There's not much you can do about intake, unless you are thinking about converting it to open element style. Exhaust, I'd recommand custom made one just so you get best bang for the bucks.<p>Man...I can't keep on pretending I know about this 40 series..hehee, I'll let others finish this up. But everything else should be pretty straightforward like how you would modify on some other cars. I know there's a group buy going on for custom KW coilovers for 40 series.<p>Spark plugs? Not sure any aftermarket one will really make any significant difference. Rims...that's a toughy...
For wheels, I would recommend, from my recent research, the Mille Miglia Cello wheel from Italy, which, in design, is a close replica of the new S40 OE alloy, and it is available in a 42mm offset which is very close to the OE 44mm. If you can still find the 15X7" wheel, this is the way to go to reduce your rotating wheel inertia due to the 15" diameter which will weigh less than a 16 or 17" wheel, as the alloy metal is heavier than the rubber tire. One doesn't want to lose the HP to the rotating wheel weight. <p>One can fit a 205/55/15 tire to this wheel for the max correct fit, and I would recommend the ultra high performance tire--Bridgestone Potenza S-03, which one can purchase cheaper than the OE Michelin MXV4 by $25+, and still get reasonable mileage and great performance. My S-03's have 16000+ miles, and have only worn down 40% for spirited driving and cornering. My MXV4's only gave me 36,000 miles to the last 2-3/32" of thread. Run snows--Michelin Artic Alpins in the winter on the OE wheels. <IMG NAME="icon" SRC="http://********************/smile/emthup.gif" BORDER="0"> <BR><BR>
[Modified by jone, 1:23 AM 9-29-2002]
I did a little research, and I found this site, and there were two sizes for the cello ryms 15"x6.5" and 16"x7", you said go for a 15"x7", but there is not, I am still looking around, but if I can't find a 15"x7" rym that I like, i am guessing a 6.5" would be the next best thing?