Huge Shot Gun Bang On Boost!

[TTT]

just to question everyone with the same problem.

1.) do you have the correct heat range spark plugs?

For those guys with gt30’s and what not, have you tried a $25 set of NGK BCPR7ES-8 (the 7 is the colder heat range,, stock is BCPR6ES which is good enough for mild mods like anything using stock turbo) and the -8 is the 0.8mm gap.

Even try 0.7mm.. I’ve heard of some people going as little as 6.5mm at high power levels.

2.) Have you taped up the coil packs?

It’ll cost you nothing but 30 minutes of your time and you can be sure that the coil packs are not arcing out and making you lose spark.

Yes some of you have said you’ve replaced a couple of them but at idle they might read fine on a multi meter, but under load at hi revs and boost, it’s a different world for them.

Just tape them up to be sure.

You got nothing to lose.

3.) Those of you with AFM still in use… Clean them and resolder them

I keep repeating myself on this topic but it seems that they are logical things to check/do first.

Here is the thread in which I posted more details for something similar.

http://www.skylinesaustralia.com/forums/in...c=122908&hl

Post 5

[Mark-R33]

same prob here too.....popping and then a bang, it was at night and when it went bang i looked in2 the review mirror and saw like lil red dots get sprayed outa the exhaust (prolly red-hot metal)...

i got a stock ecu, cooler, pump, boost at 10psi, pod.....new plugs didnt make a difference

[The Dan]

Plugs in good condition?

Coils working?

side note 604 - 14psi/gt30/rb25 300rwkw = impossible

Ring 101 motorcafe and talk to Rob. He tuned one a couple of months back with the exact same and it made 302rwkw on 14psi.

[The Dan]

I would start by doing what Nismoid said...check spark plugs. Then move on to check you fuel setup. Is your pump flowing enough or at all? You need to chekc basics before you start spending a whole day sorting out 'common faults' and hoping you nail it.

[WiZardOz]

i am having the exact same problem...

only under WOT and at high rpm, it starts popping like im bouncing off a rev limiter, very rapidly, it almost sounds like popcorn popping. my sparkplugs are new/gapped...this is pissing me off

I was having this exact problem a couple of months ago RB25 running 13 psi PFC blah blah blah

problem wasn't as bad as I turned the boost down to 10psi (eboost makes this so easy)

Put a new set of BCPR7ES-11 plugs in (gapped down to 0.8mm) started the car up and it was missing really bad (thought I had stuffed something up)... left it idle for 15 mins in the driveway, turned it off

later in the day when I started it up to go all was fine .. and has never had the problem again

Never understood why it ran so rough when I first started it up after doing the plugs, as before doing it was idling and running fine off boost.

[Endless604]

I was having this exact problem a couple of months ago RB25 running 13 psi PFC blah blah blah

problem wasn't as bad as I turned the boost down to 10psi (eboost makes this so easy)

Put a new set of BCPR7ES-11 plugs in (gapped down to 0.8mm) started the car up and it was missing really bad (thought I had stuffed something up)... left it idle for 15 mins in the driveway, turned it off

later in the day when I started it up to go all was fine .. and has never had the problem again

Never understood why it ran so rough when I first started it up after doing the plugs, as before doing it was idling and running fine off boost.

I just installed a set of ngk BCPR6E-11 (Copper V-Power) in my rb20det....start it up and it misses BAD. lumpy idle that's shaking the whole car. god. how am i gonna fix this?

i hope it'll sort itself out like yours did, but if it doesn't looks like im going to put BCPR5EIX-11's (iridium ix) back in, atleast those didn't miss till 5000+ rpm...

i taped up the coils while i was in there though, so hopefully that rules them out.

[brett33]

I had similar prob............... siliconed bottoms of all coils, gapped to 0.6 mm. Now runs 17psi 250rwkw no worries.

[humz]

how do you silicon the bottom of coils. thanx

[Tex Willer]

We have had some problems with the 1. Generation RB25 (with external coildrivers).

Seems like the spark dissappears over 14 psi boost, even lower on big turboed/hp engines.

Don`t know if it is the coildriver or coil that is the weak link, but most likely the coils.

HKS dli box did not help(as it does on the supra`s)

Generation 2 coils seems better, but probably not working with the external amps.

[604cefiro]

Hey guys,

Thank you VERY much for all the input.

Well a couple days ago we started to play around with the spark plugs / coils.

I replaced my HKS plugs with some NGK heat range 6 (yea i know, too cheap to want to foul expensive plugs right now). Siliconed and cleaned the coils.

I think it was cylinder 2 or 3, the coil looked like it was arcing outwards.

Took it for a spin, 1st gear and 2nd gear was OK. mid to high RPM in 3rd, the car still goes BANG BANG.

I'm thinking of picking up the Splitfire coilpacks, we'll see if that helps any.

[Endless604]

you know what,

before you dish for splitfires try running a bottle of Redline SI-1 in your fuel.

i know, it sounds way too simple, but try that first and see if that helps any

[Guilt-Toy]

make sure there is no boost cut / limit set in your ecu

[2_eclipsed]

i got the exact same problems as u guys.

i have a stock rb26/T04R/HKS GT waste gate/splitfire coils/NGK plugs heat range 6/stock injectors/stock ecu un-tuned running 1bar.

did everything u guys suggested except changing the spark plugs. will change them l8er this week to heat range 8 with 0.07mm gap.

problem only occurs at WOT(wide open throttle)

but another ploblem is that iam scared shitless to even check if the problem is still there cause i don't want it to go kaboom. i know iam playing with fire but car will be tuned as soon as this problem is solved. just waiting to get power fc.

Edited September 14, 2006 by 2_eclipsed

[53TUP]

IMO i would go the 7 heat range and gap the plugs to .8mm i have seen problems with the 6 heat range under higher boost.

[2_eclipsed]

n e other opinions, b4 i go out and buy some plugs. wanna change them tomorrow morning

[2_eclipsed]

changed my plugs as well to heat range 7 and still haveing the same problem, n e other suggestions. on a side note ill be changing the injectors to 555cc in the next couple of days as i sus my stock ones to be leaking.

[james young]

ok i found this

http://www.uniqueautosports.com/pricelists...electronics.htm

the item on top being the BEE*R REV LIMITER

makes the car do exactly what you are all talking about

thought it might help solve your problem.