TBI Mods.

[oldred95]

Hey guys, I thought I would let you know that I finally got my TB and TP spacer today. I shaved the TB spacer so it looked like the cfm-tech spacer but I almost ruined it. I used a gasket that came in my TB rebuild kit cause it already had the center cut out for the opening but it was off set to one side. I ended up grinding threw the aluminum into the open void on the underneath side of the spacer. No big deal just a little 1/16 inch hole and I filled it it with JB weld and kinda smoothed out the rough surface with it. I'll let you know tomorrow how much it helps.

[addiction2bass]

LOL JB weld..... that stuffs almost as good as duct tape!!!! LOL

[oldred95]

That stuff works good. My dad was overhauling an engine one time and one cylinder had a broken piston. He filled in the deep scratches with JB weld and honed it out and put it back together and it ran for years.

[addiction2bass]

Originally Posted by chevyforu

That stuff works good. My dad was overhauling an engine one time and one cylinder had a broken piston. He filled in the deep scratches with JB weld and honed it out and put it back together and it ran for years.

NOW THATS GHETTO!!!!!!!!!

[oldred95]

If its cheap and it does then job then don't make fun of it. I also got the fuel pump back in today and I went for a test drive. All I can say is its like driving a completely different vehicle. When I get on it, it actually takes off, not bog down like it used to. I got on it pretty good and had it at about 3/4 throttle and it pulled hard in every gear. It kinda lost a little momentum around 85 but it was still pulling way harder then it used to. I backed off at 95 and it was still going strong. Throttle response is a lot better to. I goose it and she goes, before it would take its sweet time building up power but now it scoots right along. Even during shifts I notice is has a lot more power. Before the mod it would fall flat on its face after a shift, now it actually accelerates faster after the shift. If I would have thinned the throttle shaft I bet it would be even better but I didn't want to mess anything up. I think I might try to find a throttle body at the junkyard and do some mods to it and make it even better and bolt it on. This is the first "real" performance mod I've ever done and it made a big difference and I love the added get up and go power. Now I hope I have enough will power to keep my foot off the gas so I can see if my mpg goes up.

[oldred95]

I ended up gainging about 2 mpg's around town but I haven't really driven it on a long enough road trip to tell what highway mileage is. I also wanted to show this to anyone who might be interested in a bigger throttle body. http://cgi.ebay.com/ebaymotors/ws/eB...7970 938&rd=1

[gmc_z71_95]

You have to modify your intake manifold to use that bored out TBI, don't you?

[oldred95]

They same seller has bored out manifolds, or a whole intake kit.

intake manifold

intake kit

It looks like they just use a stock manifold and bore it out. I wouldn't think the stocker would flow all that well even if it is bored.

[redneck pimpin]

Which ones do I do first?

[91_454SS]

Originally Posted by taz104

So, you just pull it out and put nothing in it's place, right?

thats what I did

[redneck pimpin]

What can i do?

[redneck pimpin]

Come on guys I need some info on a good starting point for some mods

[Beaver Customs]

Hey,
Depends on how much "disposable income" you have. I would suggest cat-back duals, Flowmaster/Dynomax search around for reviews. One of the most effective mods I did to my truck was a high-flo cat, increased my fuel mileage by a lot (gives a lot better exhaust tone too). Take a Saturday and do the TBI mods. Grind down the throttle ridges on your 220 unit, thin out the centre rail on the twin throttle butterflies. A cold air intake or open element style breather work are good bang for the buck addition as well.
If you can put aside 2 g's to really rip into the motor you could look at your intake, heads and cam. They were all designed with fuel efficiency in mind yet are some of the worst designs power wise to come out of GM. Edelbrock's 3704 intake is a great bolt-on mod for under 300$. Weiand makes an intake as well but it takes some modification to get it to function properly. If you felt like really getting into your motor, change the heads. Edelbrock makes a set, although thier are mixed reviews. AFR produces the best EGR compatible set as far as I've seen.
Again without knowing your budget and technical abilities it is pretty hard to help you out.
Brendan

[redneck pimpin]

Well with the miles I have I don't want to rip into the motor yet. I would like to get the macthed fuel injectors, and the bigger throttle body, and the adjustable fuel pressure regulator for now. Will that help?

[Beaver Customs]

If you're going for an adjustable FPR I would spend the extra 40 bucks or so and get the Vaccum controlled one from GM. You have to plumb a vaccum line (very easy, just don't draw vaccum from the nearby MAP sensor). It adjusts fuel pressure throughout the RPM range and goes one step closer than just accurately setting your fuel pressure to 14.7 or using an A/F guage.
I have to say though I am not a fan of the larger throttle bodies (Holley's 670 cfm unit or the 454 440 unit). On a 350 (more so even on a 305) you tend to give up low end tourque in a bad trade for high end hp. Low end tourque is a 305/350 TBI's best asset. I also don't know what mods you have done so far. Judging by your sig, my next move would definately be to the tranny shop.
Get a shift kit in and set it to stage II. Get yourself a 'vette servo or if you want to spend the extra 100, a billet super servo.

[oldred95]

I would keep the stock TB and do the ultimate TBI mods to it. At first I just shaved the ridges and there was a pretty big difference between that and a TB spacer. I week or two ago I went all out and shaved the throttle shaft. The instructions say to prop the throttle blades open but I found it much easier to leave them closed and grind the shaft from the bottom side of the TB. You will instantly notice more WOT power and if you have any sort of intake setup you will hear it roar some as well. Next I'm going to throw away the plastic spacer ring and flip the lid for good. From what I've read it will make a defening roar at WOT compared to my stock exhaust. I don't know a whole lot about the matched flow rate injectors but for the price I think I would put my money else where, I mean heck the stockers can't be that much different can they? Another easy mod is to cut a notch out of the TB spacer so air and fuel can be drawn from both bores. I've seen one that was cut clear through but I cut mine about 5/8 deep and an inch or so wide. Just be careful and make sure there is no open void on the bottom side of the TB that you might grind into. After you get that done I would definitely get a shift kit and a tranny cooler if you don't have one already.

[redneck pimpin]

oldred95, I want to do this but there is one problem this is my daily driver so I can't do all the work myself. When you take out the plastic ring what do you put in its place, or do you put anything?

[oldred95]

Nothing goes in its place. The whole air cleaner drops down and sits directly on top of the TB. Air can be sucked directly into the bores instead of being funneled through spacer ring. The only thing is you will need to make new shorter studs that hold the air cleaner down. They are meter 6mm 1.0 threads. I haven't done it yet but I'm gonna round up all the parts I will need tomorrow and hopefully get it done sometime next week.

[redneck pimpin]

I am going to a hardware store and find some bolts!...Have you tried any other mods yet?

[oldred95]

Just make sure you get the right thread. The only other mods I have are a gutted cat which really isn't a mod. My truck runs strong and has good mid and top end power compared to stock but I still want more. I'm hoping to get true duals put on this spring.