8V92TA Performanced Characteristics

[77newell]

I've had a 37ft coach with a 6V92T rated at 350hp for a decade. It is geared toward climbing hills; about 1950rpm at 60 or so mph. It weighs about 28,000 pounds. From a standing start it accelerates really well, I can merge easily with traffic on Interstates even while towing a Civic.

I just purchased a 93 coach with an 8V92TA rated at 500hp, the coach probably weighs around 36-37,000 pounds towing the same Civic. It seems to be geared more toward running the flats; 1700rpm at around 62mph. It is an absolute slug from a standing start. Given that this coach is hauling fewer pounds per horsepower than my old coach this behavior makes no sense. The engine starts and runs fine, we've gotten about 7mpg towing the Civic. Turbo boost gauge shows typically around 7 with occasional excursions to maybe 13. All the other readings seem normal to me. Oil consumption is negligible, exhaust is clear and all fluids are the correct color so I doubt I've got leaks anywhere.

I'm curious how other v92 powered coaches respond from a stop and what your turbo boost does. I'm not even sure what to ask as everything seems perfect except for what seems to be anemic power. I don't know how long it has been this way, could be forever, but at least it has been this way since I've had it.

I'm not in a panic, just bewildered as usual (just ask my wife)

[GORDON HUMMEL]

My coach is 41.2K +3K toad. Sounds like we have the same gearing. I cruise @ 64 with 7-8 lbs of boost & will go to 20 in the hills out west. 6MPG while towing, 6.7 without.

Mine is also a slug off the line, but if you drive it like you stole it & keep the rpm's & boost up it's not to bad.

[rellick]

My 8v92 475hp is pretty much the same as what Jon and Gordon say about the 8v, I like the sound and it is nice in the flats and at about 70-75 around 2000-2100 it seems the happiest. My 77 with the 325hp 8.3 cummins has quite a bit better pick-up and pulls better in the hills, just doesn't need the rpm to make power like the 8v92, 10,000lbs weight difference but 150hp less with the 77. Haven't checked into rpm torque differences between the two but the 8.3 definately will take the checkered flag in a race, as far as mileage, I haven't checked that either, but what I hear the 8.3 mechanical will get between 10 and 12 mpg in this size of coach.

[folivier]

Jon I think I remember that when taking off from a stop that it's a little bit faster if you start with the throttle about halfway to let the turbo spin up for a 1/2 second or so then mash it. Try that and see if it's any faster.

[Chester B. Stone, Jr.]

I do not run a 8v92, but the boost of between 7 to 13 seems low. I suggest some research on what the boost should be under load.

[folivier]

Jon don't trust the dash gauges since they're analog with such a long run. I was seeing boost pressures up to 24 # in the mountains using the vmspc.