Well, haven't posted on the board in awhile, but with the Miata coming out I've got the itch back. My question is simple. I've got the stock greddy dp, but I have a 2.5" custom midpipe, JR CAT, and a Borla exhaust. I'm wondering if I could up my boost from 10psi (9-10 actually) to 12psi. I tried to last year, and my boost was bouncing alot causing a stuttering accelerate feel so I turned it back down. Maybe a helper spring would help? I have the 4.3 LSD now and I replaced my tired stock miata fuel pump with a GSS250 walbro since. The rest of my setup can be found in my sig.

 

I would FOR SURE replace the downpipe. I just saw a Turbotony downpipe in person saturday, MAN what a difference. It makes the Greddy one look like what it is...a piece. I think I read phillip had 12psi with the stock downpipe, so I suppose it's possible with the Greddy. With a big downpipe it would be alot easier I'm sure.

And you most likely need a helper spring, I know nothing about it besides when I read posts with 8+ psi, they usually have one. If I remember correctly the wastegate can is just weak above 6psi.

Good luck, I'm hunting 10 psi this year but will most likely settle with 8.

 

I have had it up to 15 with a mbc, only the boost drops back to 12...still save...
Greddy downpipe, 2 inch from there...

I think the greater boost is blowing out your candles...
Try gapping your sparkplugs (factory is 0.043", now gap it to 0.028"-0.030")
PS do not regap irridiums... they brake...

 

I think I'm gapped around .032 with colder plugs....I'll give that a try though. I think it had more to do with my stock fuel pump because I was seeing lean patches past 10psi on the wideband.

 

replace the DP and Exhaust and you wont need more boost :gay:

 

I used to turn the boost up for winter?
But the hotter it got the more I would turn it back down. This year I have been running the summer setting, But I did adjust the bipes.

 

I have a thermocouple installed after the intercooler this year, so it will be interesting to see the heat soak temps. I'll compare 10psi to 12.