Built 1.8L NA8 with FMII & GT2560
 

This is a customer car, not mine. Car and engine is a ’95 NA8.
Bottom end rebuilt by the owner. Head P&P by a local shop.
Manley Rods
JE pistons in stock size, 9.0:1CR. Cylinder bores honed.
SuperMiata damper
Supertech OE size valves
Supertech springs, titanium retainers
Combustion chambers and area behind the valves cleaned and smoothed

Turbo kit:
FMII, GT2560, 2.5" downpipe
Boost pressure set to 16psi with Hallman Pro RX
Hydra 2.7 ECU
Exhaust, FM 2.5", no cat

I’m really surprised by the power. I was thinking it would make about 280hp with the NA8 head and 2.5” exhaust. When the first run made 282hp and 267ft-lbs I knew we were in for a good day. I never thought I could get more than 300hp out of a GT2560. The dip in power at 4500RPM is due to a dip in boost pressure. Boost peaks at 16psi at 4000RPM, dips to about 14psi at 4500RPM, then recovers to 16psi to redline. Typical MBC stuff on an internally gated turbo making a lot of boost.

93 Octane? That seems a lot for 93. What's the timing at full boost?

is this gauge pressure or absolute pressure on the hydra? Ive noticed that the absolute pressure on my hydra is usually about 1.5-2 psi greater than the physical gauge in my car

Stefanst: I do not recall the exact numbers in my head. I'll let you know tonight when i get home. I'm thinking in the 18 to 19 degree range from 4500 to 5500RPM then increasing to redline.

Lownslow616: I'm quoting the pressure logged by the ECU. I have no idea what the boost gauge in the car registered.

I log mine right off the ecu like you do. I made 261whp on 12-13psi and between 11-18 degrees timing from 4500-7200rpm. Its nice to know I should be able to hit 300 with a little more boost and some actual timing.

Also, do you know anything about the customers bottom end? :giggle: was it checked for out of round and taper? P/w clearance? or just honed and 83mm JEs thrown in?

Since all my customers so far have been men I try not to pay any attention to their bottom ends :^) Bottom end is a basic rebuild, new bearings, APR main and head studs, a hone on the cylinders with a drill-mounted tool and then reassembly with the forged parts. He did it all himself with guidance from a friend. As I said above, I was shocked with the power level. I think the lack of a cat and the head work is what made the difference.

My memory was pretty good. Ignition advance is raises from 18deg to 20 at redline at 16psi.