Anyone here tried out BMC Race Products?

Mazda 18L Header Manifold Flange Standard - 1/2" mild
Model #: MAZDA18LHF
Our Price: $37.50
Mazda 18L Header Manifold Flange Standard - MAZDA18LHF - BMC Racing Products


T25 Turbine Inlet - 1/2" mild
Model #: T25TI
Our Price: $14.50
T25 Turbine Inlet - T25TI - BMC Racing Products



Unfortunately they do not offer the BP head flange in their "Premium" profile. According to BMC: "Premium flanges are port matched from 1 1/2 inch Schedule 40 Pipe to the head port. Reliefs are machined on the flange to help isolate the heat from the manifold."

What cooks my noodle is these guys don't appear to sell a standard Garrett 5 bolt outlet flange

BMC wants $7.00 shipping to the left coast so that's $59.00 for both flanges in 1/2" mild. Weir wanted $62.32 shipped for the same thing, but in 3/8" mild.

I'll let you guys know how they look when they get here

 

That premium option would be awesome. I'd call them and see if they'll do it. If I knew what I know now about building a manifold, I would've definitely sprung for that additional option.

 

That's not a bad idea actually. I'll give them a call tomorrow morning and see if they are willing to make the change. They probably just cut these things to order anyway seeing as how they are on a CNC.

Edit: Just sent them an email, I'll report back with any response.

 

A welder buddy tried the bp flange they offer, claimed there was slight fitment issues

 

I guess I'll find out when it gets here, but that would be a bummer. Come to think of it, I haven't heard back from them as of yet.

 

Anyone remember the size of the tubes for a 1.8 turbo manifold?

 

McMaster-Carr Mild Steel Weld Els seem to be the norm. Also available in stainless if that's your thing.
http://www.mcmaster.com/#catalog/118/75/=js03tr Steel Pipe Fittings & Pipe

Example:
Long Radius 90°
Standard Sch 40
1 1/2 "Pipe Size"
0.145" wall thinkness
2.25" radius
PN 43425K151
McMaster-Carr

FYI: Internal diameter ends up being 1.6" w/Sch 40, that's why it says "Pipe Size" in quotes. Same part in Sch 80 has actual 1.5" ID

 

Does the 1.5" end up being the best match for the exhaust ports? I'm going to dive into a manifold soon and have been leaning towards 1.25" for the sake of higher exhaust velocity but would ditch it if it does not end up matching well.

 

I honestly don't know, I've never built one before! I was just going off what BMC said about their particular flanges. This started as Baron340's thread and I believe he did Sch10 SS? Stein, Wayne_curr, 18psi and others have DIY'd, but only Stein linked his in this thread (post #13.) 18 has like 6 build threads so good luck finding his. The Stein/Wane_curr/baron340 manifold is basic enough that even a caveman like me should be able to blunder through it.

So to make it easier on myself, I decided to take advice from those before me and go with Sch 40 1.5" mild.

Stein's build thread has the best pics I've found thus far

I <3 this thread

 

lol I only have like 4

 

I should start one that involves less fail

 

1.5" matches perfectly to the exhaust port size, that is after you oval it out. Like I mentioned before, if I had known how big of a PITA it was going to be oval the pipes and do all of that part of the pipe fitment, I would have shelled out the extra money for the CNC oval to round port flange. I really need to update this thread too. I finally got my exhaust housing ported out and need to finish the manifold now.

 

Just add to this one and we can collect all the win in one diy manifold thread instead of having to scour build threads looking for useful information.

 

I just hope my ramblings will be useful

 

Thanks for the info. Why was it a pain to oval them? Heat and beat didn't go so well?

 

It worked fine, just a big aggravation. Getting the ovals to be at the right orientation with respect to the bend, and getting them all the same (or close), and lining them up properly with the head flange etc. I think a lot of that would've been much easier if I had a decent work table and a solid vice. With that cnc'd round opening that fits perfectly to the weld els everything would've been much easier and gotten about the same results.

On another note, I finally finished my turbo hot side to my satisfaction, so the manifold building can commence. Hopefully this significantly helps spool.

 

OK cool. And that port matching looks nice! Remind me of what turbo that is? It's not a Mitsu 13g is it?

 

OEM TD-04 off of an 04 WRX. Beyond that, I don't know any more details.

 

Are the 1.8 and 1.6 port sizes pretty close? I know the spacing is different.

 

Same port size, or at least pretty close. I'm building a 1.6 manifold for a local guy and used 1.5" tubes as well.