92firebird 305

is a lt1 cam good enough since i allready have the cam now i was gonna stick it in my 305 but now im going 350 tbi. is the lt1 cam better than the l98 cam? if iuse the lt1 cam how much power can i make from it

justcallmeclassy

iTrader: (1)

Lt1 cam is a little more agressive but not much different than the L98. If you have the motor out anyway wouldn't hurt to put a new timing set in and while you're doing that since you already have the cam I see no reason not to.

If I were you id go to 1.6 rocker rollers, the 113 heads will except them. 10 to 12 hp increase right there. The 113s have old style intake bolts, unlike your tbi. You can get a new intake, or modify your old one which is stupid easy. Here's a link to make it simple
http://persh.org/pickup/TBI%20Intake%20Manifold.htm

In order to get that motor in you'll have to use a Camaro oil pan, vette one won't fit. In order to use the fbody pan you'll need a fbody oil pump to fit it in there. $20 for pump $40 for pan.

You're 305 tbi is the same a a 350, you'll just need new injectors. 350 truck injectors can be found cheap, got mine for free. 89 thru 93 caprice copcar 350s have even larger injectors.

You'll need a new knock sensor for a 350. Can be found on the passenger side of them block below the exhaust. You can get them from 350 vans trucks whatever, but I went safe and just bought one around $30.

You'll need a new prom for the ecm. The same cop cars have a chip that would be better than your 305 one, but won't be anywhere close to perfect. Do a search on EBL flash.

Id do, (and did) headers and the ultimate tbi mods at the same time. Maxize your efforts

92firebird 305

so i need a new oil paan and oil pump what year oil pan and oil pump should i get thnaks for your help how much power you think ill get out of doing this my 305 tbi right now dynos at 202 hp to the tires and 268 to the tires i have proof if you dont beleave me i just want about 320 hp and 350 tq dont have to be to the tires but i want atleast 280 to the tires or close to it what roller rockers do you think i need thanks for your help

justcallmeclassy

iTrader: (1)

The oil pan and pump on your 305 are what you need. If you can't use those go get identical ones, pretty sure (not possitive) trucks use the same.

You'll want self alligning roller rockers. I don't know about what brands are thebest tho.

I think your goals are very reasonable, you may need a more powerful fuel pump for it tho.

You should definetly look into getting a torque converter too

92firebird 305

well igot the motor its not a l98 its l05 350 truck motor my bad so what all can i do it ? and keep tbi

Ron_90

Well you've still got the swirl port heads. You could port the heads and make loads of torque up to about 4500rpm or you could get a set of traditional heads for cheap and give them a port and valve job, or if it's in your budget you could pick up a set of Vortec heads.

You can do pretty much anything to an engine and keep TBI. Hell, you could even run 2 TBI's on a bored and stroked 454

hatemail72

Whow lots to read and digest!

I have a couple of choices to make with KIJJI and Craigs list. One guy is selling a 90'S LS. With 150,000kms on it for $1600 no computer and missing wiring from the distribution block to the firewall. I viewed what was on youtube and it looked easy enough but no warranty and taking a guys word that it is worthy

Then I have done alot of reading between this string and CFM tech regarding the TBI. It has alot to offer. I beleive that my exhaust valve is cracked Therefore I have to repair or replace as this will definatly not pass the emmisions test

Currently it has a 305 L03 TBI. I will be doing the recomdations made by CFM Tech in the near future. Have decided to stay with the system I have and up grade it! The question is
What head? 14101083, L05, L98, LB9, VORTEC
What cam? I am lost hear LT1 or what several have been recomended this being the top
What intake? I read only the one entry of a RPM performer intake with TBI set up.

I am not a engine guy. I enjoy the drive the look the feel. Needing your suggestions before spring

Thanks

justcallmeclassy

iTrader: (1)

If I were you I wouldn't put a 350 head on a 305, you'd loose a lot of compression. Besides L05 heads are just L03 heads but bigger. They're desinged for extreme lowend torque, I mean low like run outta breath at 2500 rpms, so poor choice. Vortec heads folw nicely, but there are many aftermarket ones that outperform them that would be brand new, but once again I wouldn't use those on a 305. LB9 heads are a popular choice for the L03 with the LT1 cam, because of how cheap they are and the huge performance gains over the little disgrace of a V8 called the L03.

If you stuck with stock GM castings my vote for heads would be the Aluminum L98 heads (casting ending in 113) found on 87 thru 91 Corvettes and the ZZ4 crate engine. They have the same compression ratio as 305 heads so know worries there. Plus they're much lighter and have d port exhaust which is supposedly superior in scaveging. GM says they'll support up to 350 hp.

Best advice hands down is to get a 350.

Race-Dave

Hey, not to change this thread, but what do LB9 heads come on, I'm interested in upgrading my 305 with better heads and cam.

justcallmeclassy

iTrader: (1)

TPI 305s, engine code LB9......

Ron_90

Either those or the LG4 heads (casting number 416). Even the lesser-known 418 casting works well.

hatemail72

what is the casting # for the 416?

the l98 was one of the heads that thought would work. They are dificult to find and when you do they are sitting at 800-1000 bucks
Now what cam

Ron_90

416 is the casting number; well the last 3 digits of the casting number. The engines with the 416 heads are the LG4's- carbureted 305 engines. Pretty much any carb'd 305 heads will work.

Don't discount the L03 heads, though. They're great street heads and make a crazy amount of torque up to 4500 RPM when properly ported.

justcallmeclassy

iTrader: (1)

I've seen several sets sell for $400

WilliamSilver

iTrader: (6)

Just a suggestion.

Vortec heads, LT1/LT4 cam with EBL could = success?

I mean, its cheap, and has potential, mill the 350 vortec heads down to get the right compression ratio. Could be possible right? Pretty sure you can mill the heads down to a safe level to get the desired CR

sorry if its a repeat of what was said.

hatemail72

Yeah they are costly I have seen them around a grand as well looking for a cheeper head but same options or better now for the cam lt1 lt3 what supplier

justcallmeclassy

iTrader: (1)

That hasn't been suggested on this thread but has all over this site lol

Not sure if Vortecs will accept the lift of the hot cam

Ron_90

Not many people do it for some reason, though. robertfrank has the ZZ4's, mw66nova built a 305 Vortec not too long ago

Ideally you'd want the 059 Vortecs with the 58cc combustion chambers.

and here's a surefire formula for a 14 second car. I don't think he even ported the heads. This belongs to mw66nova's friend Kody.
port those bad boys and run TBI, you might have a 13 second car.

petrolhead

Now to throw another iron in this controversy! I'm looking for the bang for the buck as far as tuning goes. From what I've read, the ebl flash is the way to go, any other ideas?

hatemail72

Check out these to sites
http://www.tbichips.com/305mods.htm
and
http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm

hatemail72

sorry what is EBL

Ron_90

Probably the best thing to happen to tuning since the pocket programmer

http://dynamicefi.com/

Rob (RBob on the forums) produces this and he offers a great product and great support

hatemail72

Did you buy yours or send out yours. What was the cost to do so and do you get much business having one

petrolhead

For the price, it seams like the best way too. To get a chip from tbi is the same price, and you don't get to keep the equipement. Am I right?

Ron_90

Chips are about 150-250 and you can't tune your own or use a Vacuum Referenced Fuel Pressure Regulator, which means you'll have a pretty bad idle once you get high up in power (and therefore fuel pressure). Furthermore, you can't program it to accommodate upgrades. But still, Car Craft got their 305 TBI to turn 330fwhp using a chip.
Figure EBL is 350-430 depending on what package you got and how much.. well worth it.

Of course, the other option is to tune your own PROMS- this is a solid option as well. Definitely an option if you plan on upgrading to higher fuel injectors (do you don't have to run high fuel pressure)- there's a breakdown of all the fuel injector/pressure math in the Budget TBI build thread.

And @hatemail- I bought the whole ECM from someone that bought it but ended up going in a different direction with their build. If I hadn't gotten the deal I got on it, I would have gone with larger injectors and PROM tuning setup.

Once my engine is finished I will post the Ultimate Guide to building a 305 TBI that I've been working on. Hopefully I'll be able to consolidate much of the information I've spent hours finding and reading and answer much of the questions surrounding the building and tuning of these engines

one92rs

iTrader: (5)

i think it depends on the mods as to how it will idle. i dont have a whole lot of internal mods and mine runs perfect. everybody pushes ebl flash which is great. BUT! YOU HAVE TO TUNE IT YOURSELF! if you are not up to it and dont want to learn a whole lot (since every engine is different no matter if same mods) it is very time consuming. it is all up to you.
couple things.
is a custom chip mail order going to be spot on perfect---no but close to it
is a custom flash from your laptop in which you are going to learning going to be spot on--no not for a while.
its your decision. best of luck.

Ron_90

Very well summed up. Except for the EBL Flash part. Technically you can be lazy and simply tell it to "learn" to adjust to things and not bother with much other than that. Probably wouldn't justify the cash outlay but it would definitely run better

hatemail72

But is it gaining everything it needs if it learns by its self

Ron_90

I guess you could say so, but you're still going to have to plug it into a laptop and do some adjusting. It seems kind of overwhelming at first but after you learn the basics it's really not that bad.

Once again, it all depends on what your goals are. By the way, what do you want from your car/new engine?

b1k1w1

I like the lt1 cam trick has anyone really done this to know how it works. Or is this just a thought to save a buck. Since your are going with tbi just use an adaptor on a good intake. But the one guys right it just a 2bbl carb with injectors you don't get the throttle response. And be careful for a grand on stock heads is a wast of money better aftermarket for same price or less. Even new vortec 650 and if your going to get intake vortec cost about the same a tbi intake.

b1k1w1

vortec as 060 or 906 if your going to 350

Ron_90

LT1 cam is really just to save a buck. It's a decent stock grind but there are definitely better options for a street engine- I'll probably upgrade after I get everything tuned up with the LT1.

I wouldn't say TBI is just 2bbl with injectors- it's better than any 2bbl or 4bbl setup for 355 on down due to the normal carb tuning problems that are solved by the use of a computer, not to mention the better fuel atomization produced by injectors.

petrolhead

I didn't know the ebl would self learn, that is very encouraging for someone like me who has never done it before. That will at least give a starting point and fine tune from there. I have a 454 tbi on a performer intake on a 350 with a lt1 hot cam. It runs so bad with the crossfire ecm, I've considered parking it until I can afford a ls1 swap or something. But I'm beginning to understand that I can get good performance and good milage as well, so I'm gonna go for it and I might save myself an ls swap.

mw66nova

iTrader: (13)

i did NOT build a 305 with vortec heads. i built it with 113 casting aluminum vette heads.

Ron_90

That sounded wrong as I typed it. Were those ported and milled?

hatemail72

i heard that 059 heads wont work with the TBI intake

Ron_90

Correct, they will not. The 059's bolt onto the manifold with 4 bolts on top instead of six on the side

I'll get back to your PM soon- I had exams this past week so I let my PM's and such slide

mw66nova

iTrader: (13)

they had a light bowl blend, and the valves were back cut/polished. they have a 58cc combustion chamber factory, so the scr didn't go down any, so no mill work needed. i did go with a steal shim head gasket to boost the scr up to around 10:1 to take advantage of the aluminum heads' detonation deterant properties.

mudmonster

my 89 k1500 came with an l98 with tbi performance chip and throttlbody spacer. Couldnt get it to run so it got replaced with my stock 350 tbi from my other wrecked truck. Upon inspecting the l98 I fount timing gear was installed wrong and they put 1 1/2 in center intake bolts in and they got into pushrods bending the **** out of them. I plan on rebuilding l98 with afr 195cc heads, cc306 cam and forged bottom end and stickin with tbi so dont feel alone in this little buddy lol

SCCAjunkie

I can at least make an apples-to-applesauce comparison. This is all butt-dyno, but mine is consistent and well-calibrated, according to many around here.

Old car: 1990 Formula 350

Got it stock (except 3" single cat-back Flowmaster). Ran well. Good torque and power. Swapped in 3.73s, ported intake with SLP runners, I burned chips. Notice: stock exhaust manifolds. More mid-range (a LOT more), no loss of bottom-end, and woke up nicely with the gears. Fell on its face at about 4500, but would strain to 5300 if you pushed it.



New car: 84 Z28 with a 91 L98 in it- Holley Projection, same old flowmaster exhaust (literally I think), 3.42 gears, and a T5.

Right when I got it, it felt AMAZINGLY like my Formula did when I got rid of it. Lots of mid-range, great low end, and fell of in the mid 4000 range. Felt *slightly* snappier, but I attribute that to auto-vs.-stick.

On my local test road, the new car ran 85 mph trap, and the old ran 92. I thought this was weird, since they *felt* so similar. Then I figured out (just this week), I have the wrong speedo gear (red, for a 3.73). Take this into account, and the speeds are very close.

Moral- *IN MY PERSONAL EXPERIENCE*, the TPI did not make a substantial difference versus the TBI.

BTW- just threw headers on 2 weeks ago, and now the car pulls right through 5500, and is running 91 mph through those traps on the speedo (about 99-100 corrected...).

stealthram92z

iTrader: (2)

I did my great running 92 L98 out of my 92 Z in my 92 RS with a tbi on it . It works pretty good and can run next to my buddies 92 L98 Z28 till about 85mph then he slowly pulls on me.

thomas1976

Sounds like something is wrong, or the tune and fueling are not set up properly.
I remember my "old" LO3 with upgraded exhaust, LT1 cam, 46mm bore 3704 intake manifold, DIY flat base CAI, 3.23 gears and DIY EBL flash tune, would run pair with my old 91 5.7 Z28 all day long.

stealthram92z

iTrader: (2)

I'm going to swap to 350 injectors , chip and possibly a knock sensor, just to see if it helps on the top end. From a dig I can pull half a car on him and like I said by 85 or so he catches me and very slowly passes me. I'm not sure if I'm running out of fuel from the L03 injecters and tune or ?

thomas1976

For sure will be like night and day once you set up the TBI to feed that L98 long block.
The LO3 injectors and tune are set up for a 305 that produces 170hp at around 4300 rpm. The L98 long block will probably be capable of something like 280hp at around 5000 rpm.

If you want to discuss your set up and details it would be better for you to start a new tread in this forum.

ninetyone

iTrader: (2)

They should have used tpi in trucks and 350 tbi on the cars instead