This is my best friends car, 92' Firebird 305 TBI auto, and we want to get it faster, in the mid/low 14s without getting a newer engine. Right now he has is a computer chip, 3.42s, shorty headers(still stock exhaust from there on back though), and thats all I think it has for mods. With a 2.2 60ft time on BFG Street Radials(there was no spinning tho) he has gone a best of 15.6(I forget the mph but I think 86-89) in fairly hot weather. Where would these mods put us?

1. All the TBI Mods/porting.
2. 3" Exhaust with aftermarket mufflers.
3. Vortec Heads(milled or smaller head gasket to obtain stock compression, maybe a little more)
4. Vortec Performer RPM intake manifold with the TBI adapter plate.

Even with the stock cam, tranny, torque converter, could these mods put him in the mid 14s? Would a cam change be next to compliment the heads? I'm not sure the specs of the stock cam in this car so if you guys could fill me in I would be happy.

Thanks for the help...I'm exhausting the search function right now but didn't find much info on anyone using 305 TBI with vortec heads.

 

a small shot of nitrous would get him there alot easier then anything else right now...

 

would be a descent combo.

ditch the stock cam, no use going ot all that work, and leaving the weak link in there.

any changes like that are going to freak the computer out, make sure you can get it tuned properly, if he doesn't already budget for the equipment to tune it yourself.

for a cam i would go in the 210/218 range at 0.050. keep it on a 112 or 114 LSA, that will help keep the computer happier. with a cam, and heads like that, you might want to consider a new converter. any mods you do to get more HP, are going to raise the powerband, you will need ot adjust accordingly. it is the nature of the beast.

with a cam in that range, and the other stuff you listed, assuming a good tune, and traction, it would easily go mid 14's or better.

 

How much do the aftermarket cam/lifter kits cost for these cars?(I have an older block and alls I know is that roller lifters are ridiculously expensive, like 300+, for those)....I figure the scoggin dickey head package for the vortecs(Vortec heads, head gaskets, head bolts, rocker arms, intake manifold, intake gaskets, point intake bolts) will cost $900 and have everything I need, exhaust $250. About how much should I 'buget' for the cam/lifters?

PS- Vortec heads will be compatable with all the smog stuff correct?(We just have visual here)

 

if the block is a non-roller block (pre-87) just get a cam/lifter flat tappet kit, upgrading to retro-fit roller setups are expensive (300 for a cam, another 300 for lifters) a flat tappet cam/lifter kit will probably be $200 or less.

i have never really looked inot the smog laws for vortecs, i don't beleive they have EGR provisions, so you fail there. but again don't quote me on that.

 

look at my sig. Im hoping to be in the 14.5-14.6 range when i get new track times with my Probuilt tranny and 9.5" 2400 stall torque converter.

 

vjo90RS8: Your sig does not tell anything about your cam and heads. They aren't stock, are they?
This is interesting thread since this is near to my target: low 14's with TBI. 350 is an option but it'll be iven better if i can keep my 305

 

Guys, I just ran some #s through desktop dyno and even still with the peanut cam in the 305TBI I see nearly a 30Hp increase 5-10Tq from just from going to the vortec heads(I didn't have exact flow numbers for the swirl port heads but going from what you guys say about how bad they were I gave them about 170/105 cfms which may or may not be 100% correct)...with the exhaust and manifold I'm hoping that would be bumped up 20HP or so....do you guys think that this is accurate, that we could see a 50hp increase while retaining the stock penaut cam(eventually be changing it) and maybe be running high 14s?

 

if you're going into the motor anyway, id replace the cam too.

a cheap LT1 cam is around $50.... you can sometimes get them for less... i had one for $30 but i sold it before i used it ( for $60 *w00t*)



since you're going into the motor, i HIGHLY reccomend changing the timing chain anyway. so that cost doesnt add in...

about the only additional cost besides the $50 cam is the oil pan and timing chain cover gaskets... and if you're getting a gasket kit, you get thoes anyway.


you have the intake off, and everything i would do the cam then.
otherwise, you're just going to be disappointed with the result and have to redo some stuff when you swap the cam.

 

Wouldn't I have to buy new roller lifters too or would it be okay to use the stock ones?(this is a low mileage car) Also, are used cams a good idea?

 

as long as theres nothign wrong with them you can reuse stock ROLLER lifters.... you cannot reuse flat tappet lifters.

 

Thanks for the help.

How much will an aftermarket custom PROM chip cost for this setup if I go with the vortec heads and lt1 cam?(I think the homemade chip burning is out of scope of this little project)

 

Easy route, like Mr dude said, is to spray it. Stuff it full o suspenion mods in the back, get a good catback, and a 100-125 shot will probably yield low low 14s.

Hard route, my route (haha), is what I did in the sig. Head gasket you'll want is the FPP-1094, and you'll need gobs o tuning if you do a cam, you'll need it with heads only, too, but it should at least idle ok with a stock cam.

 

Chuck- Any track times? What do you think it will run if you ever raced a car that had times?

 

*excuse mode on*

My best time on this setup was 15.5 @ 93 on a 2.4 60'. MPH was there for mid 14s, traction was not (is now though ). That was me pulling it out of the garage, driving it 500 miles and taking it to the track. No tuning, stock tbi, and a lot of bugs. Fuel pump went bad this year so I didnt get any new times (also fixed now), but Im going home tues and it should be driveable again. A 454 ss tbi is going on hopefully over break, and if the snow holds out I'll do some tuning. I wont get track times but I got a g-tech and I'll hopefully grab some numbers off that. I'll keep everyone informed. The ol butt-o-meter says its running stronger than when I pulled the 93 off now, but we all know how accurate that is.

 

my sig says nothing about my heads and camshaft because they are both STOCK