for the pipe, and about $7 for the elbows.
2.) For flanges, i have found bmcrace so far there pricings are as follows,
-d16 exhaust flange $28.50
-wastegate inlet / outlet $15.25
-t3/t4 turbo inlet $19

if you know anywhere thats cheaper please chime in! thanks for the help in advance

-didder

 

i just ordered in bulk from ace in the past because it saves on shipping, but they have the best prices along with good customer service and fast shipping.
1 1/2" is fine
crush the pipe so it's an oval shape where it meets the head flange, it matches up to the ports better that way
focus on penetration rather than making the weld pretty using a pulse etc
make sure you securely bolt down the head flange to a thick straight piece of metal when welding, do the same for the turbine flange
i used a stainless flange for my s2000 manifold, and even with bolting it down it still warped. ive used mild on four other manifolds i built and none of those warped....maybe i put too much heat into one area, maybe it was the stainless, im not sure. but just use mild and 308 filler on the stainless to mild weld

thats all off the top of my head...good luck!

btw im farrr from a pro, this is what i learned from my own experience

 

Thats 309 filler for mild to stainless.

 

i use 309L for mild to 304ss joints.

piping: ace sells the 1.5" 304ss schedule 10 90's for $4.95 not sure where $7 comes from. but yeah, schedule 10 is plenty thick.
flanges: bmc flanges are nice because they are cnc machined, but that is overkill on something you are going to weld anyway. a laser cut flange is much cheaper and almost as nice. i've seen them as cheap as:
-d16 exhaust flange $20
-wastegate inlet / outlet $6
-t3 turbo inlet $10
that is only a total of $36 compared to the total of $62.75 at bmc. just google "weirtech"

 

Best flange out there for Honda engine is the SLS flange since you dont need to crush the pipe to fit an oval. They're pricey but the time I save with not having to oval the pipe is worth it IMO.

 

how are you ovalling your pipe? it takes me 5 seconds. i actually don't like the abrupt change in shape from oval to round in only a 1/2" of distance in the ehxuast path. i like the transition to be even a little more gradual.

 

woops i meant 309, that was off the top of my head sorry lol
and yes the SLS flanges are very nice, pipe fits right up to the nice cnc'ed opening.
but aaron has great customer service, i've ordered from him in the past...cant go wrong with that! speaking of which i think i need to order again soon

 

I use a vise and I usually bend a 90* pipe so the transition is still only 1/2" to 3/4" before going to round. It still a PITA for me to crush a pipe, weld inside and then grind smooth.

 

Here is our premium flange

B Series http://www.bmcrace.com/product_info....products_id=81
D Series http://www.bmcrace.com/product_info....roducts_id=124
http://www.bmcrace.com/images/bhfp2.jpg

No need to crush the pipe with those...

 

Very Very nice!

 

X2 on the sls flanges, well worth the money. When your done you'll be much happier you spent 50.00 more for cnc flanges instead of water or laserjet. The flanges a re such a small portion of the cost in a manifold, but make the finish product 10x nicer.

 

Sorry to bump an old thread, but Arizona Forced Induction http://www.afiturbo.com/store/ has some nice flanges at a competitive price also.
And anyone looking for buttweld fittings, make sure to look locally. We have a place called Adel in Bettendorf Iowa. They're a plumbing wholesaler that will sell some stuff to the general public. And theirs were about $7.50 for 90* bends for Sch 40 steel. The guy cut me a little better deal though.

Not trying to take business away from BMC or anything, just saying that buying locally can be a little cheaper.

 

Well my problem with the CNC sls flange is its mild steel. Its a nice piece but what about rust?

 

Its obvious you know nothing about building manifolds or else you'd know better..What company uses stainless steel head flanges?

 

I ask a question because I dont know. i am not a fabricator. Just asking a question about the flanges being mild and not stainless. If no one uses stainless, why does vibrant sell stainless flanges?

 

BMC ALL THE WAY. **** is sharp as hell. deff worth the 55$.
we are lucky they sell them that cheap, crazy not to fork it up.

 

I am pretty sure that it is because of the thermal expansion differences between stainless and steel. I think that the stainless is more prone to warping when welding. Not 100% on that but it is my best educated guess.

 

since i saw this thread got bumped anyway, i got one more question.

how do you guys fab the hole up for the wastegate? a holesaw? because we have been doing a custom cage for my buddies sand rail (dropping a northstar v-8 with a turbo strapped on to an 1200lb street legal buggy! mwahhaa!) and our bi-metal holesaw lasted like 5 cuts into the 1 1/2" 220 wall mild steel...

just a question

thanks for the input!

edit: i walked outside after posting this and my buddy who owns machine shop was just pulling in.. he said he would have to mill in the holes for me and that that was pretty much my only way he could think of off top of his head? I really dont want to burden him and i actually want to start making these manifolds for the local race scene if everything goes well. So, is there any at home small time shop way of doing it without a mill?

 

buy nicer hole saws.

 

where do you get them? i cant find anything except the p.o.s. bi-metal saws

 

Stainless flanges warp to easy. and then you have to get the manifold decked.

To cut your wastegate hole turn up the tig amperage and burn it out then clean it up with a die grinder. That's how i do it its pretty fast.

 

if you can't make a wg hole in mild steel with a hole saw you are doing something very wrong. i do them in stainless all the time and don't seem to go through too many bi-metal holesaws. here are some tips:

1. make sure your collector is secure so it doesn't move around while you drill it on the drill press.
2. run the hole saw as slow as your drill press will go.
3. use lots of coolant. overheating your material will work harden it making it even more difficult to cut.
4. start the hole so that as many of the teeth of the holesaw are engaged in the collector as possible. this will prevent jumping and skipping and breaking teeth because the chip load is more evenly distributed.
5. use lots of coolant.
6. feed it steady and slowly into the material and take pecks to remove chips.

 

let me add to weiR on this....

7. Use LOTTTTS of Coolant!
8. Keep the drill speed low!
9. USE LOTTTTTTS OF COOLANT!



We speak the truth.

 

weiR and wade - if you could choose to make a turbo manifold out of the following two options which one would you choose and why?

1 - mild flanges, ss runners, uncoated
2 - mild flanges, mild runners, coated

 

I see both people do it. I know a friend who use to do the MS flange and SS runner, but seemed his had a high failure rate, so he went to all MS and coated and hes been fine. Myself, I use MS flanges and SS runners and NEVER had a failure, ever. And, I dont even purge weld. I think it comes down to the welder himself and how good they are and their skill level. I know MANY people who do MS flanges and SS runners and they hold up great.

I guess, what do you wanna look at in the end? A coated manifold or a raw finish SS manifold?