scorpiansniper

i just recently added the msd cd ignition box with the blaster coil i pretty sure im still getting a little detonation under higher boost numbers. plan on running 17psi in the end. autolite ar93 are in it now thats the stock heat range they definitively need to be colder so i was wondering what plugs people like and what heat range and gap i should run on them. comments from people who are actually running this set up would be nice thanks

n2oblkz

iTrader: (1)

I may be wrong, but I believe a lot of the forced induction guys use the NGK TR6 plugs. Maybe someone else will chime in.

merim123

iTrader: (11)

you may want to try in the forced induction forum may get more leads/ideas that way.

bigj2717

iTrader: (15)

With 17 lbs of boost I would run BRE7's

scorpiansniper

i decided to try the BR7EF NGK plugs for now. any other comments or opinions would be awsome

scorpiansniper

bumpp

Wicked94Z

iTrader: (26)

you are wrong. instead of giving bad advice, go back to polishing stuff under your hood.

Wicked94Z

iTrader: (26)

AR93 is a pretty cold plug actually (9 ngk heat range!) but it has a projected tip... b9efs would be an equivalent non-projected tip plug, but I'd stick with a b8efs. As for the detonation, what's your compression ratio, a/f ratio, and timing? Fuel?

n2oblkz

iTrader: (1)

LOL!, take a break, you don't have to be a ******* ***** every day of your life???

Fastbird93

iTrader: (10)

These were HIGHLY recommended by my tuner (who did my vette and which see's these also) due to the short reach design and the pre-gap at .028. They've run in my vette for over a year without fouling, ect, and I will be running them on my T/A once I put it into boost and full tune. Right now the T/A is seeing Autolite 104's for break in, ect.

Purple Poncho

iTrader: (1)

I am having plug problems with my blown setup as we speak. I was running NGK plugs with an 8 heat range. They foul way too easy especially at start up. They are done right off the bat then the motor starts to pop and miss.

I'm switching to a heat range 6 which I've run for years and see how that goes.

scorpiansniper

compression ratio 8.5:1. when i got the car the air fuel ratio was off the wide band rich under 9:1 but ive been cutting fuel. spark timing under boost i have in the mid to high 20s fuel unleaded 93 octane and i have meth injection set up for when i get to the higher boost

1toofastlt1

iTrader: (4)

when I did all this reseach I found that the autolite 104 gapped to .035. Im only running 6 psi. im pretty sure you might want a little colder plug and a smaller gap for 17 psi.

scorpiansniper

The car actually runs really good but it shakes under higher boost I did a lot of data runs and you can see the ripple in the injectors and rpm I just misread that the ar93's were a stock heat range and paniced a little

scorpiansniper

More data is needed I geuss it could be the plug gap or how he had the injectors wired up cause something in the car is drawing alot of voltage under load and the injectors are on that circuit

scorpiansniper

new problem im having with plugs any ideas the back is 1-2mm longer causeing the ceramic boots to not fit over one of them

scorpiansniper

the left pic show the boot not fitting over the plug and the right shows a old plug that already has the ceramic boot touching the exhaust. theres a couple thing i can do ive already tried prying on the center section of the turbo to pry the pipe back a little but it wasnt enough i can loosen the driver side front header and see if itll come out a little more or i can order the same plugs (AR93) or get the AR94s and gap them smaller cause the gap was a little over .05 when i took them out or i could just gap the ones that were in it smaller. i could also put a little dent in the exhaust where the boot touches in the right pic i mean it is only 2mm max thats causing the problem

Wicked94Z

iTrader: (26)

at that boost level... any gap over .030 is gonna have problems. i searched for about an hour and couldnt find a shorty plug for what you're trying to do. get a good close up pic (macro mode on your camera) of the old plug and i could tell ya if you're getting detonation. how much timing are you running?

scorpiansniper

I think I'm gonna go with the AR94 plugs gaped at .028 for now I figured I don't run over 12psi often and I got meth injection for when I do so I think it'll run a little smoother and keep em a little cleaner. As for the pics and timing I'll post when the power comes back on I tried from phone but it didn't work

scorpiansniper

heres the spark plugs ignition timing is between 25 at lower rpm and 30 at higher @ 8 psi and we cut it down a little as the boost goes up