FM's sway package is the easiest and a great price at $200 for both. Although RB's hollow 1.125 bar and the Mazdaspeed 14mm bar is 949's choice. $450 for their package with end links.


Yeah, he likes the t3. I've never used it myself. I just like the cheapness of a genuine Garrett turbo. It spools incredibly quickly and still makes 200hp. Not enough for some on this forum, but it is for me. It's really just a choice you'll have to make.

I am going the sr20 t25 route as well... but I come from the 240sx world, then got an RX-7, then a Miata...

Basically there was 3 different variants of the sr20 engine.

• s13 sr20
• s14 sr20
• s15 sr20

Generally it goes that the s13's came with t25. S14 came with t28 journal bearing. S15 came with t28 ball bearing.

The power kind of scales with that too.

t25<t28<t28bb

So if you go the t25 route, and you end up wanting more power later on, you can always just find an s14 or s15 turbo, or any of the other T2 turbo's(gt2871r .64 ar) without having to get a new manifold. That would be plenty of power for a 1.6 build IMO.

A *19* mm rear? I've never seen a rear sway bar that big on a Miata, and I suspect a 22/19 combination would unbalance the car to the point where it would do a complete spin pulling into your driveway.

22 sounds like a stock front bar (not sure what the NA 1.6s had), I think stock rear was 11mm.

FM's package is a solid 1" front and a 5/8" (15.8mm) rear, and IMHO that's too loose. Note that that's less front bar and more rear bar than the 949 setup. If you want to approximate that balance with cheaper parts, an FM front with a 12mm (99 sport) rear is probably close.

--Ian

Hornetball:
I'll definitely check out your build thread. Sounds like you've got the winning formula I'm looking for.

Here is a pic of my undertray:
https://www.miataturbo.net/attachmen...ine=1393994634
I only had a few hours to make it, with limited tools, so it doesn't look very pretty (it's not even complete, so I'll figure out a way to secure it in the rear, don't worry) but I think it seals fine.

Mazdaspeed engine mounts need to be replaced every so often, don't they? Would you still recommend them in spite of that? I was thinking of getting ones with stiffer (poly or something) bushings.

Door Bars:
Did some reading on door bars and they definitely look worth it. Something I haven't been able to get a clear answer on, though. Do door bars negate the benefit of the butterfly brace? Should I just keep the frame rails and sell the butterfly brace when I get door bars?

About the 1.6 vs. 1.8 topic:
I'm seriously torn on this subject. Will need to think about it some more, but I definitely do see the logic in it.

Sway Bars:
Thanks for the suggestions, and going into detail regarding the measurements. The "norm" is definitely different on Subarus so I would've never guessed a balanced setup would consist in such thin rear bars. I'll look into the brands you guys suggested.
I could've sworn the rear one was 19mm, but I could be wrong. Will measure them again over the weekend (when I have access to measuring tools).

Curly and Carbon:
So do you guys disagree with Braineack then, regarding the suitability (or lack thereof) of the size of the sr20 t25 turbine housing? It definitely looks laggy on that dyno sheet he posted. Peak power output doesn't seem to be his complaint. It's spool, which you've claimed is good.

If you aren't worried about classing, I think the Frame Rails are worth it just from being able to slide the jack under the car and lift it.

It also helps protect them if you make a mistake like this:

https://www.miataturbo.net/attachmen...ine=1394024993

Dumped it off around 55 or so? Just kept my foot in it and drove it back on track.

This is all that happened and when I later removed them the frame was barely touched.

https://www.miataturbo.net/attachmen...ine=1394024993

I know it's an easy place to save some of the budget but I'd hate to see you pick up an eBay intercooler. :facepalm:

Let me know when you get to that point. Our smaller unit is a direct bolt-on. You'll likely eat up the money you saved on an intercooler trying to get an eBay unit mounted.

(Same installation procedure on the NA)
https://www.miataturbo.net/attachmen...ine=1394030244

Basically, if you keep your HP target at around 200HP and use good engine management, you should have a reliable car. You are far from breaking stuff at that level.

On the undertray, make sure the radiator is sealed to the mouth. There should not be a gap on the side of the radiator to let air around it. That is the challenge with fabricating an undertray from a flat piece.

As for the picture of the scraped up frame rail, +1000. That's exactly why I have them. You should see some of the curbing at MSR-C.

If you add door bars along with a roll bar, sell the butterfly IMHO.

I would recommend safety wire on the turbo fasteners when you complete the install. The nuts would back themselves off from the sustained high RPMs leading to a massive exhaust leak.

I'd recommend TSE stud kit for the turbo fasteners. Nothing to do with sustained high RPM, everything to do with temperature.

There's a nice picture in my Silver build thread of what happens when you use steel connectors and try to keep it together with safety wire. It will stay together at least, but it won't be sealed. Get the TSE stud kit and it's set and forget.