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rich
Dodge Dakota
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3/13/2004
16:56:10
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 Subject: Improve drivetrain efficiency
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Here's a thought.
I've been reading alot of post about getting more HP, torque, and gas milage.
It hit me last night. Improve the efficiency of the drivetrain.
Most trucks are about 80% efficive. The Dakota is about 76%. If we found a way to make it more efficient, we would gain in all three areas (HP, torque, and milage)
Let have an example by using the Dakota R/T
250HP @ 80% efficiency = 200 RWHP
250HP @ 76% efficiency = 190 RWHP
Difference of 10 HP
345FT/LBs @ 80% efficiency = 276 RW FT/LBs
345FT/LBs @ 76% efficiency = 262.2 RW FT/LBs
Difference of 13.8
Now lets say that we add some mods to the truck. (www.drcperformance.com - Lightning killer package)
321 RWHP, 317 FT/LBs
Reverse the formula's and you get
401.25 HP at the crank @ 80%
396.25 FT/LBs at the crank @ 80%
422.39 HP at the crank @ 76%
417.16 FT/LBs at the crank @ 76%
What this means is that at 76% efficiency, you have to produce 21.14 more HP and 20.91 more torque then a truck with an 80% efficiency.
According to the following article, the R/T has a drive train efficiency of only 61.88% on HP and 58.06% on Torque.
http://www.trucktrend.com/roadtests/pickup/163_0208_fun/index4.html
So...basically, what I think, is that we need to find ways to make the drivetrain more efficient.
Does anyone have any ideas on how to do this?
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Gen II Geoff
Dodge Dakota
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3/13/2004
17:24:26
|  RE: Improve drivetrain efficiency
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I don't know about making it more efficient, but the guys at krcperformance.com might have something to say about that :-)
geoff
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Pittdawg
Dodge Dakota
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3/13/2004
18:16:51
| RE: Improve drivetrain efficiency
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that truck trend article is complete bs...most r/ts put down at least 190 with many over 200. I would say the range is approximately 190-210rwhp, 190 being the worst and 210 the best. If we take the average of the two, 200rwhp, you are right at 20% drivetrain loss, which is pretty much industry standard for an auto. If the r/t only put out 154rwhp as that article claims, i don't think the durango r/t (same engine and drivetrain) could even move itself let alone dakota r/ts running low 15's stock.
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rich
Dodge Dakota
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3/13/2004
18:55:03
| RE: Improve drivetrain efficiency
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Yeah I agree about the article being bs with their numbers.
However, my example still stands.
If the R/T is only putting down 190 RWHP that equals 76% efficiency...200 RWHP equals 80% efficiency and 210 would equal 84% efficiency.
I realize that this may seem like a pretty small difference, but I think that it could make a pretty big difference in the end.
-Rich
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WipLash
R/T
3/13/2004
20:00:42
| RE: Improve drivetrain efficiency
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I'm thinking about changing out all my fluids to synthetic. Has anyone used Royal Purple in their diff?
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Kowalski
Dodge Dakota
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3/14/2004
09:25:05
| RE: Improve drivetrain efficiency
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Where did you get those #s, Rich ? Too much generalization, it depends on what transmission is in the truck. The manuals are the most efficient, around 15% loss; and mopar already has a higher efficiency automatic; the 45RFE and its derivative, the 545RFE that I've seen claimed at 17-20% loss (80-83% efficient).
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jd
Dodge Dakota
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3/14/2004
18:01:57
| RE: Improve drivetrain efficiency
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the first place to start is synthetic lube. synthetics are known to noticeably reduce heat generated by highway tractor diff's lots of truckers run it eventhough those diffs hold 20L of oil each, gets expensive
later
jd
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rich
Dodge Dakota
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3/14/2004
19:36:52
| RE: Improve drivetrain efficiency
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The numbers mostly came from other post and articles that I have read.
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WipLash
R/T
3/14/2004
19:59:09
| RE: Improve drivetrain efficiency
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Did anybody see "Two Guys Garage" today? They dynoed a 3/4 ton Sliverado and it barely broke 180RWHP in stock trim. They downloaded a performance program tailered for towing and managed to get the HP up just over 200. The torque was even a bigger joke. It only managed like 280ft-lbs at the rear wheels after the upgrade. That's pathetic! It ran like 240ft-lbs stock. They never did say what size the engine was. I'm assuming it was a 5.3l. It was a 3/4ton HD.
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gen1dak
Dodge Dakota
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3/14/2004
22:43:07
| RE: Improve drivetrain efficiency
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Makes ya wonder about the big picture. I mean, we landed on the moon almost 35 years ago, but this is the best we get in our vehicles with so-called advanced technology....digital, no less. Hmmmmm...
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aden
Dodge Dakota
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3/14/2004
22:46:24
| RE: Improve drivetrain efficiency
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yeah may be we could just get our trannys to react right in the first place
my wifes seddona could possably smoke my o1 3.9 dak and it probably weighs in at 5000 lbs
the reason is its 5 speed auto tranny,its just so
much more responsive
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Mark
Forum Moderator
3/14/2004
22:49:18
| RE: Improve drivetrain efficiency
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Wiplash. I use royal purple in my rear. Works great.
-Mark Hryckiewicz
1993 Sport RC SB 5.2L Auto
Mark.DodgeDakotas.com
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WipLash
R/T
3/14/2004
23:23:48
| RE: Improve drivetrain efficiency
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Mark,
Do you have LSD? I'm thinking about trying the Royal Purple in my rear. I'm hoping to reduce a little friction. Who knows if any of that stuff actually does anything..... I notice a slight chatter when I turn a sharp right and give it the gas. It doesn't do it turning left. I figure it's the clutch pack in the LSD. I thought I might upgrade to a better rear end lube and additive to see if it might help. It's probably too late.
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Mark
Forum Moderator
3/14/2004
23:38:17
| RE: Improve drivetrain efficiency
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Yes its LSD, the only noise I get is a little bit of whining at highway speeds but thats because of the 3.92 gears, not the differential. I also put in 2 bottles of friction modifier from the dealership. You only need two quarts of royal purple. You can get it from Jeg's for $8/quart I think.
-Mark Hryckiewicz
1993 Sport RC SB 5.2L Auto
Mark.DodgeDakotas.com
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deerridge
GenIII
3/15/2004
13:06:56
| RE: Improve drivetrain efficiency
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The stock engine in the Chev HD is the 6.0 liter V8 which has way more torque than that. I pulled a six horse gooseneck 26'X8' trailer to Lexington with one and it didn't even breath hard with four horses on board.
Real Horsepower
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WipLash
R/T
3/15/2004
19:31:59
| RE: Improve drivetrain efficiency
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It may have not been a HD. The older HD's had 8 lugs. The one they did the upgrades to also had 8 lugs. Do all of the new 3/4 ton Silvers have 8 lugs? If the LD 3/4 tons all have 6 lugs then this was a HD. Who knows? They were extremely quick to cut the film and move on to something else after they made the base line dyno run. You could tell they were extremely upset. There was obviously something wrong with it. They weren't too enthused over the dyno results after the Hypertec Download either. I bet somebody called in sick the next so they could work on their truck!
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deerridge
GenIII
3/16/2004
13:27:41
| RE: Improve drivetrain efficiency
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The 1500 HD might have the 4.8 V8 in it. I believe its torque is about that standard. They claim 275 Chevy horsepower (not to be confused with real horsepower)but their torque is usually pretty close.
Real Horsepower
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WipLash
R/T
3/16/2004
13:58:25
| RE: Improve drivetrain efficiency
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They called it a 2500 several times. They also called it a 3/4ton several times. It had 8 lug wheels on it. They showed a close up of the lugs because they were installing a 5th wheel hitch in the bed. They had to remove the rear wheels to do the install. So the only question is it a HD or LD? If the LD's have 6 lugs then it's a HD. That would mean 6.0. Right?
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deerridge
GenIII
3/16/2004
16:09:49
| RE: Improve drivetrain efficiency
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I just looked on the Chevy website. The standard and minimum engine in the 2500 is the 6.0 with 300hp/360ft lbs. I amazed that thing could dino that low. The hopped up version is what's in the new SS. The one I drove to Lexingtion with the big trailer could really pull too.
Real Horsepower
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deerridge
GenIII
3/16/2004
17:07:44
| RE: Improve drivetrain efficiency
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The older 2500, another friend has a 95, have the 5.7 that was rated 210hp/300ft. lb.. That would make more sense. I don't know why anyone would fool with it now though.
Real Horsepower
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WipLash
R/T
3/16/2004
20:59:26
| RE: Improve drivetrain efficiency
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I'm not exactly sure which year model it was, but is wasn't very old. Depending on the year it could have had the 255hp 5.7L. That would have been about right for the RWHP and Tq for a 255hp 5.7L.
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