drifter-x

Will the grinding and spacer actualy make a difference if I already have headers, no cat, cat back, Edelbrock intake, chip, and custom simi-cold-air? If so, how much?

ShiftyCapone

iTrader: (7)

I don't think you will feel the difference but it will be there and every little bit counts. You can really increase the air flow and velocity of the intake charge with this mod in conjunction with your other mods. However, it will only take you so far until the size of your TBI becomes the next restriction (heads and cam).

lykan

I too am hesitant to do the mods to my 350 TBI. I have stock exhaust manifolds, but a big fat x over pipe, and 3.5" single all the way out including a high flow cat.

The TBI is BONE STOCK. I would love to take it off and open it up, but I am afraid that after all my work it might not make much of a difference. ;(

There is also the screw up factor heheh.

My question to you guys is, how expensive are junkyard TBI's? I wouldn't mind buying one and modden it before it hit the truck, so I have a spare if they are cheap enough. I would also be more inclined to do the Fuel pressure regulator mod.

One more Q while im in Hi-Jack mode heheh

Will a 454 TBI bolt onto a 350 TBI intake? if so would you even bother to put one on? Benifiets/drawbacks? I mean if I am pullen a junkyard TBI to mod, why not a 454 tbi unit?

And whilkst I am in pick and pull ode, is there anything I should keep an eye out for that might be a bolt on upgrade for my 350 TBI?

ShiftyCapone

iTrader: (7)

A 454 TBI will bolt right up. HOWEVER, you have to rewire it, and make sure you have a carb manifold or a TBI manifold with 2" bores. it is a lot of work but it is the cheapest way to go as far as a larger TBI unit is concered. I bought a junk TBI unit off ebay for around 35 bux so I could practice on it. Very easy to do and the practice unit went great and I did an even better job on the one on my car.
You can see in this pioc that is pretty self explanitory.

lykan

Is a 454 TBIO, and the 2" intake going to make much of a difference in power for me? or would it only be needed if I were to upgrade engine internals?
IM going to do headers for sure

ShiftyCapone

iTrader: (7)

Well you will eventually need 2" bores if you want to do heads and cam. The point about the 454 and 2" bores is that the stock unit has 1 11/16" bores. If you use the 454 TBI unit and you open the blades you will see a lip from the smaller bores on the stock intake (edelbrock performer TBI has the same size as well). That lip will not be good performance wise and you may actualy lose power. You can radius it down a bit but you wouldn't get the most out of that TBI unit. So in essence no matter what your combo is, the .3125 difference in bore radius is your problem.

BronYrAur

iTrader: (1)

Lykan, based on the sole fact that you have a 350 TBI and not a 305 TBI I would say you'd benefit greatly from a 454 or holley 670 tbi unit along with a 2" bore intake. Tell us more info on your setup because you would probably need to change injectors on the units if you got the 454 and if the injectors are changed you'll then need to burn a new prom.

lykan

I am running a completely bone stock TBI 350, I did a few mods to the air cleaner/intake, and noticed a real difference.

The only real hardware mod I have done is the exhaust. I am using stock manifolds, and x over, but run to one 3.5" high flow cat, and 3.5" all the way out. After the manifolds, it is really opened up flow wise.

I do however have a set of block hugger headers on their way soon.

I just figure if I am out at the pick and pull, and I get ahold of a 454 TBI, why not do the ultimate TBI mods to the bigger one and see how well it does.

I am definetaly not against getting a new intake for the larger TBI, if it will make a difference.

BTW do these wire up ok?

BronYrAur

iTrader: (1)

Headers are good you definitely need them. The 454 TBI doesn't require the ultimate mods done because it doesn't have the ridges that our 305 or 350 units have. What kind of heads and cam are on/in that engine though?

lykan

Odd i didnt get notifcation on this thread, stock cam and heads so far. I am really mechanically inclined and in the middle of soing the ultimate TBI mods.

I am wondering how hard a cam/head swap is. The technical difficulty factor.

lykan

Anyone? If i pickup the 4 barrel intake, with the 2" bores, and swap in a 454 tbi is it going to make a difference with the stock heads/cam?

Or is this just a setup I should pickup as I find it (in the pick and pull) and save until I have the cam/heads I want?

Chuck!

Free mods are real nice. I went from 16.40 to 15.812 with the ultimate tbi (shoddily done at that) and a timing advance.

nick harmon

dude my car is basically stock, i didnt even do all the mods i just made my bores extremly wide with a very, very smooth radius. wish i could show yall, im quite proud.but anyway, i was suprised that i was able to notice signifcant increase in throttle response and over all power. and it only took me a friend two twelve packs and a bunch of dremel bits. cant wait to do the other mods to the tbi.but my increase may be because my car is stock and ran pretty rich before.

ohh yeah, i did grind the throttle shafts too.

25THRSS

lets see some pics. I am particularly interested in how you guys ground down the throttle shaft.

92rsv8

i will look for my pics at home but basically you turn the tb over so you are looking at the bottom and you flatten the round bolt that goes through the blades. i think it is black and it has 2 nubs on each bore where the screws go in from the top just flatten it down and smooth it out and thats all!!! it took my a couple of hours to do the whole thing. plus i used some polish with the dremel and i polished the whole tb to gove it a shiny appearance!!

nick harmon

ditto, easy as cake!:lala:

90RS305

Someone just needs to bust out and make a friggin' 'How To' video. I'd love one... I want to do the ultimate TBI mod to my 305, but the thought of me screwing it up is just too much. And I'm too cheap to go get a practice one. Ohh well, yeah for me....

Bruce (90RS305)

ShiftyCapone

iTrader: (7)

You really can't mess it up unless you use a serious tool and just fool around carelessly. it is pretty straight forward. If you do not trust yoursefl skip the part where you grind down on the throttle blades and just do the ridge around the TBI.

90RS305

Never thought of that, I may just do that...I have a few days before I start my new job....

Bruce (90RS305)

RJ Isdell

Maybe someone can help. I'm building a 90 tbi motor. I'm putting on 062 heads,I'd like to upgrade the cam,throttle body,intake obviously because of the new heads. All on a budget. What is everything I need to gather for build.

Schurkey

Why would you dig up a thread that hasn't been posted in since 2003?

robertfrank

iTrader: (27)

I swear this question pops up EVERY WEEK.