I'm interested in changing the intake on my 1988 305, because i've heard that it is one of the easiest ways to give third gens more power, but im not really sure what this entails. Any links/tips/info on what i need to buy?

Also I was thinking about maybe getting a new cam and would like to know what this involves/tips/what i need to buy. And also if I am going to replace the cam should I first rebuild the whole engine while it is partially dismantelled? It has 140,000 miles. And if so where can I get a kit for this and how many hours can I expect to spend doing this? Thanks for any help.

 

Well its hard to tell you anything when we don't know what intake, cam, or heads you have! Could you atleast tell us what engine you have?

 

If you have a stock 88 305 TBI, about the last thing you need to be changing to get more power, is the intake.

The correct way to mod a car (CAR, not just engine) is to identify the one thing holding it back the most; and upgrade it. Then that will expose another thing holding it back from its full potential; so you upgrade that. Then another, and another, and another.

It is NOT to simply un-bolt and re-bolt big shiny thing that sit up on top of the motor where everybody can see them, and can oooh and aaaaah over the shiny new metal. The only way that will make your car faster is by lightening it..... specifically, by reducing the weight of the driver's wallet.

Whoever told you that, or wherever you "heard" it from, is a highly unreliable source. I would not recommend believing another word out of that person's mouth. They don't know what they're talking about.

You'll find that there are a whole long list of things that are what's really preventing the engine from reaching its potential, a whole lot more than the intake.

In the case of the 305 TBI motor, the first things are the exhaust, every piece from the heads to the street; and the air cleaner. Then the cam. Then the gears. Then the torque converter. At that point, you'll discover you have a traction problem (I doubt you have that now) so you'll need some suspension work. The heads will be the next bottleneck in the engine; if you plan ahead a little, you should replace the swirl-port TBI heads with the ones off of a TPI or carb 305 from 87 up at the same time you swap the cam.

After you do all of that, you might, maybe, find that upgrading the intake would actually accomplish something.

 

Hmmm I think that post just convinced me that I might as well port my heads while I have my intake off since I wanted to swap my cam anyways :-D

Anyways, yeah I'm doing things backwards with my car actually. I have a 305TPI and the first thing I did to it was a tune-up (always get your car running right first!). Pretty normal right? Well, the next thing after that was a 3" cat-back....still somewhat normal really. Now the next major thing I'm doing is swapping my TPI intake to an LT1 intake and swapping my peanut cam to an LT1 cam. Total cost is like $450-500 that would've been much better spent on headers and some new gears (or cheap converter). Then after I do the intake/cam I'm going to get into chip-burning. My reason for upgrading the intake is because I want to have more power up top, and I thought I was going to be one of the first 305's to convert, but apparently I'm not.

Will it be worth it? Honestly, probably not. But I'll be able to use the intake on my 350 whenever I get around to building that anyways Hell, I should've just gotten some nitrous for that kinda money, but oh well.

Anyways, don't bother with the intake at all. Do all you want to the air cleaner though as they always hold these cars back. Exhaust, gears, suspension.

 

Yeah Im hopefully going to get some exhaust work done this weekend and im trying to get some suspension stuff, I don't know if i will do anything with getting new gears because if i get steeper gears my gas mileage will suffer tremendously so ill probably put that off for a while. As for headers, when I talked to the guy at the muffler shop he said that he doesnt like to put headers on cars because they blow gaskets all the time and get loose pretty easy, im not sure if he just doesnt want to be held liable if something breaks though.

Anyway what do you think is the first engine mod i should do after i take care of exhaust and suspension? I was thinking maybe a new cam but im also thinking of rebuilding the engine (im not sure how many miles you can put on before something major goes wrong) any suggestions?

 

Full tune-up (cap/rotor, plugs, wires, all filters, all fluids, O2 sensor, PCV valve, etc.).

Exhaust (headers and full cat-back with hi-flow cat preferred. If you have a 305TBI, the exhaust will help HUGELY, though even on a 305TPI the headers will make quite a difference).

Intake. K&N filter depending on your application (TBI/TPI). If its a TBI, get rid of the airbox and put an open element K&N filter on. If its a TPI like my '88 Trans Am, get rid of the crappy restrictive airbox and replace it with a cone filter.

Suspension. Sub-frame connectors, Lower Control Arms, Lower Control Arm Relocation Brackets, poly bushings (torque arm mount, transmission mount, swaybar endlinks, "Hyperflex" kit etc.), new shocks/struts and springs, as they don't do much after 140k miles. If you decide to get lowering springs, then make sure you get an adjustable panhard bar as well.

Motor. If TBI, do all of the "free" mods. Same with TPI, there just aren't as many. After this you could go with re-worked heads (might as well change the intake I guess too) and a cam. If TPI, I'd recommend going to aftermarket runners/base/plenum, or porting your stock stuff. Personally, I'm getting a LT1 intake modified for my heads. Might as well upgrade the valvetrain too if you get the heads worked over and are getting a new cam. By this point, you should also get into burning your own chips as well. It will help you out immensely at this stage.

You can hold off on gears until this point, depending on your head/cam/intake selection. If you have TBI, get rid of the stock crap heads and get some ported TPI heads or go with some SR Torquer 305 heads. You will definitely need a new fuel pump (if TBI) at this stage as well.

Once you have all of this, upgrading to an MSD 6A(L) box should make quite a noticeable difference in the upper RPMs. You shouldn't need to touch the internals (I consider pistons/rods/crank as "internals") at all for a while unless you really want to get into performance.

By this time, depending on some of your selections, you can have upwards of 300HP+ and you'll need a way to stop your car. Here's where you will realize you need more braking power. Hopefully you would have noticed it by now, but if you haven't, by this time you will definitely want to upgrade it.

If I've forgotten anything, someone else please chime in

 

Thanks for all the tips. But I still have a few more questions. For headers should I get long or short tube? Are there any major differences and can they just bolt right up to the old piping or do I have to get custom made pipes? Also you talked about all the mods for a TBI engine vs. TPI. I have read a few articles about swapping from TBI to TPI, do you think this is worth the time/money at all or would it just be smarter to just work with the TBI that i've got on it now? And finally you talked about puting on a K&N air filter and getting rid of the old air box? how exactly would I do that? Thanks.

 

You want shorty headers, get some for a L98 TPI car. You will also need a Y-pipe to connect to your exhaust. I went with Hedman Hedders because there is a Y-pipe available for them and the are cheap, $100 for the header and another $100 for the y-pipe. You should also get a catback or new 3" pipe all the way back.

Long tube header require hours of fabrication to work. Its not worth it unless you are building and all out car, which you are not.

 

The main problem with your car is the heads, not the intake, though the TPI setup does make a lot more torque. I'll be removing mine in the next few weeks and porting and pollishing it before I sell it. It'll be just the runners, base, and plenum (I need to keep the ECM and injectors)...but they'll be ported and nice and shiny PM me if you're interested at all and we can talk pricing. The runners are in PERFECT condition (no dents)

 

Here's some honest to g0d advice that helped me, and I think most of us here would agree.

Take the time to learn why you're going to do a specific mod. Anyone looking for "what should I do first" info needs to do some research.....and that's EXACTLY what you're doing. Just be sure not to take the first peice of advice that you get. do searches on similar subjects. TGO is a tool at your disposal. There is SOOOOO much info here.

Don't do exhaust because you were given advice to start with the exhaust, do it because you KNOW it's a good place to start! It may take a few weeks or even months, but before you know it, you'll be answering these very same questions to other newbies!

...does that all make sense???