I may have missed what type of wastegate you are using, but if the diaphragm inside the can was compromised, it might not be able to hold boost. But you probably have a log to show that it is, so if I think of anything else I'll comment again.

Have you posted up the pics of your downpipe in this thread or only the other one? The downpipe could easily be the limiting factor,
With the wastegate fully open I can imagine the flow right behind the turbine to be pretty turbulent and crappy. Build that new 3 inch exhaust and I bet your power will show up.

Just a quick comment. Notice that your car is making more power sooner compared to the other car with the similar setup. Are you sure your turbos are EXACTLY the same? Same turbine housing? If you had a smaller turbine housing than the comparison car, with everything else exactly the same, this is what you would see. The smaller A/R spools a bit sooner, but the larger makes more power at the top end. For example the GT2560R can be ordered with either a .48 or a .64 A/R turbine housing from ATP.

Also +1 on where you are picking up your wastegate signal line. You should move it to post-intercooler if you have not already done so.

There's obviously a fucking difference between the cars since they don't make the same amount of power. You're not giving us all the important details OP so this thread is 1 star.

I mentioned from the begining of the thread that there are some differences between these 2 cars and I shall list it out again:
- different design turbo outlet pipes (me: seems like it is more restrictive)
- different exhaust manifold (me: Flyin Miata, him: ebay tubular)
- i am running AEM water injection with starting psi at 4psi and ending at 14psi with the smallest nozzle that came with the kit
- I am running COPS but he is not
- wastegate signal is post intercooler from the intake manifold
We are both running the same turbo, both bought new from the same bendor, Nissan Silvia S15 turbo part number 14411-91F00, same exhause(-turbo outlet), same injectors, same intercooler. Both ran on the dyno on the same gear and same dyno settings.

Perhaps, the differences in bhp is because of the difference listed above?

Here's the ignition map, we are running 98 octane petrol here.
https://www.miataturbo.net/attachmen...ine=1316504225

Any real reason why your is map is retared so much above 61kPa?

You are referring to above 61kpa and below 2500rpm or are you referring to across?

If former, it is something i have not cleaned up because the full load dyno rum map does hit that portion of the map.

that timing map sucks.

I run more timing in my 300kpa row than you do in your 200kpa row.

Looks like little timing but timing is relative. I am 10* degrees up in the upper boost levels. Anyway, I think you may be overlooking the effect of a restrictive exhaust. You make more torque sooner and less later.

I think that is true with a non-FI car but not so sure it is true with a turbo car?

I started off with a GT2560 on a stock 1999 engine. When I ditched my factory exhaust and moved up to something larger and more free-flowing, the turbo spooled much sooner and made more power everywhere, including at low RPM. The improvement was dramatic.

Wow, you are running 300kpa?

a restrictive exhaust would spool slower and top end would suffer.\


case and point

https://www.miataturbo.net/attachmen...ine=1316542542

What numbers are you running in your 300kpa row? Trying to gauge when compared to my map.

I run ALL OF IT.

Here ya go. OP's timing map with part of mine. Yes, my timing is pretty darn conservative up there because I only dyno tuned for 24psi. With WI though, I am running 3-5* more timing everywhere except for 4500-5500RPM.

https://www.miataturbo.net/attachmen...ine=1316550129

Makes sense. I'd say you are running 5-7 more dgrees than me at 300kpa

That is the wrong location. Never take the wastegate signal from the intake manifold. Take it somewhere after the intercooler but before the throttle body. You will make much more heat in your inlet air taking the signal from that location. You will also keep the wastegate closed much more often which could restrict flow at higher rpms.

What diameter exhaust are you using? Are you using a cat? What muffler are you using?

If you take it after the IC but before the throttle body your spool will suck dicks because your signal line is so fucking long. This matters when your turbo is larger than a tennis ball

(Posting from my phone.)

:facepalm:

UHM, What? It has been proven here many a time that signal line length doesn't make a lick of difference. Diameter, however, that's a different story. Come on fiance Fae, figure it out.