Forced Induction Turbo Installed, Black Plugs And Fuel Smell...

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
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a van down by the river
Hey guys, finally got my car done and ready to go. Or so I thought. Took it out for a spin yesterday and all seemed well, a little rich on the idle afr's at 13.5, and part throttle cruise at low 14.xx's. WOT afr's were right at 11.5. I noticed at the upper rpm's it started it sound like it was breaking up. Got back home and pulled some plugs and they were all black with soot and smelled of fuel. Could the bit of richness be causing this? Tune is done with a Quarterhorse by Willie at Dirty Dirty Racing. I've been dealing with him for a few months while getting everything straightned out and he's done a good job so far. I just upgraded to an hpx slot maf and this is the first tune with that maf. Think its just the maf curve needing adjusted a bit yet?

Combo is 333 ci, h/c/i,on3 kit with 70mm turbo, 60# injectors, hpx slot maf, ngk5671-8 plugs gapped at .028, msd box etc. motor only has about 1500 mils or so on a build by a reputable shop
 
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This is your first tune with the turbo? If so I would talk to the tuner. Never had my first tune run perfect especially since its a long distance tune through data logs. My last car was tuned the same way, but not through dirty dirty.
 
I prefer the -10 NGK's in anything with boost or a lot of spray. We run the -8's in all of the N/A cars. I would keep the gap at .028. I run mine at .024 and that has been fine at well over 30 lbs of boost. The target a/f for mine to idle is 13.7 so I don't think you are far off the mark with that.
Do you run a blow through maf? Does your blow off recirculate or vent to the atmosphere? If it recirculates, before of after the maf?