| Author | Message | ||
| chicken-lady
Unregistered guest Posted From: 69.19.14.41 Rating: N/A |
is it possible to increase horse-power of a 8V92? we have a '93 Prevost with 8V92. What could be done to give it more power? | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 291 Registered: 10-2003 Posted From: 69.162.3.30 Rating: N/A |
We first would need to know what the horsepower is now and what is your total gross weight when traveling.Do you need more top speed or more speed on hills or both.Axle ratio would be helpful or the rpm's at 60mph. | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1004 Registered: 12-2000 Posted From: 71.195.113.23 Rating: |
"We have a '93 Prevost with 8V92. What could be done to give it more power?" A '93 8V92 is going to be a DDEC electronic engine. IIRC, the only way to hop it up is to take it to a Detroit Diesel dealer and have them reprogram the DDEC. Costs about $1 per HP - IF they will even do it. Many are very, very skittish about EPA smog violations related to such HP modifications. Another thought - if you bump the HP to 500, you're going to have to deal with cooling issues - 8V92s generate a LOT of heat, and more HP means more heat. In addition, 500 hp is going to suck even more fuel all the time, not just when you need the extra "umph" to get up a hill. Have you run your coach across a set of scales? Two-fold purpose for this: One - to adjust your tire pressures properly, and two- to see if maybe you need to put your coach on a "diet" and get rid of some stuff. 100 lbs/hp is sort of the magic number when it comes to buses. Much over that, and your fuel mileage suffers, acceleration suffers, hill-climbing ability suffers, brake life is shortened, etc. Below 100 has the opposite effect, but it much harder to obtain. Finally, you cannot drive a bus and expect it to perform like a car - too much mass involved. As I've said before, think of the children's fable of the Tortoise and the Hare. If you try to drive it like a Hare, you're going to be disappointed. Drive it like a tortoise, and you'll thoroughly enjoy the journey! HTH. . . | ||
| chicken-lady
Unregistered guest Posted From: 66.82.9.88 Rating: N/A |
does 425-430 sound right? Top speed is good, it will do 80 easy. it's taking off and climbing hills a prob.when loaded with passengers [48] thanks | ||
| chicken-lady
Unregistered guest Posted From: 66.82.9.69 Rating: N/A |
You are Right! Johnson & Towers [Detroit dealers] won't do it.We keep the fuel filters and air filter clean, which is all they said to do. We cross the scales in Maryland all the time, we never get weighed, they green light us. @60MPH...the tach is 1600.I thinks she runs good, but I am a woman, my drivers think it's lazy!I appreciate all your comments! THANKS | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1005 Registered: 12-2000 Posted From: 71.195.113.23 Rating: N/A |
Sorry, thought it was a conversion coach, not one still in revenue service. You can thank the EPA for this bus's performance. It's slow out of the hole because the computer won't let the engine go to full fuel right away, to keep the black smoke in check (emissions). Based on the 60 mph @ 1600 rpm, that tells me it's got a fairly tall rear axle ratio in it, for better fuel mileage. This also plays a part in the slow acceleration and poorer hill-climbing ability. Teach/tell your drivers to downshift that automatic manually for better performance climbing hills - the tips at the end of this link should help: http://www.busnut.com/artrjl2.html IIRC, charter buses came with either 400, 425 or 450 hp versions of the 8V92TA, depending on who ordered it and the manufacturer's option list. Call Prevost w/ the coach's VIN and ask them what the HP rating was when it was delivered. They should have it in their Vehicle Records database. The Serial Number off the engine will give you the same info if you call Detroit back, they can look it up in their computer system, too. (VIN's easier - you don't have to get dirty!) RE: weighing the coach - since it's in revenue service, it's going to weigh something different each time it's out on a charter. But if you want to weigh it, take it to a private set of truck scales, not the ones alongside the highway. Will cost you about eight to ten bucks for a certified weighing. HTH. . . (Message edited by rjlong on August 25, 2006) | ||
| Henry Bergman
Unregistered guest Posted From: 74.32.175.172 Rating: N/A |
Take you bus to your local friendly Detroit Diesel dealer (non-factory related, if possible) and ask to take the computer guy out for lunch. Your $treat$. Nicely explain your situation regarding your "doggy" 8V92TI DDEC II or III mill and ask what can be done. He will PROBABLY say "nothing". Sossss...then ask him if he would consider "acting" as a private "consonsultant" (SP) (I'm a lousy speeeller) A private $fee$ MAY have to be paid. Maybe, just maybe he will grab his laptop thinkin-dinkum and plug it into the access port on your mighty (to be) 8V92TI. You see---he has the secret codes. Also...depending upon where the coach is registered, NO SMOG laws MAY be broken. How much power to you want? would up to 600 hp be sufficient? And....if you keep your foot out of the mill, your mileage will remain the same. Only when you REALLY want to go up that hill or pass that other bus really fast will you burn that fuel and create that heat. Goood luck. | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 244 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
If you take it up to 475 to 500 HP you should get good life and power out of the motor, I wouldn't go over 500 HP. I have 475 HP in mine and it will pass any series 60 on a hill. Ron | ||
| Greg Peterson (Gpmci102)
Registered Member Username: Gpmci102 Post Number: 17 Registered: 8-2006 Posted From: 71.228.18.37 Rating: N/A |
If you have a 400 hp engine you probably have 5234960 injectors. These will limit the power even with the computer change, If you want to go up to 450hp or more you need the bigger 5234965 injectors. The 500 hp engines use the 5234775 injectors; these injectors will go to 540 hp on an industrial rated engine. The higher ratings all use a TV8513 turbo with an A/R of 1.39. This info is from my growing collection of DD manuals. The computer engines do allow a wide range of horsepower adjustments but with range jumps they require a different injector. The A/R of the turbo also may change. The last book I got showed some fuel usage vs. horsepower for the 92 and 71 engines. The 92 engines are more efficient then the 71 engines. I would guess this is because of the turbo and intercooler. The turbo recovers some of the waste heat from the engine and makes use of it. The bypass blower takes some load off the engine and lets the turbo provide the pressure when available. This would support the theory that an 8v-92ta will not get worse fuel mileage then an 8v-71n if it is putting out the same horsepower. In fact it may get better mileage. In practice, if you have an 8v-92ta you are not going to climb hills at 20mph like the 8v-71n. The extra horsepower to go fast up the hill will naturally lower the mileage. | ||
| Edwin C. Boso (Dred)
Registered Member Username: Dred Post Number: 1 Registered: 8-2006 Posted From: 72.65.153.106 Rating: N/A |
A previous poster stated his Prevost with an 8V92 at 475 HP could pass any series 60 on a hill. I seriously doubt the statement to be true. Was there any testing done to confirm the statement or is it just pure owner boast??? | ||
| chicken-lady
Unregistered guest Posted From: 66.82.9.55 Rating: N/A |
Ron Walker What's your fuel mileage? Ours is about 6 - + | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 245 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
I get about 6 if I keep my foot out of it...may around 4 on a 6% grade. Edwin, I live in the west coast mountains there is not a flat road out of this town where I live, 6% min grade out of here. We are on route for all the tour buses, 90% are Prevost H345's series 60, 20 to 30 a day, heading towards Banff and Jasper National Parks. Myself and a friend with a MCI9 /8V92TA have no problem passing them on a grade, they pass us when they get back on the flat, they have way more top end. We both top out at around 80.. but only run at 70. On a 6% grade for 6 miles I can run that at a steady 65 MPH, no problem. I doubt that many tour buses are running 475 to 500 HP. I suspect that they are running 400 to 450 HP with the 12L motor (Message edited by prevost82 on August 27, 2006) | ||
| Greg Peterson (Gpmci102)
Registered Member Username: Gpmci102 Post Number: 19 Registered: 8-2006 Posted From: 71.228.18.37 Rating: N/A |
Your correct Ron most of the buses are set at 400hp and you would not have too much trouble with them. If the computer does not limit the speed that B500 with the high-speed sixth gear would beat you on top end. The series 60 computers can easily limit the MPH so you may beat them even on the flats. The other day I went over to the Chicago MCI parts and service center to get something for my 102A3. There was a guy dropping off a new converted coach for some simple service. This was a new style big buck conversion. The guy said he pulls a big trailer so when he ordered the bus shell he paid $20,000 more to have the 14L series 60 set up to 600 HP. Ron, don’t try racing that guy especially if your putting any money down on the results. | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 246 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
You're right Greg ...there's way way I would race that guy for pink slips...LOL. "Hummmm...If I could just get wifi access to Atec or ECM on that bus before I race him...hummmmm" | ||
| JR Lynch (Njt5047)
Registered Member Username: Njt5047 Post Number: 41 Registered: 7-2006 Posted From: 69.132.238.127 Rating: N/A |
Be careful with providing gratuities until you get your HP increase...it's my understanding that the computer that performs this service is on a dedicated link with the big DD in the sky and when you link up, it'll only reset, or lower the parameters. They won't make changes that increase emissions. What you could do, is find a wreck with an appropriate (500 HP) 8V92 DDEC and buy the ECM. You can buy the matching injectors without issues. Preferably you can locate an ECM programmed with your transmission...although, they can reprogram for whatever trans you wish. And they will do that. May want to get a copy of the serial number from the donor coach....? These EPA folk are a real PITA for the "Racebus" community. Good Luck...JR | ||
| Craig (Ceieio)
Registered Member Username: Ceieio Post Number: 236 Registered: 12-2004 Posted From: 207.101.213.58 Rating: N/A |
"I live in the west coast mountains there is not a flat road out of this town where I live" Ron - amen to that. I have a first or second gear pull to my driveway (depending on if I take a run at the hill) so I can't even go for a coke without pulling a hill. The 8v71N really grunts through the climb... it is only a seven to eight hundred foot elevation rise up to the house, but it is a steep rise. Leaving for a trip for me means hills, crossing the cascades with 5000+ foot passes, Cabbage Hill on I84, the up and down through the Siskiyous to the south on I5, or even crossing the coast range to the beach. It would be nice to pass something faster the bicyclists, but that is not my lot in life with an 8v71N! Craig - MC7 Oregon | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 249 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
Craig ...had the same problem when I first brought the bus home, I think the cyclists were passing me. LOL So I found a wreaked truck wih a new 8V92TA in it, 10K miles, sold the 71 and parted out the rest of the truck's running gear and the motor was just about free. Just as a side note, I pulled out of Mexico this spring with a bus nut with a MCI 5 (35 ft). He had put a new 6V92TA with an B400 6 speed, out of a fire truck he had bought. We both had pulled out of Mazatlan so we had a couple of fuel stops on the way. The thing that supprised me was it would only cost me $10 more for fuel than what he put in at each stop...and my bus was way heavier and taller that his. Ron | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 120 Registered: 7-2006 Posted From: 65.142.253.223 Rating: N/A |
just kinda in the same conversation,when I took all my seats out, (70# per pair) & install my house stuff,it brought it back to the same weight with the seats. figureing 250 for each passenge,incl. luggage ..you are hauling 12,000 pounds 'extra'.the diesel engine is designed to run so many gallons of fuel in it's lifetime,the more fuel goes thru ,the shorter the lifetime.tell your driver to learn to smell the flowers. | ||
| fingers Unregistered guest Posted From: 68.251.63.241 Rating: N/A |
I was once ridiculed at another similar forum for suggesting that I would like to rig my toad, a half ton P-U, remotly, and use it as a pony motor when nessesary on long grades and such. Some people just dont have any sence of humor! |
