I should be getting a 1986 Z28, 305 TBI.
is this a 5L?

I don't have to worrie about emmissions.
What are the first upgrades that should go on it? Specs, gains, Brands, prices & locatins on where to buy would be great.

What is most coast to power gain efecient? I'll be using it as a dialy driver for the next 3 months.

[This message has been edited by Wil (edited November 17, 2001).]

 

First: get a K&N open element air filter
Second: Headers, high flow catalytic converter and Cat-back exhaust.

Those are the best two mods for a TBI engine, after you do those, you should have a better understand of how everything works.
After that you can do things like distributor cap, rotor and coil
ultimate TBI mods
spark plug wires, the list goes on and on

Just do alot of reading on the TBI message boards and youll know exactly what do to, and what to buy. It will be alot of fun, i cant wait until thanksgiving break so i can do somemore stuff to my car when i get home.
Also, look online at Summitracing.com or Jegs.com

 

sig

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1990 5.0 TBI
1 5/8" Edelbrock TES headers, 3" Catco hi-flow series cat, 3" Hooker Aero-chamber cat-back, K&N 14x3 flat based open element, MSD 8mm Heli-Core plug wires, cap, rotor, and coil, AC delete

 

z28 never came with a tbi

 

toosloz what is in the car?

 

First off, this kind of question is asked virtually every day. The search function will likely give you all of the answers you need.....

Also, some Z28s (and Formulas - not sure about TAs for sure) unfortunately could and did come with TBI 5.0L LO3 engines...

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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

Matt, thx for the reply.
I did do a search befor posting & i did not come up with anything exactly on my grounds.
(The search feature gave me to many round about answers & nothing exact.)

Maybe i searched for the wrong thing.

Will


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1978 ElCamino, Night Hawk -- 350 4barrel
1992 3000 GT VR-4 -- BPU
1993 Stealth Base

 

Yeah, the search can lead you all over sometimes - ya just gotta get used to the way it executes the search and manipulate the words that you are searching for.....

If you haven't read them yet, check out the technical articles on this site that pertain to your car... There is a lot of good stuff in those articles.

Well, I don't really know that much about modding a TBI engine, but the usual mods like the headers, high flow cat, cat back exhaust, and high flow air filter are a good place to start. The Ultimate TBI mods that have a technical article written on them on this site, are also a good mod for TBIs from what I hear.... Aside from that, I haven't really seen too many blisteringly fast TBI cars. A swap to a carb or port fuel injection setup of some kind will likely be necessary if you want to make big power. It all comes down to how much money you want to spend in the long run... just like everything else......

I don't really know how far you want to take this, or your level of knowledge on cars, but if you think it might be for you, check out the article on PROM burning and the stuff on the DIY PROM board. There is still a lot of stuff that you can manipulate in a TBI system's PROM (if you keep it TBI). And if you want to go to a TPI (or other port fuel injection system like it) the PROM burning might be more useful to ya.....

Hope that helps a bit....

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

Hey Man, I made a site just for people with 305 TBI's that want to make them faster. Has part numbers, descriptions, pictures, installtion instructions and do's and don't from my own and others experinces. A LOT of people have told me it helped them out a lot and they still use it today. Its the second site in my sig. If u have any questions, just e-mail me and I would be more than happy to help you out.

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Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
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

 

yes some Z28s came w/ TBI... but it wasnt used until 87 if memory serves... are you sure its not carbed?

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Bone stock blue TPI 85' Z28 42k original miles.

*previous car: lightly moded 89' Formula 350

 

TBI (LO3)was not used until the 1988 model year...Trans Am's did come with TBI, as did Formula's...the base Z-28 did not exist between 1988-1990 model years, as they were strictly built as IROC models. Hope I helped somehow.

 

if you dont have to pass smog, ditch the tbi setup and get a carb with a performer rpm manifold, get a replacement pipe to replace your cat, get headers and an exhaust, and get some 3.73 gears. also, for some good horsepower get a cam. this should help you out some.

 

Its rather important to determine what engine the car has... If its an 86 with TBI, you're in for a lot of work since it's not factory and could have any combination of parts in it. Post the VIN number or run it thru the VIN decoder on the main page, and it'll tell you what engine it had stock. If its not the stock engine, I'd suggest staying away from the car. There are too many unmolested cars out there to mess with something that someone else pieced together.

 

its probably an lg4, depends what you want to do, either do a tuned port motor or a carb motor...depends if you like alot of tuning or alot of electrical problems...

 

If it's a Carbed motor, get the CK metering rods or DR metering rods, and an F or lower lettered hanger, loosen the airvalve adjustment to a quarter turn over zero air valve tension, and bump the timing up to about 8-10 degrees, you'll feel the difference.

Those mods will cost all of about 15 bucks, and a trip to some local junk yards.

After that i'd suggest gears, 3.73's. That will give you about the best power for the stock motor and exhaust.. YOu'll notice a big difference.