Originally Posted by MadCow
Sorry if you were mislead by the title. I am not trying to put a Cummins into a Ford. I am going to be building a diesel motor in the near future and I was wondering is there is a kit/crank that can shorten the stroke of a 7.3 motor? The motor will be for racing and not towing/sled pull. I thought a big bore short stroke diesel would make for a good race motor. I was wondering if there was a way to get more RPM out of the 7.3? Maybe I am stuck in car world and don't need RPM to go fast. Or is it better to build a 6.0? I see 2.0L cars spooling Holset HX35's and even 302/351W motors using 2 hx35/hy35's. They boost anywhere from 3-5K but they have 6-8K redline. So to my understanding a motor with 1/2 displacement revving to 2x RPM can utilize a similar turbo? I have been reading about people who can't get some big turbo diesels to "light". Would more RPM help? Or am I all wrong about diesels. And do i need commonrail to go fast? Does that just make the dodge/chevy diesels cheap and easy hp? And what is the difference between big HP diesels and fast diesels? I have seen some high HP trucks but some of them aren't fast at all. Is it about the torque curve? Are they dyno queens like in the car world? Anyways I am a mustang guy and now i need some diesel power so I figured I am goin powerstroke. Sorry if these questions have been answered previously but I searched the net and this great forum for about a week and found lots of info but nothing specifically answering these questions. This is a great forum and everyone seems so nice. All answers, replies, and suggestions are appreciated and that thanks in advance
If you're going to build a 7.3, your budget had better be huge. It is very costly to get a 7.3 to keep up with the Cummins and Duramax trucks - and i'm talking about the ones running 11's not the 10 and 9 second ones. Unless they've run quicker since I last saw, the quickest 7.3 is only
at 11.2xx. You don't really have to have common rail to go fast either. The old 12v (89-98) Cummins engines have been putting out massive hp/tq numbers and the fastest diesel 1/4 times. A 6.0 would be cheaper, but it's still going to cost quite a bit. Transmissions have a lot to do with being faster or slower, as well as weight. For instance I have a manual with the strongest single disk clutch that money can buy. I have dyno'd 525hp/996tq but a guy with 75 less hp and automatic trans could likely beat me in a 1/4 drag race. The autos don't loose boost between shifts, and manuals make for long throws rowing gears. As far as weight, two trucks might lay down very comparable numbers, but if one outweights the other by a significant margin he's likely to lose out in the quarter. Like you said, you've seen high hp trucks that are slow. What do you consider "high" horse in a diesel? A few years ago 500 was likely to awe people, but now 650+ seems to be the more magical number to start wowing people. There are several well beyond that, as well as several 1000+ Cummins diesels and at least 1 Duramax (NastyGirl) that I know of. I think it also depends on the engine. If it's a 7.3 500 can really turn some heads, but in a Cummins or Duramax it is not the biggest surprise, the bar is just so high now. The highest 7.3 numbers i've read of are Dockboy's 700+ on nitrous, not sure about 6.0 numbers. 500+ psd's seem to be few and far between. But don't let it discourage you, if it's what you want to do then go for it.