It was nice to not have to mess around ordering the parts individually. Although I did select the wrong inlet flange. I ended up taking 2 thousandths off of one side and 6 thousandths off of the mating surface. I know it wouldnt have made a difference, but its been a slow couple of weeks at work. lol

 

Can I just say this thread was inspiration to actually commit to a turbo build. That picture of everything on the motor sold me. Well done sir your work is gorgeous.

 

Hope that your turbo build turned up well, here is how my EFR turned up on an NB with AC and PS

 

I am currently working on gathering all the parts. But I have a v3 megasquirt, id injectors, walboro fuel pump, ls2 coils, wideband o2, boost gauge, intercooler core and a bloush 16g turbo from one of my subarus with a welded wastegate with a tial 38mm wastegate.

Just got done mounting BRZ seats in my 1996 so now I can start on the fun things.

 

Good, be patient and do it right!

 

Quick question about material choice. Never made a manifold before, but keen to have a go. Car is a '95 1.8, and I plan to use the good 'ol GT2560R.

I have purchased a PRL motorsports head flange which is a very nice piece... Basically like any of the premium flanges out there. (Mazda Miata 1.8L Exhaust Head Flange). It's made from 1018 mild steel. I also have some stainless weld els, so am i better off forking some extra cash for a stainless flange? Or just going with the mild and welding the stainless els to it using 309L filler? Or get some mild els and go with that?

Given that this will be my first manifold, should I Keep It Simple Stupid, and worry about fancy stainless colouring on version 2? I live in a dry climate, so rust isn't much of an issue, but I'd like a nice finish for the aesthetics.

Thanks.

 

Don't worry about a SS flange. You will spend 4-5 times the cost to get one that is the same quality as the PRL flange. Get the T2 log flange from PRL also. It will make your life much easier. If you search the classifieds you can find a somewhat recent FS add I had for a t2 log and just copy that manifold. It is AC/PS compatible.

 

Thanks mate. I wish I'd noticed the turbo flange when I made the order... Shipping these things to Australia certainly adds to the cost! I will be ordering it for this build though.

No AC/PS to worry about, so that helps. Already planning to copy a log style for version 1. In my head I'm thinking of a tube style for version 2 (after much practice) with a turbo size upgrade after some supporting chassis/driveline mods. This forum is invaluable!!

 

I still have a 316SS flange for sale.

https://www.miataturbo.net/miata-par...flanges-90769/

 

Don't mix mild steel and stainless as it requires a special weld metal. Welding dissimilar materials is not a good idea. Go all stainless or all carbon.

 

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Art I do not in any way disagree with what you have said. I was only making the point that if you are welding then sticking to similar materials is an easier and less trouble prone method. If using the services of a compentent fabricator then yes there should be no issues welding dissimilar metals if they understand what filler wire etc to use. Maybe even have an actual WPS based on a approve PQR, however on this forum that would be rare.

 

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He stated he has 309 filler, which will work just fine for joining stainless and mild steel. I have 2 years on a stainless manifold welded to a mild steel flange with 309. No issues.

 

I"m not a competent welder though!

Welding is a bit of a hobby for me though, so if I have to go through a few versions to get to something I like, that's not an issue. I mean, aside from throwing money away.

 

I disagree. At and around room temperature mild steel and most other carbon steels are better materials mechanically than 3xx series stainless steel. However at elevated temperatures certain grades of stainless really start to become better mechanically. 304 its up for debate compared to mild at the temperatures turbo manifolds will see, it wins in the corrosion department though (remember corrosion happens faster at higher temperatures). 316Ti is clearly better mechanically than mild steel at elevated temperatures, but the king daddy of stuff we're likely to want to spend money on is 321 stainless.

 

Here is my manifold i just built with the PRL steel flange and 304ss weld els. I used tig 309 wire which is what it required to join the two properly.

 

Well, there you go! Damn fine job sir.

 

​​​​​​​Looks good. Did you test fit the log on the car before you choose the place on it to put the t2 flange?

 

Thank you for the complement. I did test fit it (a few times) before the final location was cut and welded. I also looked at some other kits and manifolds to get the angle of the turbo and proper space to clear the p.s pump and for downpipe.