Time to change the plugs I believe, what do you recommend for gapping on a Turbo? I was thinking NGK Copper but just need to know my gap.

 

OEM Volvo .28 gap

 

+1 OEM & .28 gap.

 

Another +1 for OEM.

 

I dont know what the OEM variant for the 850 is but for turbos I stick with NGK Copper one step colder(7) plugs. Never fail, better conduction, and cooler spark is safer. thanks for the gap info!

 

OEM and if your modified then you may want to think about the gap somewhere in the .026 area to avoid blowout.

 

You'll have no issues with spark blowout on a stock Volvo up to 16psi. Blowout is ricer code for poorly maintained ignition system.
Volvo have been turbocharging engines for well over 60 years, install what they recommend and the engine will go forever.

 

Im boosting 13psi, Put the plugs in today, have them gapped .27, car feels stronger, nicer idle and start, and a tad bit better mpg, nothing to shout about.

 

Oh, okay. Let me run through my check list:

MSD Ignition Coil - New
IPD performance wire set - New
Bosch Cap - New
Bosch rotor - New
OEM Volvos gapped at .028

5800 RPM burnout

Blowout!

I dont smell any rice.

Set the gap to .026 based on some good advice

5800 RPM burnout

No blowout!

Still dont smell any rice.


Speaking from experience.

 

Boxpin, I shouldn't have had a go at you or your car. I wasn't specifically referring to you when I mentioned rice.
However, too many people blame spark and fuel issues on "spark blowout" and don't chase the real issue. It's one of those phrases that puts my rice radar on high.
I still say that a properly maintained ignition system with correct fuelling shouldn't need the gap closed up from stock until very high boost pressures are reached. Certainly on a mild street car, plug gap is not an issue.