persian451

I was looking throuh ebay and some guy was selling mass amounts of Denso Iridium Spark plugs for the SC/GS series.. But i was wondering if we could throw those in the 1st gen LS4 and add some extra HP

any idea if this wouldnt work for the LS4?

Lvangundy

My only input is that you might want to stay away from Torque Master (TM) plugs on the LS's. I don't know what kind of 'tip' these are.

Many people praised them here and one user (on an SC400) posted dyno results showing somewhere around an 18HP improvement, but it's not known if the +18 was the difference from a 60,000 mile old OEM plug..

Some say the TM plugs gave them no problems, but in 2 cases (my self and a guy with a GS430 ) there were problems with the engine mis-firing. The car would stutter and.. that was about it.

I took them back to TM headquarters in El Segundo and had them check the plugs and re-adjust the gap but this didn't solve the problem..I went back to toyota factory plugs and the problem went away.

persian451

i see.. yea i think i would stay with Denso or NGK... but i herad HGK are made for Hondas and Nissans.. and arent good for LExus... supposedly...

But I still want to know if Iridium plugs make any difference as far as performance goes