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454 low-mid range torque build?

red EOD said:
A cam that would improve torque from idle to 3k and either maintain or even improve fuel economy would fit wonderfully. It could fall on it's face at 3500 without much issue from me.

So step by step list would be: Exhaust plus headers, Cold air intake, tbi performer intake manifold, tune, cam?

Long tube vs short tube headers, thought long tubes were better for higher rpm?
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I Have done almost everything you are talking about to a TBI small block Chevy. None of it made that much difference that could be really felt, A cam for a OBD I / TBI engine has to be a single pattern cam. depending on the cam specs, it has to have a lobe seperation of 112 to 114 degrees because if you use a carburetor type cam it will drive the OBD I/ ECM crazy with vacuum fluctuation. The stock TBI intake manifold is already an aluminum intake. The aluminum Edelbrock performer intake is only a tiny bit better than the stock one. A custom tune chip for an OBD I / ECM will only net a small amount of increased power. This is why I try to tell people that that the OBD I / TBI is a very limited system that can only handle a little amount of tweaking that will only give you a limited increase in power.
 
1-ton said:
I Have done almost everything you are talking about to a TBI small block Chevy. None of it made that much difference that could be really felt, A cam for a OBD I / TBI engine has to be a single pattern cam. depending on the cam specs, it has to have a lobe seperation of 112 to 114 degrees because if you use a carburetor type cam it will drive the OBD I/ ECM crazy with vacuum fluctuation. The stock TBI intake manifold is already an aluminum intake. The aluminum Edelbrock performer intake is only a tiny bit better than the stock one. A custom tune chip for an OBD I / ECM will only net a small amount of increased power. This is why I try to tell people that that the OBD I / TBI is a very limited system that can only handle a little amount of tweaking that will only give you a limited increase in power.
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That's why any OBD 1 truck I've ever had stayed pretty stock. Generally not worth messing with them.
I think the only way to go about IMO is to dump the factory setup. I'm sorry, but burning chips and all that crap is a waste of time and money
I did bump the cam size up a notch and gave a touch more timing to a tbi 350 I rebuilt for a plow truck once. That's about all its worth imo.
 
beags86 said:
That's why any OBD 1 truck I've ever had stayed pretty stock. Generally not worth messing with them.
I think the only way to go about IMO is to dump the factory setup. I'm sorry, but burning chips and all that crap is a waste of time and money
I did bump the cam size up a notch and gave a touch more timing to a tbi 350 I rebuilt for a plow truck once. That's about all its worth imo.
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I think that's a bit harsh. There are (or were) guys running 12s and 13s with TBI setups, this setup is certainly far from stock: TBI Van Obviously the point is that a stock TBI wasnt running 12s and 13s from the factory, and those numbers indicate decent power from 305 and 350 TBI setups that are not possible with minor mods.

No argument that TBI is a bit antiquated, and tuning is a learning experience, but I'm pretty confident saying the folks with the much more modern self tuning setups will agree, they are only self tuning to an extent. But that's another discussion. For injection to run right, and get the most out of it, it's going to take effort in tuning.

I don't really see much difference if someone decided they wanted to modify an LS, still have to deal with tuning timing, fueling, etc. Chip burning is really the Achilles heel of the OBD1 stuff, even that can be mitigated I'm sure, with things like Megasquirt, EBL, perhaps some of the OBD2 TBI components.
 
I've got the Moates APU1, but it's still a learning process to tune these things, and most people aren't interested in that learning curve. Plus it's another device to buy, then the chip adapter. Then some hassle running a wideband O2, etc.

I believe some of the other ones, like EBL and Megasquirt, eliminate the PROM entirely, which makes sense to me.

The OBD1 systems are really past their prime in the realm of innovation IMO, kind of stuck with what has already been done, unlikely anything better will be coming for them.
 
dyeager535 said:
I think that's a bit harsh. There are (or were) guys running 12s and 13s with TBI setups, this setup is certainly far from stock: TBI Van Obviously the point is that a stock TBI wasnt running 12s and 13s from the factory, and those numbers indicate decent power from 305 and 350 TBI setups that are not possible with minor mods.

No argument that TBI is a bit antiquated, and tuning is a learning experience, but I'm pretty confident saying the folks with the much more modern self tuning setups will agree, they are only self tuning to an extent. But that's another discussion. For injection to run right, and get the most out of it, it's going to take effort in tuning.

I don't really see much difference if someone decided they wanted to modify an LS, still have to deal with tuning timing, fueling, etc. Chip burning is really the Achilles heel of the OBD1 stuff, even that can be mitigated I'm sure, with things like Megasquirt, EBL, perhaps some of the OBD2 TBI components.
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Maybe. But who the hell cares about running 13s In a gmt400? Camaro you say? Get tpi, impala? Swap a lt1.

General speaking a tbi350 comes in some pretty undesirable shit. A gmt400 is just another throwaway appliance. Unless it's a big block.
And if you have one like I do. Not screwing with it to decrease the tough as nails, I'll still be running when Jesus comes back reliability that a tbi system and gm powertrain affords you.
 
What I’ve found to work almost instantly when needing or wanting to increase performance, is add stickers, preferably CK5 stickers. Your gain in everything you desire is almost unthinkable but achievable...

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The thing with Megasquirt is, no go with emissions. ‘Cause race car haha.
 
I am not saying there is nothing that can be done with OBD I / TBI, but there are limitations. Right now I am putting together a stroked 383 that will be using OBD I / TBI set up, but it will be a very mild build. It is going to have the same 9.25:1 compression the TBI came with stock. The heads will be aluminum Edelbrock direct replacement swirl port heads, with straight plugs, 2.02 / 1.80 valves, and screw in rocker studs. The cam will have a 260/260 duration with a .444/.444 lift, and a lobe separation of 114 degrees. I already have a TBI that has been modified buy Morse Machine to flow more CFM's, and an adjustable fuel pressure regulator with a stock aluminum intake modified to match the flow of the TBI. A rough guess of HP will be about 300 HP and 400 FT of torque...about the same as a stock big block, but without the weight.
 
beags86 said:
Maybe. But who the hell cares about running 13s In a gmt400?
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Potentially someone that wants a factual statement in regards to how limited factory TBI is with tuning I suppose, and examples showing that they can be made to run well with a significant number of engine modifications?

I guess I'm a little confused as to how tuning is being conflated with reliability. Changing some 1s and 0s around, done right, isn't going to affect reliability one bit. Certainly no more so than changing engine hard parts.
 
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dyeager535 said:
Potentially someone that wants a factual statement in regards to how limited factory TBI is with tuning I suppose, and examples showing that they can be made to run well with a significant number of engine modifications?

I guess I'm a little confused as to how tuning is being conflated with reliability. Changing some 1s and 0s around, done right, isn't going to affect reliability one bit. Certainly no more so than changing engine hard parts.
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Generally speaking. Adding high performance parts, whether it's carb, tbi. Or LS stuff....
The term high performance and reliability don't go hand in hand.
This is not a new concept. It's widely accepted as the truth.
Now can you make a high performance engine, run reliability? Yes. But in the days of the tbi. You might add headers, and high flow cylinder heads. Then burn a chip. And then you pop the chip in and it's not 100% right. You drive the truck and it stumbles down low. So you say OK, I need more fuel at 1600 rpm.
So the chip comes out for a reburn...send it out get to get new chip in the mail.
Meanwhile, your trying to drive the truck as a DD, while waiting for chips to come back in the mail. No chip, no daily driving = lack of reliability.
This is a fictional example, but one that used to happen with the tbi saga.
Certainly we have tuning that can be had in other ways. I get that.
But not everyone is a tuning guru. So guys start messing with things, go down a rabbit hole and never get out. And end up with a truck that never runs right again.
If you never heard of this happening with a tbi truck then you lived under a rock in the 90s. Of course in the 90s we didn't have websites like these to pull from either.
With the limitations of the tbi system, IMHO your better off just leaving it be. The small gains to be had are not worth the cost and pain. This thread proves I'm not the only one to feel that way.
If had a tbi powered camaro or something your money ahead to swap a carb.
Is that a old school outlook? Yep, surely is. I get that.

Your right, there is a guy out there that wants to go fast on tbi and prove he's a tbi tuning guru. That's fine. But that's not me. I simply don't care enough about it.
For me, my tbi powered big block, peanut ports and all, pulls around my k2500 just fine. Would I like more power, sure, who wouldn't. But it's a slippery slope once you start with that.
 
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454, Headers, "RV" cam, Edelbrock intake. hardest part, which was providing enough fuel to feed it, would have been solved with an EP381, and basically nothing other than increasing fueling across the board. One and done, at home...I had the chip burner, EagleMark sent me a .bin to try.

There are options for people. From carb to high end aftermarket EFI. I don't presume to know everyone's tolerance for wallet or intellectual pain.
 
dyeager535 said:
454, Headers, "RV" cam, Edelbrock intake. hardest part, which was providing enough fuel to feed it, would have been solved with an EP381, and basically nothing other than increasing fueling across the board. One and done, at home...I had the chip burner, EagleMark sent me a .bin to try.

There are options for people. From carb to high end aftermarket EFI. I don't presume to know everyone's tolerance for wallet or intellectual pain.
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I agree. Everyone has a different outlook.
For me I generally don't want to work or mess with my regular truck. Once it's not my regular truck. Then it's different. But for not I don't want to spend any time one it. Just want to hop in at any given time to go if I need to.
 
For what it's worth, I have personally ran the gauntlet with BBC's. I have used every scenario as far as trying to make the OEM TBI system actually "Perform" like a decently built 454 with a carb or quality aftermarket injection. So to be clear, I have upped compression, bored throttle body, bored edelbrock intake, higher pressure pumps, adjustable regulator, mulitple custom chips, "781" heads with port and bowl work, aftermarket camshafts etc! You get the idea. I am also a 32 year GM Parts Manager and have a lot of resources to help me. In my opinion, on a BBC tbi setup there is no possible way to get ground ripping power. I have actually made 2 different attempts with basically no limit on dollars spent to try and make this setup work and have been disapointed both times. I still love the TBI systems and run it on my crew--I just know exactly what to expect. NOW, on the other hand I have built multiple BBC's both carbureted and injected that will blow up 37" tires and pull like crazy. My son's 84 K30 is a good example of this, and is even currently just running a quadrajet. A lot of the same parts apply, but the engine is just getting more air and fuel. I definitely don't want you to think that the cam is the same as the ones used in a tbi build, but they are not that much different. In general, I think I'm reiterating what quite a few people have posted. BBC with power & fuel economy really don't exist. My son's truck gets about 5-6 mpg, and my 88 crew with 1/3 the power gets about 8 mpg with both rigs running 37" tires and TH400's. I am currently building a "budget" 454 for my son's M1028. The combination I'm going with will probably get him around 10 mpg as we're also installing an overdrive trans. A bit of technical info for those of you considering building your 454. The gen IV BBC was built through 1990. These are a very good platform especially if you upgrade the cylinder heads to "049's" or "781's". They are flat tappet camshafts though and that can be troublesome. I generally upgrade them to a retro fit roller cam system and have yet to have any issues. The gen V big blocks built from 1991-1995 are pretty much scrap iron, avoid them if you can. Gen v's are not compatible with any other generation of bbc as far as oem parts go. Gen VI engines (1996-2000) are also a pretty good choice for truck guys. They are already roller cam and the heads actually perform decent (better that peanut port). Downside to Gen VI block is that the majority of them do not have a fuel pump boss, the valvetrain is non adjustable and use 3/8" bolts to secure rocker arms, and can be troublesome finding a timing chain that fits under the stock cover. Still a pretty good choice though, and that's what we're currently using for the "budget build". I don't post much, but was hoping this might help the o.p. and anyone else looking to go bbc.

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bigblock454 said:
Is that not the same with any aftermarket FI?
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I still have an old edelbrock tbi to multiport conversion unit. Part #3505.

Smog legal.

Thinking of combining it with a 0411 PCM to use on my L31 crate motor I bought in '05...

Gotta take it apart and see what shape it's in first...

Probably needs new valve springs and rings from sitting...
 
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