I have a 91 305 tbi, automatic. I have put a 10 bolt rear, 3 inch exhaust, hooker headers and that is it. But for a High school kid with minimum wage I think that is pretty good. But I only run 15.9. My problem hear is how can I get a faster time from my 305 with out breaking the bank. I realize I have bought a slow car but I am trying to make the best out of my first car that I can. Please help!

Desperate High School Muscle Head!

 

Dual snorkel air cleaner or open element (dual snorkel is better)

Underdrive pulleys

Remove smog pump (if you can)

Remove A/C

Loose weight

Those are a few inexpensive things you can do.

The heads on that motor really choke it.

 

Oh and bigger plug wires with less resistance and a better coil.

 

Welcome to Thirdgen.org!

To tell you the truth, I would skip all the little things like AC delete, underdrive pullies for now, and attack your issue at the source. Bottomline, the whole TBI setup is *****. (I know, I just picked up one as a donor)

The intake, heads and cam are the issue that is making you run slower than a stock honda civic.

The cam that they put in that engine has a whopping duration of 179/194 with .350/.384 lift @.050
(if you are a newbie to cams...that's like tieing cinder blocks to Michael Jordan's feet and telling him to dunk from the free throw line)

It has come to my attention that the intake itself along with the heads flow horribly, but I haven't really looked into it.

If you want the best results with the best bang for your buck, I would seriously consider swapping over to a TPI top end. You can find all the parts cheap (as there are hundreds upon thousands of 3rd Gens in junk yards right now). If you are lucky, you can find a 3rd gen in a junk yard that hasnt been touched yet (although it's very rare), in which case, you can just take everything and take out all the guess work. Or you can even find alot of these parts on ebay as well.

You are going to need the heads, the tpi plenum, tpi base, tpi runners, as well as fuel rails, injectors, EGR, fuel pressure regulator, new ECM, wiring harness (i believe), throttle body, etc...and afterwards, you are going to want to get a cam to suit those modifications...but you can get a mild one and stay on the cheap side, but it's not going to wake up unless you get a new cam...that's probably the most important part. Just to give you an idea of what to look for, the cam that came stock with the 305/350 TPI motors after 1990 was a roller with 202/207 duration and .413/.428 lift @.050

If you use the search feature and ask around a bit, you can get a list of EVERYTHING you are going to be needing. Google is your friend as well (search "TPI Swap" and things of that nature.) After all is said and done, you will end up spending roughly 600$ on everything, but it will be WELL worth every penny, and you can expect to run in the mid to low 14's.


Again, you can play around with a few free mods, pulleys, weight reduction and knock off a half second off your ET, but the source of your problem lies in the three most important part of the engine in terms of making your power work for you: Intake, Heads, and Cam.


_Clark

 

Removing the smog pump is a zero-gain performance mod.

Good news is you've taken care of the exhaust. Without that, nothing else would matter much.

"I have put a 10 bolt rear..." I don't understand that statement. All 3rd gens have a 10 bolt rear (except those that got the Aussie 9-bolts or Dana 44's).

Putting a TPI on swirlport heads isn't going to result in much gain. I'd say nix on that.

In case you haven't picked up on it yet, you basically are in a no-win situation on a minimum wage budget. You could look for deals on used parts, otherwise you're just going to have to wait until funds allow more extensive upgrades.

1st step is to go to the TBI forum and read all the stickies about performance that is documented there.

 

I said to rebuild the entire top end, meaning getting the heads off a TPI car, whether it be Camaro, Firebird, or Vette. Junkyard would be cheap as hell to get that.

Even though he is on a budget, if he saves, he can get the TPI upgrade. It's just a matter of commitment, and being able to manage your money. I was a broke high school kid when I decided to get my Camaro in the first place, but when I made the decision to get it, I cut down on all my expenses, and sure enough, a deal struck and I got a nice one for $1700 some 5 months later, and fixed it to run optimally for $300 more.

In his case, $600 isn't too far of a cry, and for what he'd be getting, it's worth it.

 

Sorry, scanned through your post too quickly (comes from reading 100+ posts a day).

Still, I can't support the TPI idea. There are better, cheaper alterntives.

 

pick up a set of vortec heads off of ebay for $200-$300 (or at the junk yard if you can find a set). Edelbrock Vortec intake manifold and pick up a decent 600 CFM carb, and a good cam. high 13's to low 14's on a stock 305 bottom end.


If you wanna stay FI then it might be possible to use the whole vortec top end. Not sure on that but anything's possible.

 

Where are you from? Do you have emmisions testing? If not, you can look around for a cheap used engine. Get a standard carb'd 350 and swap it in. If that isnt your route, you would rather have FI, then a TPI swap isnt a bad idea. You would definately need the heads with it, the swirl ports just dont cut it, IMO. Its going to cost. Bottom line is, how bad do you want it?

 

Ehhh...I'm going go go with Five7. Swapping to T.P.I. is something you could do...if you really wanted to. But that's a big swap especially if you're just beginning, you could do it in a few dedicated days. But it's not really what you NEED to do if you're wanting a cheap, fast fix to go fast. Truth is there is no cheap fast way. But with some dedication you can pick up a little bit pretty easy. Read sticky's. Get a diegrinder and modify your T.B.I. to flow better. Make your F.P.R. adjustable. Higher flow air filter. Start a little minor tuning by your O2. Go Here and start reading up on things. If you do that and get your fuel pressure right, along with the exhaust you already have...you will pick up quite a bit.

Almost any mild cam can be an improvement and can be done in an afternoon. Then you need to ditch your heads. 081, 416, or vortecs. You can pick up the 081 or 416's for 50 bucks and a little machine work. Then DIY tuning. Then bigger cam. Then more tuning.

If you mean that your rear has been replaced...does it have aftermarket gears?

 

If you made it so far as to get headers on, hopefully youv'e done a BASIC tune up?

Plugs, wires, dizzy cap & rotor, timing?

 

I sold my TPI heads for $50, could have been a good start if you were to do the swap. I'd say:
Headers (and catback)
Cam
Rear gears
And a tune up if you haven't had one

 

I would have to agree with ljnowell and five7.

If I were going to tear a 305 down that far just to add a TPI, which has it own performance issues. I would just find a used 350 and go carb. If you are that far in , might as well go all the way. He would definatley see a lot more gain. Besides, the TPI has a restrictive intake as well (but still an upgrade).

Now the vortecs, that's an idea. But it will require the appropriate intake and a carb.

Bottom line, start saving your because nothing is cheap beyond the little boltons I first mentioned.

 

Iam talking about paying about $800 to be running high 14's. All I really want to do is beat my buddy in a 01 SI. I just get allot of **** because i have more pistons and he beats me by 2 car lengths. But I also don't wanna go to TPI I want to stick with my Throttle Body. Iam willing to do any kind of work. I just need your help to run 14's

 

did you take the advice five7kid gave you and go to the tbi forum and read the stickies? if you can't get enough info from that then post this question there.


"I got $800 to spend, what should I buy to go faster?"