DYI - S4 Starter Kit with GT2554R
 

Hi Guys,
Long time lurker, first time poster. You may recognize my van.

I have been considering putting together a DYI kit for my 94R package. I've owned two Ubercharged miata's and my current car is NA and has been for the last 10years I've owned it.

I really want instant response and predictable power. My goal is 200 to 220whp and a very reliable setup.

The car will be driven on the street mostly and I am looking for a quiet setup that I can kick sideways at low rpms and focuses on 'fun'.
I don't drive particularly fast anymore and big power and speed are not what I am after.
I do occasionally track the car and want something that isn't going to overheat and let me down.

I've considered the off the shelf setups but I am leaning towards a DYI setup that is less compromised, less expensive and lets face it more unique.

I'm strongly leaning towards the BEGI S4 Starter kit paired with the smaller GT2554R.
BEGI 1.8L S4 Starter Turbo Kit 94-97

I like the flow of the manifold and sound it produces in comparison to a log.

The rest of the setup is where I would like some help.

Here is what I have so far.
JDM BP FWD 1.8 with Exhaust Cam Swap (has larger FWD coolant port - blocked off currently)
MSPNP MM9495 - gen 1 I think. (no longer installed)
Innovative LC-1 (no longer installed)
RX-7 550cc Injectors (never installed)
Full 2.25 NA exhaust - JR/RB and Spun Cat
RB Intake (reuse filter)
Devils Own Water Injection (never installed)
MAP sensor (never installed)
Koyo Rad
RB Flywheel

What I think I need...
BEGI S4 Starter Kit
Oil/Water SS Lines
DYI Intercooler (maybe CXRacing?)
BOV
Boost gauge
ECB for MSPNP
Full exhaust (eventually)
Upgraded Studs and Locking hardware

Anything glaring that I am missing? Any recommendations for this setup?

Thanks
Andre'

If you like the flow of the S4 mani, get a turbo that can actually flow. I don't see the point of using it with the GT2554 when the cast log is stronger. The log won't be a restriction at GT2554 power levels.

No Steve, no!

ALLOFIT 2554 GO GO GO GO GO!!!

Ben's right, the way to go is GT2554 with a ported '99 head on a built bottom end. Then leave in the 8lbs wastegate spring and tighten the arm until you get 12psi. Winning.

Full boost at 2500rpms at 50% throttle! Much win! So easy to drive!

Ok but seriously OP, you're on the right track. Just get the log instead.

So the manifold is too good for the little turbo? I find that hard to believe. Seems as though the best situation would always be to have the best flow going in regardless of whether it needs it or not.

Eventually the car will get a 99' head if that is a factor.

Seems as though I have seen other setups with the AVO style manifold in the 'I want your spool data' thread that have benefited from an improved manifold.

Does EBC offer any ability to control the progression of the boost so that it can be made to be more linear? TPS based boost control would be ideal IMO, but I don't know if the MSPNP supports that.

Thanks for the inputs.

No, the manifold isn't too good for the little turbo, there's no such thing. We're just saying that the log manifold on that turbo won't take away any power worth talking about, and will be more reliable.

It just won't look as cool.

MS3 should be able to do TPS based boost control.

But i think what we're saying is that there's no point to actively try to improve spool on a 2554. No matter how terrible your setup is, it's going to be instant.


When Steve made the little joke about how to do a 2554 setup, he was referring to my car. I can assure you that there would be no usable improvement from swapping to the S4 manifold over the log that's there now.

You can flow all the exhaust gas through the turbine that you want, but the tiny little compressor wheel will only flow so much. Put that GT2554 on an octupus-long-tube manifold and strap it to an LS1 and it will still only flow so much air through the compressor.

Now if you wanted a GT2560 or larger there would probably be some significant gains to be had on the S4 vs the cast log. But as even Corky Bell will tell you, the 2554 is too small for a 1.8 (or maybe it's Keith from FM who says that, I don't remember).

Thanks for the replies on those items.

Any other comments on or thoughts on the rest of the setup?

Nah the rest looks pretty good, sell your WI system and your NA exhaust to fund a full 3" exhaust.

calm down.

a well built 2554 setup is still very predictable and easy to drive.

Does anyone know if the MS3 can do TPS based boost control?

It's not awful, i'm just laughing at how quickly it hits full boost at small amounts of throttle.

this should be indicative of every good turbo setup.

Savington's 2554 Bell kit vs. his 2871 AF setup:

https://www.miataturbo.net/attachmen...ine=1398182026

Nice plot and I get what you are saying there. Doesn't really address the goals of the setup I am after.

IE - less power, less expensive, more predictable power curve.

Keep in mind I am coming from an ubercharged world where power was pretty much instant and extremely linear. I'd like to mimic that but with the efficiency of a turbo.

Yes: it's DIY, not DYI :giggle:

There's one thing you won't really achieve: linearity. Turbos give you a big swell of torque that, especially with a smaller turbo, comes on very suddenly. You can learn to control it and many find it very fun, but it isn't particularly linear. You can make a full throttle pull linear, but the feeling of off throttle to throttle on is going to be dramatically different than on a supercharged setup.

That's exactly what I was hoping to avoid by using TPS based boost control or some kind of rpm or load based EBC.