350 TBI to 383 Vortec fuel help!!

[darksurfer11]

Sorry it has been soo long since I have last been on, I just got back from my military training not too long ago. I know this topic has been beat to death, but currently I am having a 383 built with vortec heads and a comp cam (I don't have the specs on it right now, but will post them as soon as I can) to replace my old and tired 350 for my 95 Suburban. When I last talked to my builder, he said that this particular motor he is building for me will make about 375-395 and he as gotten as high as 425 hp out of it. I tried to search the forum for some advice on fuel support for this motor, but either my computer is being retarded or the search box is currently inop. What I have been able to find is that while you can get the 454 tbi to support those numbers, you will run rich at idle due to the injectors not being able to get the pulse widths low enough to remove enough fuel and still have enough fuel for your top end (if I understood red94chev's post correctly as found here: http://www.fullsizechevy.com/forum/g...-carb-tbi.html). I tried looking for the edelbrock 3502/1 and could not locate one for sale. If anyone has any alternate solutions that will not break the bank it would be appreciated. And if I am just completely retarded please point me in the right direction, thanks for your help

[darksurfer11]

Update: Here are the engine specs:
383
vortec heads
GMPP vortec to tbi intake
comp cam 12-388-4
hypereutectic piston 18cc dish
4340 steel 5.7" I beam rods
3.750 Stroke Crankshaft 9000 series
decked and balanced internally and externally

So it looks like the engine is going to be more around 370hp, so I was wondering if maybe just using the 454 TB with the 350 injectors and upping the fuel pressure would be able to support this motor. Any help is greatly

[darksurfer11]

anyone??...

[canadianstroker]

Buy a prebored SB TB and use BB injectors you will also need to upgrade your fuel pump. A custom tune will also be needed or she won`t run.



Update: Here are the engine specs:
383
vortec heads
GMPP vortec to tbi intake
comp cam 12-388-4
hypereutectic piston 18cc dish
4340 steel 5.7" I beam rods
3.750 Stroke Crankshaft 9000 series
decked and balanced internally and externally

So it looks like the engine is going to be more around 370hp, so I was wondering if maybe just using the 454 TB with the 350 injectors and upping the fuel pressure would be able to support this motor. Any help is greatly

[darksurfer11]

Buy a prebored SB TB and use BB injectors you will also need to upgrade your fuel pump. A custom tune will also be needed or she won`t run.

So, a bored sb throttle body will flow enough air?

[canadianstroker]

So, a bored sb throttle body will flow enough air?

Yup no problem you can get a 2" bore SB TB ( BB TB is 2" bore )....lol I have one sitting on the shelf with BB injectors bore matched spacer and intake that is also flushed out to try to keep the stock look. It worked very well easy to set up and tune very reliable performance mod but you need the motor to support it or all a waist of $.

[darksurfer11]

As of right now, the cam has been swapped for a comp cam 12-256-4, and I have been talking to Brian at tbichips.com and it looks like I am going to go with the 2" bore SB TB, SB injectors with a 22 psi spring in the FPR, a set of shorty headers, new y-pipe as well as a chip from him. I am pretty stoked for this motor to be finished and installed. The reason I don't wanna use the BB injectors is because they have more issues with running too rich at idle and performance, fuel consumption and extra wear and tear aside, emissions are stupid here...

[YeKong90]

If not conditioned arid enough, the sole of the basal or plantar fascia can become affronted or damaged with activity.

[darksurfer11]

If not conditioned arid enough, the sole of the basal or plantar fascia can become affronted or damaged with activity.

What?? :wtf:

[Botan]

What?? :wtf:

dont worry i reported the guy, he has been spouting nonsense all over the forum

[canadianstroker]

The only issues with BB injectors is the tuner that can`t level out the fuel trims and as far as performance there great I rolled 21 mpg out of a built 383 and easy 15 in town driving like a mad man....2- sets of rear tires a year from daily driving.
Don`t for get to run a vacuum refurance fuel pressure regulator it will help smooth her out. I only needed to run 14 psi with a higher volume fuel pump the stock pump won`t do....you will run out of fuel.


As of right now, the cam has been swapped for a comp cam 12-256-4, and I have been talking to Brian at tbichips.com and it looks like I am going to go with the 2" bore SB TB, SB injectors with a 22 psi spring in the FPR, a set of shorty headers, new y-pipe as well as a chip from him. I am pretty stoked for this motor to be finished and installed. The reason I don't wanna use the BB injectors is because they have more issues with running too rich at idle and performance, fuel consumption and extra wear and tear aside, emissions are stupid here...

[darksurfer11]

Ok, so with a vrfpr, would it be better for me to find a local tuner, or would brian at tbichips.com be my best bet? I am in utah and don't know of any local tuners, so if anyone has any recommendations that would be awesome.

build thus far:

383
vortec heads
bored sbc tb flowing 700 cfm
sbc injectors
255 lph fuel pump
y-pipe: http://www.summitracing.com/parts/FLO-Y250300/
shorty headers: http://www.summitracing.com/parts/SUM-G9014/ (still unsure which ones I should get, want to stick to single exhaust for more low end tq)
GMPP vortec to tbi intake
comp cam 12-256-4
hypereutectic piston 18cc dish
4340 steel 5.7" I beam rods
3.750 Stroke Crankshaft 9000 series
decked and balanced internally and externally

[1.721afr]

I wouldn't sweat a VRFPR unless you intend to use over 35psi of fuel pressure.

Get it tuned right with an EBL Flash.

http://www.dynamicefi.com/EBL_Flash.php

[darksurfer11]

Problem with the EBL is I have no idea how to tune it myself...

[Doober]

It's not too difficult to learn. I'd never done it myself before getting an EBL either. You won't get what you need from a mail order tune... about the only thing those are good for imo is a stock engine, or one with minor mods like air intake, headers, etc.

The EBL (or any other self-tuning standalone system for that matter) will tune it precisely and way better than the best mail order 'tuner' in the world.

[darksurfer11]

I will most likely invest in one, I have run out of budget for the time being though...and I am currently for my back-ordered rotating assembly from scat...

[40ozthreat]

I got everything you need up for sale. I also have an inline fuel pump to bump up the pressure. I can work on a package deal for you if you are interested. http://www.fullsizechevy.com/forum/classifieds/sale/engine-drivetrains/497441-tbi-performance-parts-autoprom.html

[darksurfer11]

Thanks for the offer, I got everything figured out fuel wise, new problem is going to be tuning. I looked at the EBL idea, problem is that I have the 4l60e, I am looking at the autoprom or ostrich 2.0 option. Any advice or autotune helping option would be nice

[darksurfer11]

New problem...figured out the EBL, just need to piggy back the EBL ECM along with my pcm and repin...but on to the new problem. Doober I had read that you did a similar swap and had egr plumbed in. 1. the headers I ordered have an o2 bung already on the drivers side, so is there any relatively easy way to run the egr tube from a 96-99 from the intake to the o2 bung, which is placed right where all the primaries combine, and if so, what all parts do I need to do this. I hate the fact that I have to have emissions...

[Doober]

I'm pretty sure the intake has a fitting for it and you just use a stock EGR hose. I have the valve on the intake but I don't actually have the tube that runs to the headers.

[darksurfer11]

I know the GMPP intake has the port for it, but I don't know whether or not it has the actual fitting. I think what I am going to have to do is take the thread pattern for the EGR port and my o2 sensor port (my current o2 is located right in front of the cat) and custom make a pipe with those threads. I'll post back when all is said and done for those who are in a similar boat (visual inspection for EGR...).