THIS IS MY FIRST POST. JUST BOUGHT A 91 FIREBIRD, WITH A 5.0 TBI ENGINE. I WAS WANDERING ABOUT A GOOD STARTING POINT ON MODDING THE ENGINE. AND ANY SUGGESTIONS ON MODS TO THE TBI ENGINE???

 

advance the base timing 6*
Get some cheap ebay headers and exhaust.
Get an better intake
Get 3.23 or better gears.
Get an lt1 cam or 1.6RR.

check out sig if you have more questions.

 

Caps means you are yelling in cyberland so turn them off

Go to www.thirdgen.org and look over their tech articles, as well as the TBI forum. Tons of info just like you want!

 

I'd start with a full tune up:
fuel filter, "K&N"air filter, Bosch "Super"plugs, Accel Super Stock plug wires, Accel distributor cap&rotor button, PCV valve, oil change with Pennzoil Synthetic oil, Bosch Platnum 02 sensor.
Start with initial timing at 10*BTDC, if it pings back it off 2*'s at a time until it stops.

Flow tech headers ($89.95 @ Summit Racing/Jegs)
Catco catalytic converter($55 @ Autozone/Advance Auto)
Cat-Back exhaust ($156 @ Summit Racing/Jegs)
Lakewood Lower Control Arms ($87.99 @ Summit Racing/Jegs)
670cfm Throttle Body($369.99 @ Summit/Jegs)

 

Whatever Engine Mods you bolt on will not make this engine a screamer. The biggest hold ups are the Heads and Cam and until you relize this, you may be wasting your money. Only so many things you can do within these big limitations.

 

14's are possible with stock heads and cam, if you want a good basis to follow search for Blackbird305's mod list on www.thirdgen.org , he went 14.9 I believe. Deadtred1 (I think is his name) also did it, but he now has an lt1 cam in it and is trying to go 13's with stock heads. I dont know how close he'll get, but hopefully we'll find out here soon.

 

I have had 3 TBI cars and here is where I started.

5.0 H.O. Dual snorkel air cleaner
CatCo. Converter
Larger Y-Pipe
Cat-Back with 2 1/2 or 2 3/4 Intermidiate pipe
MSD Ignition module
MSD Plug wires
AC Rapidfire sparkplugs
Decent chip mostly for speed limiter removal
Low temp fan switch
Underdrive pullies

Before my 91 Formula was totalled I was in the middle of a VORTEC conversion and an upgrade to 3.42 gears.

 

Only Mods that added any Horsepower are the Exhaust ( about 10/15) the rest are just tune Items.

 

Underdrive pulleys will free up some extra hp and a 5.0 H.O. air cleaner adds 1/4 second in the 1320! good luck

 

You will be lucky for any gains with underdrive pullies ( 1Hp or less). Don't belive the Mfg claims and the only thing you get with them are alernator problems. Not a item for a street car.

1/4 sec gain in the quarter mile, in your dreams again.

I am not trying to bust someones balloon, but be realistic with this engine. It was not designed or meant to be a high performance one, only a Base V8 to move a 3500# car around better then the Imports at the time.

So you have nice transportation, but its a 15+ sec car no mater what. Spend your money on appearance items or swap out the engine. My opinion like it or not

 

I like 87DJP2001's idea better AND it's cheaper hehe

 

geuss the summit catalog got me on the pulleys and someone told me a 1/4 sec i was skeptical but just passin on info. now that yall mention it....JBIRD91 why dont you do an L98 or somethin?

 

You're not the most observant guy are you . It's been done, and done, and done, and done. Numerous mags have have documented anywhere from .2 to .5 gain over the stock single snorkel on a stock or very close to stock 305. There are literally at least a hundred guys over on www.thirdgen.org that would agree. Do you have any personal experience on this... thought not.

Don't add your advice if you don't have the knowledge or experience to back it up. You just end up confusing and angering others, not to mention make yourself look foolish.

 

85Z28
I see that you are running a Carb on your 85 305 with the dual
snorkle. Now with 20HP more then the 91 TBI you may run faster.
I have enough knowlege to know you cannot compare a Carb to TBI set up on different engines.

 

DJP-cover half your air filter with sheet metal and run the 1/4. Then take it off and run it again and see if you don't gain .25 sec over your previous run.

I fully agree about the pulleys though....they don't do much more than cause charging system problems.