| Author | Message | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 10 Registered: 4-2009 Posted From: 204.62.111.51  Rating: N/A |
do you floor it? I find myself stepping on the pedal all the way to the floor to get it moving. according to instructional movie at michelin (Thanks Jaime) you should always leave yourself a little room when accelerating. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 252 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Peter That is how you drive a 2 stroke diesel. To the floor on acceleration and ease up when you get her up to speed. You will find the tranny shifts better under full throttle as well. Bill | ||
| John and Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 160 Registered: 9-2007 Posted From: 24.179.147.233  Rating: N/A |
I thought those had a Cummins and were 4 stroke, shows you how much I know! | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 13 Registered: 4-2009 Posted From: 204.62.111.51 Rating: N/A |
apparantly you know a lot  my bus has a 4 stroke engine, electronically controlled 24 valve. (Message edited by WhiteBus on April 28, 2009) | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 694 Registered: 8-2006 Posted From: 65.1.88.54 Rating: N/A |
They do have a 5.9L Cummins engine all the ones I saw and are pretty slow on the getup and go | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 650 Registered: 7-2006 Posted From: 75.211.121.125 Rating: N/A |
Cummins....one hears very little on the boards about them.....Hmmmm.... . I have one too!!!,,, Care to "drag"?... ( I have no problem with the "getup and go"... RJ...where are you? RCB (Message edited by chuckllb on April 28, 2009) | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 875 Registered: 11-2005 Posted From: 208.54.200.36  Rating: |
Acceleration is something I gave up when I bought my 4104! I sort of got used to it driving an 18 wheeler. Now I think in terms of locomotive acceleration. Planning ahead is what I do a lot more of now!! I have no complaints, it actually makes you a better driver. | ||
| Wec4104 (Wec4104)
Registered Member Username: Wec4104 Post Number: 33 Registered: 7-2008 Posted From: 68.80.242.72 Rating: N/A |
Okay, so hypothetically speaking, let's say you have a 2 stroke DD in good condition and generally operating as it should. Depending on the injector size, with the accelerator pedal at 90-95% of the way to the floor you start to see black smoke exiting the tailpipe. (Temperature and altitude dependant, also) Black smoke of course, is unburnt fuel. Let's assume the air filters and intake are unrestricted, too. The question is, would you still put the pedal to the floor? Or is the only thing you will reach faster the next fuel station? | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 16 Registered: 4-2009 Posted From: 208.54.94.119 Rating: N/A |
RCB, I am near las vegas, and I will take you up on your challenge at any time. I am sure I can find a quarter mile of strip somewhere | ||
| David Lower (Dave_l)
Registered Member Username: Dave_l Post Number: 135 Registered: 11-2007 Posted From: 67.58.201.132  Rating: N/A |
The salt flats! Bus drags and flying mile speed runs, now woudn't that be a bus rally to go to :-) Wec I would say put the pedal down merge on to the freeway as safe and quick as conditions allow so as not to cause back ups behind you! Dave L | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 655 Registered: 7-2006 Posted From: 75.208.220.214 Rating: N/A |
Peter...which Las Vegas...NV or NM?...not sure a quarter mile would do it for mine. I'm with Gus on the matter, really. Has made me a much more alert and patient (well..that is up for debate) driver. Many on-ramps are "uphill" and there is only so much once can do to make 40,000#, +-, move swiftly. Generally speaking, I never have the pedal to the floor. This Crown will do 85 easily...and not on the floor. (might depend on which way the wind is blowing ) MPG usually 10-12. Manual transmission gives one lots of choices and I attempt to use mine to best advantage most of the time. Black smoke to me is $$ and when possible, I avoid it. Your mileage beats mine!!!...how'd you do that? FWIW RCB | ||
| Wec4104 (Wec4104)
Registered Member Username: Wec4104 Post Number: 34 Registered: 7-2008 Posted From: 68.80.242.72 Rating: N/A |
Dave: In retrospect, I am not sure I asked my previous question very clearly. Under the situation I described, I am asking myself whether the last 10% of pedal travel really gains me anything in acceleration. From the driver's seat it is certainly hard to tell. No question about it, I want to merge as quickly and safely as possible. I want to use all the hp and torque available to me, as well as optimize the shifting points (manual). So, assuming the rack is properly adjusted to distribute fuel equally to all cylinders, does overfueling beyond the point where I start seeing black smoke gain me anything? If the exhaust starts telling me at 95% throttle that the engine is getting more fuel than it can use, is there a reason to give it more? Of course the true answer can be found by breaking out a stopwatch and doing some controlled tests, but I guess I am wondering if folks have reason to suspect one way or another. | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 17 Registered: 4-2009 Posted From: 204.62.111.51 Rating: N/A |
RCB, it's the tiny tiny engine that gets the mileage. I was shopping for a 671 when I found this. I am near las vegas NV. One thing I do envy about the big buses with 2 stroke engines is their ability to run on WVO without much modification, it would become handy when the price of diesel hits $5 again. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 656 Registered: 7-2006 Posted From: 75.208.220.214 Rating: N/A |
I know absolutely nothing about "2 strokes", so can't comment on how they perform, etc. With a manual transmission, when I see black smoke, (on-ramp situation)I either back off the pedal or shift to a lower gear which, if the truth were known, I probably should have been in to begin with... . FWIW RCB | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 882 Registered: 7-2006 Posted From: 74.162.95.136  Rating: N/A |
Re: "does overfueling beyond the point where I start seeing black smoke gain me anything? " No. Nope. Absolutely not. Nothing. Zip. Nada. Zero. | ||
| Tom Caffrey (Pvcces)
Registered Member Username: Pvcces Post Number: 1282 Registered: 5-2001 Posted From: 65.74.69.200 Rating: N/A |
John, most of the time, I agree with you. However, I think that additional fuel after the first traces of smoke does increase power. This probably is why I floor the pedal on onramps; I don't otherwise. The heat generated by furning fuel comes from oxidizing it. When there is no smoke, the hydrogen and the carbon in the fuel are oxidized. When too much fuel is injected, the hydrogen is fully oxidized and part of the carbon is not. This is the soot that we see. I know that I have driven rigs that could put out a lot of smoke, and quite a bit of power was added as the smoke increased. One old boat engine I ran would easily double it's horsepower by adding smoke. This leads me to think that oxidizing hydrogen produces more work than oxidizing carbon does. Fifty years ago, almost all of the semis put out a pretty good cloud of smoke. I think that they were set up that way because it was a cheap way to get the most horsepower out of an engine. And, you will notice, the cost of the extra power came entirely out of the operator's pocket, not the maker's. This worked as long as the fuel and the environment were not valued very highly. Thst's the way I see it. Tom Caffrey PD4106-2576 Suncatcher Ketchikan, Alaska | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 156 Registered: 1-2009 Posted From: 24.129.235.190  Rating: N/A |
I had notice that a good trail of black smoke does increase the distance between my bumper & tailgaters impatiently waiting to unsafely pass. Is this a gain or a loss ? | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 878 Registered: 11-2005 Posted From: 208.54.200.2 Rating: N/A |
If you push the pedal and the bus accelerates then fuel is theoretically not wasted. However, if pushing more adds nothing to acceleration then fuel is wasted. I stop pushing when acceleration stops or smoke starts. I doubt that smoke does any harm to the engine but I don't like it regardless. Again, I quickly got over the idea of acceleration when I got the 4104! | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 658 Registered: 7-2006 Posted From: 75.208.170.156 Rating: N/A |
Clint..... ...I'm still prayin' for you ...and JTNG.......and Gus ..........??? I agree with YOU, Gus!!!!, Tom,..and...and..most all that have posted in this discussion(??). U know what I mean...Thanx, Ian for a wunnerful, wunnerful forum! Mark B...RJL...where are you? RCB | ||
| Keith Wood (Ft6)
Registered Member Username: Ft6 Post Number: 105 Registered: 8-2008 Posted From: 75.208.98.50 Rating: N/A |
"The salt flats! Bus drags and flying mile speed runs, now woudn't that be a bus rally to go to" Last I heard, all you need to do is reserve the strip for a time when nobody else has reserved, and hire an ambulance to stand by. There may be a little more to it now, but it's certainly within the realm of possibility. "Busville Rally . . ? Even better, it's only about a mile from the Utah weigh station to the offramp from I-80 to the World's Fastest Mile, so you could get an accurate weight for "handicapping" the acceleration, braking and fuel-consumption trials. Other attractions include the casinos just over the line in West Wendover, and the historical Wendover Army Airfield (where they trained for the A-bomb drops in WWII). Not to mention a truck stop right there at the I-80 ramp for fuel, food, etc. I think something like that would be a lot of fun, and worth setting up. | ||
| Keith Wood (Ft6)
Registered Member Username: Ft6 Post Number: 106 Registered: 8-2008 Posted From: 75.208.98.50 Rating: N/A |
"does overfueling beyond the point where I start seeing black smoke gain me anything?" Yes, it will get you more room between you and the guy who thought he'd tailgate you up the ramp. | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 77 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
This is as simple as it gets. ALL bus and truck diesels are made to be floored. The only time you should back off is on a long up hill grade where 3/4 pedal is more prudent. When pulling a hill, you should be able to accelerate gradually in the gear you're in, then you're pulling the hill in the correct gear. Good Luck, TomC |
