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454 low-mid range torque build?

red EOD

red EOD

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Looking for ideas and doing some research on the big block since I'm much more familiar with diesels

Engine is a 1995 454 TBI all stock. Curious on upgrades for it with the main operating rpm range being idle-3200 without destroying the fuel economy which is currently 10mpg empty, not sure towing yet but goal of 8mpg pulling 10k camper trailer. Able to run 87 grade gas ideally.

Naturally aspirated vs forced induction? Would a low psi of boost still require higher grade gas given the compression ratio on these engines?
 
Up the compression ratio if your rebuilding it, or just put a set of long tubes on it and an RV cam.
You'll probably have to get a program change because of the tbi though.
 
no he WILL need a chip burnt for it . tbi dont like changes over stock much at all so plan for a chip or some other efi system
 
You don't increase low end by camming, unless you are going smaller, and generally factory is about as small as anyone is willing to go.

Small tube headers (appropriate for that engine) will help, but there is no miracle to be had. Velocity builds torque, big heads, big valves, big intakes all serve to reduce velocity on the low end.

I'm no forced induction guru, but judging from the TDI I'm driving now, RPMs are a necessity there too.

Better gearing, more trans gears definitely help low end and keeping an engine in it's power band. 8 speed retrofits don't seem to be real common yet.
 
red EOD said:
Looking for ideas and doing some research on the big block since I'm much more familiar with diesels

Engine is a 1995 454 TBI all stock. Curious on upgrades for it with the main operating rpm range being idle-3200 without destroying the fuel economy which is currently 10mpg empty, not sure towing yet but goal of 8mpg pulling 10k camper trailer. Able to run 87 grade gas ideally.

Naturally aspirated vs forced induction? Would a low psi of boost still require higher grade gas given the compression ratio on these engines?
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Friend of mine took this exact spec engine and put a carb on it (yes I know that’s not your plan, stick with me...)

In doing so, the platform it was in picked up almost 2 seconds at the drag strip in Denver, no other changes.

That just shows how poopie the factory tune is on that. If your willing to dig, to software exists to get quite a bit more out of those without any other changes
 
obijuank5 said:
Damn! From 36 to 34 seconds in the 1/8th?
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From 35 to 33 at 500’ :deal:

Installed in a 65 AMC Marlin. Ran 14.8 at the end. That’s on par with most of the production cars with no mods. Forgot the MPH. I’ll have to ask

based off the weight vs mph, the Moroso speed calculator says it’s 375 hp
 
There are things you can do, but sticking with 87 octane fuel really limits your options. The factory peanut port heads are actually pretty good at lower RPM torque but their open chamber design limits quench and raising the compression with 87 fuel isn't going to work out real well.

I have been considering a build for my factory 454 91 Burb:

4.25" Stroker Crank
Factory Peanut port heads with a tad of porting and a full bowl polish to help with detonation
9.5:1 Compression
Custom roller CAM with torque in mind, max RPM 3800-4000. (hard to get right now as pretty much everyone is out of cam blanks)
170F thermostat with factory TBI retuned to match the above.

300HP@500+lbs should be easily achieved.
 
Hahaha well when it comes to acceleration I've hauled pretty heavy with naturally aspirated 6.2 diesels and had a m35a2 deuce and a half, a fast person could outrun those off the line hahahaha.

Boost numbers can vary depending on forced induction type but can be designed to build at low rpm just becomes a potential restriction at higher rpm (which isn't a problem for me). Besides a motorcycle or other small engine I don't go over 3500rpm with any kind of regularity.

Gearing for the truck is 4.10 with roughly 30" tires, planned to go with 33-35" tires and no gearing change. Not towing over 10k. Right now the engine runs well with the only known issue being a broken exhaust bolt on the driver side, figure that will get fixed when headers go on. Expedition and tow rig, not a racer or hardcore offroad.

Admittedly eyeballing a 177 series supercharger so forced induction is not off the table. If the stock TBI can be modified to work with that after tuning and kept similar fuel economy I'd be happy.
 
Don't know if that's possible though. Seems like the upgrades almost require going back to carb or a different injection system. Will run 89 grade if necessary due to compression or forced injection.
 
You won't be happy with that style of supercharger, it will add too much IAT for towing and the factory TBI could not be made to work.

The factory ignition timing is pretty conservative, you *might* be able to score a touch of free power and economy by advancing the base timing by ~4 degrees or so, but use your ears and listen for detonation, especially when really hot.
 
What about tuning software such as Dynamic EFI? Claim the GM tbi can be tuned for some boost effectively (they say up to 30psi). That would be far higher than I'm thinking of haha.

Truck is a 1995 model.
 
If I was you I would dump the tbi.
Lots of messing around with it to get it run like you would with tuning. Blown or NA.
It would cost you more upfront, but going with a aftermarket efi seems like the only solution to me if your serious about making this engine sing.
I would think the 177 blower and some sort of aftermarket efi would really wake up this engine.
I've driven a 95 tbi 454 with a Paxton super charger, and I was not disappointed in that at all. Nothing but smiles. This was 20 years ago but the owner spent a pretty penny burning chips and messing around to get it running right.
If you figure a aftermarket efi kit is 1500 bucks. I would think that would be well worth with to not mess around with tuning gms tbi.

In fact I like the idea of a aftermarket efi on a 177 so much I might just have to do that to my 93 454 tbi.....
 
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The OBD I / TBI system is very limited on how much you can modify it for more HP. The best thing you can do is make sure the engine has good compression, no vacuum leaks, and tuned-up right. Burning a custom chip is an expense that will only get about 20 more HP, that you will never notice in daily driving.
 
beags86 said:
If I was you I would dump the tbi.
Lots of messing around with it to get it run like you would with tuning. Blown or NA.
It would cost you more upfront, but going with a aftermarket efi seems like the only solution to me if your serious about making this engine sing.
I would think the 177 blower and some sort of aftermarket efi would really wake up this engine.
I've driven a 95 tbi 454 with a Paxton super charger, and I was not disappointed in that at all. Nothing but smiles. This was 20 years ago but the owner spent a pretty penny burning chips and messing around to get it running right.
If you figure a aftermarket efi kit is 1500 bucks. I would think that would be well worth with to not mess around with tuning gms tbi.

In fact I like the idea of a aftermarket efi on a 177 so much I might just have to do that to my 93 454 tbi.....
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Keep ideas coming, I am sitting on a 93 454 tbi and would like to see some improvement without spending multiple thousands
 
imiceman44 said:
Keep ideas coming, I am sitting on a 93 454 tbi and would like to see some improvement without spending multiple thousands
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The cheapest way to make more power would to go carbureted. You can run any cam you want then. Increase cubic inches is another way to make power. This is all stuff everybody knows anyway. Been posted a thousand times on this site.
 
1-ton said:
The cheapest way to make more power would to go carbureted. You can run any cam you want then. Increase cubic inches is another way to make power. This is all stuff everybody knows anyway. Been posted a thousand times on this site.
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No I mean upgrade not downgrade.
I am considering an MPFI system and maybe supercharger...
 
red EOD said:
What about tuning software such as Dynamic EFI? Claim the GM tbi can be tuned for some boost effectively (they say up to 30psi). That would be far higher than I'm thinking of haha.

Truck is a 1995 model.
Click to expand...

4L80E? Unless they've came out with a new Dynamic EFI it has no trans control.
 
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