| Author |
Message |
Greg Roberts (172.144.82.27)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 30, 2001 - 7:17 pm: | |
Gentlemen, What is the most economical RPM to run the 6V92? My belief is that best economy should be near the RPM where peak torque is created. I am interested in re-gearing the rear end on m y eagle to get better economy at about 70 MPH but I certainly don't want to make hill climbing too slow either but then that is what multiple gears on a transmission is for, right? Looking for some experienced opinions here. - Greg |
RJ Long (24.130.101.25)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 30, 2001 - 8:20 pm: | |
Greg -
From a 1985 DDA spec sheet I have on the Silver 6V92TA, it says:
"Gear vehicle to attain maximum desired cruising speed between 1600 - 1800 RPM for best fuel economy, with 2100 RPM available for hill climbing or off-highway conditions."
HTH,
RJ |
Greg Roberts (172.148.80.102)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 30, 2001 - 11:15 pm: | |
So I should shoot for 1700rpm at 70mph according to your info RJ. I have an excel spreadsheet that shows that I need to change my gears to 3.00:1. What gears do you other 6V92 guys run in your buses. My bus is an Eagle so no V drive. My trans is an HTB748 Allison. Right now I get 66mph at 1950rpm. Wheels are 24.5". Please share your gear ratio and speed/rpm. Thanks in advance for replies guys. |
RJ Long (24.130.101.25)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 01, 2001 - 1:38 am: | |
Greg -
I've got a 4106 with a stock powertrain in it - 8V71 & 4-spd manual, 4.125:1 rear axle, 0.808:1 bevel gearset, 12x22.5 tires all around. The bevel gears in the angle drive give an effective ratio of 3.33:1.
OEM from the factory, the 4106 was geared to run 60 mph at 1650 rpm using tires that turned 495 revs per mile.
Spec sheets I have for Eagles show the 01, 05 and 10s powered by the 8V71 came with a Rockwell Std R162 axle, ratio 3.70:1. The Model 10s and later again used the Rockwell axle, but when equipped with the 6V92TA, the ratio was 3.36:1. Stock tire size was 11Rx24.5.
YMMV,
RJ
PD4106-2784 |
greg roberts (172.161.87.140)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 01, 2001 - 10:32 am: | |
The 3.36 ratio would give me 70mph at 1875rpm which is on the high side of where I want to be. If I put gears in it around 3.0 to 3.15 range it will give me 70mph at around 1700rpm on the 6V92. Does anyone have their 6V92 geared anywhere near this ratio? Sure would like to know what the effect to hill climbing would be overall. Seems this would be a good place to spend a few dollars to get a little better economy. Anyone have any experience with this? |
Jeff Pack (131.107.3.86)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 02, 2001 - 6:39 pm: | |
Just consider that at lower RPM, you arent moving
water as much, if you have a rig thats prone
to gettng hot. |
Clarke Echols (216.17.134.97)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 03, 2001 - 8:58 pm: | |
I suspect you'll have a tough time finding ratios below about 3.33 or 3.30, although I don't have the data on an R162 (I have misplaced my data sheets). When you start cruising at over 65 mph, air resistance becomes a big energy drain as well, dropping fuel economy rather severely over 70 or so. |
Tom Hamrick (Tomhamrick) (65.204.251.231)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 05, 2001 - 8:18 am: | |
My 1984 Eagle Model 10S has a Rockwell 3.33 and the 6V92TA engine. The axle is Eagle part# 1040202522 and is listed in the Eagle parts book. According to the parts book my bus was supposed to have the 3.36, but that is not what the tag on the axle housing says. I have not driven my bus a lot of miles since most of it's tenure with me has been in the welding shop, but it seems to climb hills fine. It certainly has a good top end. On a test drive after I had the engine rack adjusted I backed off at 80 mph and I will not go that fast again!! This is a bare shell by the way.
Tom Hamrick Eagle 10S |
Greg Roberts (63.73.123.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 05, 2001 - 9:28 am: | |
Tom, any idea yet what your fuel mileage is with your rig? Is yours set up for 350HP? Thanks for your reply. Clark, I am thinking you are probably right and at least the carrier would need to be changed if not the whole rear end to get taller ring. |
Tom Hamrick (Tomhamrick) (65.204.251.231)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 05, 2001 - 2:43 pm: | |
Greg,
My 6V92 is set for 350 horsepower, but I have not driven it enough to calculate the mileage yet.
Tom Hamrick |