Advice on freshening up a 350 tbi

[bucket]

That sounds pretty cool a 4 barrel tbi unit. I had read that some people did some serious modifications and got impressive dyno numbers. If there was a mod system that was plug and play available I'd be all over the tbi thing. Or if there was a shop around that did tbi mod work I'd build an engine and go pay them to set up the tbi for me. It seems anyone who used to specialize in this kind of help has gone to the wayside, hense my reasoning on it being limited. Also have read many I did it myself testimonies of it ran good but always had a hiccup that steered me away from trying it myself Lol

Yes, the tuning is also why I have not experimented much myself. It's an area that I have not learned yet and also an area that I never find myself willing to pay somebody else to do, lol.

 

[4WDKC]

I would never go vortec heads and stay tbi. The tbi unit is very limiting from what I understand and it's a mismatched setup that seriously limits the vortec head. With a carb and vortec heads I can go 300 hp, 400 hp, 500 hp whatever I want to do.

I plan on spending a bunch of time in the mountains with the suburban sometimes 1000 miles from home. Old school setups can be fixed in the woods if you carry 3 spare parts that fit in the glove box and a small tool kit. I like simplicity and its a system I understand.

The tbi 350 is simple and reliable as well it sure would have been nice is they didn't set it up to be such a detuned dog

In stock form yes the tbi is very limited, but making the fpr adjustable and a pump to support new pressure then you just need to tune it. I did all of these things and was working on tuning it when I sold it because I moved to Florida. You can use the tbi and an adapter to carb intake like I did. 300hp sure stock tbi can support it, 400 not with out major help or a 454 tbi and injectors. 500 not gonna happen. Instake of porting the stock heads and the still have the huge combustion Chambers find a set of tpi heads or aftermarket, you will much better off. Then you can use those tbi for their best use ever, counter weights for your booby traps in the woods.

 

[4WDKC]

Yes, the tuning is also why I have not experimented much myself. It's an area that I have not learned yet and also an area that I never find myself willing to pay somebody else to do, lol.

Go here and read the tuning 101/ intros www.gearhead-efi.com

 

[RecklessWOT]

Sorry to hijack, but for you guys who know a lot about the TBI setup, I have a few questions myself-

I understand the ECU controls fuel, but how does it compensate for mods? I'm going to be putting a crate engine in my truck when the weather gets nicer (or when I close on my next house that has a big ass garage, whichever comes first), but want to keep the TBI. If I do a few mods to it before I drop it in or buy an engine that's already a little hotter than the stock '87 TBI engine, will the computer try to limit it back to stock performance then get all confused like the way modern cars will when you mod them without re-tuning the ECU?

Also, I'm currently running the wrong ECU. I plan to rectify this once the new engine goes in regardless, but just wondering how much has this been hurting me the last few years. My truck has a 350, but long story short a while back I discovered the root of all my issues was that my ECU took a ****, so a dude from work gave me the old ECU he had laying around from his '87 shortbed with a 305. I was dailying the truck at the time and lived in the mountains, and the "new" brain made it stop randomly cutting out and stalling on me in traffic or while going up steep hills so I considered it "fixed" in my book, but I feel like it never went back to optimal performance. How bad has this been ******* me?

And if I do stick with the stock TBI but put in an engine with a better cam/heads than stock, should I be looking for an ECU that's better than stock (aftermarket, stock one from a 454 truck, etc) or would the regular one from a 350 truck be sufficient? Not trying to go crazy with it, but it would sure be cool to have 300hp or so. Hell even 250-280 would feel so much better than the 210hp this tired old engine once claimed to have...

 

[bucket]

Sorry to hijack, but for you guys who know a lot about the TBI setup, I have a few questions myself-

I understand the ECU controls fuel, but how does it compensate for mods? I'm going to be putting a crate engine in my truck when the weather gets nicer (or when I close on my next house that has a big ass garage, whichever comes first), but want to keep the TBI. If I do a few mods to it before I drop it in or buy an engine that's already a little hotter than the stock '87 TBI engine, will the computer try to limit it back to stock performance then get all confused like the way modern cars will when you mod them without re-tuning the ECU?

Also, I'm currently running the wrong ECU. I plan to rectify this once the new engine goes in regardless, but just wondering how much has this been hurting me the last few years. My truck has a 350, but long story short a while back I discovered the root of all my issues was that my ECU took a ****, so a dude from work gave me the old ECU he had laying around from his '87 shortbed with a 305. I was dailying the truck at the time and lived in the mountains, and the "new" brain made it stop randomly cutting out and stalling on me in traffic or while going up steep hills so I considered it "fixed" in my book, but I feel like it never went back to optimal performance. How bad has this been ******* me?

And if I do stick with the stock TBI but put in an engine with a better cam/heads than stock, should I be looking for an ECU that's better than stock (aftermarket, stock one from a 454 truck, etc) or would the regular one from a 350 truck be sufficient? Not trying to go crazy with it, but it would sure be cool to have 300hp or so. Hell even 250-280 would feel so much better than the 210hp this tired old engine once claimed to have...

Everything I've learned over the years tells me that a speed/density type system (MAP sensor) is less forgiving about modifications. The map sensor reading basically lets the ECM make assumptions about the incoming airflow. But other systems like the '85-'89 TPI use a MAF sensor, so the incoming airflow is known as fact. It makes them more adaptable to modifications... although those maf sensors can be problematic, lol.

I don't think the 305 chip is hurting you much. It's my understanding that the fuel curves tend to be similar because the bigger engine used bigger injectors. I've ran bigger engines (with correct injectors) on stock tuning before and they seemed to run well.

But again, I only know enough to be dangerous.

 

[4WDKC]

Sorry to hijack, but for you guys who know a lot about the TBI setup, I have a few questions myself-

I understand the ECU controls fuel, but how does it compensate for mods? I'm going to be putting a crate engine in my truck when the weather gets nicer (or when I close on my next house that has a big ass garage, whichever comes first), but want to keep the TBI. If I do a few mods to it before I drop it in or buy an engine that's already a little hotter than the stock '87 TBI engine, will the computer try to limit it back to stock performance then get all confused like the way modern cars will when you mod them without re-tuning the ECU?

Also, I'm currently running the wrong ECU. I plan to rectify this once the new engine goes in regardless, but just wondering how much has this been hurting me the last few years. My truck has a 350, but long story short a while back I discovered the root of all my issues was that my ECU took a ****, so a dude from work gave me the old ECU he had laying around from his '87 shortbed with a 305. I was dailying the truck at the time and lived in the mountains, and the "new" brain made it stop randomly cutting out and stalling on me in traffic or while going up steep hills so I considered it "fixed" in my book, but I feel like it never went back to optimal performance. How bad has this been ******* me?

And if I do stick with the stock TBI but put in an engine with a better cam/heads than stock, should I be looking for an ECU that's better than stock (aftermarket, stock one from a 454 truck, etc) or would the regular one from a 350 truck be sufficient? Not trying to go crazy with it, but it would sure be cool to have 300hp or so. Hell even 250-280 would feel so much better than the 210hp this tired old engine once claimed to have...

the stock tuning is barely adequate for a stock engine and it doesnt identify mods. the ability to tune is limited and a slow process. Stock heads, cam and intake are bad for performance you can mod it but youre better of ls swapping it.

 

[RecklessWOT]

the stock tuning is barely adequate for a stock engine and it doesn't identify mods. the ability to tune is limited and a slow process. Stock heads, cam and intake are bad for performance you can mod it but youre better of ls swapping it.

Yeah I know an LS would be better performance wise, but I'm trying to keep it simple (and cheap). I actually have a 6.0L at my disposal but really don't want to go down that route. A- I'm not good with electronics and wiring to begin with, and B- I really like the simplicity of older vehicles, I've already sworn off buying another OBDII vehicle ever again after my current daily dies. It would kill me to put some fancy new electronic engine in my simple old square.

I'm not necessarily looking for tons of power, but the idea of a little more is appealing. I'm probably going to stick with a basic crate engine and keep my TBI, just wasn't sure if I should stay full-on stock, or if I can get away with a few mods besides intake/headers. Either way, my engine is toast and if I'm gonna spend the time and money to rebuild the thing, I may as well get a warranty with something brand new so I can use it a lot with no worries.

Thanks for the input guys, I'll stop derailing this thread for my own personal reasons lol

 

[Overland Suburban]

Yeah I know an LS would be better performance wise, but I'm trying to keep it simple (and cheap). I actually have a 6.0L at my disposal but really don't want to go down that route. A- I'm not good with electronics and wiring to begin with, and B- I really like the simplicity of older vehicles, I've already sworn off buying another OBDII vehicle ever again after my current daily dies. It would kill me to put some fancy new electronic engine in my simple old square.

I'm not necessarily looking for tons of power, but the idea of a little more is appealing. I'm probably going to stick with a basic crate engine and keep my TBI, just wasn't sure if I should stay full-on stock, or if I can get away with a few mods besides intake/headers. Either way, my engine is toast and if I'm gonna spend the time and money to rebuild the thing, I may as well get a warranty with something brand new so I can use it a lot with no worries.

Thanks for the input guys, I'll stop derailing this thread for my own personal reasons lol

Lol, no worries friend! This forum is pretty big so sometimes you have to message fellas where you find them. Your welcome to step into my thread anytime

Tracy

 

[4WDKC]

Yeah I know an LS would be better performance wise, but I'm trying to keep it simple (and cheap). I actually have a 6.0L at my disposal but really don't want to go down that route. A- I'm not good with electronics and wiring to begin with, and B- I really like the simplicity of older vehicles, I've already sworn off buying another OBDII vehicle ever again after my current daily dies. It would kill me to put some fancy new electronic engine in my simple old square.

I'm not necessarily looking for tons of power, but the idea of a little more is appealing. I'm probably going to stick with a basic crate engine and keep my TBI, just wasn't sure if I should stay full-on stock, or if I can get away with a few mods besides intake/headers. Either way, my engine is toast and if I'm gonna spend the time and money to rebuild the thing, I may as well get a warranty with something brand new so I can use it a lot with no worries.

Thanks for the input guys, I'll stop derailing this thread for my own personal reasons lol

sell the 6.0 to fund the rebuild/swap. putting a stock replacement in there will be a disappointment. Something like this would be my choice since you dont want an ls
https://blueprintengines.com/products/355-ci-crate-engine-small-block-gm-longblock-bp35513ct1

 

[Rusty Nail]

Is this thread for real? I coulda swore I replied but guess I got busy.

 

[Tmich396]

Google Tbichips lots of good info on TBI upgrades.

 

[Tmich396]

This one is a little cheaper, and will give almost the same results. Put a carb on it or a modified TBI setup.

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[Ricko1966]

ATK has basically a cammed stock 350 tbi engine making 290hp.The tbi heads make good torque and flow well below 4500 which in my opinion is perfect for a truck pulling trailers etc. I'm building something similiar to the atk engine for my truck as we speak.Vortech heads would be great but not worth the extra expense and other hassles on a D.D. truck.

 

[Craig Nedrow]

355 9.6 to 1, weiand stealth, 284 Crower cam, installed straight up, full advance of 41 degrees best power. 650 holly, (have used a quadri puke, works good.) Cam is lumpy in my motor. ported 194 heads, three angle valve job. Dyno 325 hp, 310 tq with open dyno headers. I run regular, but could use better gas, don't really want to detune it. Farm truck work the poop out of it towing hay, cattle, equipment. Switching to a 454 in about a month. Gas mileage is around 10 mpg with 4:11 and 35 inch tires. That blue print engine is nice, but hard to believe you can get those numbers with that compression.

 

[Rusty Nail]

Aye, 9.3 aint much.