Jump to content
SAU Community

Recommended Posts

Hi guys,

I have the dreaded mis firing problem with my GTR. I will be looking at replacing my coil packs and will be replacing my spark plugs at the same time for good measure.

I have done the searches and read the spark plug thread but I'm still confused as to what to run??? I'm hoping a GTR owner could point me in the right direction ie part number or plug :down:

At the moment the car has HKS2530 turbos and running about 1.2Bar of boost. Based on what i have read, I want to run the NGK copper spark plugs as I dont mind changing out my plugs every 10,000kms (weekend car).

Any help would be greatly appreciated.

Thanks.

just get the NGK coppers .. heat range 7 if up to 270rwkw or heatrange 8 if higher, I think.

BCPR7ES or BCPR7ES-11 (I think)

I'd get the latter which is pregapped to 1.1mm and get mechanic to reduce gap if you get a misfire at that gap size, but you should be fine with 1.1mm gap if you're changing coilpacks (plus more power/better fuel economy over lower gapped plugs)

Everyone will tell a different story/experience on the gap sizes and most ppl will recommend .8mm (ie. "BCPR7ES") plugs with more boost ... but some people run plenty of boost with even a 1.1mm gap and no misfire at all. Bigger gaps gives you a better spark, more power etc

Edited by Delta Force

thanks Delta Force. Pulled out the plugs from my car and they were the NGK copper V power ones. So I replaced them with the same ones heat range 7 gapped to 0.8. Also did the quick fix on the coilpacks (tapped them up + silicon). Unfortunately the missfire is still there. Under WOT the car will feel like its hitting limiter at 5k rpm and only hitting 0.6 Bar of boost.

Perhaps its time for some splitfires or does anyone know what could be wrong here?

Cheers

I had a similar problem with mine, im running 1.6bar.

Dropping the plug gap down to .7 made a big difference.

Problem was solved with a new ignition pack (on the rear top of the engine).

Will rev out now without a hint of a miss.

Hope this helps you.

Edited by GTRPSI
I had a similar problem with mine, im running 1.6bar.

Dropping the plug gap down to .7 made a big difference.

Problem was solved with a new ignition pack (on the rear top of the engine).

Will rev out now without a hint of a miss.

Hope this helps you.

thanks man. Yeap looking to get some splitfires, hopefully that solves the problem. I guess the coilpacks are about 10yo now so would be worth replacing. What heat range are you running? We gapped them down to 0.8 as recommended by most people on here and the guys on the UK GTR forum.

I had a similar problem with mine, im running 1.6bar.

Dropping the plug gap down to .7 made a big difference.

Problem was solved with a new ignition pack (on the rear top of the engine).

Will rev out now without a hint of a miss.

Hope this helps you.

did you try going back up to standard gap (1.1mm) after getting a new ignitor? From my understanding, lower gap is a cheap hack only needed with old/factory coilpacks.. If I were to get new splitfires/ignitor first thing I'd try would be standard gap.

did you try going back up to standard gap (1.1mm) after getting a new ignitor? From my understanding, lower gap is a cheap hack only needed with old/factory coilpacks.. If I were to get new splitfires/ignitor first thing I'd try would be standard gap.

In saying that though, it wouldnt hurt to run new coil packs with a smaller gap?? I know larger gap = more spark = more power but as you increase boost I was reading in another thread its actually better to have a smaller gap? I'm still learning all this stuff, quite confusing as there is so much info and sometimes its contradicting haha

ive heard that too. but i cant understand why a smaller gap is required for higher boost if you can run the bigger gap at desired boost with no missfire issues.

Edited by Munkyb0y

kudos motorsports I think has them .. also most tuners/mechanics do too.

In regards to the smaller gap with higher boost .. I think the higher boost can 'blow out' the spark if its high enough, but I don't believe 1.2bar/18psi would do that, I could be wrong. I'm running 12psi on factory coilpacks and 1mm gap with no missfire.

obviously if your spark is being blown out, ie. your coils arent up to the job, then you would gap down as most ppl do on stock (old) coils.

but if there's no issue with spark blowing out at 1.1mm, THEN what is the purpose of running a smaller gap?

the reason i find this perplexing, is that its been recommended by knowledgeable people.

kudos motorsports I think has them .. also most tuners/mechanics do too.

In regards to the smaller gap with higher boost .. I think the higher boost can 'blow out' the spark if its high enough, but I don't believe 1.2bar/18psi would do that, I could be wrong. I'm running 12psi on factory coilpacks and 1mm gap with no missfire.

Thanks very much for that. I went with the smaller gap plug since the car is tuned to 1.45 bar.

My coil packs are stockies, i gaped down and the misfire improved but didn't totally disappear.

Checked the coil packs for a lightning show at night and they looked fine, no arcing.

It totally went away after i changed the ignitor module on the rear cover, no i didn't go back to open the gaps again as she was purring like a kitten to well over the redline. :)

Next weekend ill pull a plug out, 1 heat range colder from what i remember last i had them out.

Edit, shes been fine for the last 2 years like this but just develop a misfire at 1500-3000 rpm 2 weeks ago. It corresponded with the idle speed going up to 1400 rpm.

Solution...replacing the throttle body and intake gaskets right now, they were blown.

Edited by GTRPSI

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My take on gg2 48mm, 54mm, 58mm, and 62mm compressor map for same size compressor vs gg1 : All gg2 only outflow gg1 above 20 psi. As all g gen 2 surge line at lower left of comp map move to the right, all gg2 sacrifice spool vs same size gg1, surge line move to the right worst for 54mm gg2. So for same size compressor if you want best response, use gg1, if you want max hp at >20psi use gg2 but you will be laggier vs same size gg1. Max compressor efficiency drops to max 75% on all gg2 vs max 76%-80% of same size gg1. Iirc lower efficiency means hotter iat less dense air so lower hp at same operating point of comp map. Also curious why gg2 is mapped to lower max rpm vs same size gg1 (only 48mm size both gg1 gg2 mapped to same rpm) : 54mm gg1 165,000 rpm  vs  gg2 160,000 rpm. 58mm gg1 150,000 rpm vs gg2 140,000rpm. 62mm gg1 145,000 rpm vs gg2 140,000 rpm. If gg2 can safely spin to gg1 rpm then they can flow a bit more than as mapped. Good thing that all gg 2 interchange compressor and turbine housings with same size gg 1. So gg1 owners can buy gg2 chra only if planning to boost >20psi.
    • My stuff is all with Shannon's, granted, I don't really have imports I'm driving on the road, however, I've had multiple cars at the same time with them. Presently we have the Landcruiser on laid up cover, Sarah's Kluger on full cover, and the house insured. About 18 months ago Sarah wrote her Subaru Liberty GTB off, insured with Shannon's, and the payout, and buy back of the wreck was super quick. In 2020 we had the VF Commodore totalled in a major hailstorm. Storm was on the Saturday, I called on the Sunday and lodged it, vehicle was towed on Tuesday night, assessment team called on Wednesday to say it was a total loss and get payout details, money was in the bank on Thursday morning. Have had a few other claims both at fault, and not at fault, over the years, and never had an issue with them.   Funnily enough, they're also the cheapest insurer I find for things like Sarah's Kluger.   I will say I'm less impressed dealing with them lately around "the experience", as a lot of their staff that you deal with aren't car enthusiasts. Shannon's has a much more main stream feel ever since they decided to become "big corporate", laid a heap of staff off, and then hired a bunch of non enthusiasts. At the same time they've been making a push to be less "call us and we'll personally have someone who cares help" to "hey, this computer can do stuff for you" and are trying to get more square pegs to fit round holes. (That's just the vibe I get from them). Again, have had no issues with claims with them, but get a bit of a "less personal" feel from them.
    • A thing I wasn’t happy with with enthusiast was during the initial phone call they told me they’d insure it for 130k but needed photos.   I then sent them photos and they told me $80k as there were other cars either similar modifications available for around that price, I told them to send me the links to said cars so that I can buy them. i then sent the modification list with prices of the parts (no labor) and the price then came to 115k, which is still shy of the 130 that was agreed in the initial phone call 
    • Ask me a bit later this week before payday
    • I agree that delayed payment probably isn't the most suitable solution. It seems a solid complete transaction would be best. As I wouldn't be using this sale as a line of credit that would typically earn interest, we can probably arrange a much cleaner single transaction deal. I can do $92.52 today. Would you prefer EFT, or Cash on Pickup?  😛
×
×
  • Create New...