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[urbex]

Anyone know off hand what the WMS measurement is on the stock rear axle?

[Surfnut]

Is that "Wheel mounting surface" ?
I'm not familiar with WMS.


Dave

[urbex]

That it is.  I tend to forget that different groups have differing terms for the same concepts.  Seems most of the import car groups use "hub face to hub face" measurements, while most of the domestic and 4x4 crowd uses WMS, Wheel Mounting surface.  

Either way, it's the same measurement I'm after.  

Although, as I mentioned on the email list as well, I probably shouldn't have called it an axle either, lol.

[Surfnut]

Gotcha.  I always used the "Hub mounting face to hub mounting face" but WMS is a lot shorter so that's good too...

Unfortunately, I can't tell you what the rear WMS is but I can tell you that I measured the front repeatedly and I always came up with 58 and 5/8" from mounting face to mounting face.
IF the rear track width is the same as the front, I'd venture to say that the rear WMS is 58& 5/8" but of course, you'd better measure for yourself 'cause I ain't too good at counting and measuring and stuff    .

I hope that helps,
Dave

[Rocketman]

I have my FSM here - it states front "tread width" as 54.7" and rear "tread width" as 55.7"

So the rear is 1" wider than the front - but I dont have a solid number for you. I'll see if I have my old rear end laying around somewhere I can measure it.

Curious as to what you've got brewing - care to detail us?

[urbex]

What I'm brewing?  That a 8.8" rear end from a Fox body Mustang should nestle right up in there pretty nice    

Yes, I'm fully aware that none of this will be even remotely bolt in, and will require major surgery of the sheet metal and unit-body frame work.

[Rocketman]

Major surgery is an understatement, LOL- But I'd like to see someone finally pull off a nice RWD conversion.

Are you thinking V8? or small tuner motor?

[urbex]

I think a 302 could go in there fairly easily, relatively speaking, of course, lol.  It's a fairly compact engine.  The biggest concern as I see it is transmission tunnel clearance.  Obviously, it's going to have to be opened up quite a bit, and the two problems that I'm seeing right away is going to be weight bias front to rear due to engine placement, and radiator mounting.  

The weight bias being that if I want to maintain some sembelence of a street car inside, I may have to position the engine so far forward to accomodate the bellhousing that it may end up negating any advantage I'm going to get from a RWD setup, and possibly make the whole setup worse.  Without having actually taken a tape measure to the car yet though, I think there is enough dead space behind the dash to make a pretty big clearance for the bell housing, and still be able to get the stock dash back in place.  

This also bring radiator clearance into play.  I really don't think the stock radiator is enough for a 250HP+ engine in Phoenix.  But there isn't enough room to go much bigger either.  That's something I haven't put much thought into one way or the other yet though.  

My other thought was to maybe use something like the 3.2L Taurus SHO engine, but I don't know off the top of my head if there are any RWD transmissions that will bolt up to it.  

I'm likely going to stick with something domestic, whether it be V6 or V8, only because I'm much more familiar with them, plus it seems like all the really cool stuff has be shipped in from Japan which means big $$$$$ over here.

[Surfnut]

The SHO engine is too heavy and doesn't give nearly as much power as a decent 302.  Put an aluminum intake and aluminum heads on a cammed 302 and you'll hit an easy 300 horsepower with great torque.  The SHO's only rated (stock) at I think 220 horse and it's heavy as Hell.  I looked into a SHO motor for my Triumph and concluded the 302 was a WAY better option.

Do a rear mounted radiator blowing through a louvered trunk lid / rear fascia and you'll have all the room you need up front.

You'll also have to fab up lower control arms for the front or do some serious reworking of the existing control arms.

It's a neat idea but you might as well save yourself a ton of frustration and just figure on building a custom frame / suspension and dropping the Capri body on top of it.  That would be a LOT easier than trying to make everything fit under a Capri.

Dave

[Rocketman]

There is some room to be played with for the tunnel, I dont know exactly how much as a measurement but it can be done. Last I looked though I would need to be moving the pedal assembly over a smidge as the accelerator is in prime tunnel real estate.

Joe (RciCustoms here) managed to cram a large aluminum radiator from a DSM into his Capri - I think the cooling issue will easily be tackled.

Off the top of my head I dont know of any RWD engines that will bolt to the SHO motor. Is the 3.2 the Yamaha V8?? I think Lincoln has a RWD transmission that will bolt to the Duratec...

The Miata guys manage to cram the 5.0's and many other large domestic engines in their cars, IIRC they mention it only adds ~200lbs to the car? You might be okay.

[Surfnut]

I'm pretty sure most Ford 5 speed RWD transmissions will bolt up to the SHO engine.  I'm 99% sure the Ranger / Mazda pickup 5 speeds will fit.  There were at least two different 5 speeds offered in those pickups and I'm pretty sure both will bolt up.

Dave

[Gostlrs]

If your gonna go RWD on this car...

SR20DET will fit real nice and would be perfect...

[urbex]

I have no idea what that even is, nor would I have any clue what car I could even use as a donor.  See above comment about using domestic engines due to familiarity.    

So I pulled the wheels off the car last night to get a good look at what I'm in for.

Ok, I'll admit it...I had never really looked at the car before deciding this might be a fun road to go down. Turns out I should have looked at the car first, lol.

No way the stock rear struts are going to work with driven axles back there. Maybe I could swap them for front struts, and build a mount off the axle? Whichever way I would go, a solid rear is going back there, not IRS. Fuel filler, and likely the gas tank as well, would be in the way. Most likely would replace with fuel cell in the trunk area.

I think I could reuse the lower control arm mounts, but I have no clue what I would do for uppers (I seriously doubt the strut would live long trying to keep the axle housing from twisting up), maybe a radius arm setup, or torque arm mounted to the trans, similar to a 3rd/4th gen Camaro/Firebird setup.

As for the front, I see no reason why I could keep the stock front suspension setup, just installing an outer stub to keep the wheel bearing together, and possibly changing to a higher spring rate to accomodate any extra weight up front if needed. I think attempting to retain both a manual trans and power brakes isn't going to happen...that brake booster would get in the way. If I did go with the Mustang rear end, I have no clue yet how I would tackle the increased track width to match on the front, nor the bolt pattern difference issue. Bolt pattern issue might be taken care of just by running staggered wheels/tires, so it wouldn't matter at that point. Ideally though, would probably get a rear end narrowed, and redrilled to match the Capri pattern, so I could use stock wheels.

Ideally, I'd probably switch to an auto trans, and ditch the power brakes. Would probably ditch the A/C as well, and give myself a little more room up front to work with if I come up short.

Looks like I should have plenty of room under the dash to enlarge the exhaust tunnel to handle a bellhousing as needed, perhaps even to route exhaust down it as well.

I'm sure there will be plenty of other little things too, these are just the major ones that jumped out at me right away. The more I think about it, the more I keep going back to "at least start with something that began life as a RWD vehicle....."

There are a couple of Chevettes for sale near me on Craigslist, lol.
 
 [ December 09, 2010, 11:56 PM: Message edited by: Rocketman ]

[Rocketman]

Hey, I moved some posts around I think got stuck in the wrong place.

There isn't much in the capri rear to work with    I highly doubt you'd be able to do anything with the stock rear struts, most solid axles I've seen use shocks and seperate springs mounted much further in the body, and a couple bars with bushings. Solid beam, I'm think = tubbed rearend

On my AWD conversion I used the IRS from a 323 GTX - had to do cutting and lots of drilling and reinforcing to make it fit, but it's there. Dont rule out an IRS! lol. I was able to make it work, I had to modify some different struts to work in the rear but it worked out.

Here's the GTX rearend as opposed to the stock subframe
 

This is what I had to cut just to clear the subframe/diff:
 

The drive bits:
 

"Start with something that began life as a RWD vehicle" - I've often thought that, and while so much easier, whats the fun? Hahaha.

My $0.02
-Rocket

[urbex]

Eh, I wouldn't say they got stuck in the wrong place, just more that we started to drift well away from the original topic.  It doesn't bother me none...I just look at it like general chit-chat that would happen in person.  

Anyways, solid rear vs. IRS...it's not so much an issue of can vs. can't, or difficulty of install, rather a cost and availablity issue, coupled with power handling.  I know an 8.8 will handle 300HP to the ground no problem in a Mustang.  My goal was 300 flywheel HP, so I figure an 8.8, Detroit locker, and alloy shafts will handle all the abuse I can throw at it.  If I do happen to break something, it's an easy trip down to one of the local speed shops to pick up a replacement.  In terms of the GTX rear end, I've never even _seen_ a 323GTX, much less been able to just buy the bits I'd need.  

Also, as something I'd be building primarily as a street/strip car, I think an IRS setup would be counter productive.  

The more I think about it, the more I'm thinking the best case scenario would be to basically back half the car, and build out a tube frame to handle the rear end.  But then, that's getting really far away from the weekend cruiser idea I started with.