YakATK

Ok, I will try not to sound like a n00b here, but just bare with me on this, it may sound retarded on some questions. :P
Questions will be about my 1990 NA

#1. I am wondering about switching my gas tank to a S4 tank because I hear they are smaller, I would like to shave off the weight. I am wondering if this is possible to do and what would need to be changed along with the tank if anything at all?

#2. Does anyone know how good the headlight cover with vent from Mariahmotorsports works? I am considering getting that for the passenger side and having it vent into my filter. I would then build a box around the filter with front and top being open of course. Has anyone done this or know if it is worth the money? I would also be getting better fuel pump and injectors, and an S-AFC possibly. Is that worth doing or not though is mainly what I am wondering? Does anyone know what kind of power gains you could get outta that?

#3. I also will be getting new springs all around soon. I have some 17x7 rims with 205/40R17 tires. I know the eibach springs are good quality but they only lower the car by .8inch and would leave it looking terrible, I know looks are not everything but I would like there to not be such a big gap between rear wheel and fender. So I am also considering the Intrax springs (lowers by 1.75inch). My concern with those springs are that the front may rub if I go over bumps and **** untill I get stiffer suspension installed. Anyone know if they will or not? And would it be better to go with the Eibach springs for the quality or are they pretty much equal?

I thank you for your time and replies, all constructive critiscism is welcome.

HeffBoost

18.5 vs. 16.6, just leave out 1.9 gallons. I really don't think it would be worth the hassle. How much more can the bigger tank really weigh?

The cold airbox & cone is definitely worth it. I saw huge reductions in my initial intake temps after I built a heat barrier. There are guys building those induction headlight covers for a lot less than Mariah wants.

IMO none of this is worth doing. The stock injs & pump are fine with light mods and the only thing you can really do with the AFC is trim it lean for relatively small gains. Plus impossible to do w/o a wideband oxy sensor or dyno. There's lots of people around that have done all that you mentioned. Some searching would yield their results.

On the springs issue, I think Intrax springs are really stiff and of a linear rate. I had some on a first gen and they were bad harsh, so I'm assuming the stiffness thing would carry over. I think they're known for being on the stiff side of harsh. Check the poundage & compare. I run Eibach Prokits which are progressive and like them a lot. They offer a pretty decent everyday ride with added performance when you push it. You're right about them not dropping the car much. My rear didn't come down much at all and the front came out just right for me.

Cheers