Manifold advisers post up.
 

I need a T25 flanged manifold with an external gate for a 1.8L Miata. I've been raking this over the coals for awhile now and it's time for some outside advice.

I am torn between a BEGi or FM cast manifold with an external gate added on, or an ETD shorty tubular. I am working in a fab shop so I am not concerned about the availability of downpipe & IC piping.

Which would you guys run?


GOALS:
My turbo is a GT3071R with 0.61 A/R , external gated, T25 exhaust housing.

Initially I will run it in the 250-300 range on a stock 99 engine while I build up a forged short block. After that I'll bump it up to 300-350 and see where the power bug takes me.

out of the three I'd go with the shorty.

Why don't you make your own?

+1 buy flanges and make it yourself you'll save plenty of $$$ that you can spend on other parts (MSPNP, intercooler)

yeah what they said. Make your own #1.

Buy one of mine #2.

Buy the ETD shorty #3.

BEGI or FM cast mani #4.

Get the cheapest, they will all work equally well.

I'd put Tim's over the shorty. ;)

why go buy the cow when you can look at the butcher's ass by sticking your head in there?

huh?

Thanks Scott, but my mani not the cheapest unless you buy it with my GT2871R, in which case it's very cheap.

Why a T25 flange when you are going EWG? I'd do a T3 housing.

hey check this out i can help you with the manifold you want
https://www.miataturbo.net/forum/showthread.php?t=20270

Sorry that was mis-leading. I work FOR a fab shop, part-time, on the business side.

I can't weld.

Also, I prefer a tried and true manifold that doesn't suffer from boost creep issues, isn't likely to crack, and is easily replaceable if it does.

I like your manifold, but I love A/C and powersteeing more.



Spool and A/R selection.

My housing is T25 external wastegate housing from HKS. They have a whole slew of A/Rs for this turbine with the same footprint, so I can experiment/upgrade with out springing for a new manifold/downpipe/IC piping etc.

The T3 housings from Garrett have only one usable A/R for 0.63, and the T3 Flange is oversized for the 0.63 scroll anyway.

you work on the business side... then offer your car up as a mock up mule to develop a new product. get them to make the manifold for nothing and then they can sell them once they have a jig made up.

seems like the cheapest, easiest solution to me.

Whoa that's scary I was just looking at your flanges on HMT.

I will talk to the main fab guy at the shop, but they want way too much money for the manifolds they build esp for what you get. Corky's stuff is a way better deal.

Who cares how much they want, your's will be free.

yeah me too. I will never get rid of my P/S or A/C. I actually never tried fitting Paul's manifold with either of those, I just assumed it wouldn't work. Either way I'm going to do one for A/C and P/S soon; doesn't help you much now though. I guess I'd go with the ETD one then.

i'm selling custom mani's you'll get your monies worth..he he

It was a quote from Tommy Boy.

ahh alright, I missed that.

just dont use his BOV, your piston will turn sideways in the bore ;)