Horton what Turbo are you running? It seems like your exhaust is ok. Do you have a way to measure Turbine Inlet Pressure (ie TIP)? This will confirm or eliminate the turbo as a source of the problem. I suspect your TIP is going to be sky high. It should be less than 13-18 psi at that boost pressure. I bet yours is 25+

A 2554 I think.

And no I don't have a way of measuring that

What size exhaust are you using?

I'll write a technical reply when I find 5 minutes - for those who haven't read my intial reply above please do.

The exhaust is without doubt part of the restriction at the top end.

Connor please stop saying what boost it makes peak - some of these people genuinely think it's making 13PSi @ peak power still.

Might be worth you plumbing your boost gauge up to a pre-intercooler port connor, try and see what kind of pressure drop you've got through the IC.

are you sourcing boost pre-intercooler?

the dyno plot suggests it's peaking boost at 4K and then dropping off significantly at redline.

I mean... is it dropping to like... 1-2psi at redline?

it's making 140-150rwhp at 7K. a stock 1.6L on that dyno would be making like 70-80.

Yeah but how many torque curves have you seen look like that? I can think of some diesel ones, or some subaru's :giggle:
I mean even stock exhaust cars still don't drop that hard.
And his tune looks ok. I didn't see anything wrong with it.
I dunno.

Boost for dyno & ECU are inlet manifold sourced.

Which is why I suggested to Connor to source his boost gauge from the pre-intercooler source and see what it reads - if his intercooler is shit then the turbo could still be making over 1bar and be running out of efficiency. I didn't pursue this on the dyno because his IAT's didn't look bad at all.

Dan

a lot.

He's asking where the boost control reference point is.

on a miata?
interdasting. maybe it looks more drastic because the curves are separated.

Either the turbo inlet is a garden hose (WRC anybody?).
Or the cam timing is off.

With everything that has happened in this thread, just saying "the cam timing is not off" does not satisfy me.

Pretty sure Dann posted a dyno plot just like that...motor blew up in a similar fashion :)

cars with restrictions don't make that much torque in the first place.

im assuming the boost plot looks exactly like the torque plot.

Correct

so you disagree with me that the plot looks problematic, then point out that the last one like that blew up?


Make up your mind Scott :giggle:

Sorry mate it's all a bit over my head. But yes as dan says it doesn't hold at 13psi.

Even if the car should make more power or the torque curve is weird or whatever I'm not fussed. The car drives great and I just want it to last more than 4 days.

As long as it's safe I'm happy

Well, what happens when someone starts to choke you? I mean, they haven't fully closed off your trachea, so you should be fine.

I don't think he understands the meaning of the word "safe".

I think he understands "safe" to mean "low power, and hasn't blown up yet"

if it's just a boost controll issue it's fine. if not, it's not.