FD Explorer 8.8 Diff Kit

[frijolee]

UPDATE 2/13/14

The FD Explorer 8.8 is now released for purchase!
http://www.roninspeedworks.net/index.php?route=product/product&path=59&product_id=88



Why?  The Ford 8.8 is a substantially stronger diff than the factory Mazda rear end.  It's available in a huge range of gear ratios (3.08:1 up to 5.71:1) just looking at Summit Racing.  Gears are also cheap since Ford has used the 8.8 in so many varieties.  You can also find just about any style of differential from factory clutch packs, to spools, to helical gears.

We use a donor rear end from a 2007-2010 Ford Explorer (some 06's work but it appears that there may be a half model year split, you want dual front mounts).  It's Ford's classic 8.8" ring an pinion in a stout aluminum case.  This particual case is noteworthy because it uses massive dual front mounts.  The support points on the Explorer makes the Cobra 8.8 front mounts look tiny by comparison.  Furthermore, the Explorer parts are both easier and cheaper to come by than the comparable Cobra pieces.  The Explorer diff even has fins which the Cobra doesn't for slightly better cooling.

Here's the 8.8 Cobra from a terminator Mustang (note the tiny front mounts)






Explorer (in our test fitup!):




You're not breaking these ears off!




Our front mount is a weld in cradle which is well triangulated to the subframe.  Everything mounts from the topside which dramatically improves the load path AND you'll retain close to factory like exhaust clearances.

Lots of space for exhaust!




The rear mount uses a sandwiched ring with the ears cut off the factory cover.




Note, depending on which year of explorer you end up with you may find that Ford changed the rear cover design.  Some 2006 covers are the same as the 02-05 setup and use a high rib count.  Here's the comparison with what the never cover looks like (cover on the left has already had its ears cut off).




Kit includes:

•   Front Mount Support Bridge (weld in)
•   Rear Mount Diff Ring Cradle (bolt on)
•   2X Custom 4340 heat treated axle bars (Ford to Mazda conversion)
•   2X EMPI CV boot kit 86-2127 (outer CV joints)
•   2X EMPI CV boot kit 86-2103 (inner CV joints)
•   All Mounting Hardware
•   RTV silicon (for rear cover installation sealing
•   Instructions, specs, and recommendations on mating parts (IE driveshaft) sent electronically



Users must provide:

•   FD Outer CV Joints (typically donor from the car being swapped)
•   Ford 8.8" Rear End (2007-2010 Ford Explorer) including inner stub axles/CV joints
•   A Driveshaft (install instructions include a variety of recommendations)
•   FD rear diff isolators (user's choice of style but we like polyurethane).

Pricing will always be current on www.roninspeedworks.com but we're launching this at $1195.  All in, including donor parts $1800 to $2000 is a reasonable budget depending on what you want for a driveshaft.

How much power will it hold?  A LOT, but to be fair we don't really know since we haven't broken one yet.  One of the early adopters is making 1000 whp in a road race application.  No issues thus far.

-Joel










PS (for posterity sake I'm keeping all the thread with the development, twists and turns).  The current configuration was first launched around post 90.
http://www.norotors.com/index.php?topic=15911.msg231470#msg231470

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Start former thread>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Hey guys,

Just wanted to give you a heads up that we're about to launch our FD Explorer 8.8 setup.  It's something we've had in works for a while but it's finally ready start talking about formally.  The design is effectively complete, we should be finishing up the first article this week (so we'll have pretty pictures soon). 

Basics:
-Uses an 2006-2010 IRS rear end from a Ford Explorer (we need to verify if the 2011's and newer work too).  This is an aluminum case with dual front mounts and each front mount is massive.  The support makes the Cobra front mounts look tiny by comparison.  Explorer parts are both easier and cheaper to come by than the comparable Cobra pieces.
-100% bolt in, no welding required.
-Everything mounts from the topside which dramatically improves the load path AND you'll retain close to factory like exhaust clearances.
-Includes 4340 heat treated halfshafts and boots which will mate to Mazda outer CVs. 

Axle design has been finalized and are being ordered today.  That's our long lead item so we should be ~6 weeks from shipping out the first kits.

Pricepoint will be similar to the FC setup (may jump a bit, but not much), so all in you're looking at <$2000 including both the Ronin purchase and the donor/purchased parts, to be sourced separately.

Wanted to put out a call on the early side asking for testers.   We'll cut you a discount in exchange for helping us figure out if there are production tolerances we need to be aware of (fitment check) and your impressions of the kit.  Let us know if you're interested in this thread and I'll send everyone details in a few weeks. 

More info coming soon,
-Joel (for the Ronin crew)

[digitalsolo]

Awesome!   Look forward to seeing what you guys came up with!

[Mir]

Looking forward to see the finalised article

[Jordan Innovations]

I saw the first one over at Anthony's, nice to know that if I blow up my Kaaz, there's a realistic 8.8 IRS setup that'll let me keep my exhaust that runs right under the diff.

[wickedrx7]

Curious if this would work with 03 cobra dif with explorer cover? Of corse the axels wouldn't but the mount. Let me know if interested in test fitter...

[V8-rx7]

It won't work with the cobra case do to the hole spacing on the front bushings being different, and a massive height difference.

[wickedrx7]

It won't work with the cobra case do to the hole spacing on the front bushings being different, and a massive height difference.

Thanks,
I might still be interested in doing this kit instead of the cobra.

[V8-rx7]

I already bought a brand new case and cover for less than you can ussually find a used cobra one for. Pm me of you need info on where to order one.

[frijolee]

Curious if this would work with 03 cobra dif with explorer cover? Of corse the axels wouldn't but the mount. Let me know if interested in test fitter...

I'll spin this a slightly different way:  You could maybe make it work, but I think it'd be more trouble than it's worth.  As Anthony mentioned, the front mounts are different so offset spacers would be needed to have it bolt up.  Halfshafts are also going to be a different length than the FC's as well so your AndrewB70 axles are unlikely to be long enough. 

That said, you should be able to sell the Cobra setup for profit if you feel like trying ours.

[spacevomit]

Interesting.

[Donthitme]

In for testing. 

[Ruler_Mark]

dang if I only didn't just buy everything for the cobra swap sent this to a few friends who have fds though.

[mefarri]

Interesting.  So.  What's the axle situation like in regards to the usual DSS axles people get when they convert to 8.8? Who's making your axles?  What's the inner tulip like compared to the 31 spline Cobra stuff?  If I was to buy  a housing and cover, which LSD would I be looking to buy?  My plan was to just buy a new diff with the carbon clutches and accompanying R&P. What R&P do these come with stock? And I assume this fixes the issue of Justin's design pulling the washers out on high HP cars? 

That's a decent amount of questions.   

[frijolee]

In for testing. 

Awesome.  And a so-cal local no less...

Interesting.  So.  What's the axle situation like in regards to the usual DSS axles people get when they convert to 8.8? Who's making your axles?  What's the inner tulip like compared to the 31 spline Cobra stuff?  If I was to buy  a housing and cover, which LSD would I be looking to buy?  My plan was to just buy a new diff with the carbon clutches and accompanying R&P. What R&P do these come with stock? And I assume this fixes the issue of Justin's design pulling the washers out on high HP cars? 

That's a decent amount of questions.   

-DSS has an entirely separate product that works with Cobra setups.  We wanted to be a one stop shopping experience so you don't need to order multiple things. 

-I'd rather not announce who builds our axles.  All warrantee issues would be handled through Ronin since we're the original purchaser for the purpose of the axle's lifetime warrantee.  No takers thus far...  We spend a great deal of effort designing halfshafts, optomizing stress risers and the like, and I wouldn't want anyone to tempt our vendor to sell around us.

-Axle seals are different between cobra and explorer, so the easiest thing to do is match stub axles and tulips to your diff.  The explorer parts are much easier to come by.

-You can run any LSD you want, all the 8.8 internals are interchangable.  The only difference between IRS and solid axle is that a groove for the circ clip to snap into the splines.  Personally I like the Detriot Tru Trac for bang for the buck, but that's me.

-Ratios:  I'd have to hunt it down, but the 02-05 stuff was mostly 3.55 and 3.73 and I'd be surprized if it were different.  "Sport Trac" models tend to come with the sportier gears and LSD.  That said 3.55s are perfect for a stroker.

-I'll be doing some finite element analysis to optomize the kit but yes, load path above means no washers to have issues.  Engine braking can't put nearly the same twist in that a launch will.  In terms of high horsepower applications in general, I did hear that Frank at DSS has an explorer based stub axle.  If anyone puts themselves in that "high horsepower" category and wants to run Frank's pro-level axles, we have no issues selling kits without halfshafts so you can do Frank's package instead. 

[flexnlsx]

Id like to get in on the testing if possible. Just say the case at Anthonys and we spoke on it briefly HIGHT INTERESTED in see how it works out..  Im in so hit me up. L8