Hello everyone! I'm pretty new to this board :)

My friend has a 1989 240sx with an Sr20det in it. Currently we have some Denso Iridiums gapped at .032 i believe. We couldn't get accurate ignition timing reading with them so i checked on this board to see what spark plugs people were using. I tried the NGK BKR7Es gapped at .030 and the engine idle was a little irradict. It sounded like "put put put put put". With the Denso's the idle was perfect. My question is, what should I gap these plugs at? Right now the only current mods we have on the car is a spearco front mount intercooler, blitz air filter, 3 inch downpipe with 3 inch piping all the way back. We're pushing stock boost as of right now. Can anyone help me out please? We plan on upping the boost to around 11 psi's so what should i gap these plugs at? Any help would be greatly appreciated! Thanks a lot everyone!

--James :)

One word.... "SEARCH"

the ignition system is a little different on the S-car DET's than the US ones right? So I dunno what the spark plug wires are like but check those; it is generally thought that the stock wires are the best. For a stock DET, most of us run 6 heat range plugs. And try searching the se-r.net archives.

Khiem

Yeah; 7-range plugs are constantly on the virge of fouling at idle and low-load operation. At the track, you may want 7s, but the 6 is really a better idea for street. That gap, from what I've seen, could likely work very well, though you may want to tighten it up just a snitch to see if that helps. You may also want to look at an ignition coil booster, such as that which Nology makes. Even Mike Kojima said that this was a nice improvement over stock, since all it does (and it actually does do what's advertised) is up the input voltage side of the coil.

S13's have direct coil packs with a cam sensor for timing. Much better than your conventional spark plug wires. As for the plugs I run the IK22 which is a heat range of 7 gapped at .32 You should check out other stuff to see if its within spec first such as timing and Tps which affect idle as well.

D'oh! Ignore this monkey behind the keyboard...

Thanks for the responses guys. Yea, i tried the search button, so I'm sorry if this topic is getting kinda repetitive. The reason why i posted this is because we're pretty desperate, my friends poor car is performing very badly. We replaced the turbo, blow off valve, there was no pressure leak in the intercooler nor the piping. The plugs look fine. There is no white or black smoke coming outta the exhaust. As of right now the timing is set to stock. Currently we are running 91 octane. We tried retarding/advancing but nothing helped. I mean the only thing i thought about was the ignition after everything. The boost guage reads a consistent 7 lbs. The problem with the car is that it lags when it hits around 4,500 rpms and slowly increases all the way up to 7,000. Next we plan on doing a compression test to see if the motor is ok, but before doing that i was wondering if there was anything else that i may have missed over?? I'm sorry for the long response, but any help, i mean any help would be appreciated. Thanks guys, you guys are very friendly and helpful. Thanks everybody! :)

How far is Walnut from Sacramento? I want to take a look at it.

lol, it's like 6 hours haha. Thanks for the offer though, I really appreciate it. My friend is planning on selling the car, but if he doesn't I'm going to change the plugs to the 6 heat range. (I really hope he doesn't) Do you guys think it could be the intercooler??? He's pushing a spearco front mount, just thought that might be the problem. What kind of boost do you think we can boost it up to?? Maybe i can put the 7 heat range in, boost it up and see how she runs. Any thoughts guys? Thanks for the help again! Nizmo power! lol :)