Spark Plug Gapping Help

[cobra96]

the stock gap setting for a 96 cobra is .054...i was wondering how far i could gap it without it causing problems and givin me more power

[99MustangGTman]

what kind of plugs are you using. For a tr6 set it to .035

[Herbstang]

0.050 - 0.055 ----------0.054 seems to be the most popular from what I'm reading, if the gap is to big the spark wont be strong enough to jump the gap

[PureVenom]

Quote: Originally Posted by 99MustangGTman what kind of plugs are you using. For a tr6 set it to .035

Holy moly man....that's ported/twin screw 03/04 cobra range. If he is N/A, that gap is going to cost him power.

By rule, you should run the most gap you can without getting spark blow out. This allows for a bigger spark to completely ignite the fuel mixture. Narrowing the gap is only done to alleviate spark blow out. If you don't have that problem, don't touch your gaps.

[99MustangGTman]

i ran TR6s when i was N/A at .035 and it ran strong still

[PureVenom]

Quote: Originally Posted by 99MustangGTman i ran TR6s when i was N/A at .035 and it ran strong still

It may still run strong, but that is way too narrow for a N/A car. Shrinking the gap does not generate power unless you have spark blow out.

[99MustangGTman]

Hmm interesting, I didnt know that. Good info

[Thomas91169]

Quote: Originally Posted by PureVenom It may still run strong, but that is way too narrow for a N/A car. Shrinking the gap does not generate power unless you have spark blow out.

+1

run the largest gap possible until you start to get blowout. For FI applications, we have to run a smaller gap due to boost and high cylinder pressures causing blowouts and misfiring at higher rpm. Too small a gap may also cause misfiring due to the spark not being enough to ignite the mixture.

for my 03 cobra i run .032 but i could probably open them up a bit. IIRC my 02 GT was .054. I have my 90 GSX gapped at .032 as well.

[cobra96]

Quote: Originally Posted by 99MustangGTman what kind of plugs are you using. For a tr6 set it to .035

im using the autolite double platinum...i gapped them to .55 and it runs good...still have a rough idle at times though...anybody got an idea what could be causing it

[PureVenom]

Quote: Originally Posted by cobra96 im using the autolite double platinum...i gapped them to .55 and it runs good...still have a rough idle at times though...anybody got an idea what could be causing it

Gap could be slightly too wide...try dropping it to 53 or 54 and see what happens. If that doesn't help, then it could be something else.

[Thomas91169]

a 96 is still COP (Coil on Plug) correct?

if so, make sure they are seated right, and might want to put a little dielectric grease on the coil boot or a the end of the plug (not the electrode end either!)

if its not COP, check the wires and/or replace.

might be other things as well. check/replace all filters (Air, Oil, Fuel), maybe clean the Maf with some non-residue forming electrical plug cleaner. shit like that.

[Scut95]

Quote: a 96 is still COP (Coil on Plug) correct?

96 isn't coil on plug....there's 2 coil packs and then the 8 plug wires