Hi guys . I have read the TBI mods and a lot more and I'm confused . I have a 305 with headers and cat-back and Edelbrock Performer intake and 8.8 Acell wires . I am wanting to get a little more horsepower with 400 dollars or less because I am getting a 350 next year . Can I have the injectors ported to allow more fuel ? And would it help to increase the size of my fuel lines ? A guy I met who builds engines said he could do something like what I described and make my throttle body perform close to a Holley Street Ram . Any advice on this or reccomendations would be appreciated . Shifty , I have read a lot of articles on here and you seem to be the definitive TBI guy , so help please if you can . Thanks ,
Dave

 

my take,
dont spend more if your planing on geting a 350, inless you can re-use your parts on the 350 you well have...

 

You can't do anything to the stock injectors other than having them sonic cleaned. You cannot bore them or enlarge them in any way. Also, enlarging the fuel lines won't do anything. The stock lines can support like 500 or 600 hp if i recall correctly. That is with the right pump of course. With $400 I would look into chip burning stuff. You can get everything you need for as little as $200 and use the rest on a used LT1 cam. You would be really happy with those parts

 

I agree if your getting 350 soon wait and spend the cash on it, the chip burning hard/software can reused even if your going with larger engine.

 

nitrous can be reused too.

 

Full exhaust gets my vote. Absolutely needs to be done if you plan to ever make any power. Stock manifolds, y-pipe and everything back are terrible, replace it all with 3" and 1 5/8" primary headers.

 

O.K. First , thanks for all replies . I also have underdrive pulleys . I have someone who will burn a chip for free but he says its not worth it until I do heads or cam . So I don't really have a reason I know to buy that equipment . The cam is a good idea but I will probably not do that as I would need to pay someone to do it . Shifty == I'm a little sketchy on exactly what the guy said but I remember him saying something also about runners on the TBI . And he said I couldn't get bigger injectors but he could send off to a place to ( enlarge or bore or port or something like that ) Does any of that sound right at all ? He didn't seem like a BSer and he seemed knowledgeable . Boy is there a lot to learn about these cars . Any help or more suggestions will be appreciated.
Thanks ,
Dave

 

BORE the injectors, you can not bore them. you can bore out the stock tb, and radius the edges to smooth out airflow. TBI does not have runners thats TPI. the guy is full of it about not being able to get larger injectors, there are different injector ratings for 4,6, 8 cyl engines. PIC's

 

The only thing I can think of is having them flow matched. That does not require boring though. I would have him leave the injectors alone all together. There aren't runners on a TBI sytem as Z28GEN3 pointed out.

 

I think part of the problem is I may not remember exactly what he said . And I think he is more the money man and not the mechanic. So could you add runners to a throttle body ? Would that achieve anything ? It is starting to sound like he knows some things but doesn't do too much of the actual work . He runs a car lot with and has lots of non stock F-bodies and does some racing . So anyway thanks for the info . Next time I talk to him I'll listen harder and ask questions and get better info . Then I should be able to know if he really knows some things or just has some knowledge from paying his mechanic to work on all those cars and picking up some information from them . Sorry if this seems pointless to you guys , but I am really trying to learn and he seemed to have some cool ideas . I'll let you guys know what I find out next time I talk to him . Thanks .

 

You can't add them to the trottle body. A TBI unit is like a carb. Runners as he is describing them to you are a way to take air from a central plenum and direct them to each individual intake port as found on LT1 and TPI and LS1 applications.

 

I'm almost positive he said he would bore out the throttle body. He also probably said something about increasing the fuel pressure, not the lines....

if he owns a car lot.... dont trust him - just kidding. (family owns a gm dealership, dont trust me)...

anyway..... 400 bucks. forget the engine if you're putting in a 350, upgrade the rearend now... grab a 4th gen disc rear and put it in. gear ratio and disc brakes etc will be great bang for the buck. next idea is nos in my opinion... just dont spend cash on the engine... tranny or rear...

shifty is the definitive tbi guy now eh... ? Prevost, z28boy, Pablo, eric, Taz...., guys... we've gotten outdated.. LOL

o the good old days......

honestly though... shifty has put more time into this board than us oldtimers ever did... shifty sure does help a lot of guys out.

 

I don't know if I would say that judging by the hate mail I recieve now and again I was learning from you guys back in '00 when the TBI dream team was posting new stuff all the time I finally registered after reading this board for a few months once I got my hands on some mods. It was all downhill for my wallet from there! So you guys should pat yourselves on the back. We need to include Dewey, Dimented, 25THRSS, and Bron into the mix as well. Those guys are without a doubt tops on this board over the last year or so. Dewey and Dimented have really taken TBI tuning to the heights where JPrevost started and have gotten a lot of people to stay with TBI because of their efforts and incredible tuning skills. There has been a huge repsonse over the last year to mod these cars and it is really fun to be a part of huge site like this that can help guide folks in the right direction. Everyone has their strengths and we make a pretty good team where at least one guy is a pro with a specific area of expertise on these cars. I have just as much fun helping people out now as I did when I actually did all those mods to my car.

 

i just gotta stop buying new toys and get back to my roots. my thirdgen.. -

I could really get back into tbi if i was willing to give up driving the porsche and go to working on it: i really would like it to be converted to dual crossfire throttle bodies

My problem with spending so much time on tbi now is that i can easily afford to just say, screw it, and buy dfi if i had the urge to... back in 2000 i was a totaly broke college student....(with a girlfriend- doesnt help AT ALL) and my only choice was to mess with tbi....

i still love it though, trying new things... in fact... i should put my 454 tbi and match 65 lb per hour injectors into my truck tomorrow.... i mean, they've only been sitting around for over 2 and half years now. - That would be fun, and i never had hooked the laptop up to the truck to see why i get a dipping idle every once and a while. ahhhhhhh.... the time - where does it go.

 

Thanks again for all responces guys . I have put on a Edelbrock Prow Flow air cleaner . And I may just get a rear end that I find at the junk yard today . It is in a 85 Z28 , it is posi and disc and 3:23 gears . Price is $ 150.00 . Would I be a fool to pass this up . I can get it tomorrow if it is still there. The guy who went with me [Aarons91RS] says I should get it for sure . What do you think?

 

That is a pretty good price for a 9 bolt. I would get it if it is in good shape.

 

Oh yeah , and KUDOS to all the people Shifty listed . I am just new and saw lots of info and advice from Shifty . Looking forward to learning from all of you TBI titans . By the way , I noticed that noone rlse has mentioned using the Edelbrock Pro Flow like I just did . Wish I could post pics but my USB port is not working for some reason .

 

I accidently made a new post when I was trying to add on to this one . I was saying that I wanted to give Kudos to all the people that Shifty mentioned above . I am new here and just saw lots of info and advice from Shifty . But i am looking forward to learning from all of the TBI experts .

 

Oops . I messed up . This was supposed to be a add-on to my other post . Sorry .

 

I merged the two for you.

 

Haha, TBI dream team, that has a nice ring to it. I think my obsession to tbi dates back to my highschool days when I first got my car and everyone said how great tpi was and that tbi was crap. Being the person I am, I just had to prove them wrong.

 

Well I got the posi rear end . It's now in my garage . Now to install it .