lol no worries

I ran a GT2554 at 14 psi on an HKS log. It hit real hard but did struggle at the top end like a MP62 ;-)

I've been thinking there's so many factors going on.

Manifold volume
Pipe diameter
Number and bend radius of gas direction changes
Package space
Downpipe location, number of bends etc
Cost
Power goal

Its between an equal length ram horn or flow directed collected very short unequal length tubular

I have some 1.25" schedule 10 stainless 304L cast elbows that I'm going with. Quality is good and a machined manifold to head flange from these dudes: Exhaust Head Flange - Mazda - Mazda Miata 1.8 Exhaust Head Flange

I wouldnt use sch10 stainless. I'd contact BMC race to get that same style manifold you linked but custom made as 304 stianless and to the pipe size you're using.

I have an Artech ramhorm manifold with my EFR 6258. I made 315WHP @ 12PSI and 323WHP @ 14PSI on a Mustang dyno in El Paso, TX (approx 4000' elevation). I also have a 3" exhaust and 2.75" intercooler pipes with a Precision 600 intercooler. This a a mild steel manifold, not SS.

315WHP and 251TQ at around 12PSI (179kPa)
https://www.miataturbo.net/attachmen...d-sam_0272-jpg

323WHP / 262WTQ @ 14 PSI
https://www.miataturbo.net/attachmen...psf01030ba-jpg

There was a problem with my manual boost controller in the second dyno. I could have made more power. I'm now running EBC.

Moar pics of manifold

https://www.miataturbo.net/attachmen...ps91430744-jpg
https://www.miataturbo.net/attachmen...d-109_1188-jpg

https://www.miataturbo.net/attachmen...d-p1020016-jpg

https://www.miataturbo.net/attachmen...d-p1020018-jpg

https://www.miataturbo.net/attachmen...d-p1020023-jpg

https://www.miataturbo.net/attachmen...d-p1020031-jpg

Ok what in the world is up with the wildly different EFR numbers?

Wo
That is some manifold. Nice welding on that.

Its almost like with the EFR6258 your forced to go top mount to keep the PS..

I'm hoping to retain it with a tight to head canted orientation similar to Soviet's

The problem is the BW turbo's are a mile long and to clear the body your forced to do unpleasant things

Lloyd, I have power steering with the manifold I have. but my power steering pump is trunk mounted.

B nice to see a data log on those numbers, I'm no ware near that HP/PSI ratio.

I got in touch with ARTech and ordered the same manifold & downpipe as Swimming108: https://www.miataturbo.net/build-thr...llo-efr-77075/. It looks very, very similar to what Mazdaspeeder is running.

These are Swimming108's pics, not mine:

https://www.miataturbo.net/attachmen...92284694_n-jpg

https://www.miataturbo.net/attachmen...ine=1389965431

According to Abe, nothing needs modification to fit this manifold. Its both PS and AC compatible, and should require no modification to the mixing manifold.

Interesting enough, I need to get in touch with Abe as I can't remember if I ordered mine in 1.25 or 1.5. Swimming's looks like 1.5?

https://www.miataturbo.net/attachmen...14706989_n-jpg

Anyway, I honestly don't think it'll make that much difference with my 6258. I'm not shooting for SovietPower™ on the top end. Dem throttle response y0, et cetera...

My manifold IIRC was built by Abe on the specs of 99MX5's manifold. Except I retained PS, pretty sure he did not.

I believe it is sch40 mild steel runners with both flanges being SS, with 1.25" runners.

https://www.miataturbo.net/attachmen...ine=1403270082

https://www.miataturbo.net/attachmen...ine=1403270082

pre-coat
https://www.miataturbo.net/attachmen...ine=1403270082

post-coat
https://www.miataturbo.net/attachmen...ine=1403270082

https://www.miataturbo.net/attachmen...ine=1403270082

If you want more photos let me know. Here is a link for the coating: http://swaintech.com/race-coatings/r...aust-coatings/

Also just as a personal opinon, with the kind of power the EFR turbos make, you'll be hard pressed to notice a difference between a log or ramhorn maniflold, for most people anyway.

I think you would notice.

I have used both types that I built. The results in this writeup feel accurate from what I had to do to the fuel map in my car.

http://www.full-race.com/articles/Bs...st_writeup.pdf

That's a good link I read it

It's a compromise then between whether you want the power low or high in the rev range. Bit like the ar ratio on the turbine housing

300rpms for 50fltbs? Seems like an easy choice. AND its not like the tubular setup was making less power than the log even though the tubular wasnt completely spooled because it was making the same power with less boost.

Very true Leafy very true

Damn it! I've got to buy more elbows lol

if you order them from somewhere not local, get more than you need. one miss calculated cut and if you don't do a lot of these you might end up with an elbow less than you need.

just voice from someone who has done it. ;)

Now I stock a bunch of them.

Ok I made something... its a short unequal ramhorn

Volume is about 550cc. Wanted this as small as possible to keep spool good but not limit flow. Angle changes are kept to a minimum. Cylinders 2 & 3 have very little angle change. Cylinders 1 & 4 are as large radius as possible.

http://postimg.org/image/4b4qfhli5/

http://postimg.org/image/7xajs4rvh/

http://postimg.org/image/7cvipfyn1/

http://postimg.org/image/tarzj8dnh/

Stainless MIG welded, she isn't pretty I know

Good show, probably better than I could have done. :bigtu:

Time to bust out the dremel and kill some of those weld boogers, last thing you want to do is push those into the turbine. Also, lets get a shot of the inside of that collector.

interesting design.

is that going to clear the steering shaft? looks like it will be super low

Doesnt look that much lower than mine, if at all. I'm more worried about how far away from the engine it is and if its going to clear the frame rail. Like mine is this close to the frame rail.

Attachment 184846

And this close to the engine block

Attachment 184847

Holy hell margin rape WTF?

Its RHD...

Compressor housing is about 40mm off the sub frame. I had to move alot of stuff. PS pipes (reservoir and pump feed), and get the water pump outlet modified. The frame rail lip was also cut back and re-welded.

http://postimg.org/image/m1b0e9ogt/

View image: P1010633

http://postimg.org/image/4pf96kkd9/

http://postimage.org/image/qd47h0krh/

View image: image

http://postimg.org/image/7nc809s0t/

Its been cleaned and smoothed internally as best I can with a long reach die grinder

thats cool
you RHD guys have it so good not having the steering rod there, so much more room for downpipe