The car isn't tuned very well, but it runs, and the local Diesel Tuning Shop was having an open dyno day so I thought I'd run and see what I was making.

Setup:
1.8L '94
TD05 14b turbo from a 1g DSM
Starion FMIC (Core dimensions are 16.5 X 8 X 3)
Standalone Megasquirt with EBC and 460cc Injectors

I am still working on the EBC, but I'm trying to run 12psi. It goes to 12.5 nicely but then falls to about 9.5 for steady pulls. If I increase the duty cycles though, it overboosts pretty badly when I step on it above about 3500rpm.

Anyway; since it was a busy dyno day, I don't have an electronic file of the run. Useless, I know, but please accept my apologies and this picture of the printout.

And the MLV graph of the run


Horsepower: 183
Torque: 196

I'm pretty pleased, considering I'm still using the MSPnP spark map, and my boost was down to 9.5psi for most of the run. I figure with a little more VE tuning (mostly for shifting and in-town driving) and some serious spark tuning, I will have a pretty respectable Miata.

 

Get it to hold boost to redline, and you will be well over 200whp.

Looks good, keep working on it.

 

Anybody got suggestions on how to make it hold boost? At the current settings (which I can't seem to make load on this desktop) I get good spool up to my target boost, but then it backs off. If I increase the duty cycle after it's spooled I hit overboost repeatedly.

 

Ok, I got the duty cycle table.



That's what I've got now. It's surprisingly steady up higher in the rev range, but it's lower than I want.

 

what gear did you make that duty table in?

 

4th. I followed the instructions exactly and this is what I end up with. I can hit my 12psi at any RPM by stepping on the throttle at that RPM, so I can't increase the duty cycle or it will overboost under that condition, but the way it is set now, I don't get as much boost as I want because it just spikes then settles at 9-10psi.

 

What RPM does the boost start falling at?

 

Looks like about 5000. But that seems high. It's also very uneven at 12psi, then it settles low and is pretty steady. The datalog posted above is pretty typical even though it was on a dyno instead of the ground.

 

That's kind of strange. So you can hit the throttle at 5k and it'll reach your target boost but if you start going WOT from 2k it'll start falling off at 5k? It'll overboost even if you raise the 5k column by a point? Maybe you're BOV is leaking boost? Wierd.

 

Yeah, pretty much. I'll try raising only the upper columns. I hadn't tried that yet. I was raising all of the ones that are currently set at 48. We'll see what happens if I go up with just the 5k and 7k columns. I bet I will still overboost if I hit the throttle though.

 

I have to drop the upper columns.

 

Yeah yeah, rub it in. We are all jealous of your superior turbo setup.
So long as mine spools quickly and stays spooled without overboosting, I'm happy with my 2.5" exhaust.