spark plugs?

[croat]

I just boosted my 33 gtst today up to 9 psi (approx). when giving it a boot the car when hitting high rev's starts to backfire constantly and feels like it is pumping massive amounts of air through the exhaust as it shakes back and forth. The mechanic says i need irridium plugs... Anyone had this problem? I thought the car could be put up to at least 14 psi before needing spark plugs...

[Guest Robo's]

Mine does exaclty the same, just boosted it last weekend, and now i have problems. I changed plugs but to no evail.

People say gap them to .8 as the spark will not be as easily flamed out with the rich fuel. That is the backfiring, unburnt fuel.

[croat]

So you think that just buying new spark plugs wont do it? does this happen to all skylines with factory plugs?

[4 Doorz]

may just be a weak coil, have seen rb25det boosted to 1.1 bar on standard plug, but I had problems with mine just on 7 psi.

Had to replace a coil and clean the rest

[BOOSTD]

NGK BP7ES or something like that its the 7 that makes the difference. gapped to .7mm also. ( probably try gapping down ur own plugs first)

[Sumo]

the cut i get is a boost cut.. computer controlled. My EBC is spastic in the way it works, I can never seem to get boost stable. And when I get up too 5000 rpm thats where I get the cut. like I can run 10 PSI (on the manifold gauge) but cant hold it at that over 5k rpm before the computer retards the timing and cuts your power.

[confak]

regap and clean your current plugs. I am using normal copper plugs BCP6's gapped at .7mm. Run 14psi wuth no bacfiring.

[rev210]

.8mm gap will probably fix it on the existing plugs.

The 7's will work too. Use R's (resistor type) if not racing around all the time. Copper plugs will do, the platinum or iridiums are just 'self cleaning'.

[Frosty]

What ever you do dont put iridium plus in. They are gay if your running more than stock boost!!!! even if you do waste the money dont gap them they heat up and corz the car to miss fire like all phark!!!! if you want good plus get some NGK Platnium and gap them to .08mm and youll be sweet

[croat]

So is it best to just gap my existig plugs (which are clean and have no probs with them) or buy irridium plugs? i dont care if i have to spend $$$ as long as i get the best parts for the job. I also hear that the stock plugs when boosted a lot can melt and stuff everything up?????

[Frosty]

what plugs are u running at the moment?

[croat]

The plugs i have are the standard from nissan

[Frosty]

yeah invest in some NGK platniums then just get them gapped. Who ever puts them in should be able to gapp them for you. they are hell cheap plugs too depending on where you get them from. i know i can get a set of 6 for the price that you pay for 1 Iridium and they are better

I have used iridium and they are crap loss of ponies too was really dissapointed

[rev210]

autolite plugs are better than NGK I've found