Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-26-2014, 03:11 PM   #11 (permalink)
EcoModding Apprentice
 
KrautBurner's Avatar
 
Join Date: Mar 2014
Location: SUNNY Sequim, Wa
Posts: 239

Cavalier of D00M - '05 Pontiac GTO LS2 T56
90 day: 23.2 mpg (US)

The New One - '10 Toyota Prius II
90 day: 51.55 mpg (US)

Chick Magnet - '91 Geo Metro 3cyl/5sp
90 day: 48.07 mpg (US)
Thanks: 79
Thanked 40 Times in 34 Posts
[QUOTE=dtmerritt;417160]The vehicle I want economy from is a 1955 Pontiac Star Chief ( almost 4000 lbs and square as a brick. It has the very old dual range Hydro Matic without a park position. Economy is one factor, another is, who knows how to fix it id it breaks?

Van get a $800 adapter and put a GM overdrive trans behind the engine for about $2500 Total, will pay for it,self in 40,000 miles.At 69 and with various heath issues, driving 5,000 miles a year, that is a chancey bet.

I could put a Gear Venders OD behind the hydromatic for about $3,500, then I still have the worry of the original trans.[/QUOTE]

Gear Vendors under/overdrive transmissions the most awarded auxiliary transmissions.

__________________
2005 GTO 6.0 V8 (600hp)

1991 Geo Metro 1.0 3/5 base

2010 Prius II (replaced 2001 Tahoe 5.3 V8 April 2014)

1994 F-350 7.3 TurboDiesel (Rollin' Coal)
  Reply With Quote
The Following User Says Thank You to KrautBurner For This Useful Post:
dtmerritt (03-27-2014)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-26-2014, 05:09 PM   #12 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,762

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,555 Times in 2,218 Posts
I'd convert to 5-speed stick or modern a/t with OD and locking converter before adding a GV or another trans. Multiple gearboxes = more driveline efficiency losses.
__________________


  Reply With Quote
The Following 2 Users Say Thank You to Frank Lee For This Useful Post:
dtmerritt (03-27-2014), samwichse (06-18-2022)
Old 03-27-2014, 02:05 AM   #13 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
If you would be getting something like a TH400/3L80 backed by a GV overdrive it wouldn't be so bad, but would be more cost-effective to just get a self-contained 4-speed OD transmission (or even a 6-speed if you can deal with the controllers). Working around a secondary transmission would definitely be too much of a PITA for eventually getting a slight mileage improvement if you would manage to cross-shift properly...
  Reply With Quote
The Following User Says Thank You to cRiPpLe_rOoStEr For This Useful Post:
dtmerritt (03-27-2014)
Old 03-28-2014, 01:37 PM   #14 (permalink)
Master EcoModder
 
Big Dave's Avatar
 
Join Date: Jan 2008
Location: Steppes of Central Indiana
Posts: 1,319

The Red Baron - '00 Ford F-350 XLT
90 day: 27.99 mpg (US)

Impala Phase Zero - '96 Chevrolet Impala SS
90 day: 21.03 mpg (US)
Thanks: 0
Thanked 186 Times in 127 Posts
As Post #9 showed this is an old idea. It works, within limitations. all you really have to do is deal with the mounting and sealing issues, and it will downspeed the engine (to use the term in vogue in automotive engineering circles) and probably improve MPGs.

Post #11 brings up a valid point. Automotive automatic transmissions rely on the torque converter to pump ATF to the cooler. If you downspeed the TC, you reduce oil flow to the cooler. You'd risk cooking the transmission and getting spectacular transmission failures.

I have the GV second-stage overdrive, and like in Post #12, I view it as sub-optimal but I am already down on the lowest ratios commercially available. I suppose I could substitute a Tremec 6060 with its 0.50:1 top gear for my setup (net 0.56:1 in double overdrive) but it seems like a big project to gain not much more overdrive.
__________________
2000 Ford F-350 SC 4x2 6 Speed Manual
4" Slam
3.08:1 gears and Gear Vendor Overdrive
Rubber Conveyor Belt Air Dam
  Reply With Quote
The Following User Says Thank You to Big Dave For This Useful Post:
dtmerritt (03-29-2014)
Old 06-18-2022, 09:25 PM   #15 (permalink)
Master EcoModder
 
Join Date: Oct 2009
Location: Phoenix AZ
Posts: 788
Thanks: 4
Thanked 64 Times in 56 Posts
Post #11 brings up a valid point. Automotive automatic transmissions rely on the torque converter to pump ATF to the cooler. If you downspeed the TC, you reduce oil flow to the cooler. You'd risk cooking the transmission and getting spectacular transmission failures.


Close, the front pump of a automatic is driven by the spinning engine, via the TC. And the lower RPMs can lower it pumping action, so coming off a big mountain by dopping into natural can with only idle to lower the pumps action and can harm you auto, BUT at 1000RPMs I believe things are good.


I have the GV second-stage overdrive, and like in Post #12, I view it as sub-optimal but I am already down on the lowest ratios commercially available. I suppose I could substitute a Tremec 6060 with its 0.50:1 top gear for my setup (net 0.56:1 in double overdrive) but it seems like a big project to gain not much more overdrive.


You did not tell Make, model, year of you car, nor is it stock or hot rodded.

You need to have an engine that can make use of lower RPMs, you need to map out you engines torque peek, and find where it loses power and starts lugging.

Example: SBC 350 1980/90s, torque peek at 2800/3000 RPMspms, drop that engine to
1500 and it will be lugging. the lowest most likely will be 2200 RPMs.

But take a 350/383 where the torque peek is 2000, then dropping it to 1500 can work.

Rich

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com