Spark Plug Gap Poll

**94Cobra** · 09-20-2006, 08:53 AM

I spoke to Matt at Kauffmans yesterday about a tune. He told me to set my Autolite 3924 plug gap to .025. That seems narrow to me since the factory specs are up to .054. Perhaps some of the Windsor NA guys could post their plug gaps. Does anyone know what reason they would ask for a .025 gap? I do run the stock TFI ignition and distributor, but it is a good ignition since the factory calls for .054.

I put on a BBK 75mm Throttle Body last night. We'll see how she runs tonight.

**Viper_ed** · 09-20-2006, 09:15 AM

I've always gapped Plugs between .028 and .035. You will be fine.

**Rodeheaver's** · 09-20-2006, 09:38 AM

i never take my stuff above0.040, remember... tight gap is used for high cylinder pressure/boost/nitrous/jumbo compression

**Killercanary** · 09-20-2006, 10:33 AM

I'm definitely not the norm here I can see, but I run .054 on my car, and that's with a 100% stock ignition except for a set of motorsport wires. I've made dyno pulls to 6300 at Kauffman's without a single hickup.

My dad however had to tighten his to .040 in his NA '91GT. He has a screamin' deamon coil, MSD 6AL, dyna mod, and motorsport wires. We had his gap at .050 and the car would sound like it hit a rev limiter at ~5900 before we had all of these ignition parts. They did nothing to help, then Ed Curtis told us to try a tighter gap on the plugs and BAM it'd pull to 7000rpms. I never thought it'd be that dramatic but it made a huge difference in his car. It'd have been nice if we would have tried that before he went and spent all that money on ignition parts, but they're not hurting anything either.

**yeahloh95** · 09-20-2006, 10:43 AM

mines at 32 and will be tighter the next time i put plugs in

**coralcoupe1993** · 09-20-2006, 05:34 PM

Awesome topic! My Notch is at .054 (stock block trick flow heads up and cam, stock TFI). My 64 Galaxie (390/417 tripower Edlebrock headed, stock but pointless ignition) is now at .032. I was running the 64 at .045 but it was back firing and running like crap. It was very strong in the upper RPMs but not running right. When I shrunk the gap, she runs very well!

**Sonic03snake** · 09-20-2006, 05:38 PM

I have a way different application but mine are set @ .028.

**Cam99** · 09-20-2006, 06:07 PM

.028 for me also

**mikeymustang** · 09-20-2006, 07:06 PM

i run .025-.027

Mike

**venom** · 09-20-2006, 08:11 PM

.025 here as per kauffmans directions

**burntire** · 09-20-2006, 10:12 PM

.32 Here no blow out

**u1arunit** · 09-20-2006, 10:48 PM

.034" here, no blow out.

**Twin01cobra** · 09-20-2006, 11:00 PM

.032 here no blowout

**Chris00GT** · 09-20-2006, 11:55 PM

One thing you have to take in consideration is the 99+ Mustangs with COP have the best ignition on a Mustang to date. You can make 600rwhp on the stock ignition. Now when you go to pre-99's the stock ignitions don't support as much power before dealing with blowout. Usually it's nice to have an ignition like a MSD DIS-4 on the 96-98 and a 6AL on the fox'es in the 400rwhp depending on combo's.