So I finally dyno tuned the car. Too lazy to scan sheets right now or anything but here goes.....

1990 Miata
15G turbo @ 13psi
2.5 turbo back to an OBX muffler
550cc Injectors
Megasquirt PNP
91 Octane
Boost was controlled by a MBC

209whp and 196wtq On a dynapack dyno

I did a compression test on the motor and these were the numbers i got starting from the cylinder nearest to the radiator
150-155-155-170

Does that seem normal guys? Only thing Im complaining about is I was getting full boost by 4500 RPM. That is RIDICULOUSLY LATE for a small turbo. I need to get rid of that muffler and get more runs and take the boost up a notch

 

bigger downpipe!

good luck brother!

 

I originally wanted to get a 3" turboback but everyone clowned me and said that its too big for a turbo thats too small but i still think its that stupid muffler thats robbing power.

 

post the graph

 

I got 220's compression numbers warm on my 150xxx mileage (turboed for 60xxx miles) 1.6. Never checked the 1.8.

 

i think yer engine is wore out

 

run it till it dies. Thats what I am doing

 

so you guys think my engines about to take a dump? lol I dont mind because i have a 1.8 motor sitting in my garage.

 

btw my mileage is at 125k

 

compression numbers are low... I get roughly 180 across all cylinders and I seem to recall the 1.6s ran slightly higher (190-200).

Do a leak down test... may just need your valves/seats cleaned up.

 

if i were to guess, i'd say that #4 has bad rings.

 

Do you say that because since it has bad rings, it let oil through, and thats why it reads a littler higher?

 

something along those lines.

 

Personally all i cared that the numbers were around the same, and they werent spectacularly low. But thats just my rule of thumb.

 

hmm im considering selling my 1.8 motor and buying a used 1.6 motor with low miles to drive aroudn with at 14-15 psi because Im really happy with the cars speed right now. 1.8 motor i will end up spending too much money on the car and bigger turbo and what not....my dream is still to own a z06! lol