| Author | Message | ||
| frank-id Rating: N/A |
Does anyone know any information or formula about horsepower anf torque gain with certain engine improvements or assists.. I have been told a turbo gives a flat 30% HP gain. Also I was told an intercooler will make an increase in HP at the rate of 10HP for every 100 degrees of lowered incoming air charge. Which is more effective, an intercooler, or an aftercooler? Which method is most expensive. Cooling the turbo aircharge is often called "free" HP. I have read that there is substantial gain in HP/torque by increasing both air inlet pipe size and exhaust pipe size. It has been suggested that 8 inches inlet pipe and at least 6 inch exhaust pipe make the best HP. Is fuel milage affected by these changes? My bus has a turbo. I removed the muffler in hopes of gaining 100 HP with very little increase in exhaust noise. The engine sounds much more powerful. Any factual insite and views appreciated. | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
Hiya Frank, Don't know about gains but I do know the opposite... Power output on a naturally aspirated diesel typically decreases 3% per 1000 ft. of elevation above 1000 feet, and 1% per 10 degrees above 60 degrees Fahrenheit. And believe me this is true... I found that out with my Crown up in high desert 115 degrees 10,000 ft, what a WHIMP without a turbo!!! And after I put my turbo on, what a MAJOR DIFFERENCE even though I limit the boost to 5psi to avoid having to change anything else in the engine.... So you can back those figures into your question and get that an intercooler or other means of cooling your turbo's boost air will absolutely help you to NOT loose 1% of your horsepower whatever it is, per every ten degrees that it makes the turbo output cooler... yes, basically free horspower if you have a turbo... and you can also do the altitude thing- 10,000 feet is roughly 5psi. Since an engine looses 30% of it's horsepower if it's inlet pressure is dropped 5psi, it follows that it can probably gain that much with a 5psi boost if you also add extra fuel to utilize that extra air. I'm sure it's not quite that linear though if you extrapolate to 40psi.... Removing the muffler won't get you a lot of horsepower gain. It will get you traffic violations that will cost bunches more than the price of the fuel you'll save, and it will annoy everyone around you... Making your inlet and outlet pipes giant will help a tiny bit with the horsepower but again, over 4 or 5" and you're mostly wasting your time and money... | ||
| Doug Wotring
Rating: N/A |
I don't know of exact forlulas but" Cold air= more dense air= better effeciency = better performance. Better inflo and better outflow generally increases performance. But then you do need some backpreasure on the exhaust side. you also can't force more air into the intake than the Blower can handle.... as far as Turbos, No flat # for a turbo. It is all dependant on turbo boost preasure.....which also is contigent on a host of other perameters. Wondering why you need an aditioanl 100 HP. Keep in mind. any modification you make to gain HP decrases Engine Life. I for one would love to put a chip, big ass exhaust and a cold air intake system on my Powerstroke Deisel Can gain as much as 200 HP.....but at what cost. Stock the motor makes 350 or so and should live the way I drive for 500,000 miles. put it to 200 and crap will start to break and may cut engine life in half. | ||
| john w. roan (Chessie4905)
Rating: N/A |
Engine size and brand would be helpful...Renault turbo diesel? Detroit two or four cycle, Cummins, Cat or what? What is your HP rating with the present turbo? How much does the coach weigh and how much are you going to tow if anything.100 horse power won't do much for a 45,000 pound coach. Some of the turbo'ed engines are already at their useful limit for their size, even though you could probably get another 100 horse from most of them. The problem then becomes....excess smoke, always keeping an eye on the temp gauge etc.It could be better to go larger instead to keep reliabability. It is all going to depend on what you have. Please fill in the blanks. | ||
| frank-id Rating: N/A |
Hey John, I am not looking for design criteria for a new engine. All diesel engines seem to react to the same equiptment in a similar way. Most diesel engine have the power accessories mentioned. I'm an old guy 68 years. I'm not looking for a 30 year relationship with my present bus engine. I need about 425HP comming from my Cummins. I have a 1986 Crown-Ikarius bus with a Cummins 425HP. My inquirey was just to maybe put a value on power enhancements. Is it cheaper to intercool or after cool? Yep, I am considering adding propane. I do have several spare engines for my Crown bus. Frank | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
Frank, what on earth are you going to do with more than 425 horsepower? Try to outrun highway patrol cars while going up 8% grades? I can't imagine... I'm happy as can be with 220 !!!! Better mileage too... | ||
| frank-id Rating: N/A |
The US Army has a saying "be all ya can be and have as much fun as is legal".. kidding. I really like horsepower. A horsepower described is the ability to lift 33000 pounds one foot in one minute. There is no substitution for cubic inches and horsepower. One of my last buses, I replaced the DD 8v71 making 240 HP with a 6v92ta which made about 350-375HP. That GMC went anywhere nicely. My original question was directed at what modification to a diesel makes the most horsepower. After watching the tractor pulls and the Pikes Peak races, there are ways of making a great cruising Crown bus. Many folks raise the roof to help slow down the bus, I want to create a lower profile. The boat folks and aircraft owners have a saying, "if ya must ask the price of fuel milage, don't buy".. Yes, I do know a Crown bus is not a Vette, as I did that. Be well and enjoy life. I'm trying... Frank in Idaho | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
Wow, what a concept... lowering a roof !!! Hmmmm, ok... yes... ahem... ....better mileage, no fear of bridges, keep tall people out of your bus automatically, park in a garage (well, some of it anyway) easy parking in airport parking structures...  As far as the horsepower, go for it !! Having fun and enjoying it is all it's about!! Keep hanging in Frank! gary | ||
| Marc Bourget Rating: N/A |
You can leave the roof the same height, just reduce the aero quotion "Q" and you'd obtain a better benefit | ||
| motorcoach1 Rating: N/A |
flow the heads and add nitrous oxide . 4-0 valves will help..up the injectors and inter cool the turbo | ||
| john w. roan (Chessie4905)
Rating: N/A |
Adding 100 horse power to a 425 Cummins is going to cost more than it would cost to add that much to, say a 250 Cummins.However, I remember a 475 version that they used compound turbos on from the factory....with a little more fuel added you should get 525 with a good sized air to air intercooler with an electric? fan mounted at the rear opposite side. So many of the current trucks have intercoolers that you should be able to purchase one used from a truck salvage yard at a reasonable price. The more you cool the incoming air, the more boost the engine will tolerate. If I recall, the 475 Cummins utilized 14 to one pistons, but I don't think they had an intercooler back then. The propane would probably be the best setup as the cold propane also cools down the incoming air as it is injected; also can be set up to be used only when needed. If you need the power all the time and money isn't that big a problem, how about a KTA600 Cummins with the appropriate transmission. |