I am running part time now but I have had a few members tell me there is not a noticeable mpg change worth discussing between FT and PT 4wd.
Registry 8x Series V8 Swaps (6 Viewers)
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bloc
SILVER Star
PT = 2mpg gain @ 70 for me. Also on 315 KM2s
I'd seriously worry about your transfer case, drivelines, and rear axle with LSA power/torque levels. Not that I want to discourage you from doing it.. but 6l90 and very different axles/transfer case might be a good idea.
I'd seriously worry about your transfer case, drivelines, and rear axle with LSA power/torque levels. Not that I want to discourage you from doing it.. but 6l90 and very different axles/transfer case might be a good idea.
If your milage statement is accurate that means I would be getting 10 mpg if I left full time 4wd. Good info. As for the integrity of the drive train parts you might be right. I plan to keep my foot out of it as much as possible.
I am also in the market for some spare parts. I am running the chromoly RCV axles up front and was told the rear axles are strong. I would like to take a factory transfer case apart and see if anything can be strengthened in there. Josh runs over 1,000 hp through the 6L80E on some of his street cars with no issues. They are a lot lighter though. I don't plan to drag race this heavy beast and would most likely show off the power from a roll on when some youngster pulls along side of me in his 400 hp mustang or camaro. I have to admit I like extra power and have made the same mistake with a turbo side x side I built a few years back. It's a garage queen now. I keep telling myself never again....leave it stock. It's a sickness for sure. Thanks for your input and after I break something you are welcome to quote your post and remind me that you told me so!
bloc
SILVER Star
Do you have factory lockers? If so on the rear you should look into machining the splines to make it easier to get apart if you twist an axle. Known issue, if you haven't heard of it search in the 80 tech section.
I will definitely be doing that to mine. Guys are twisting them with the stock power train.. adding 150lb-ft torque and a lower first gear makes it even more likely.
No sir I am running ARB air lockers front and rear.
bloc
SILVER Star
Something occurred to me about stock tires.. you'd be turning a lot more RPMs on the freeway.. I don't think your mileage would actually get any better without regearing to something taller than stock.
In my diesel 4runner I regeared to 3.73 as these were readily available at junkyards in the states. Not sure what one would do for an 80
I think the effect of the rotating mass is worse than the effect of the smaller diameter tires. Nothing worse than heavy tires and wheels to hurt performance and mpg in my opinion. It takes a lot to get them turning and to maintain that rotation.
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I changed the tires on my 2wd 2006 Dodge 2500 Ram with the 5.9 cummins from a Michelin LTX A/S to Cooper Discovery and went up two sizes. MPG went from 24.5 to 19.5 mpg.
bloc
SILVER Star
I get that, but there is a balancing act between rolling resistance and staying in an efficient range for the engine. In the hypermiling world guys see the best gains if they lower cruising RPMs along with decreased rolling/air resistance, as less power is now required to push the car along and therefore less RPMS are needed.
A few people on this board (not many) report their 80s getting better mileage when swapping to 315s, all else being equal. It probably also depends on whether we are talking about freeway or around-town mileage. And even then, mileage reports are notoriously unreliable and difficult to confirm. Not to mention the other variables like other mods done at the same time..
I did 2" lift and 315s (stock gears) at the same time.. so hardly scientific.. but my mileage stayed the same as stock on my 290k+ mile engine. Add 800LB armor (more front of tire "visible" should hurt mileage), winch, extra battery, and PT kit? gain 2mpg on the freeway. Around town probably dropped 1mpg.
Oh, and as long as tires are properly inflated weight isn't much of a factor on the freeway. Around town, definitely.
In my case at least, the part-time kit, which many forum members report didn't help their mileage, apparently made enough of a difference to override the negative impact of large mud tires and slightly increased aero drag. Personally I don't feel this tells the whole story. I think things are helped by lower cruising RPMs than stock, which my truck can get away with because while it is heavier than stock, it isn't "much" less aerodynamic (no roof rack). Keep in mind that many "trucks" are given more cruising RPMs than are really necessary when unloaded, to make hauling a trailer or being weighted down still work.
The guys doing vortec swaps and improving mileage even with a 4-spd are probably getting most of that gain from the GM engine being so dramatically more efficient than a 1FZ from the start.
A stock escalade turns ~1878rpm at 75mph
6L80 and 315 KM2s, 4.10s = 2043rpms
6L80 + 315s+ 3.90= 1944
6L80 + 315s+ 3.73= 1859 (IMO ideal, though probably not worth the cost to install)
6L80 + 275s+ stock 4.10s = 2279. That's 400 more than a stock 'slade, in a smaller vehicle. Not exactly 4k cruising, but you'd notice it.. and my gut is telling me it wouldn't improve mileage as much as you think.. if at all.
Since I was doing all of the math..
A442F + 4.10s + 315s = 2343
same with 275s (stock 93-94 '80 confit) = 2614 (IMO large contributor to poor stock freeway mileage)
Point to this disjointed wall of text is? want better freeway mileage? Reduce drag, THEN match the adjustment with cruising RPMs (if possible.) Yes, stock tires/height will have less drag, but for the vortec engine you'd need to regear to something basically unavailable to our trucks to get the most benefit.
A few people on this board (not many) report their 80s getting better mileage when swapping to 315s, all else being equal. It probably also depends on whether we are talking about freeway or around-town mileage. And even then, mileage reports are notoriously unreliable and difficult to confirm. Not to mention the other variables like other mods done at the same time..
I did 2" lift and 315s (stock gears) at the same time.. so hardly scientific.. but my mileage stayed the same as stock on my 290k+ mile engine. Add 800LB armor (more front of tire "visible" should hurt mileage), winch, extra battery, and PT kit? gain 2mpg on the freeway. Around town probably dropped 1mpg.
Oh, and as long as tires are properly inflated weight isn't much of a factor on the freeway. Around town, definitely.
In my case at least, the part-time kit, which many forum members report didn't help their mileage, apparently made enough of a difference to override the negative impact of large mud tires and slightly increased aero drag. Personally I don't feel this tells the whole story. I think things are helped by lower cruising RPMs than stock, which my truck can get away with because while it is heavier than stock, it isn't "much" less aerodynamic (no roof rack). Keep in mind that many "trucks" are given more cruising RPMs than are really necessary when unloaded, to make hauling a trailer or being weighted down still work.
The guys doing vortec swaps and improving mileage even with a 4-spd are probably getting most of that gain from the GM engine being so dramatically more efficient than a 1FZ from the start.
A stock escalade turns ~1878rpm at 75mph
6L80 and 315 KM2s, 4.10s = 2043rpms
6L80 + 315s+ 3.90= 1944
6L80 + 315s+ 3.73= 1859 (IMO ideal, though probably not worth the cost to install)
6L80 + 275s+ stock 4.10s = 2279. That's 400 more than a stock 'slade, in a smaller vehicle. Not exactly 4k cruising, but you'd notice it.. and my gut is telling me it wouldn't improve mileage as much as you think.. if at all.
Since I was doing all of the math..
A442F + 4.10s + 315s = 2343
same with 275s (stock 93-94 '80 confit) = 2614 (IMO large contributor to poor stock freeway mileage)
Point to this disjointed wall of text is? want better freeway mileage? Reduce drag, THEN match the adjustment with cruising RPMs (if possible.) Yes, stock tires/height will have less drag, but for the vortec engine you'd need to regear to something basically unavailable to our trucks to get the most benefit.
I understand what you are saying and agree with most of it.
I am going to go throw my stock wheels with 285/75R16 Michelin LTX A/S tires on and do some mpg calculations and compare them to the 35/12.50R17. I will weigh each wheel and tire and see what my findings are. Might take a few weeks to find the time but I will do it. Real world testing versus theory. Should be interesting to see what the difference turns out to be.
I am going to go throw my stock wheels with 285/75R16 Michelin LTX A/S tires on and do some mpg calculations and compare them to the 35/12.50R17. I will weigh each wheel and tire and see what my findings are. Might take a few weeks to find the time but I will do it. Real world testing versus theory. Should be interesting to see what the difference turns out to be.
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Makes me wonder if you would have better mileage with 4.88's on those 315's. Would bump your hwy RPM but around town I would think it would help.
bloc
SILVER Star
315 KM2s + 4.88s = 2433rpm @ 75mph
And I doubt the 6.2, especially with a 6-spd transmission, has any trouble hauling a cruiser around town with stock gears. Keep in mind 315s and stock 4.10s are effectively shorter than stock GM gearing. you'd need around 3.8/1 axles with 315s to match a stock 6.2 escalade/tahoe 3.42 gear & stock tire combination.
@azcrackshot mentioned that the LS3 isn't exactly tuned for mileage either. That's a big part of why I'm so curious what mine will return with the more "normally" tuned 6.2 engine but similar tires and gears.
And I doubt the 6.2, especially with a 6-spd transmission, has any trouble hauling a cruiser around town with stock gears. Keep in mind 315s and stock 4.10s are effectively shorter than stock GM gearing. you'd need around 3.8/1 axles with 315s to match a stock 6.2 escalade/tahoe 3.42 gear & stock tire combination.
@azcrackshot mentioned that the LS3 isn't exactly tuned for mileage either. That's a big part of why I'm so curious what mine will return with the more "normally" tuned 6.2 engine but similar tires and gears.
You already know this but for others out there. I would not change the 4.10 Ring & Pinion gear ratio if you are running the 6.2 with a 6L80E. . It's like it was meant to be. If I were running the 4.5 motor with 35" tires I would most definitely go with a 4.88 or 5.29 gear set.
bloc
SILVER Star
Sortof on the subject of wiring harnesses...
Do you guys have good sources for blank Toyota and GM connectors and pins? I'll need to repair a connector or two on my toyota harness (water temp gauge), and a few on the GM harness, as well as add a pin to the TCM harness in case I have to go direct to it to get TUTD working.
Are there good ways to identify which type of terminal is needed and cross reference part numbers?
ALSO: for those that built their own harnesses..
The stock toyota oil pressure sender wire is shielded before and after it taps into the front clip harness under the airbox. How are you handling this? making a new shielded circuit that is longer? moving it into the main engine harness going through the firewall? Is the shielding that important?
Thanks
Do you guys have good sources for blank Toyota and GM connectors and pins? I'll need to repair a connector or two on my toyota harness (water temp gauge), and a few on the GM harness, as well as add a pin to the TCM harness in case I have to go direct to it to get TUTD working.
Are there good ways to identify which type of terminal is needed and cross reference part numbers?
ALSO: for those that built their own harnesses..
The stock toyota oil pressure sender wire is shielded before and after it taps into the front clip harness under the airbox. How are you handling this? making a new shielded circuit that is longer? moving it into the main engine harness going through the firewall? Is the shielding that important?
Thanks
I got the VR swap 100% done. Now I'm putting out 14.3-14.4V and it regulates depending on how many accessories (lights, blower, turn signal, etc) are running or whether the engine was just started, etc.
I'm dealing with FJ60 wiring, so YMMV, but I just hooked up the factory alt. wiring to the appropriate terminal on the new VR.
All in all, this was fairly painless and the way I'd go I were doing another one.
Toyota connectors....
Toyota Connector Name Toyota Part # Male or Female Seal/Unsealed # of pins # of rows Pin size (# in housing)
EB1 90980-10944 Male Sealed 3 1 4.8 (3)
EY1 90980-11016 Female Sealed 3 2 2.3II (3)
C4 90980-10930 Male Sealed 7 3 2.3II (7)
EC1 90980-11086 Male Sealed 12 3 2.3II (12)
IH2 90980-11203 Female Unsealed 17 2 1.3 (17)
E7 90980-11392 Female Unsealed 22 2 1.0II (16), 1.8II (6)
IH1 90980-10881 Female Unsealed 24 4 4.8 (4), 2.3II (20)
What does oil p sender connector look like? you can look up in the wire harness thing....
I contacted Ballenger motor sports and they're more expensive than going directly through toyota parts, unless you want to buy 100-500 of them.
I have the gm connectors somewhere as well. All are easily sourced from mouser....let me look it up.
Still working on the wiring guide, slowly but surely.....I have 3 kids, a peakbagging habit and a house falling apart....
Toyota Connector Name Toyota Part # Male or Female Seal/Unsealed # of pins # of rows Pin size (# in housing)
EB1 90980-10944 Male Sealed 3 1 4.8 (3)
EY1 90980-11016 Female Sealed 3 2 2.3II (3)
C4 90980-10930 Male Sealed 7 3 2.3II (7)
EC1 90980-11086 Male Sealed 12 3 2.3II (12)
IH2 90980-11203 Female Unsealed 17 2 1.3 (17)
E7 90980-11392 Female Unsealed 22 2 1.0II (16), 1.8II (6)
IH1 90980-10881 Female Unsealed 24 4 4.8 (4), 2.3II (20)
What does oil p sender connector look like? you can look up in the wire harness thing....
I contacted Ballenger motor sports and they're more expensive than going directly through toyota parts, unless you want to buy 100-500 of them.
I have the gm connectors somewhere as well. All are easily sourced from mouser....let me look it up.
Still working on the wiring guide, slowly but surely.....I have 3 kids, a peakbagging habit and a house falling apart....
bloc
SILVER Star
Where are you getting those part numbers?
The water temp sender plug is designated W3. My oil pressure sender wires are OK, but they are O2 and O3
I can't find my gm spreadsheet. This "pocket" dude on the thirdgen board has done a lot of work on it....
Connector ID, PN and interchanges - Third Generation F-Body Message Boards
eficonnection.com sells almost all gm connectors. A bit more than sourcing from mouser...
Connector ID, PN and interchanges - Third Generation F-Body Message Boards
eficonnection.com sells almost all gm connectors. A bit more than sourcing from mouser...
bloc
SILVER Star
Got it, thanks. I didn't know an index like that existed.. super useful.
