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 Post subject: AWD Locost?
PostPosted: June 8, 2010, 4:51 am 
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I'm guessing the AWD locost threads will eventually end up here as well? I'd really like to see the problem solved, and as someone with a lot of track time in an AWD turbo car, I have great personal appreciation for the the performance advantage AWD can provide. I appreciate the thought and effort being put into the idea, but I think the concept is still seeking practical solutions for a number of the challenges facing AWD in a locost application.

Alright, I surrender .. Here are the links to every prior AWD / 4WD locost / middy thread I could find.

Listed in roughly the order they appeared on this forum. From as far back as 2005. Please make posting new threads with this information an offense punishable by being walloped up side the head with a clue bat. Or just delete / merge the new ones so we don't keep seeing the same ideas over & over. :BH: :BH: :BH: :BH: :BH: :BH: :BH: :BH: :BH: :BH:

I dug through 51 pages of "search" to help keep you newbies from first-post embarrassment like this. So until there's a completed build log or two to reference, here are the "idea" links:

4wd locost?
fwd as awd
AWD Locost (Non-7 stylings)
twin engine four wheel drive?
How about four wheel drive AWD Locost? Donor?
List of longitudinal front engine, awd/4wd cars?
I think I may have figured out AWD locost
Potential AWD donor? Mercury Milan
awd mid engine spider idea
AWD: Subaru based platform, NON-typical
Awd Bec
Another AWD hopeful

Here are a couple information threads on differentials & the scoobie-doo gearbox. There are more (if you actually search), but these should get you started:

BEC Front Diff Options...
Clockwise rotating diff
Subaru transaxles

Here are the AWD builds actually in progress: (let me know if I missed one)

Project Widow Maker

Please don't be too discouraged by this post. I'm a huge fan of AWD and I like the idea of an AWD midi or locost. I own an Evo, so I get AWD performance. But please take a walk through what we've already discussed before starting a new thread about the topic.

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Last edited by erioshi on December 7, 2010, 1:46 am, edited 3 times in total.

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PostPosted: June 8, 2010, 12:00 pm 
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a piece i've always found interesting...
the new venture gears model 147 transfer case. its a single speed (the 1 in the first position) chain drive(comparatively low friction loss) unit with a load rating equal to whats in a military issue humvee(the 4 in the middle position indicates the max torque capacity of 1,486 ft. lbs) with a gear pump controlled "locking" mechanism(the 7 at the end position. i really like naming conventions that are so linear don't you?).
it was used on the mid 90's jeep grand cherokee quadratrac 2 systems only so its not as common unfortunately but a lot cheaper than a gear type unit when you find them. biased towards rwd 65/35 iirc. only problem (for me) is you have to go rhd or have a rather intrusive driveshaft bump in the drivers footwell area.

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PostPosted: June 8, 2010, 1:01 pm 
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Hey fellers! If you want to discuss the above topics start a new thread about them below. Don't wanna junk up Dave's sticky now do we? :P

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PostPosted: June 8, 2010, 1:07 pm 
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It's going to take somebody a loooong time to move all of the purely theoretical idea threads on this site into this forum...Glad it isn't me! :cheers:

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PostPosted: June 8, 2010, 1:24 pm 
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i'n just throwing the nvg147 out there if anyone wants to, don't have a need for it myself.

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 Post subject: Re: AWD Locost?
PostPosted: July 18, 2010, 4:27 pm 
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I disagree as to the the 147 being a good bet. It is not as mechanically simple, and if I'm not mistaken, needs external controls [switching] to engage the front.

I found the AMC Eagle T5 & NP129 combo to be preferable. At one time parts existed to convert a World Class T5 to Eagle output spec, and that's what I have done. You then have AWD via self actuating viscous, which is also entirely disengagable.
I would have used an Astro/Bravada/Syclone BW4472, but it's not disengagable, and more importantly, there is no known manual trans output housing to match to the 5 bolt front pattern on that TC, whereas the legacy "Dana 300" 6 bolt pattern is what the Eagle T5 output housing (or more common Jeep to fixed 4x4 output housing) is cast for.
The NP129 having that pattern can be turned upsidedown for passengers side output, another benefit of the 6 bolt pattern. You can also buy "clocking rings" on Pirate4x4 to do alternate positions of the NP129 due to its commonality with the Dana 300. Where readers there clock downward to reduce driveshaft angularity on dramatically raised vehicles, those here would want to clock upward.
The only downside is, this is a large piece of equipment, and getting old, but mine from the autowreckers with 282,000 KM (~170K miles), is functionally like new.

My second choice would be Ford of Europe T9-AWD (4x4 in their terminology). The earlier transfer case is removable, and that's what you'd want. It has passenger side output.
The latter MT75 4x4 has the TC incorporated in the gearbox which has a fairly unique cast in bellhousing pattern, so unless you were willing to go with that specific assortment of Ford Europe engines, it isn't easily adapted.

Distant 3rd choice would be bmw e30 325IX, but it has drivers side output.

All of the above is assuming you need a manual transmission, and are electronics-shy, like I am.
Auto's are much easier to find workable combos.


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 Post subject: Re: AWD Locost?
PostPosted: July 18, 2010, 5:17 pm 
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the nv147 is always on. .. its locking mechanism is applied by a internal gear pump and controlled by the rate at which the outputs rotate in relation to each other, all internal valving no external controls needed. no low range, no 2wd option and no neutral position.

the altessa system is a possibility, can it be set up for simple controls? i know its hydraulic but don't have access to service manuals for it so i have no idea what its control circuits are.

another possibility (in a middy) is using a belt drive from the rear output of an awd compact car such as a celica alltrac or one of the dsm/mitsubishi products (maybe a honda crv?) to a shaft underneath the trans running forward to a matching diff. it would have a rear bias on the center diff (if it was a fwd bias in its originally intended application) and should be possible with mostly off the shelf parts. ground clearance might become an issue. have a short shaft to the (vehicle) front of the powerplant then a cv joint(or splined yoke?) to soak up any offcenter movement and a fixed length tube running forward to a u joint and a solid mounted diff. the short shaft would be similiar in construction to whats currently used to get equal length driveshafts on a fwd so that part isn't a newfangled concept just the direction it points changes. you'd have to figure out the carrier plate for the pulleys and have some way to loosen/tighten the belt so it can be adjusted and changed when needed. the belt has to be equally loaded so you have to be able to adjust both ends of the shortshaft equally, probably need some kind of calibration markers on the mounting brackets to keep things level. should the belt fail it would get caught up in a guard rather than become shrapnel and you would still be able to get off the track or roadway under your own 2wd power which would be a good thing. ..

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 Post subject: Re: AWD Locost?
PostPosted: November 24, 2010, 3:30 am 
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It's been a while since I was last on here. Had some problems with displaying the forum but have since switched to Chrome and it seems to have fixed it. I had a pretty extensive thread going in the drivetrain forum, viewtopic.php?f=4&t=8764 should probably be moved here. I was, and will continue to look into turning a FWD Transaxle into both transmission and center diff for an AWD setup. The main problem I'm having is in finding suitable front and rear differentials that won't kill the final drive ratio. The center diff should also be some sort of an LSD, preferably a Torsen type that distributes power automatically. The main problems facing an AWD locost is parts, you have truck and suv transfer case based that could be placed how you want but are just too big and heavy. Then you have most AWD with longitudinally mounted engines that have the engine way in front of the front axle, which doesn't fit into the design of the locost. Finally you have my idea which may have a slight possibility but reliability and parts availability are both issues as well as cost. I could probably build it pretty easily with custom parts but then it wouldn't exactly be locost now would it.


Last edited by FireStorm005 on March 30, 2011, 3:07 pm, edited 1 time in total.

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 Post subject: Re: AWD Locost?
PostPosted: November 24, 2010, 10:18 am 
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FireStorm005 wrote:
...The main problems facing an AWD locost is parts....

:idea:

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 Post subject: Re: AWD Locost?
PostPosted: November 24, 2010, 11:48 am 
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I still reckon a Mitsubishi 4WD setup wouldn't be a bad bet for a Locost even if you leave as 4WD (not AWD).

I have driven a number of 4WD's hard and I don't reckon it's that big a deal and imagine it's not a big deal at all with reasonable HP to weight ratio. Sure it's crappy around a shopping center but hey, pop it back into 2WD.

For those who don't know what I mean, 4WD means all wheels driving at all times with no slip and AWD is a setup with available bias control.


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 Post subject: Re: AWD Locost?
PostPosted: November 24, 2010, 12:26 pm 
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Location: St.Thomas Ontario
cheapracer wrote:
I still reckon a Mitsubishi 4WD setup wouldn't be a bad bet for a Locost even if you leave as 4WD (not AWD).

I have driven a number of 4WD's hard and I don't reckon it's that big a deal and imagine it's not a big deal at all with reasonable HP to weight ratio. Sure it's crappy around a shopping center but hey, pop it back into 2WD.

For those who don't know what I mean, 4WD means all wheels driving at all times with no slip and AWD is a setup with available bias control.


I would think on a track a 4wd would cause some extra excitement as it might almost force a sideways drift at speed due to the wheels being forced to turn the same speed.


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 Post subject: Re: AWD Locost?
PostPosted: November 24, 2010, 9:00 pm 
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dilbert wrote:
I would think on a track a 4wd would cause some extra excitement as it might almost force a sideways drift at speed due to the wheels being forced to turn the same speed.


Glad you said "think" because thats not what happens, in fact not only is it very safe it's actually a bit boring.

Initially you get understeer and to overcome bind (which shows it's head quite substantially anytime you lift) you need to be WOT as soon as possible driving through the apex and out often with a little oversteer at the exit.

Thats experience from a couple of Subaru RX Turbos and a Mitsu L200 with turbo, all competition vehicles as well as owning a Subaru Leone 4WD road car. This model was very competitive in rallying all around the world too all with fixed 4WD (rear LSD, open diff front).


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 Post subject: Re: AWD Locost?
PostPosted: November 25, 2010, 9:06 am 
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When I think of 4wd, I think locked so you don't have the slip provided by an LSD.


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 Post subject: Re: AWD Locost?
PostPosted: November 26, 2010, 1:53 am 
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dilbert wrote:
When I think of 4wd, I think locked so you don't have the slip provided by an LSD.


I guess your meaning is front to rear dis-connection such as a Torsen, LSD, the more common Viscous Coupling or just a simple central differential?

Yeah lack of creates bind but also creates cost and complication, a Locost will have enough power to weight to overcome the bind and overall be considerably safer and faster (except for tight autocross and shopping center car parks where you will also get some odd stares!).

A lot of the myths of 4WD bind and locked diffs come from heavy vehicles but at the very low weight of a Locost it's only a small issue.


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 Post subject: Re: AWD Locost?
PostPosted: November 26, 2010, 4:57 pm 
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I just imagine 4wheels locked going the exact same speed. Thats where I'd think you'd end up constantly doing a 4wheel drift!


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