Why is the 7.3 weaker?

H

high toned sob

No Smoke
Joined
Jan 12, 2007
Messages
209
I am still forging ahead with my Crew Cab Chevy buildup (collecting parts), and still planning on running the 7.3 powerstroke. Most of my questions were answered in a previous post I made, but I do have a couple more.

Why is the PS the lowest on the totem pole for power? I know that I don't need 1000hp, I will be using my truck for working, farming, pulling, etc. But what holds it back? The Cummins and Dmax are well over that mark, why no PS? It seems that with the oil supply, turbo, and fuel, the sky is the limit.

What is the weak link in the PS engine? If you go with the forged rods, and studded heads, what is the next "brick wall"? Heads, crank, block breaking, etc??

Just curious why they don't make the "big" numbers the like other two.

thanks,
mike
 
7.3

the 7.3 i a 16v motor so it isn't going respond as easy as a 24v and 32v motor. If you want to build a bad 7.3 and not get ripped off on parts you don't need. you need to call david lott at 713-984-9441. he is building a nasty nasty combo in snow white. he knows everything about that motor. billet rods, injectors, heads, headers,etc....good luck*nx*
 
The injection system on the 7.3 is a dinosour. Supplying enough oil volume is not a problem now thanks to big oil, but getting the injectors to use that volume and pressure efficiently is the problem. The injector design works for stock power levels, but HEUI is not the best for making big power. It seems that after you cross the hurdle of injectors, oil pumps, head studs, rods, pushrods, pistons, turbos, etc. the block is the final hurdle. It is hard to get it to hold together well at higher power levels. Big power can be made with the 7.3 block when coupled with a mechanical injection system like in the double overtime pulling truck which is supposed to be around 1500 horsepower (at least it was before it grenaded itself :doh: ). It is very expensive and risky to choose the 7.3 for making bigger power numbers.
 
phale said:
The injection system on the 7.3 is a dinosour. Supplying enough oil volume is not a problem now thanks to big oil, but getting the injectors to use that volume and pressure efficiently is the problem. The injector design works for stock power levels, but HEUI is not the best for making big power. It seems that after you cross the hurdle of injectors, oil pumps, head studs, rods, pushrods, pistons, turbos, etc. the block is the final hurdle. It is hard to get it to hold together well at higher power levels. Big power can be made with the 7.3 block when coupled with a mechanical injection system like in the double overtime pulling truck which is supposed to be around 1500 horsepower (at least it was before it grenaded itself :doh: ). It is very expensive and risky to choose the 7.3 for making bigger power numbers.
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I respectfully disagree with most everything you just said.
The biggest drawback is tuning, most don't understand how the HEUI system works much less how to properly control it.
 
you can put all the billet rods, head studs, huge injectors, monster sized turbos you want to the 7.3 and produce a butt load of torque but not as much horse power because the computer want let us turn the rpms we need to. once someone figures out how to increase rpms that will increase horsepower and keep torque numbers to a bare minimum, then the block will less likley rip in half. so for no more than your going to use your truck for the PS is a good choice for you!
 
Powerstroke Racer said:
I respectfully disagree with most everything you just said.
The biggest drawback is tuning, most don't understand how the HEUI system works much less how to properly control it.
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I will admit that I do not completely understand the HEUI system, and I also admit that you probably have as much understanding of the powerstroke engine as anyone, but what exactly do you disagree with. From what I have seen, the injectors in the 7.3 have a very hard time maintaining enough oil flow to produce proper injection timing and pressure to ensure atomization. I understand that you are at the forefront of 7.3 technology, and you certainly are up to date on technology that I know nothing about, but from what I have seen that is the conclusion I can draw. Elmo and Bigr are certainly making great progress toward making the 7.3 a contender, but how long can the motors live at the 700+ horse power level without having to address issues with the block. I agree that tuning is a major hurdle for the 7.3, but currently there is not a real fix for the problem of controlling the injection system properly. Once again, I am not questioning your knowledge, but would just like you to elaborate on your statement.
 
imelmo said:
How much power do you think it takes to do this at about 8350lbs :D ? :

http://rides.webshots.com/video/3093495350078600951nnrqYi

I wouldn't worry too much, the power coming from 7.3's is gonna jump up significantly by the end of the year I believe. ;)
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Will the cost to do so also jump significantly as well? I know it costs alot to make horsepower, just wondering if would be more than would be expected.
 
Pat T. said:
Will the cost to do so also jump significantly as well? I know it costs alot to make horsepower, just wondering if would be more than would be expected.
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Prices should stay nearly the same as they are now as the 2 main changes are cosmetic yet very functional changes.
Unfortunately we only get time to work on R&D at night and on the weekends.
 
Funny that a guy today asked me if I had a Cummins, then asked if it was a D66 INTL. He wasn't sure what to say when I told him it was a lethargic old dinosaur.....
 
Ah the suspense is killing me!!! What is this big breakthrough?!?

Are we going doing this wih the HUEI system? Or will we see a stadalone mechanical setup? Tell me I promise I'll keep it quiet!!
 
oldschoolPSD said:
Ah the suspense is killing me!!! What is this big breakthrough?!?

Are we going doing this wih the HUEI system? Or will we see a stadalone mechanical setup? Tell me I promise I'll keep it quiet!!
Click to expand...

On the edge of my seat with ya!!! :pop:
 
you can never go wrong with a 12V cummins with a big P-pump! It will be cheaper, run longer, run harder, and sound a lot cooler that a PS could ever hope for. A side from that it was deigned around old technology. They arn't as simple as throw big sticks and a big charger at it... Good luck.
 
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