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Ford Super 8.8 irs swap thread. Rear brakes too


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The story of how it all began, including pictures of ugly prototypes and crude early versions...


What it all amounted to is a simple, strong bolt in swap that utilizes factory control arms and r200 mustache bar and allows the use of 2015 mustang brakes, hubs, cv axle ends and differential.


The pinion yoke is a 1350 u joint one off a 1993 f250, it can be found at Denny's drivetrain.


The struts that work with this setup are modified 2004 srt4 neon struts with their tops changed to the datsun 3 bolt camber plates.


Most people simply contact bc racing and have them supply the 280z coilovers and exchange the bottom sleaves with the 2004 srt4 neons ones.  


Other people just use the coilovers they have and weld on the coilover tabs I also developed, so struts that work are basically anything you want.


The brakes are either 13 inch rear brakes off a 2015 mustang or 11.8 inch brakes off a 2014 mustang.  Both are dirt cheap, and both have a built in parking brake.


I'm constantly updating the design with every batch, but here is what one of the components for a tacked cradle looks like.  Pictured here is version 6, and the cradle bolted to the differential is version 4 I believe.


*** Here's a picture of what it all ended up being in the end.



Edited by Invincibleextremes
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Yes, it will all revolve around a custom knuckle.  Just like the intrepid based setup, and just like the r230 z32 knuckle from Arizona Z car and so on.

The key difference is the hub, brakes, and struts will all be off the shelf, keeping costs down for everyone, including me.

No boring out a wilwood rotor hat or anything like that.  Just off the shelf bolt on and go brakes, crack a rotor? Go buy one and be driving the same day, don't like your spring rates?  Go order a different wrx strut and bolt on and go...

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Yeah, except I'm not a fan of q45 or z32 parts, their strength or their pricing...

I like the pricing of their backing plates front mount and mustache bar, in theory someone could just order those and the axle conversion they sell and get away with it on the cheap... except they'd be stuck building a strut.  So more or less you're stuck paying the full asking price of the kit, which btw isn't cheap.  And still need to source the short nose r200, and axles and brakes.

I don't know know man, it just doesn't sit well with me.

I like the idea that someone could buy some backing plates, a diff mount, and custom length axles and some cheap $250 coilover struts and be on the road with a setup that can handle 800hp...

Edited by Invincibleextremes
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I followed Will, I follow Spitsnaugle and very much applaud your efforts.  I have an LS1 powered 240Z and it already has an 8.8 in it.  The 8.8 is from a Lincoln MK 8.  I used the TTT front mount which is for a Q45  and is dimensional almost exactly an 8.8.  Had to trim the drive shaft area little  We made the rear mount which is really cobbled together but so far has held up.  Bought DSS output stubs for the diff side and they are off the shelf to 930 CV.  I bought 930 CV to Z flanges and then had custom axles made.  I know the outer stubs are my weak link and have a set of 280z stubs waiting for winter project time (discs, springs etc. will happen at the same time).  In short the only thing left Z is those outer stubs, which if/when they break I will just buy good ones.  From the outside the car looks like a stock 240z with ZX wheels, which was the goal for me.  We chose to keep it simple.  Not re invent the wheel.

I would like a better rear mount but the Z car Depot seems expensive, Spitnaugle is on the right track but need to find out pricing from him when he is done.  If someone comes up with even better, great.  Keep working on it.  R.   

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I found a guy in CA who made them.  One of the retail guys who makes dune buggy axles gave his number since only sold certain lengths.  I measured the distance and then he made them.  I have his number but can't find the exact amount, and in all honesty I don't remember how much they were but I think they were about 250 a pair. BUT DON'T HOLD ME TO THAT.   By dealing with the machining guy they were less than retail, I did have to wait a while but I was ok with that.  I would have to call him to ask if I could give out his number and it has been about a year.  I think since we are also in the industry he did me a favor.  HTH, Richard. 

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  • 3 months later...
  • 3 weeks later...

Got the rear suspension knuckles designed.  I was actually able to design it to work with the 2015 bolt on mustang hubs, and work with both the 1995 and 2014 mustang brakes.  


This allows you to use 1995 mustang brakes and use 15 inch wheels with slicks.


Also, had no problem designing it to work with 240sx s13 bolt on hubs as well, meaning people will be able to buy just the knuckles, and use 240sx bolt on hubs, and disc brakes and stay 4 lug and just use custom length 240sx axles and cheap 2004 srt4 coilovers.

The Longnose r200 and shortnose r200 have an interchangeable to some degree carrier which means 240sx cv axles should work if they are shortened.


Win win in my book.  This setup can be used completely to support high hp or just piecemeal to get rid of the stub axle and companion flange get up and be able to use a much better priced coilover option.


Still working on designing the mount for the super 8.8 itself.  I'll keep everyone posted.

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I'm keeping my eye on this to see how it progresses. I recently bought an '02 expedition 8.8 diff, but am liking the removal of stub axle part to the equation you present here. Subscribed to this thread...

Edited by Nelsonian
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  • 1 month later...

The ugly proof of concept prototype fits like a glove, both on the car, and on the diff itself.  So far so good.  Obviously still missing the front diff mounts and some other improvements, but the beta version is almost ready to go into my datsun.  Its 2 inches shorter than an r200 to boot, so I'll move my engine back some...


And no, the final product won't be hacked together with a flux core welder.


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My main takeaway from watching everyone else try building these kits if the pricing of support parts... a cheap 8.8 does you no good without cheap brakes... And cheap struts etc...  


Also, I worked very hard to design my setup as a one piece cradle for the hardmount version, and a 3/4 cradle for the bushing mounted one.  


I believe that the current offering from others on the market put too much stress on 4 small welded nuts on the factory r200 mount...  especially when they hang an arm out to give it even more destructive leverage and put a flexible bushing on there...  bad engineering at its finest.


The isolated version will basically be what you see there, but have the bushings located above and in between the 4 bolts... seeing only vertical stresses, no twisting force.


Also of note, in both the isolated and the hard mount version, the bottom plate is tied in to the control arm crossmember.  And if the end user wants, the whole cradle can be welded to it, making the hardmount setup extremely strong.


Oh, and it all fits with the factory verticals and the r200 mustache bar... meaning you can use a stock one or a fancy aluminum one.... whatever you please.  Also means that it should work with sway bars, provided the axles themselves aren't too big in diameter...  that I'm not sure of yet.


These are very important things that I spent serious time working around.


Can't beat 12 dollar rotors and 30 dollar calipers and the ability to run 15 inch wheels for slicks, if that's your need.


Or run 2014 mustang brakes and rock a bad to the bone street beast.

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I have been watching this via FB as well.  I have one of the original WFritz 8.8 swap kits.  I had a little mishap and was the one who ripped the subframe from the unibody at the passenger LCA frame/ mount location as well as destroyed the front diff  mount.  We have that back together now and the front mount is corrected.  ( I was the one who posed the question to you... lol) I look forward to seeing how you do with this set up.  Currently I am only at 700whp on my LS/ supercharger set up.  You can see other pics of the car on Instagram @datlszguy Good to see someone else on this path.


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Yeah I've concluded that I'll only be making the bushing version, and that those who want a hardmount can simply buy aluminum bushings... Which should be a win win for everyone.  I'm back in Portland today and will spend the next few days bolting up everything in my car and cutting and welding as needed to see the final prototype.


Yeah I've seen your posts on insta, it's one cool ride.  Currently barely have 300 or some odd horsepower but I do plan on going FULL retard with it in the future 

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