91 replies to this topic

[jbc3]

I drilled out a mustache bar with wider spaced holes and raised them as per suggestions found doing searches and raised the R230 in place. I have already purchased a billet 6061 aluminum plate that I am going to make a rear support out of and I have not cut the upper Transverse Link bushing perches off of the stock support yet since the stock rear support won't clear the cooling fins, but I bolted the support up on one side to test fit the TL for clearance. There are a number of issues that are showing up.
With the rear bolted up tight to the mustache bar, a small spacer will be needed as the curve of the cover hits the mustache bar, but I just bolted it up tight for the trial fit. In this position, the top of the rear hits the upper frame.



By moving the rear forward about 1/2 inch, (my custom cresent wrench spacer) , the rear clears the frame, but not by much.



I thought I read that someone flipped the mustache bar to push the rear forward, but that seems to me to be too extreme to keep the axles lined up properly.

The next issue is the transverse link contacts the axle flange. I mentioned in an earlier post http://forums.hybrid...ead.php?t=96702 that the R230 is wider than the Q45 rear. This may be another issue of the wider flange spacing. It's hard to see in this picture, but even with the rear pushed forward 1/2" the flange touches the TL.
I think that maybe the end of the TL can be ground to clear, but it is TIGHT. I did not bolt up the TL tight, because it won't clear as it is. I still have to deal with the CV flange width added to whatever clearance issue that exists too.



The stock fuel pump (78 280) is on a plate that is hitting the front mount, and when you push the rear forward, it's worse. But maybe after clearancing the mounting plate and getting the front of the rear up where it needs to be, the TL issue will either correct itself, or it will require less grinding.



This was just the first trial fit to see what issues I will have to deal with. I have energy suspension bushings coming for the mustache bar and once they are here, I can bolt the mustache bar tight and begin spacing, clearancing and fabricating the front mount.
I would love to hear how far others positioned their R230 off of the mustache bar, and if anyone had to clearance their TL or any other fittment issues.

Jody

[Cable]

Looking good.

What car/truck did you get the R230 from?


I am interested to see what you are going to do about CV's and their adapter(s).

Keep us posted.


Thanks!!

[jbc3]

The rear came from a '90 300ZXTT. I have 4 axles from 300ZXTT's and I will be using the 4 inner CV's, like everyone else. I had Tim send me pictures of the CV dissassembly and I took the first one apart in about 10 minutes, it's pretty easy, just messy as hell!
I bought the billet stub axles and adaptors from Ross at Modern Motorsports with Chevy bolt pattern, but they are not here yet. I also bought the Moser axles. I discussed the width issue with Ross at length and he will work with me if the axles are too long. (His prototype was the Q45 rear for the axles.) I still need to figure out rear brakes yet.

[maichor]

That's the kind of detail you need in a good write-up. Cool! Also, it looks like you have room to raise the diff (except where the unibody hits the rear cover.) By raising another 1/2" you will clear your TL with room to spare.

CUT IT UP! I cut out that same area, just weld in some extra support behind. I have a 1.5 X 2 X .125 wall tubing behind that spot running behind the original unibody that I welded in to mount the 240SX IRS with my R230, so cutting that small section did nothing to weaken the setup. You could definitely do the same. IMO the higher the better for the diff.

[jbc3]

I suspect that keeping the axles as square as possible is critical, so cutting into the frame makes sense. I have no problem cutting/welding but looking at what someone else has done successfully is always helpful.
Maichor... Do you have any pictures of your frame mod? I'd like to see how much you took out.

[Cable]

I thought I read that someone flipped the mustache bar to push the rear forward, but that seems to me to be too extreme to keep the axles lined up properly.

The next issue is the transverse link contacts the axle flange. I mentioned in an earlier post http://forums.hybrid...ead.php?t=96702 that the R230 is wider than the Q45 rear. This may be another issue of the wider flange spacing. It's hard to see in this picture, but even with the rear pushed forward 1/2" the flange touches the TL.
I think that maybe the end of the TL can be ground to clear, but it is TIGHT. I did not bolt up the TL tight, because it won't clear as it is. I still have to deal with the CV flange width added to whatever clearance issue that exists too.

I can bolt the mustache bar tight and begin spacing, clearancing and fabricating the front mount.


I would love to hear how far others positioned their R230 off of the mustache bar, and if anyone had to clearance their TL or any other fittment issues.

Jody

http://www.v8zcar.com/s30z/r230.htm

Here's a site with alot pics doing the R230 swap. Nice write up write up as too. I believe the site belongs to a member here on HybridZ.

Anyway, I think he mentions fliping the mustache bar to push it further forward. Seems to have worked for him.

Thoughts?

[jbc3]

http://www.v8zcar.com/s30z/r230.htm

That page has a bunch of good pictures, but the rear he's using is a Q45 R200, not an R230 from a 300ZXTT.
Jody

[Cable]

That page has a bunch of good pictures, but the rear he's using is a Q45 R200, not an R230 from a 300ZXTT.
Jody

I wonder how much diiferent the swap is?


I have a question about '90-'96 300zx non-turbo R200's.


I know the output flanges on a turbo model have 6 bolt holes.


Do the R200's from the N/A models have a 5 or 6 bolt output flange?


Thanks.

[Tim240z]

That site is Owen's.
With the Q45 R200VLSD, I spaced the diff forward from the MB about 1/4 inch with large washers.
To line it up, I ran a piece of string from each companion flange (lined up to the center of it's large nut), then lined the centerline of the Diff's output flanges to the string (laying underneath and eyeballing it).

Tim

[maichor]

Unfortunately, the only pic I have that shows any of the piece we are talking about, has the diff installed. Look to the right of the diff and you can see the corner of the missing section. I removed about 1" from the front of that piece and as tall as the unibody piece itself. You have to remove a section nearly as wide as the diff cover. The pics are large so you can zoom where you need to. I will also include a pic of my tank install so you can see the transverse member (in front of the tank) I installed to strengthen the chopped unibody.

http://www.theadairv.../~/misc_039.jpg

http://www.theadairv..._voyage_026.jpg

[jbc3]

BBZ, I think the swap is very similar (Q45 vs 300zxtt) but the Q45 rear is slightly smaller and there are precious few inches to spare. The larger piece just makes the fit that much tighter and that is sort of the point that I have been trying to make in my questions and posts regarding the differences. Unfortunately early on there was some confusion, and still is to some extent, between these two rears. I am hoping to help clear some of the misconceptions.

Tim, Good idea on trying to line up the flange centers and the rear with string. The rear really needs to be as close to centered as possible and if that means clearancing/reinforcing the frame to make it happen, it'll be worth it in the end.

Maichor, I see the notch you are referring to and I will start looking at clearancing and reinforcing. It does make sense and thanks for the pics.
Your rear TL is completely different than the piece that I have though. What is your frame/TL from?

I am making a billet rear support and will be cutting the stock rear support up so the stock saddles will be re-used. In the process, I think I'll cut a couple of billet spacers from the scrap (MB to rear studs) that can be trimmed to align the rear if necessary.

Jody

[TimZ]

I'm using the z32tt diff, too, and I'm finding all of the same issues that you are...

I just gave up on keeping the fuel pump in it's stock location, and moved it back between the mustache bar and the fuel tank. I then just cut off the offending side of the mounting bracket. I never much liked the idea of the pump sitting that close to the halfshaft, anyway. I always had mental images of a failed halfshaft taking out the pump, and the exposed 12v wiring sparking and starting a fire.

I used a single washer between the diff and the mustache bar - just enough to clear the diff cover.

My diff is also about as high as it can go without interfering with the frame in that area - I think I have about 1/16" of cleareance there, but it does clear. My transverse links also did interfere (more on the passenger side due to it's "flipped" orientation). I was able to solve that with a small amount of cutting and rewelding on the link. I'll try to get some pics of this as soon as I can - the parts are off getting powdercoated right now.

I decided to make a cradle that bolts up from underneath to locate the diff and the front diff mount - here are some pics of the trial fitment...

[jbc3]

Building the cradle is a very interesting idea. Looks like it will really tighten up the rear.
Where did you get the front mount piece from. Looks like a stock piece that was cut out.

Jody

[blueovalz]

Very nice TimZ. If extra time were taken with your fabrication, one could eliminate any rear toe-in problems with your "cradle" while tacking it all together. I especially like the bracing from the front bushing retainers with the rear ones (even if using the R200 casing this is a nice idea). Good work!

[maichor]

Yes, very nice! Do we have some fabricators on this site or what! WOW!

To reply as to why my setup looks so different, it is a 240SX/300zxtt subframe style multilink IRS. I'm surprised you haven't seen it, because I have posted it several times. I finally made a thread.

http://forums.hybrid...ead.php?t=96050

[TimZ]

Building the cradle is a very interesting idea. Looks like it will really tighten up the rear.
Where did you get the front mount piece from. Looks like a stock piece that was cut out.

Jody

Thanks, guys. The front diff mount is the stock piece from the 300zxtt. I notched it to fit and give the correct driveshaft clearance, and then gussetted it in.

It originally looked like this:


I stopped by the powdercoater today, and snapped a couple of pics of the transverse links. Here is the driver's side:


And this is the passenger side:


The welds aren't the prettiest, but it should hold...

[JMortensen]

I thought I read that someone flipped the mustache bar to push the rear forward, but that seems to me to be too extreme to keep the axles lined up properly.

That shouldn't be an issue with CV's like it would be with U joints. You should see the Porsche CV's in the back of a 911. The transaxle output shafts have got to be at least 3" forward of the stub axles, and they don't go bad very often.

TimZ, I love that cradle idea. I know Terry and I have discussed the rear suspension before and we both thought that someone in Japan was smoking crack when they decided to hang the rear on those 2 uprights. Your setup would provide a lot more support for the transverse link. Very nice.

If you added a piece of angle between the uprights on the top you might get even more stiffness out of it at very minimal cost. It would keep those uprights from trying to lean over in turns. I've heard of a couple ITS cars tearing the uprights out of the frame at the top where they bolt up.

[240Z2NV]

I, too think that the cradle is, at minimum, a very clever idea. Wonder how it affects ground clearance? Any issues? While I do think that it was very well thought out, I, personally, am hoping to modify Terry's (BlueOvalZ) mount 'plate' design to accomodate my R200 (Q45); but, fabrication is my absolute worst skill (along with electrical, mechanical engineering, scheduling...what did I miss?)

[jbc3]

Tim,

The TL trim that you did looks about what would be needed with the companion flange clearance on my test fit. I think that I'll try and notch the frame above the rear and trim the TL a little and there should be plenty of room. I like the 300zx mount too. I've been thinking about the cradle you built and I have some roll bar tubing left that may work perfectly. As far as clearance with the cradle, maybe a notch for the exhaust would be helpful. I am planning on using the stock tank and having a 3" single pipe out the rear.

The pictures really help... keep them coming.
Jody

[TimZ]

As far as clearance with the cradle, maybe a notch for the exhaust would be helpful. I am planning on using the stock tank and having a 3" single pipe out the rear.

I was thinking the same thing, however the exhaust routing should actually run parallel to the fore-aft brace on the driver's side, and then turn behind it. The r230 hangs down far enough at the rear that it interferes as much or more than the cradle. Maybe if you get the thing raised up a bit it will not be as much of an issue. I just really hate trying to weld from underneath the car.

Also, it's looking like the driveshaft angle will be okay as I've got it, so I decided not to bother - my exhaust exits in front of each rear tire, anyway.

One other fitment issue you should know about - the cradle does make access to the drain plug really tight. I have a 3/4 npt hex head plug that will work, but it doesn't have a magnet incorporated in it like the stock plug does. Still working on finding a low profile magnetic plug.

If worse comes to worse, it's actually not too hard to drop the cradle if I need to drain the diff, but I'd rather not resort to that.