LocostUSA.com

time to "thinkering" with my BEC project again

my project (Austin 7 Special) kinda hit a death-end

"rough- and off-road capability" has slowly taken over the priority (from "street only" canyon carver)
so the single seat/offset differential is basically off the table (at least for now )

i focus again on a two seat/center differential layout for increased half-shaft length/ suspension travel.

somehow i just dont really like the awkward long nosed Subaru R160 carrier and the STI R180 is hard to find & expensive
finding a R160 with long gears and LSD seems to be even harder

the steel Subaru knuckle is also not really very compatible with my rear suspension ideas.

i started to look into the T-bird/mark8 knuckle again (i used them already for several projects some 10-15 years ago)
but due to the popularity with the kitcar (and locost ) crowd they seems to get hard to find & expensive
on top of that the control arm pivots are kinda awkward to build in a decent looking fashion

so i started to look for alternatives ... and stumbled over the Lincoln LS/ Jaguar S knuckle;



the (iirc pressure cast "forged") aluminum LS knuckle uses a wheel bearing with slightly larger OD (3.149" compared to the T-bird`s 2.992"),
but it shares the ID (1.653") with the T-bird knuckle.
i really like the "double shear" LCA and tie rod link mounting arms .... and there are plenty of them available

so i started to search for a diff carrier/axles/hubs that are compatible with the LS knuckle
quickly discharging the S2000 (torsen LSD is standard) and RX 8 (Torsen optional) due to high (short) gear ratios
but then i discovered that BMW E36 models shares the same wheel hub OD
(E36 wheel bearings are 2.9528" OD, 1.6535" ID)

there are plenty of 188 mm E36 diff carriers around (iirc 1992-99 318i , 323i , 325i and 328i all share the same 188 mm ring gear carrier)
best of all is the available long ratios (iirc 3.15, 3.23, 3.38, 3.46 and 3.64 LSD ones seem very common)



the 188mm is compact in size and mounting points are fairly convenient



i also like the "Porsche 930 style" upper CV`s (pictures found/borrowed from trakmotive.com )...
there seems to be 3 halfshaft lengths available :







BMW mixes them on some models for different track dimensions (equal and non equal length combinations)
seems to be an interesting way to create track dimensions to fit different projects

entering the 3.15 axle ratio into the dmr-architect.com gearing calculator i ended up with very interesting gearing
(assuming 225/55ZR17 tires)

http://www.supermotors.net/getfile/1039705/original/spectresusp7.jpg

unfortunately the E36 LSD is friction and not Torsen (what i would prefer)
but at least it seems that the factory 25% lockup setting can be upgraded to 40-60% lockup

as always ; any suggestion/comments are very welcome

_________________
- Stephan -

There's always the R200 from Nissans z cars, 240sx and the G3x series

Z33 - MT - R200 - 3.538
Z33 - MT - R200V - 3.538
Z33 - AT - R200V - 3.357
Z32TT - R230V - 3.692
Z32 - R200V - 4.083
G35 - Sedan - AT - R200 - 3.357
G35 - Sedan - MT - R200V - 3.538
G35 - Sedan - AWD - AT - R200 - 3.357
G35 - Coupe - MT - R200V - 3.538
G35 - Coupe - AT - R200 - 3.357
G35 - Coupe - AT - R200V - 3.357
Q45 - G50 - R200V - 3.538
Q45 - FY33 - R200V - 3.692
R32 GTR - RB26DETT - MT - F160 - 4.111 - (Front Final Gear)
R32 GTR - RB26DETT - MT - R200 (Mechanical LSD) - 4.111
S15 - MT - R200H - 3.692
S15 - AT - R200V - 3.916
S14 - KA24DE - 4.083
S14 - SR20DET - MT - R200V - 3.692
S14 - SR20DET - AT - R200V - 3.915
S13 - KA24DE - 4.083 - (Both R200 and R200V)

The two eared carrier on the E36 is an extremely popular upgrade in the BMW community, so if you want to go that route, start looking and snatch one up.

Early Z3's 318ti's and a few other e36 models used a one ear cover plate.

_________________
Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

yes, your right

i was also looking into the R200VLSD out of 350/370Z or the G35/37
(plenty of them around for very interesting prices)
but didnt like what i was reading about the Visco LSD on the 350Z forums
(many complains about reduced performance after a couple thousand miles of spirited driving )

the Z/G cars use a unit bearing , but i`m fairly positive that the late model Maxima wheel flange would fit in its place.
the Maxima wheel bearing has a ID of 1.693" so to squeeze the hubs into the LS bearing (1.653")
would only need a tiny little lathe work.

the absolute "bargain king" would be the RX8 rear end (very similar to the late MX5 miata differential)
there are several sub $200 LSD units on e-bay
but iirc stock gearing is 4.44 (gen. 2 manuals are even 4.77 )
i could not find the wheel hubs for sale anywhere ("dealer only" part ?!?)
but again i`m fairly positive that one from a sister model with the same 31 spline count (CX7/9 ?!?) would fit
however, the Mazda bearings are larger (1.7717" ID). turning the hubs down to the LS dimension could be a problem

my favorite differential would be the Honda S2000 (all of them are stock Torsen units )
but its somewhat expensive and hard to find ... and gearing (iirc 4.10 only) is not very BEC friendly

everything Miata seems to be overpriced (big market, big demand )


i never looked at BMW before , assuming that parts are expensive ... but i guess i was wrong


btw;
there is a smaller and probably lighter BMW diff available ;
the 168mm ring gear and 94mm CV BC unit out of the 318i (compared to the 188mm and 100mm CV BC one i posted earlier)
but its older and harder to find ...

the 188mm/7.4" ring gear is probably overkill behind a BEC
but i think for my intended use (long travel = high CV misalignment) i rather have the bigger CV`s
and just live with the couple lbs of extra mass & inertia

_________________
- Stephan -

TB
thanks for the insight ....
as i mentioned i never looked at BMW parts before , so i`m thankful for any info

yeah, i like the "two eared" cover plate ... it would be roughly in the same spot as the inner rearmost LCA pivot points and the inner tie rod link points,
what would ease the fabricating of the frame

_________________
- Stephan -

forgot to mention the main reason why i dont like the Subaru "long nose" R160;

i plan on adding a inexpensive electric reverse to the rear differential
to be exact, i plan on bolting this small Bert racing transmission flywheel ...



.. to the pinion driveshaft flange and use a high torque SBC starter for a locost reverse
the Bert ring gear usually sells for $65 new

i could not find any exact dimensions yet (pitstopusa.com lists the package dimensions as W6.5” x H0.5” x L6.5”)
compared to this SBC bellhousing the 6.5" diameter seems to be about right ...



...so i`m fairly positive that it will not hang down too low on the fairly high BMW 188mm pinion;



however, the long nose R160 would place the Bert ring gear between the seats where there is simply no room for it

_________________
- Stephan -

Stephan have you considered the Merkur diff, I believe its the same as the Sierra which we have here. Lightweight ali and available in lots of ratio`s with LSD not uncommon, also 100mm 6 bolt on the flanges.Some blurb from an interesting site. http://www.super7thheaven.co.uk/Sierra_ ... fferential

Bob

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Build Log viewtopic.php?f=35&t=16640&p=187700#p187700

Mancave http://s1116.photobucket.com/user/mypic ... ow/mancave

Bob
yeah, i wish the Sierra differental carrier would be more common /easier to find over here in the States

i really like the aluminum construction as well as the lobro CV`s ... it would be the perfect size for a BEC
but shipping them over from the UK is probably too expensive

btw
when i was growing up in Switzerland my Father used to have a Cosworth Sierra 4x4 at one time
i LOVED that car ...
hammering it around turns has been an absolute blast on any of our mountain roads
(almost lost my drivers licence )

_________________
- Stephan -

Hey Stephan,
good to see you back posting. How is the Ultimate sleeper truck project coming along?
Can't comment on any of the diffs, but I did look at your gearing chart. I know ol'rowdy put a lot of work into it, however, here is the one that I have been using http://www.gearingcommander.com/
You need to convert the final drive ratio into sprocket gearing (in my case a 3.27 is roughly equal to a 17/56), but other than that it is just plugging in the numbers. With my combination (205/50-16 and 3.27 final drive) I should see about 120 km in 6th at 7,000 rpm.
Make that 205/50-15

_________________
Martin


My build log:
viewtopic.php?f=35&t=14520&start=0
My build video:
https://vimeo.com/143524140 password "matovid"

There`s one on the forum

viewtopic.php?f=40&t=16730

Rear Suspension $75

Bob

_________________
Build Log viewtopic.php?f=35&t=16640&p=187700#p187700

Mancave http://s1116.photobucket.com/user/mypic ... ow/mancave

hello Martin

the old girl (1952 DiamondT) is still not completely finished
but i managed to start painting (at least the cab & hood) ...



and i installed a turbo, intercooler & stacks just in time for my big annual Colorado trip
what a difference dragging the trailer up to the Eisenhower summit !!! (11,158 feet / 3491 m )
she made the steepest section in a steady 35 mph (last year w/o turbo it was a painful 17 mph spewing black smoke )

yeah, figuring out the correct gearing is a pita ;
if i want to be able to switch to offroad and also paddle sand tires i need to go fairly tall with the street tires
something like 225/55ZR17 or even taller would be nice ....

but it seems that even with really tall tires i`m still not able to use a junkyard BRZ, RX8 or S2000 carrier
(i would love to have a factory installed Torsen)

so i guess i cant avoid to install one by myself (or "stiffen up" a factory clutch LSD).
need to do some searching what is available for possible smaller carriers ...

the Ford 8.8 has obviously the advantage here with its huge selection of fair priced aftermarket LSD`s ,
but i guess a 8.8 would be grossly overkill for a BEC

_________________
- Stephan -

Yes, it would, but you'd never break it!

I'm lovin' the old Diamond-T. Got more pics/info?

By the way... Your avatar is laying eggs. That is NOT a rooster!
(Yes, I did grow up on a chicken farm.)


JDK

_________________
JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

yeah, i just noticed that myself ....so i guess its not a rooster then ?!? (i did NOT grew up on a farm lol )

btw
here is the link to my DiamondT build thread over at Pirate4x4 ; http://www.pirate4x4.com/forum/tow-rigs-trailers/1048598-fawk-i-think-i-m-building-vintage-truck.html
...all 92 pages of it


to get back on track ;
i`m still hunting for any easy available IRS diff carrier that is BEC friendly ...
found another possible locost alternative:
the first generation (00-02) Lincoln LS (and its sibling Jaguar S) used an 8" diff carrier that is fully compatible with any 8.8/28 spline differential
so basically all the inexpensive Mustang LSD and Torsen diffs are a direct bolt-in
iirc second gen (03-06) used an all new "offset" carrier that is not compatible with the 8.8 at all

unfortunately it is a steel carrier with only an aluminum rear cover (pics found at DIYFord.com)....



so the weight saving is probably only minimal compared to the aluminum explorer carrier
however, inertia would be lower and especially the CV`s and halfshafts are considerably lighter then the massive explorer ones or the large T-bird/ Mark VIII ones
... and naturally they would fit well together with the aluminum LS knuckles i would like to use anyway

common gear ratios seem to be a BEC friendly 1: 3.31 or 3.58
track seems to be 60.5" with LS rims (need to check what the oem specs are)

probably still grossly overkill even for a turbo BEC

_________________
- Stephan -

a couple more things i found out;



the more i look at the LS/Jaguar knuckle the more i love its design ...

... so i`m about 99% sure i will use them regardless of the differential i end up with
the base LS was using 16" wheels ...
fitting 15" wheels over the knuckle may require a little clearance work on the corners of the LCA and toe link mounts
but it looks very doable (i plan to buy one soon so that i can take exact measurements and model it in CAD )



the Nissan/Infinity R200 VLSD differential carrier (Z/G cars) would also work with the LS aluminum knuckles
the wheel hub OD is 1.694" .so it would need to be turned down 0.04" to fit the 1.653" LS wheel bearing,
but there is plenty of material there .... that should not really weaken the hub

advantage would be that the nissan wheel hubs are a very nice lightweight design;



however, the steel housing/aluminum cover R200 (200mm = 7.875") is still on the large/heavy side for a BEC
and the factory Visco LSD seems to be fairly "soft" .... upgrades to "stiffer" LSD`s seem expensive
(especially compared to the inexpensive mustang stuff)

common ratios are 1: 3.357 or 3.538 ...
rear track of the Z350 seems to be ~ 60.6" with factory rims

_________________
- Stephan -

using the LS 8" differential, axles, knuckles and wheel flanges kinda sounds like the best compromise in the moment ...

i already spotted a super lightweight brake disc that would work with the LS knuckles;



its for a 2011 Honda CR-Z : http://www.stockwiseauto.com/product_info.php/cPath/1106_1225/products_id/311322/Make/Honda/Model/CR-Z/Year/2011
... needs only minor lathe work on the disc pilot diameter (enlarging the hole from 64.2 mm to the 64.5 mm of the LS hub)

keeping un-suspended mass fairly low is my main concern
i think combining that disc, the aluminum knuckle and a lightweight aluminum Wilwood dynalite single caliper would result in a reasonable light setup
a little more "frame mounted" mass (as in oversized differential) could be easier tolerated
and for off road "abuse" it would definitely add a lot of "peace of mind"

_________________
- Stephan -