whats up folks. recently purchased a '98 GS4 and I am thrilled out of my mind. but of course, with anything new there are a few questions. first and foremost, is how to get more HP. Im sure the conventional things that worked on my civic will work but I have no clue as to manufacturers. The previous owner did put Rod Millen suspension components on, so that is a start. So who are some of the best as far as intake and exhaust? Will these things void my warranty? Who makes a lightweight 18 or 19 inch rim so as not to increase unsprung weight? Is there a trim kit that will match the interior that will allow me to put in an aftermarket stereo/DVD/nav? I guess that will do it for now. Any help in these areas or advice in others would be greatly appreciated

 

Welcome to Club Lexus,
As far as intakes and exhaust the best intakes out here righ now is swift racings ECU and intake upgrade and the new weapon R intake with ECU. The swift intake has been around for a while now and is proven, but on the other hand the WeaponR is brand new although the people who do have it are very impressed with it. For exhausts there are the GReddy,HKS,RMM,L-Sportline,Blitz,TTE, Borla just to name a few but pretty much the diffrence is looks and sound they make about the same HP.
As for warranty I guess that depends on your Dealer, some will let mods pass some will not.
Light 18 and 19 inch wheels are Volk,HRE,Work,Manaray Sports, they are forged and some are three peice wheels, they are the best when it comes to upgrading your stockers BUT they are expensive. But as Manaray says "if you play you have to pay"
I hope this helps......