Whats so big about the 454 tb unit? I am just curious if it has a bigger cfm or bigger injectors or what? what kind of truck did it come on and what year? Looks like I might be having to invest into new injectors and I might as well,I guess,find a 454 tb with injectors to replace my old ones. I beilve that the Turbocity injectors run 159.00 total (thats including the subtraction from the core charge of 220.00) so if I could find maybe one for 50-100 bucks in the junkyard or the the net that would be cheaper and maybe I would get some more performance out of the engine. Think my engine and its mods would be able to handle a 454 tbi?

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Eric Natzke
91 Firebird 305 TBI

ASCD Ram Air Hood-3" custom exaust-Flowmaster 80 Series-No Cat-Edelbrock TES Headers (coated)-March Pulleys-TBI Spacer-K&N Open ELement-TransGo Shift Kit-B&M Supercooler 28,000 GVW-Hypertech Thermomaster-180 Stat-3:42 GM Gears-Auburn Posi Unit-Edlebrock Strut Tower Brace-MSD Superconducters-MSD Cap & Rotor-MSD Blaster Coil-Rapidfire Plugs-265/50/R15 Tires-Emmison's all Gone-Free TBI mods
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

The 454 throttle bodies have 2" bores (opposed to 1.68" on the other TBI units) and big *** injectors, but I'm not sure exactly how big (85 lb/hr maybe?). Trucks with the 454 TBI V8 have "N" in the engine position of the VIN. They were available from 1987-1991.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

Whoa, 85lbs eh? 2" bores? Would I have to change intake manifolds since the one on there now probably doesn't have 2" bores, probably 1-6/8" bores like on my old TB unit?

[This message has been edited by 91Bird305 (edited January 20, 2001).]

 

you don't need a 454/Holley 670 type TBI on your 305 unless you rev over 4500.

 

From his mods, (headers and full exhaust), if he put the 454 TBI on there with a good intake manifold he would make good power up to 5,500 rpm even with the stock cam.

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Mods:Hooker Aerochamber 3" exhaust, gutted kitty,
March 2 piece underdrive pullies, smog pump gone,
14x4 K&N, 3.42 gears,
Eibach springs with KYB's all around.
Appearance: Harwood cowl hood, Z-28 wing, painted black(7/20/00)-original color was light blue
*All these mods were made this year
Stock Options:120,000 miles on motor, 5spd, TBI, 305, T-tops
Run a best of 16.7 @85mph before gears

 

But I have an auto that shifts at 4500rpm's.

 

You can always shift it manually, but I think i'd just get some new injectors and wait til I had more mods for the 454 TBI.

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1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
*****Possible summer '01 mods*****
Open Element, Auburn Posi, Keyless Entry, wonder Bar off the IROC, 4th gen seats, T/A tail lights

1985 Camaro IROC-Z LB9 Auto
http://www.geocities.com/krt80/

 

Yeah, guess I will go with maybe turbo city injectors. Hope that is what the problem is though. First time anything has ever gone wrong with the car.

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Eric Natzke
91 Firebird 305 TBI

ASCD Ram Air Hood-3" custom exaust-Flowmaster 80 Series-No Cat-Edelbrock TES Headers (coated)-March Pulleys-TBI Spacer-K&N Open ELement-TransGo Shift Kit-B&M Supercooler 28,000 GVW-Hypertech Thermomaster-180 Stat-3:42 GM Gears-Auburn Posi Unit-Edlebrock Strut Tower Brace-MSD Superconducters-MSD Cap & Rotor-MSD Blaster Coil-Rapidfire Plugs-265/50/R15 Tires-Emmison's all Gone-Free TBI mods
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

There are different injectors for our unit. I bought the injectors from a 350 tbi truck, they fit perfectly, and I had a dramatic increase in flow. I'm sure some of it is simply the fact that they were new, but they said the fuel throughput was higher. I don't know what years and such, but if you call the dealer, just tell them you need 350 tbi injectors. 100/side if I remember right.

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1badbird