Noobish Boost issue
 

Alright writing this for the second time due to the computer restarting after window updates:vash: Well I have been tuning and tweaking on this mspnp for about a month now and feel I have gotten the hang of it. I would like to thank a handful of people on this site for that. I feel I finally have gotten to the point where I can get on it a bit more and see what my old girl can do, but there seems to be an issue with boost. When I ease into the throttle boost builds slowly but surely but if I step on it boost builds for a moment then falls on its face. I thought maybe the boost protection cut out but that is set at 200 so that can't be the issue. I have done some searching on here and other sites looking for a possible reason why this happens but still haven't found a answer yet. So I figured I would make a thread and ask for advice from the experts out there to see if they could point me and my car it the right direction for maximum boost. I also am including a current setup on my mspnp as well a most recent data log which looks like I have a recently lose ground somewhere. The reason I say that is the last data log doesn't have any noise in it. For those of you who are looking at this a little help would be great. Thanks Tony

About the setup:
91 miata stock mtr
t28 churbo with 14lbs waste gate
afm delete w gm sensor
intercooled
vtps
diy dual feed rail
460cc injectors
lc-1 wideband

how much boost are you making before the cut? (I cant view log here)

10.5psi when easing into it and maybe 5 when punching prior to the fall out. Can't seem to find the fall out on the data log to give you the exact number.

take a log of it and hit space bar when it happens. a short clean log of just that event.

Will do when i get home tonight. Quick question, under full boost what should the fuel pressure be at?

~50 + whatever boost you're making.

Hmm on the data log at 10.5 psi I get 13 on the fuel press chart.

and 30+/- at normal driving

MSPNP doesnt log fuel pressure.

Never mind just read about the computer doesn't have a input for fuel press so that reading is invalid. Will post log tonight

jynx! lol Thanks anyway will get back to ya later.

Alright this was the best I could do to show the problem but any help with the problem or something you may see that isn't looking correct give me a heads up. I'm still learning. Thanks Tony

If these pics don't work then give me a heads up and I'll find something that does.

failed attempt at better pics:crx:

Better pic. Any help would be greatly appreciated. Thanks Tony

dont see anyhting in that log, you let go of throttle and boost drops off.

hmm. something doesn't feel right but I will have to get a better shot of that. Anything else you might see that doesn't look correct or problematic.

was that first gear?

I'm pretty sure it was 4th. why?

the rpm increase looks rediculous. is your clutch slipping?

Well that could be completely possible since it is the stock clutch. Good thing I have a spare on standby. But shouldn't rpm follow the boost curve?

http://www.boostedmiata.com/gallery2...II_PID_EBC.png

http://www.boostedmiata.com/gallery2...wn_coupler.png

http://www.boostedmiata.com/gallery2...BC_perfect.png

point made?

Is it just too much of a slope or just it doesn't peak above the boost that seems problematic.

ok rest of pics just showed up and now I see. But thet was just a quick stab at the throttle that I logged.

Megalogvowned!

how did your rpms shoot to redline so quickly? was that at idle in nuetral?

in the matter of ~2 seconds you built 10psi and increased the rpms from ~3500RPM to ~6200RPM. I'd only think that could be done in 1st gear. They also drop right back down to ~3500RPM...

you has a slipping clutch.

Point taken! Thanks, looks like I have some work to do.:facepalm:

Oh congrads on your 32K mark, that is crazy!