dairy

Ok so I have two thoughts of how to go for the start of my build.

Backround:
90 Camaro 305 TBI 5speed
3.42 Posi Rear out of 91 Camaro
Stock Headers with open true Dual
Stock TBI with open element and K&N X-stream top.
Stock Cam, Intake, Chip

Dyno at 150 hp and 250 Torque running on 91 Octane and no O2 Sensor(Since been Fixed)

1st Route (What Im leaning too):
Replace Plugs, Wires and Cap with Bosch 4449 Plugs, Davis Unified Ignition c9063rd 10mm wires, MSD 8406 Rotor and Cap - $150
Ultimate TBI grinding
Install Flowtech 11102FLT Headers keeping free flowing true duals - $200
Install March 4010 Pulleys Claiming 12.5 Hp at the wheels - $200
Install 350 Injectors - $50??
Install Custom Chip From HarrisTbiChips at ebay (http://www.ebay.com/itm/400184736501...84.m1438.l2649) Claming 20 HP - $150
Intall Edelbrock 2104 performer intake with adaptor -$200

This to me seems like the easier way to go because there is not really any choice of what to buy and you dont have to match parts.


2nd Route Buy cheap heads and cam then do exspensive parts of step 1 that have not been done.
Install Pro Action Ported SBC Heads - 223cc Intake runner, 62cc Cumbustion Chamber size, 2.055 intake 1.6 exhaust valves, .6 lift, 145lbs seat pressure, bowl ported, port matched, Exhaust D ported. For $650 on Craigslist (Have been on for months) at most.
Install Comp Cams CL08-410-8 .5 lift and 206 duration with hydrallic rollers. $500
Install Intake, Injectors, Chip, headers, Ultimate Tbi Mods, and Plugs and wires from above.

This is more exspensive as there are other parts needed with installing that are not calculated but I would like to attempt these mods. (I Dont know if these are a good match). The main problem is money and I would wait for winter as this is my primary driver during the summer.


3rd Route (Dont like wanna say have 305 and keep 25+ mpg at 80 mph)
Buy GM 350, FUEL INJ.TBI 150 AVERAGE COMPRESSION and chip for around $600 total.

Cheap easy most power potential.


I tryed to provide as much info as possible. Please be open minded as I am a Mopar guy but do like Gm and am fairly new to any mods with the moving assembly.

imeredith

While I do not know a lot about the limitations of the factory TBI setup, I do know motors, and the 2nd route you suggest would not work because those heads with big valves will not fit on your small bore 305 motor. Overall, I think your third choice is the most sound for making power. Remember, there's no replacement for displacement.

seanof30306

iTrader: (4)

It is awesome to have a chance to catch someone right at the start of their project, before they make any mistakes.

Before you do ANY of the above, consider this.

If you want to have a TBI project car, before you do ANYTHING else, you MUST learn how to tune the ECM. A MAP fuel injection setup is like a blind person that has memorized where everything is in their home. They can navigate it very well, but if anything changes, they're in trouble. A MAF FI adjusts the amount of fuel injected to the amount, and even the quality of the air, but a MAP relies on pre-programmed tables. If you change anything, the MAP EFI can't adjust to it.

Let me give you an example. I decided to do the exhaust on my L03 Formula. I went with SLP 1 3/4" shorties, dual Random Technologies 2 1/2" cats, a 3" mandrel-bent intermediate pipe, and a Flowmaster 40 series muffler. On a carbed car, that exhaust would have been worth a minimum of 20 hp. Probably closer to 30. On my car, I believe I got 7hp; maybe it was 9, I don't remember, but it was definitely no more than 9 hp. Why?

The answer is simple. I didn't tune the ECM to match the changes I'd made, and the MAP couldn't deal with it. Now, since the exhaust allowed air to flow more freely through the engine, I could have raised the fuel pressure, or gone with bigger injectors, but that is very imprecise, and the whole idea of having fuel injection over a carb is precision.

If you're not tuning your ecm, every change you make will yield increasingly inefficient results. Before you go any further with your project, you have to decide whether you want to learn to tune, or not. if you don't, I would strongly suggest you leave it stock (or nearly stock), switch to a carb, or go with another car.

Now, this board is full of really smart people who were exposed to chemicals and gamma rays before their birth that caused them to develop inordinately active brains, and they have chosen to apply that mental horsepower towards tuning TBIs. Guys like Dewey316, Dimented24x7, and that mad genius, FAST355, who at the moment, is busy installing Embedded Lockers on his weed whacker.

These guys, and many more just like them, would be glad to help you learn to tune your car. Leave it stock (for now), put a couple of hundred bucks into Embedded Lockers (is that still the best way to go?) and tune it. Dewey316 did that, and got A LOT more out of his stock setup, and as he began to make mods, was then able to get optimal results from each one. I've been trying to get him to do a detailed write up of his process and progress for years, but once he discovered how much **** was available on the internet FOR FREE, he hasn't been able to find the time.

The next thing to look at is your 305. Now, this is blasphemy to the L03 FanBoys, but it makes no sense to put money into the 305. As someone just said, the small bore means you can't use big valve heads, and the bore/stroke ratio aren't optimal for power.

For under 1,500 bucks, you can get a new L31 shortblock with a high-nickel block, hypereutectic pistons, and 4 bolt mains. For under 800 bucks, you can get Vortec-clone heads. Couple them with the right cam, and you have a combination that is capable of well-over 400 hp (if you could get your TBI to deliver the fuel and air, that's another discussion, entirely).

That doesn't mean you should immediately rip your L03 out of the car. I've had mine since 2003, and it is still going strong. Drive your L03 and enjoy it, and learn to become an expert at tuning while you drive it, and save your money for a 350 upgrade at a later date. Just remember one simple rule:

MAKE NO MODS THAT WILL NOT SWAP OVER TO THE 350.

For example, the flowtech headers you're looking at only have 1 1/2" primaries. They'd be OK for a 305, but not for a 350 (or bigger). Some may argue that, but they are wrong. If you look at my exhaust, it's overkill for a 305, and I knew that when I did it, but my plan was to have an exhaust that would work well with a 383, and mine is more than capable of that.

Tune, my friend, tune. That is your future.

BTW, in my opinion, that 3.42 gear is perfect for a street car. Many will disagree, insisting a 3.73 is better, but unless your goal is burnouts or drifting, all a 3.73 will do on a car with street tires is make it spin the wheels. The more power you put to it, the worse that gets.

Good Luck Young Tuner!

UnderCover89TBI

iTrader: (25)

If your going to mod the 305. retitle the thread my first and only 305 tbi engine build. you'd like yourself and your car a lot better if you went ahead to the 350. you can buy 350 tbi engines pretty cheap off craigslist. just my

robertfrank

iTrader: (27)

Looking back on my car and all the things I've done I really wish I hadn't wasted my time with my L03 ( OMG!!!!!! I know,lol) Just for fun I decided to race both my 88 tbi car against my damn near bone stock 91 L98 car with 210k and a mildly slipping transmission and the results for me weren't what I had expected. The first race I spun horribly out of the hole (both cars have Nitto NT555R radials) and I only beat it by 2 cars. On the second race after I added some weight to the rear of the car ( I only had a touch under a half a tank of gas in it) with 2 of my 35lb dumbbells I have at home we both dead hooked and I still only won by 4. I was expecting much more from it. I really wish I would have built a 350 back when the opportunity presented itself. Sadly I know my car is an honest 13.5 second car but even that these days isn't that great. So take my advice and just play with the 305 for now and build the 350 on the side or........if you can find one go with an LS based engine. I'm finding out myself that you can build one for fairly cheap and get very impressive results if you shop around and play your cards right.

dairy

Sounds like my plan that wouldnt happen for years. I thinking building up the 305 for practice would be good. I had allways wished to get the 5k+ together to buy a new LS1 from jegs and drop that in my car but I havent looked at how much work or more money is involved.
I think my first plan is the one to go with.

seanof30306

iTrader: (4)

So, in fact, you weren't looking for advice, you were looking for validation.

And, even though every bit of advice you got from people with years of experience pointed out the fallacies of your plan(s); even though one of the biggest L03 fanboys on this forum, whose cardomain page touting itself as a foolproof guide to L03 performance is full of all the L03 disinformation that's been floating around on here for years now says he's realized all that work yielded poor results, and he now wishes he hadn't been so obstinate about the 305, none of that had the slightest effect on you.

Good luck to you.

robertfrank

iTrader: (27)

I wouldn't necessarily call it disinformation due to the fact it could be applied to a 350/383 and yield positive results. I just now think that going to a larger displacement is the way to go if power is the main concern, not everyone wants a sub 13 second car. Some people would just be happy with making the car peppier and more fun to drive which all the mods that I mention in my page will definately make happen. I just realize that using the 305 is good for a "learning platform" for future mods as that is what is was for me. Luckily I don't have a ton of money in the build up of the engine itself (everything was ebay purchased and cheap) plus I did ALL of the work myself for a round about total of 1k. That includes the Head with the rebuild and port work that I did myself, the cam, intake with all gaskets and fluids. so it hasn't been a "terrible" or "poor" investment if all I wanted was a 13.5 second car.

seanof30306

iTrader: (4)

I'm not knocking your car (although, honestly, I find 13.5s a bit hard to believe), but the fact is, you call your cardomain "the future ultimate source for TBI performance in the link, yet there is much of the same incorrect disinformation that has been floating around on this board for years.

For example, on your section intakes. Carbs pulse, which is why dual planes make better torque, while single planes tend to make more hp. TBIs don't pulse, and the best intake for both torque and hp will always be a single plane, because of it's plenum volume.

Another example is your section on gears. You recommend 3.73s for manual transmission cars, when the fact is, with street tires, all that'll do is spin the tires, and the more power you build into the combination, the worse that wheelspin gets. Even with just a 170 hp L03, I get 60' times in the 2.0 range with just a set of old Michelin Pilots, because my 3.42s hook up with my T-5, while time and again, guys in the other lane with 3.73s sit there and spin.

Then there's your supposition that the underdrive pulleys made more power, when time and again, people have put them on their cars, and gotten little or no improvement in HP, or ET.

It's like the open element. People put them on the car, and suddenly they hear this big WHAAAAAAAA when the hit the gas, so despite the fact that they are now sucking hot air straight into their throttle body, they swear it makes more power. I've run my stock air cleaner down the track, and I've run no air cleaner down the track, and there is virtually no difference, but the people who run open elements will fight to the death over it, despite the fact that they have done no testing, and have no data to support their suppositions.

robertfrank

iTrader: (27)

The mods that I put on there are sound, as far as the intakes go the Performer RPM intake does work fairly well on this application, Plus it's an easier install than your typical single plane depending on brand. With the gears I have driven a few thirdgen's with 3:73 T5's and had no problem hooking from a dead stop with them, It all depends on driver skill and tire selection. If you're side stepping the clutch and punching the gas pedal you're definately going to blow the tires off. For the underdrive pullies I agree that there are better ways of gaining power, I never stated they gave me 20hp or what not. What I meant by "more power" is that the car felt better and spun up more freely. I'm sure it was more of a placebo effect than anything looking back on it. I understand your reservations as to what I put on that page but everything there is more for a beginner than anything else. Also I haven't trully undated the page in quite sometime outside of pictures so I do think myself that I need to change a few things.

seanof30306

iTrader: (4)

It's the beginners I'm concerned about. They come on here, they see you have a nice car, they see your high post count, so they naturally assume you are knowledgeable, then they see your Ultimate TBI Power page and take what it says as gospel.

If we're truly wanting to set newbs on the right course, we should put up a sticky for TBI Newbies that says nothing but: "Don't change a thing on your car until you learn to tune it", then link them to the beginner's tuning guide. Below that, we should write a simple, easy to understand explanation of why they must learn to tune if they want to mod a TBI car, then lock the thread.

Every time a newb comes in here with a post like OP's, we should all simply post a link to that thread, and nothing else.

As far as the gears are concerned, I simply disagree with you, based on decades of experience and thousands of 1/4 mile passes. The biggest mistake I see people making, not just with our cars, but with modding any kind of street car, is too much gear.

Search for a member on here named Mike Crews. he hasn't been active on here in a long time, but there is a thread on his car that is a clinic on how to think and research changes before you do them, and how to get much more out of your mods than most people doing the same ones by using your noodle. He drove his 383/Vortec/TPI/700r4 Camaro from Augusta to Atlanta Dragway in 90+ degree summer heat, let it cool down for 30 minutes, pull up to the line, stick it in "D", and run a 12.38 on horsepower, street tires, and 3.23 gears. I saw it, I was there.

My favorite car of all time, my '70 Chevelle 400SBC/Turbo 350/250 hp NOS kit ran consistent 11.80s in full street trim and 3.31 gears. Swapped to 3.73s and lost two tenths, all due to increased wheelspin. Sure, when I put a set of 10" slicks on it, it was a monster, but that wasn't what I wanted.

And as far as the intakes go, how many people run one doesn't mean anything more than a lot of people have believed what they read on a forum. Once again, TBIs do not pulse, and therefore see no benefit whatsoever from a dual-plane intake. Plenum volume is critically important, and the more plenum volume, the better. Single planes have more plenum volume. It's that simple.

robertfrank

iTrader: (27)

That does make sense, and I do agree that some of the things written are dated as I previously said. I agree as well that be fore a single bolt is touched tuning should be the first and foremost thing to do once engine mods begin. Once that a good foothold of tuning is made THEN start tearing into the engine as long as its in "good" repair. As far as the intake situation goes, my belief is that torque down low is better for these little engines.imho I wouldn't mess with a single plane unless the displacement has been raised. I.e 350/383. I'm not trying to start a flame war because we both know that it will get us nowhere. I respect your opinion as you have been a good help to some of the newbs as I have.

seanof30306

iTrader: (4)

I'm glad you realize I'm not intending to flame you. I think you have an awesome car.

I love torque, too. That's why I prefer dual planes on a carbed street application. The point is, it is the pulsing of the carb that works with the dual plane intake to make more torque than a single plane. On a TBI, there is no pulsing, and therefore no increase in torque from a dual plane intake. Maybe of the engineer on here can explain it better than I.