project89

iTrader: (1)

im planning on a single turbo on the silverado 2500 i just picked up , this truck has the tbi 350 in it .

the reason im putting a turbo on it is to get back the power i have lost being at 6500 ft above sealevel. it will take 4-5 psi just to restore the engines rated power at this altitude which the tbi will handle without issue.
i plan on 7-9 psi tops just for a lil added power and since the tbi injectors cant really handle much more then that


do u guys know anyone who makes a hat/bonnet to fit the tbi units. havent looked much but it dont look like i can even modify a carb hat to work on it

anesthes

iTrader: (12)

TBI has the same neck size, and same stud in the center to hold the bonnet on.

You will need to run a spacer, factory on L05 motors.

-- Joe

Ronny

iTrader: (1)

I bought my spacer from Jegs. Aluminum 1.0'( 2x .50 in). Need to clear linkage on 7.4L TBI. The plastic one cracked. Pieces went into TB but lodged on butterfly.

[IMG][/IMG]

project89

iTrader: (1)

mine has 2 studs

freaky

can't you drill two holes an seal the center hole up ?

project89

iTrader: (1)

maybe i havent looked at it to well yet as normally with tbi i would have ripped it all off and went tpi or other means of port injection by now.

being the modest level of boost and power increase im going to leave the tbi on this one

i just ordered a ebay gt45 turbo yesterday so this weekend ill take a closer look at the tbi unit and see what i can come up with since once i saw the 2 studs for bolting the air cleaner down i didnt look at it much more thinking the reg carb hat wouldnt work

robotic_junky

Take your air filter off and unscrew those 2 studs. Then get the single style stud and screw it in between the injector pods. Last, use a carb hat on it.

anesthes

iTrader: (12)

What he said. I have not even seen a setup with 2 studs, and I've seen a lot of L05s.



-- Joe

project89

iTrader: (1)

thanks guys since u guys know ur tbi stuff how much power can the factory injectors support ?

i figure at 7 psi i should be ok , since it would be running like 3 psi at sea level , should be about 30-40 hp more then stock rating

anesthes

iTrader: (12)

I don't know about stock, but lots of folks sell big TBI injectors now. (injectors plus for example).

Keep in mind, when you raise intake manifold pressure you need to raise fuel pressure 1:1.

-- Joe

Ronny

iTrader: (1)

Two 75 lbs injs at 35 lbs FP supports 465 HP. 15.5 grams/sec or 123 lbs per hour each inj.

My calculator does not specify DC% nor BSFC.

project89

iTrader: (1)

they flow 75#'s at 35 psi ? or are they 75# at stock presure

cause 2x 75# divided by 8 works out to roughly 19# per cyl
which if u had 8 port injectors at 19#'s each u would max around 220 hp with a turbo

or am i thinking about it wrong ? like i said ive never played with the tbi stuff im not looking to build a race truck here , this is actually my tow rig for towing my 18ft campping trailer and my twin turbo iroc out to the saltflats and drag strips.
im just looking to get back some of the power the engine has lost since it now lives its life at 6,500 ft above sealevel , + maybe an extra 20-40 hp


going to be doing flipped stock manifolds ebay gt45 turbo , intercooler + meth injection with a boost setting of 7-9psi , megasquirt controlling fuel and ignition

92RS_Ttop

iTrader: (3)

My 94 GMC Sierra has the dual studs as well. I've only ever seen the dual stud setup on the later(94-95) TBI truck engines with a 350.

project89

iTrader: (1)

it is possible the engine is the later engine as the truck was originally a 4.3 v6 which is really odd in a 3/4ton 2500

engine in the truck only has 25k or so on it 350tbi things still so damn clean u could eat off it

Ronny

iTrader: (1)

My 1994-1995 truck 7.4L TB has one stud.

project89

iTrader: (1)

do any parts stores sell that single stud? or do i have to go picking threw the junkyard to find one
and since i just decided to seafoam the truck while i was at work this is what mine looks like

robotic_junky

Can't see the pic, but Advance Auto might have it. Spectre TBI Air Cleaner "S" Stud
Part No. 4215 $2.99

Here's Summit Racing:
http://www.summitracing.com/parts/sum-239007

anesthes

iTrader: (12)

Most of the L05's i've seen were on patrol vehicles before we replaced them with the crown victorias and they had a single stud.

Come to think of it, my '89 c/k truck had a single stud too..

-- Joe

Drac0nic

I would consider a set of the late 80s 454 injectors eventually. You don't need to worry about boost referencing your regulator, it's going to be under bonnet. I would get a TPI/Walbro pump and shove it in the tank, then crank the base FP to 30 PSI. After that she'll probably run more boost than you think. MS1/2 with an HEI setup? If so I bet she'll be a good runner. I always thought these were the standard carb bonnet size, at least that's what I heard. If I were going to do it I wouldn't put a ton of faith into that flimsy, offset stud honestly. I would probably make some sort of plate/clamp setup that fits on the TBI unit and holds it down that way.

34blazer

if youre going to the yard, check the caddy 4.9 air hat, might work for you.