Hi all,

I've already done lots of searching in the last month or so on this very question and have definitely found some valuable input obviously, but none for my specific slew of modifications. I even talked to Keith at Flyin Miata (as I'll be buying the remainder of my parts from them). I trust him and Flyin Miata plenty but am just looking for other view points.

He suggested I go with the GT2560R as i'm not giving up much in way of spool (<500rpms worth), and it'd also be more efficient.
My counter to this however, is that this is primarily a street car that's driven every day to work. It DOES see track time however. I really love the idea of instantaneous spool, but am afraid the trade off in power potential is too great.

As far as power levels, I'm honestly not sure where I want to be, but I know my starting goal is ~210whp. Not sure yet if I'd want more than that.

What and how much (if anything) am I giving up or gaining with either of these turbos, given the below set up? Will my below set up allow the 2560 to spool well enough for me not to notice? Subtle or not.

I'm running a healthy Long nose 1.6 (~125k miles, good compression) with stock internals, and am "planning" to keep it that way. This is my only car so a 1.8 swap and being without the car for a little while is a bit of a challenge. I won't delve further into more reasons though since it's talked about a million times already.

I've already had Abe @ Artech make me a Manifold and 3.0" divorced downpipe. (super beautiful, and Abe was amazing to work with btw) He also provided a stainless water and oil line kit. This manifold will work with either of the above turbo units.

Motor: Stock longnose 1.6
ECU: Megasquirt PNP2 with Innovate MTX-L Wideband
Fuel: 610cc Flow Force injectors (from Trackspeed)
Exhaust: Artech Manifold > Artech 3" Downpipe > Enthuza 3" Cat/Exhaust
Clutch: FM Happy Meal (Stage 1)
Driveline/Diff: 3.9 Torsen / all associated components
Turbo: Gt2554R vs Gt2560R (Provided by Flyin' Miata)
Everything else: the rest of the kit (intercooler piping, intake, odds and ends, turbo itself) will be Flyin' Miata FMII kit.

Not sure if I should list anything else.

Apologies if this seems like a wasteful question. I'm aware the two turbos are very similar, but they are described different enough to warrant a thread I think.


Thanks much for any input.

 

for 210 whp I'd stick with the 2554. but the nice thing about the 2560 is it'll be your friend all the way to 300 whp should you want more later.

 

Would you think in any way that the rest of my set up would be -for lack of better terms- "wasted" on the smaller 2554?

 

Not at all.

 

Sr20 t25 is what you want. Will cost you between $100-200. It's about the size of a 2554. If you get the power bug and want to go to the 2560, you sell the other turbo for what you laid for it. Then buy the 2560.

 

^That's really the right answer.

 

Thank you for the responses!

Interesting way of looking at this when you throw in cost : performance. Only thing that really made me look past it is that I haven't seen very many SR20 T25 builds make 210whp, leading me to believe that the ball bearing 2554 is superior in most ways. Might be a dumb question, but does it mount and have the same dimensions as the 2554 and 2560? (I only ask because I already have the manifold and downpipe in hand)

 

The SR20 T25 will bolt in place of the other turbos. In terms of overall power potential it's about the same as the GT2554R. It's mostly a minor difference in spool.

 

Recommend the T25. My 2002 turbo car was 215whp on virtual Dyno and compared favorably (but not quite as fast to a 235 whp (real Dyno) car with a 2560.

Can't beat the pric and your turbo is worth what you paid for it if you decide to upgrade.

Was very happy with spool even against a FFS supercharger on a 2000.

 

Doing some reading, and it sounds like the minor difference in spool is a fine trade off for the amount of money saved. Like you say the power difference doesn't seem huge either.

The idea to be using the SR20 as a cheap, quality, "stepping stone" turbo is fantastic. Thank you for the suggestion.

 

Even though the spool would be better with the smaller one, I'd still pickup a brand new 2560. Drop it in, forget about it bc reliable & new. Comes online when you're actually mashing the pedal for more power & always have the option to push it more later down the road.

 

My sr20 $50 turbo which I rebuilt for $85 from gpop shop made 240 hp at 11.5psi.

 

I was in the same kind of dilemma as you for my 1.6 with same power goals.

I had access to a freshly rebuilt SR20 T25 or a used GT2560R for 100$ more from a good friend. I decided to with the GT2560R, we will see how it turns out next season.

 

You will have no problem blowing up the 1.6L with a 2554/T25. I would stick with that and enjoy the faster spool.