I'm removing the 305 from my 91 RS (hopefully sometime this year) and putting in a 350:

-350 4 bolt main roller block probly bored .030 over
-9.3:1 compression pistons
-balanced rotating assembly
-Dart iron eagle heads (ported to match intake)
-Edelbrock intake manifold bored to match 454 TBI
-454 TBI with ultimate TBI mods
-90# injectors
-Comp hydraulic roller cam with 206 int, 214 exh @.050 & .480 lift
-1.6 roller rockers
-shorty headers
-3" dynomax exhaust

Also i'm gonna have to learn how to datalog and burn chips

right now, i still have 308 one-legger rear end, but i'm planning to put in posi and 3.42's or 3.73's (any input on which gears to go with would be appreciated) Also, I have the T-5 tranny.

Do you guys think this combo has the potential for 300+ at the wheels and possibly 13's on the track??

 

Oh i forgot on thing: MSD distributor and either a 6A or 6AL MSD box

 

If you can put it to the pavement, it should break into the 13's,
assuming everything is working properly.

 

That should be an easy 13 second combo. I would start on the chip work now before you put a single mod on your car. I would then add mods to the 305 and do more chip work. You want to have some experience before you attempt to start out on a wild combo. This way you can put your car back to stock in seconds and you will see how your car responds to mods.

 

Good ole, Shifty:

Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work, Chip Work

 

I already have headers, exhaust, no smog pump, and open element on my 305...would it still be beneficial to play with chip tuning to get the hang of it? I already have a mild chip in my car and it seems to help performance (as long as the engine runs cool)

 

Yes! Chip work is the life of these cars. I know I may be a broken record but as soon as you start up you car with a new cam on teh stock chip you will realize why. No one likes a cammed car that is slower than stock and chugs at idle.

 

YES!! What shifty is trying to tell you is that getting the hang of chip tuning is VITAL for you to meet your goals. Your car won't even make it out of the driveway without chip work let alone make a 13 second pass. And yes your probably going to be able to make some pretty good gains with your current combo.

If there weren't people around like shifty to tell you that your combo won't run anywhere near right without chip work then then TBI would still be looked upon as a wast of time. CHIP TUNING IS THE KEY TO MAKING POWER WITH TBI.

 

As stated previously chip tuning is key to these engines. I understand how come people get angry when they throw money at their engine and it becomes slower than stock.

 

Good, now i just get to beat my head against a wall trying to learn how to do this stuff...(note my name) lol.

Seriously though, how hard is it to learn how to program chips and how much does it cost to get started??

 

That combo will most definately get you in the 13's. There's a guy who used to post on here with a smaller cam and worst heads, and he was in the 13's. You're biggest issue you're going to have is tuning those 90#'ers at idle. A good number of people on here say you need 90#'ers to make any kind of power, but you'll need to be putting out around 400hp for that.

Is this thing a daily driver?

 

from my experience and seeing what ben73 has done, 90 lb'ers are good TO 400 hp maybe a little more. JPrevost is making about 330 hp with 65 lb'ers with fuel pressure in the high 20's, so it's doable with smaller injectors, but you might as well get your idle figured out with the big injectors that way you can just add fuel on the top end as your engine needs it without needig to go back and retune your whole setup.

I don't think the 90 lb'ers are giving guys (myself included) fits with idle, it's the lopey cams combined with wet flow fuel systems in general. We're basically trying to get a glass smooth idle out of a cam that shouldn't idle that smooth. The scary thing is it's possible with FI.

 

My setup with 90#'ers wouldn't idle for crap. It was fine at WOT, but idle and low load, it would puke all over itself.

I'm using 55#ers right now, but I have 65#ers waiting for a WB O2 dyno session.

 

Here's my bio:

Stock 1992 RS - 16.0 sec
After heads, cam and exhaust and stock chip- 17.7 sec
After some chip work - 16.2 sec
After a dyno chip and a weak fuel pump - 15.5
After a new fuel pump, 65# injectors and PPP Inc. custom chip - ? Have not run it yet. But will find out on the 11th at the thirgen BBQ we are having in Phoenix. We are all going to the track afterward.

I was amazed at how big an issue the chip tuning was.

 

Ya it will be a daily driver for a while...hopefully not long after i get it built i can afford to buy a four banger to get to work and stuff.

I like the idea of having a smooth idle. (makes for an awesome sleeper ESPECIALLY if it's in the 13's) but.... you gotta love the sound of a nice rough idle. All those in favor say "I"

 

Also...would 90#ers be too much??? if so what injectors would work. Like i said, im hoping for 300+ hp.

And what about gears? 3.73 or 3.42? i probly will take it on the highway some thats why i was leaning towards the 3.42 gears, but i'm thinking the 3.73's will do me better for ET's (I hope everyone agrees that low ET's are more important than cruizin the highway) but will there be that big of a difference between the two? This will all be behind a T-5 tranny by the way.

 

13's are cool for the street, but to really be a sleeper you've got to be capable of killing the occasional giant (eg Vette, Cobra, Evo VII, STi etc)

You should be pretty good with that combo to win most of the time, but you might want to look into the juice to push out that extra .5.

Also, it's all for not if you don't build the suspension (tires as well) to plant it.

Right now my car spins all the way to 30mph with my bald *** Kuhmo's.

 

I know FOR A FACT that 65#'ers will support 325hp . . . and probably a little bit more.

90#'ers are for those guys trying to feed 383's with 400hp.

400hp-ish is the most I've heard of a TBI making. In theory is should be more though.

 

i live in montana @ about 3500 ft, so 13's on the street here is actually pretty rare. most of the EVO's STI's Vettes usually run low 14's...my plan is for this to mainly be a street car (i'll obviously take it to the track from time to time) but you're onto my goal...which is to sneak up on those types of cars and beat them...but like you said...assuming i'll be able to hook up.

I was planning on some subframe connectors, stiffer shocks, and maybe some mickey thompson's or BF Goodie street slicks.

Also one more thing...Will the ECU from the 305 work on the 350 with the chip tuning or will i have to find one for a 350??

 

68 lb injectors will support 375 hp easily if they are run at 32 psi. In effect I could feed an early model LT1 350 with 68 lb/hr injectors running in a late model 454 TBI regulator/injector pod with the right tuning.

I have heard of 500+ in some 454 ss trucks and still running TBI. I have seen 300 hp on the stock 13 psi fuel pressure with 90 lb/hr injectors. I also know for a fact that a 305 ecm on a 350 with 350 injectors will overfuel it to the point of blowing black smoke yet runs almost flawlessly with a mild 300 hp 383. I have heard that you can boost the early 454 90 lbs to over 45 psi and they will still work reliably. I have also seen even larger injectors used in Brazil on GM products there designed to run on ethanol. It takes roughly 2x the fuel to run on ethanol so you end up with twice the injector. Could you imagine what a TBI 454 would use? Mexican trucks also used a TBI version of the 292 I6 with a single TBI. I wonder what size that injector is?

Here are some calculations. All calculations are based on a BSFC of .5 lb/hp/hr and a 80% duty cycle as well as stock fuel pressure. I have also added the potential for you VAFPR fans.

40 lb/hr 4.3 injectors = 128 HP
40 lb/hr 4.3 injectors (with VAFPR @ 20 psi) = 172 HP
55 lb/hr 5.0 injectors = 176 HP
55 lb/hr 5.0 injectors (with VAFPR @ 20 psi) = 237 HP
61 lb/hr 5.7 injectors = 195 HP
61 lb/hr 5.7 injectors (with VAFPR @ 20 psi) = 263 HP
68 lb/hr 5.7 injectors = 217 HP
68 lb/hr 5.7 injectors (with VAFPR @ 20 psi) = 293 HP
68 lb/hr 5.7 injectors (with VAFPR @ 20 psi) = 293 HP
90 lb/hr 7.4 injectors = 288 HP
90 lb/hr 7.4 injectors (with VAFPR @ 20 psi) = 388 HP


By the way you will only need 156.25 lbs/hr injectors to make 500 hp. That can be made at approximately 32 psi on a big block injector. That is about what the later 1990s 454s ran stock in their TBIs. IF I had a 500 hp 454 in a 1/2 ton truck a TPI pump, 90 lb/hr injectors in the later model 454 pod/regulator would work well along with some tuning. A 90 lb/hr 454 injector at 45 psi will conservitavly make 580 HP. Squeeze the BSFC down to .45 and up the duty cycle to 85% and you could make close to 690 hp from TBI.

 

I used to have a very similar combo to that and it ran very well with 65 pph injectors at about 14.5 - 15psi. I think the 90's are unnecessary and will cause you headaches.

 

So it maybe sounds like 68# injectors might be the ticket

...oh and to correct myself i meant 300+ hp at the wheels...so what's that about 380-400 @ the crank??

 

The combo you listed could yeild 360fwhp with say a 600cfm carb. Now with the tbi, it will probably be around 320fwhp. Enough to get you into the 13s. The combo you listed is pretty well matched together. Teh cam is mild, which will make tunning alot easier. With good tuning that combo would nice tourque, maybe close to 400ft/lb.

 

13s shouldn't be a problem with that combo....

Personally I would go with 3.73s and a slightly bigger camshaft. It will no doubt make tuning a bigger pain in the ***, but it already is going to be the 'make or break' part of the whole scheme anyways...

 

You'll have 13 second ET's without a problem... now at that elevation I don't know. But at sea level that's a stout setup. I'd have gone with a dual pattern cam with more exhaust dur and lift seeing as even the aftermarket heads (unported) have weak exhaust flow.
Good luck keeping that T5 together.

 

yeah 13's should be pretty easy.there a member on the board with 243 rwhp and like 270 rwtq and he ran a best of 13.98 but mostly 14.1 in the 1/4 mile so with ur setup and say 13.1-13.5 but like shifty said tuning is the most important thing with these tbi cars