Spark Plug Gaps With New Splitfire Coils

[Tommyk]

Now that I have brand new splitfire coils, can i revert back to 1.1mm spark plug gaps or not ?

I've read a bit of stuff on here on the forum, and some people have said that at 1.1mm the spark is a lot better on good coils than it is on 0.8mm gapped plugs. Question is, at 1.3 bar of boost with the amount of fuel i am running, will plugs at 1.1mm run fine or not.

Does anyone know?

I'm tempted to run standard gapped plugs, with maybe a colder heat range? (7 or 8's), before the car gets its final tune on saturday

Many thanks for any help

[R31Nismoid]

well if its missing its obviously not right.

you'll soon tell.

With new coils it might be ok.

Just drop it increment at a time if you have problems. Might take a couple of hours. Just make sure ya havea few beers

[Tommyk]

Thats not a very good answer

I mean the beer part yes, but not about dropping it 0.1mm at a time. Thats a pain in the arse + a lot of dyno time.

Would it provide any real benefit if the spark was good at say 1.0 mm compared to 0.8mm ?

[R31Nismoid]

What you mean not a good answer! Every car is different.

You dont need a dyno to check it, just 2-3 hours and a quick squirt once its warm each time

If its missing under boost sometimes going 1.0 to 0.8 makes all the difference

[Tommyk]

are you endorsing me drink driving ?

I think the biggest issue, is that it would need to be a squirt up the top of 3rd or in 4th gear and that = 180+

Just playin with ya. I know that this would be the easiest way of doing it. But is it worth wasting my time doing this ? As in have you or anyone seen any benefits to increasing gap ?

[ferni]

I don't think you're going to see any performance increase as long as its not missfiring then its good.

Misfiring = bad, if its not missing can't see you getting any better performance.

[Tommyk]

Maybe not better performance, but a stronger spark. If you think about it, the larger the distance between the spark plug gap thingy (whatever you wanna call it), the larger the spark will be. Larger spark = better combustion.

Its just a thought. Im just not sure whether splitfires (which i would assume are simply brand new nissan-ish coils - they wouldnt be any better spec than brand new stock coils - provie me wrong) with stock distributor will provide a big enough spark at a 1.1mm gap to withstand 1.3 bar and 3.8L of fuel/minute

[R31Nismoid]

its been proven splitfires/nissan new are virtually the same.

There was a thread with tech info about 6 months ago.

Its more the fact your using new coils vs your tired ones.

As opposed to who made em, which is better etc

Splitfires are cheaper than new ones from nissan, so thats why people use em, no other reason

[Russco]

Ok I tried a new set of Splitfires & they were "marginally" better than a 12 year old set of RB26 standard coils - I doubt if they would be any better than new oem coils. I could increase my gap from 0.6mm to 0.635mm on platinum plugs (copper plugs could run 0.8mm no problems). As to what gap you can run trial & error worked for me, you will be able to run a larger gap using copper plugs.

[Beer Baron]

tommy, there is no distributor on a GTR mate. it's multi coil.

the bigger the spark gap you can run the better, i would think if your old coils were good then you probably wont get much gain. but if you previously closed down the gaps due to missing then you may be able to open them back up now. i would try .9 or 1.0. but i don't think you'll be able to go much more than that as 1.3 bar is pretty decent boost.

[PHaT MR30]

ive heard Mercury Outboard coils are the go, anyone know?

[Robo's]

Well ive actually tried this method after fitting my Splitfires. I went back to 1.1 gap and it started to missfire, 1.0 still misfirred, and finally .85 mm is where i absolutely get no misfire running around 19psi boost, so i have found my optimum spark gap.