fasteddy
Web Wheeler
Reged: 01/30/01
Posts: 12703
Loc: Flat Creek, GA
|
|
Jason, consider the difference between the m/t and a/t top gear ratios. The m/t is .856, and the a/t is .688.
That's an almost 20% increase in "resistance" at the flywheel with the torque converter locked up. AND a similar reduction in rpm at a given speed, which drops you down in the power band too.
I've been up the grapevine precisely once, in the mid 70's, and from what I remember of the grade, what you are seeing is normal. I was in a repo dodge custom van, and the torqueflite and 318 spent the whole climb in 2nd at high howl rpms...
--------------------
"If you can't be a good influence, don't worry, you can still be a horrid example."
|
off-roader
Mitsubishi Forum Moderator
Reged: 01/16/00
Posts: 15490
Loc: Bay Area, CA
|
|
Quote:
I've been up the grapevine precisely once...
Can you please be more exact FE? 
Sorry, nothing really relevant to add other than that. 
|
FrankR
Web Wheeler
Reged: 02/01/04
Posts: 10224
Loc: Columbia, SC
|
|
Quote:
1. On the HWY, it takes 0-3 psi to maintain around 70mph in OD. On the 5spd, I was always in VAC area but never in boost. Kevin verified this as well as his does this same.
My 3.0L blower/lockup A/T reads vacuum at 75mph on the flat in O/D, but requires a slight boost on a grade at 70-75mph in O/D.... about 1psi usually - but if the grade is severe, it might go a bit higher to 2-4psi. Mine has never yet downshifted on a grade at highway speeds. It might on mountain grades, though...... haven't tried it.
My curb weight is about 3700 lbs. without anything in the back.
The AW372 lockup unit would be a little friendlier if the O/D ratio was a closer to 1:1 and cruise rpm were a little higher. There's just not enough low end torque to pull the truck out of the O/D hole around 2000rpm..... if you're a leadfoot.
I have become fairly used to thumb-shifting the O/D at low speeds. I could instead give it more throttle and down-shift it, but that's often more than I need and it over-runs in traffic.... so I've learned to use the transmission as if it were a M/T and I can keep it in the power band quite well that way.
I'm still tuning, but fuel mileage is now 16mpg - not nearly as good as the last engine. Maybe with taller tires it'll do better.
Frank
--------------------
'89 G-Raider Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 155k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, 165A alt., Lifeline AGM, Rust-Oleum
|
fasteddy
Web Wheeler
Reged: 01/30/01
Posts: 12703
Loc: Flat Creek, GA
|
|
Quote:
Can you please be more exact FE?
Sure. "My one and only time"...
--------------------
"If you can't be a good influence, don't worry, you can still be a horrid example."
|
monte
Mudrunner
Reged: 01/02/04
Posts: 424
Loc: Sylmar, CA
|
|
This is all good info to have for sure. No doubt about it that I'm a lead foot and pushing more power then most but also more weight then any 2dr as well.
I also think Kevin has the adv because he has the 31's but also he has the TC gearing mod done as well. unless that only affects low range? I can see that helping alot with the taller tires!
Frank, I did not see in the you sig anywhere what size tires are you running? On the flats I'm pretty much no boost as well but any slight incline and I need some to compensate.
No way I'm going 35's on this. I would never want to use the OD then or I'd just go back to the 5spd.
Time for a V8 swap now?? 
--------------------
1986 SWB Turbo Pajero (aka RedCar). 2" Lift, 33" BFG ATs, Rear locker,Custom 160a Alt, 9000lbs Warn Winch,Con-Ferr Custom built Safari rack just for RedCar!, Safari Snorkel,3 AGM Deep cycles,V6 Auto Trans.
1995 SR (aka Lucky).. Custom built and modded 3.5.. everything else stock.
|
hazy_daze
Roll Me Over
Reged: 05/22/07
Posts: 4609
Loc: Athens, Georgia
|
|
Quote:
unless that only affects low range?
Yep, only low range. No effect in 2WD... IIRC, Frank's running either 31's or 32's.
Is there any possibility you have something dragging? Like brakes or bearings...
--------------------
Just another idiot...
|
FrankR
Web Wheeler
Reged: 02/01/04
Posts: 10224
Loc: Columbia, SC
|
|
I was running 32s with the last engine, but put on stock 235/75/15s for dyno tuning and they're still on the truck. The 32's will probably be better for fuel economy, but will also rob some torque. Once you get the 32s rolling at speed, though, the truck wants to run at 80mph.
Kevin once said it's easy to see why manufacturers went to electronic transmissions with small engines, but I think it's also easy to see why they now have 5 and 6-speed automatics. The AW372 needs another gear for big tires, small boosted engines and sporty driving.
V8? Maybe for you, but I'm waiting for a 3.8L crankshaft to put in a 3.5L block with a blower. 
Frank
--------------------
'89 G-Raider Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 155k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, 165A alt., Lifeline AGM, Rust-Oleum
|
monte
Mudrunner
Reged: 01/02/04
Posts: 424
Loc: Sylmar, CA
|
|
Quote:
Quote:
unless that only affects low range?
Yep, only low range. No effect in 2WD... IIRC, Frank's running either 31's or 32's.
Is there any possibility you have something dragging? Like brakes or bearings...
nothing is dragging... but like Frank said, he's got way smaller tires, and a much lighter vehicle.
33x12.5x15's are no easy task to spin around. Take almost a 5k lbs vehicle with the aerodynamics of a brick wall and a 2.6 just needs to work a little bit harder
I foresee my OD switch getting used ALOT in the future!!
--------------------
1986 SWB Turbo Pajero (aka RedCar). 2" Lift, 33" BFG ATs, Rear locker,Custom 160a Alt, 9000lbs Warn Winch,Con-Ferr Custom built Safari rack just for RedCar!, Safari Snorkel,3 AGM Deep cycles,V6 Auto Trans.
1995 SR (aka Lucky).. Custom built and modded 3.5.. everything else stock.
|
Kevin C
Trail Leader
Reged: 05/20/00
Posts: 6033
Loc: No where in particular
|
|
I did find that the OD ratio changed on the lock up converter tranny.
While the non lockup unit has the .688 ratio the lockup units have a .73 ratio. That may explain why the people that switched from a non lockup to a lockup unit noticed it drives better on the highway.
I would be happier with about a .8 ratio, the jump from direct to OD is a bit much.
Also I want to be able to control the lockup... That's where the electronic controls would be nice.
Kevin
--------------------
87 Dodge
|
monte
Mudrunner
Reged: 01/02/04
Posts: 424
Loc: Sylmar, CA
|
|
AWESOME !!!! I'm pulling 14.1 mpg now after a 104 mile drive. Granted it was some hills and "spirited" going from Sylmar to Monrovia and to Burbank and back.
But in the end, at 70mph, I'm barely breaking 2500rpm so I'm not the happiest about that. Dropped from around 17/18mpg with the 5spd.
Hooking up the trans throttle cable will help because that will unlock the converter and raise the rpm while cruising.
For now, need to work on a linkage/cable solution for the trans cable. Not fun stuff 
Temp gauge pics and center console stuff coming in the morning...
--------------------
1986 SWB Turbo Pajero (aka RedCar). 2" Lift, 33" BFG ATs, Rear locker,Custom 160a Alt, 9000lbs Warn Winch,Con-Ferr Custom built Safari rack just for RedCar!, Safari Snorkel,3 AGM Deep cycles,V6 Auto Trans.
1995 SR (aka Lucky).. Custom built and modded 3.5.. everything else stock.
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
