Anyone added significant horsepower to their 4.3?

Donstar · August 15, 2018

A truck with the same configuration as mine with a 5.3 as opposed to my 4.3 is rated to pull 2100 more lbs. I know that aftermarket modifications cannot legally increase tow or payload ratings and I have no plans to modify my engine. I am just curious. Has any member modified their V6 to rival the power of a stock V8? Ford offers a couple of V6's with more power than the 5.3 and both are smaller than the 4.3. Is the use of turbo technology a practical or realistic enhancement for an ecotec 4.3?

Grumpy Bear · August 15, 2018

One of the motors Ford Trucks used between 1965 and 1972 was the 300 in line six. 283 lbs/ft @ 1,600 rpm but only 170 hp @ 3,800 rpm. With the steep 6.69 low gear (NP 435 transmission) and a 4.11 diff. 7,836 lbs./ft. in low gear!!!

A 6.2 (460 lbs./ft.) with 8L90E (4.56 low gear) and a 3.73 gear gives 7824 in low but at 4,100 rpm before the show gets started. Don't think they put that much converter in them.

I learn from such examples that what you do with the power you have is just as important as the power you have. A little gear. A bit of converter. A trans and motor tune. A cooler. Think of it as picking up pennies instead of being handed a dollar.

If an antique FORD I6 can out grunt a current Chevy 6.2 then …….. Get off the gas Mable and just let out the clutch!!

Jon A · August 15, 2018

3 hours ago, Grumpy Bear said:

If an antique FORD I6 can out grunt a current Chevy 6.2 then …….. Get off the gas Mable and just let out the clutch!!

Heh, there's a bit of wishful thinking required to believe that. Mixing SAE Net numbers with Gross...and while the 6.2's torque may peak at 4100 RPM, it makes 400 lb-ft at 2500 in stock form so the "party" gets underway quite quickly.

3 hours ago, Grumpy Bear said:

I learn from such examples that what you do with the power you have is just as important as the power you have. A little gear. A bit of converter.

The problem is gears can only multiply torque...there's no way to multiply power. A really deep 1st gear is great...for about 2 seconds. After that, it's meaningless.

16 hours ago, Donstar said:

Is the use of turbo technology a practical or realistic enhancement for an ecotec 4.3?

There's no reason it couldn't be done. "Practical" would be in the eye of the beholder, of course. If modding a 4.3 for towing, as opposed to a street toy, there are some other issues you'd want to address--smaller cooling system, no oil cooler, smaller rear end, etc. So theoretically, if you were building a 4.3 truck to tow 10K+ trailers as the V8's can you'd have other issues to address.

Even if the 8.5 rear held up strength-wise, it would run hot and wear out a lot sooner with lots of towing so a total rear end swap would be a good call.

The cooling system would need to be totally re-done, especially if adding turbos or a supercharger. The Ecoboosts have terrible trouble staying cool in heavy towing, boosted engines are just much harder to keep cool. It would probably be more "practical" to keep the engine N/A, with longtubes and a lumpy non-AFM cam you could exceed the 5.3 torque in the mid-upper range and it would be easier to keep cool than a turbo setup. Then yes, gear the hell out of it.

pickmeup · August 15, 2018

Look no further than the GMC Syclone they made for a few years . Genuine GM 4.3 Turbo. Ran real strong and held up very well.

Grumpy Bear · August 16, 2018

8 hours ago, Jon A said:

The problem is gears can only multiply torque...there's no way to multiply power. A really deep 1st gear is great...for about 2 seconds. After that, it's meaningless.

Torque is the ability to move the load. Horsepower is how fast you can move it. If 'simply' pulling Mt. Everest up a 7% grade is the goal either will get the job done. Meaningless is a word for the impatient. With enough gear you could pull the mountain up that grade with a 3 hp. Briggs and Stratton.

Archimedes "Give me a place to stand and with a lever I will move the whole world".

Gearing is a lever. The point is valid. This statement is prejudiced by a personal preference for speed of task over completion of task. It also is a statement that says gearing has nothing to do with acceleration. Not true, is it? Why do you think they are adding gears to gear boxes? If you can't impress someone with nearly 8,000 lbs. of torque they can't be impressed.

The point was intended to show that perfecting a gear for a prime mover to a task has much benefit. OEM is ALWAYS a compromise. Removing that compromise can and will often lead to a result that equals or exceeds that manufactures next best offering whose compromises lay in tact.

Donstar · August 16, 2018

8 hours ago, pickmeup said:

Look no further than the GMC Syclone they made for a few years . Genuine GM 4.3 Turbo. Ran real strong and held up very well.

Yes, good example. That gave the 4.3 of the time a significant boost. I'm sure they could offer a similar upgrade to the current version of the V6. No real need now that they're introducing two new powerful small engines to the lineup. I think there would be a decent market for an aftermarket kit.

Grumpy Bear · August 16, 2018

2 minutes ago, Donstar said:

Yes, good example. That gave the 4.3 of the time a significant boost. I'm sure they could offer a similar upgrade to the current version of the V6. No real need now that they're introducing two new powerful small engines to the lineup. I think there would be a decent market for an aftermarket kit.

I see two issues with a pressure cooker. The stock motor has 11:1 compression. Ring gaps. Both can be fixed.

Donstar · August 16, 2018

2 minutes ago, Grumpy Bear said:

I see two issues with a pressure cooker. The stock motor has 11:1 compression. Ring gaps. Both can be fixed.

Yes, I suspect the stock engine is already making good use of its potential. As is, it's producing more horsepower than the previous 4.3 Syclone.

DONWT15 · August 16, 2018

There is a third issue with turbo and super charging. Fuel usage. More fuel is needed to make more power. Air doesn't burn by itself. The Ford 3.5 ecoboost is a prime example. Under load, with the turbos spun up, they get terrible mileage.

Jon A · August 16, 2018

4 hours ago, Grumpy Bear said:

It also is a statement that says gearing has nothing to do with acceleration. Not true, is it?

My statement was that a deep 1st gear no longer has any effect once you are out of 1st gear. It wasn't that complicated.

4 hours ago, Grumpy Bear said:

Why do you think they are adding gears to gear boxes?

Ah, you must have been talking about the "Special Edition 1965 F-150," the one that came with the 10-Speed. It really was ahead of its time....

4 hours ago, Grumpy Bear said:

This statement is prejudiced by a personal preference for speed of task over completion of task.

"Speed of task" is what makes the world go round. It's called productivity. People accomplishing work is how we survive. Accomplishing more work in the same amount of time makes our lives better. There's good reason we don't have millions of 18 wheelers littering the highways with 170 HP engines under the hood. All our lives would be worse in so many ways...your "patience" would be little solace.

SAFETY is also an issue. It's not my personal preference, but the determination of the Society of Automotive Engineers to draw some lines in the sand: If your light or medium duty truck can't accelerate to 30 MPH in 12 seconds, 60 MPH in 30 seconds, pull 40-60 MPH in 18 seconds or maintain 40 MPH up a specific grade while pulling a trailer, you need a bigger truck (or bigger engine) or a smaller trailer.

Because at that point you aren't being "patient." You are being dangerous. Endangering others. A hazard. Clogging up the highways. You may have a different opinion about that, and that's fine. Just realize your opinion is far out of the mainstream of those who get paid to do this stuff for a living.

5 hours ago, Grumpy Bear said:

The point was intended to show that perfecting a gear for a prime mover to a task has much benefit.

If that was your point, you missed it by taking a couple giant leaps way too far. I'm a big fan of having the proper gears. Note I told the OP if he built a 4.3 N/A for towing, he should "gear the hell out of it." I didn't just put 4.11's in my own truck because I have money to burn.

MY point was that a 170 HP engine wouldn't have a prayer of passing all those J2807 tests with a large trailer, no matter the axle ratio or if the transmission had 20 gears. They don't multiply HP. So the idea of it "out grunting" a 6.2 in any meaningful way in the context of towing trailers was quite silly.

KARNUT · August 16, 2018

When we started our business in early 1980 we used an old 65 model two ton for pulling. It was original a wrecker for towing school busses. It was a GMC with a straight 6, 5 speed and a two speed rear end. It had no trouble getting up to speed and had a top speed of 65 Mph. Speed limit was 60 then. I’m sure the hp of that rig was under 200. The equipment we pulled then was around 12K

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WHITESSTOWPIG · August 16, 2018

I have done a few mods to mine and it feels at least as quick as all the 5.3 loaners I have driven since then.Stock for stock the 5.3 honestly barely felt like an upgrade so that isnt really saying much.Truth is there anything " significant " that can be done to an already high strung naturally aspirated engine while keeping it suitable for truck use.A few guys have tried boosting them but there just wasnt enough fuel to make much power with them.Here are some non-intrusive things I have tried which had a positive effect on the 4.3 in case you catch the mod bug

E85 gas

JET maf

Range AFM

Overkill TB

K&N intake

Gutted 3rd cat

Muffler delete

Donstar · August 16, 2018

3 hours ago, KARNUT said:

When we started our business in early 1980 we used an old 65 model two ton for pulling. It was original a wrecker for towing school busses. It was a GMC with a straight 6, 5 speed and a two speed rear end. It had no trouble getting up to speed and had a top speed of 65 Mph. Speed limit was 60 then. I’m sure the hp of that rig was under 200. The equipment we pulled then was around 12K

This is in the category of my experiences. I absolutely loved the five speed/2 speed axle combination!

10 minutes ago, WHITESSTOWPIG said:

I have done a few mods to mine and it feels at least as quick as all the 5.3 loaners I have driven since then.Stock for stock the 5.3 honestly barely felt like an upgrade so that isnt really saying much.Truth is there anything " significant " that can be done to an already high strung naturally aspirated engine while keeping it suitable for truck use.A few guys have tried boosting them but there just wasnt enough fuel to make much power with them.Here are some non-intrusive things I have tried which had a positive effect on the 4.3 in case you catch the mod bug

E85 gas

JET maf

Range AFM

Overkill TB

K&N intake

Gutted 3rd cat

Muffler delete

Thank you! Good information. If I still own this truck when I drive to Houston this fall, I will definitely be trying E85 en-route. It is not available locally.

Grumpy Bear · August 16, 2018

5 hours ago, Jon A said:

SAFETY is also an issue. It's not my personal preference, but the determination of the Society of Automotive Engineers to draw some lines in the sand: If your light or medium duty truck can't accelerate to 30 MPH in 12 seconds, 60 MPH in 30 seconds, pull 40-60 MPH in 18 seconds or maintain 40 MPH up a specific grade while pulling a trailer, you need a bigger truck (or bigger engine) or a smaller trailer.

You've never actually driven one, have you? An old Ford 300 or GMC 292.... They weren't just half ton motors. They were school buss and wrecker motors as well. They would do their work in reverse quicker than those standards.

4 hours ago, KARNUT said:

When we started our business in early 1980 we used an old 65 model two ton for pulling. It was original a wrecker for towing school busses. It was a GMC with a straight 6, 5 speed and a two speed rear end. It had no trouble getting up to speed and had a top speed of 65 Mph. Speed limit was 60 then. I’m sure the hp of that rig was under 200. The equipment we pulled then was around 12K

Stan has. 292 was also a raw boned stump puller.

My former boss used his Ford 300 Six to pull his 5,000 lb. 25 foot Airstream all over the back bone of the Rockies. No one is doing 70 mph up Wolf Creek pass or Loveland nor Glacier National. Acceleration means nothing there nor does speed. If your idea of pulling a trailer is 12,000# @ 75 mph across Nebraska on I-80 then have at your productivity. If 65 mph is enough with a Joe Average Airstream and/or your bass boat, the Ford 300 would pull it all day. Did you know 2/3 of Americas population lives within a few hours of the Appalachian ridge? Where is the need for the mass acceleration and speed in West Virginia? Upstate New York. The Dragon in Carolina. Along the Appalachian trail. You know, the places people actually GO and camp.

You have either forgotten or are not old enough to know that in the 60's even states like Iowa had 70/75 mph speed limits. Dad pulled car haulers with his half ton 300 four speed all over the mid west and I don't recall him getting all white knuckled over it or trains of cars pilling up behind him. He's 90 and thinks 90 mph is for the slow lane.

We are not talking about moving 80,000# of commercial freight over the divide on I-70. We talking about Joe Average doing a weekend with the family in the Ozarks on the back roads.

pickmeup · August 16, 2018

Donstar my opinion if you got a v-6 truck and you are pretty happy with it but wish you had a little more for occasional towing . I would regear to 4:11 ratio and leave the motor alone. For a 4 wheel drive doing it yourself roughly $700 or so. You will notice a nice change if you got 3:42 ratio now . Worst thing you might lose 2 mpg or so but small price to pay for what you will feel . But you know what they say about opinions !! LOL.