I currently have an untouched stock 350 TPI. I am understanding cars more and I always seem to find myself staring and a sweet set of wheels somebody got on the appearance board, but every once in a while I want to read about power plants and what mods people do to get the power they want. My question is this, I do want to mod my car however, is it advicable to research, and change everything at once? or do it in stages. I would like to port my TPI throttle body, runners, plentium, etc., or get aftermarket (scared of porter, and I don't think I have the tools). I definetly want to get headers, cat-back system (I can't run true duals here in PA ( damn emissions), mild cam, heads, bigger injectors and I don't know, just stuff to make my car more efficent...stroking / boreing is a possibility I guess...total I really don't wanna spend more than 3-4 K.... and I still want it to run on 87 gas.... Does this sound like a realistic, good combo?

 

No, mods will need high octane, should probably be using it now. You have to find out how fast you want your car to run and what your specific goals are before you start modding so you can get some real advice.

 

The first thing you definitely need to do is set some sort of plan for what you want the car to end up like. Is it a daily driver? Do you want to race it? If so, street racing or at the track? N/A or nitrous? How fast do you want to go? The best place to start is with the exhaust. Headers and a good catback. Then to compliment the exhaust you may want to tyr to port your TPI yourself. You can find many posts on these boards about that. Once you get the motor breathing right, you may decide that it's time for a cam and maybe heads too. There's a lot that goes into picking the right cam, but you can cross that bridge when you get to it. So to answer your question, yes, you want to go in stages. Unless of course, you have an unlimited budget and another car that would allow you to tear apart your car and let it sit for a while.

My .02 ( almost a $1 ) I'll shut up now.

 

You also need to decide if you are looking into a corner carver, or an auto-x car. Then suspension would be the primary focus, along with a six-speed or a strong five-speed. When you decide what is the main focus of the car, than you want get parts, but you need to know if it is a daily driver.

 

Its not really gonna be a "beat up" daily driver, and I do have another car I can use to go back and forth to work..but when I go out to the movies or something, I'd take my caramo. I'm estimating about 3 - 5 K miles per year.

 

We want to know what kind of performance goals you have.

 

You can run it on 87 octane all day long if you really for some reason want to. I'm assuming your engine is untouched in the compression ratio department. The L98s were rather lower compression. You'll probably get some knock retard on a warm day at full throttle, but this is to be expected. But for cruising along on the highway or normal grocery getting it'll be fine until you put your foot down and notice it doesn't seem as powerful as with some higher stuff.

 

My performance goals would be to create an engine that will last, that is somewhat fast, I really don't care about 1/4 mile times but...12's would be nice. for under 5,000. I know thats a long shot but, eh, just throwing this out there to see what people think

 

dpav,

You certainly can't cause any problems in performance, emissions, or fuel ecomony by porting the plenum behind the throttle body and matching the intake runners to the base and plenum. This is relatively easy porting work and can create a decent response from a 350 (it doesn't hurt a 305 either). It probably isn't economically feasible to pay a shop to do this work, but doing it yourself can be inexpensive and rewarding. You really don't need much more than a die grinder and some burrs, and maybe a few files for trimming.

Depending on your mileage and the time you want to spend, there may be some other things you can do while the plenum is off. It may be a good time to remove the injectors for cleaning and flow matching. It would be a really good idea to remove and check/clean the EGR valve and passages. It is also an excellent opportunity to replace or convert the FPR to an adjustable type. You may not need to trim your fuel pressure, but it's nice to have the option.

For peak performance on even a stock L98, you might want to try a little higher octane (like 90 or higher) and a little more base timing advance. using unnecessarily high octane can actually cost you a little power, but you'll gain more in being able to advance the base timing on a stock setup.

 

thanks guys...I really appericate the advice