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BMW S54 into S30 Chassis - Build Thread


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22 hours ago, Neverdone said:

While not the exact same engine, Ron put 1/2" spacers under the front crossmember for his S52 powered Z. They don't screw with suspension geometry enough to really matter (you could always correct it if you're crazy). You can also buy them from Jags that run for pretty cheap.





If I need to drop it any further, I will definitely look at the JTR spacers as an option. I think I am going to be okay after the cutting I've already done, but the next test fit will tell us quite a bit in terms of next steps.


I also am almost done adding some small, higher gauge reinforcement pieces to the engine stand offs. Just need to clean them up and plug weld them in permanently.




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18 hours ago, grannyknot said:

Maybe next time you drop it in you can attach the transmission and start looking at the driveline angles, really looking forward to what you find, I know I had to drop the nose of the R200 diff about an inch to work right.

That is definitely on the list of things to look at next go around. 

I am running pretty much the entire rear suspension set up from T3, so theoretically that shouldn't change much, but worth noting nonetheless.


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  • 2 weeks later...

It's been a few weeks, so it's probably about time for an update. Also finally got a cart for the welder. Lifting that thing around while trying to keep the bottle from tipping over was a major PITA.



I got the sub-frame engine stand off supports finished and welded in, finished up the driver side engine adapter bracket, and then modified the passenger side adapter bracket to be able to *potentially* install an AC compressor in the future if I decide to go that route. I'll also include the wiring in the engine harness to be able to plug in the compressor so that it's already there a future proofed.





The I started to look at the steering situation. This was an issue I saw coming so it was no surprise to confirm that the steering rack will need to be moved. I have an old e46 M3 power steering rack too that I'm considering using, but haven't made the decision yet to stick with Datsun mechanical steering or to go with the BMW rack. Nonetheless, I've torn apart the BMW rack and am going to rebuild it with all new seals etc... if I end up not using it, I'll just sell it.






Now with all of the engine mounting modifications completed, it was time for test fit #2. I dropped the engine in and found that the clearance issue with the hood latch bracket was solved by lowering the engine and that the clearance to the hood should also be much more acceptable now. The other oil pan to driver side TC mount clearance remained sufficient. With the engine in and sitting pretty well, I started to bolt up the transmission for the first time. With a lot of maneuvering, I managed to get it bolted up and the tail end supported. The BMW transmission mounts line up nearly perfectly with the stock body mounts on the car. The trans cross member will take a little work, but that's expected. Also, installed the shifter just for kicks and found that I will need to shorten it up a bit, or extend the hold in the tunnel, we'll see where the seats land and how the ergo works out. Next I'll need to get the rear end in and that I can start looking at drive line angles.













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Interesting fact about the BMW steering rack. Subaru Forester outer tie rods screw directly onto it and have the same taper as the Datsun knuckle, and the BMW inner tie rods are only about a half inch or so too long on each end.


I actually just shortened the shifter arm on my Z4 trans that I'm mounting to my S52 last wednesday.


Another fun bit of "Did BMW design this engine for this car?" 



The shifter arm bushing mount fits almost perfectly where you'd want it to at the back of the shifter hole, and only requires a little bit of bending. Good times.

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I'm taking notes,  those clearances are looking good, I wonder why @m3240z felt he had to shave D/S oil pan to get enough room, you seem to have lots?

Have you considered the Saturn/Equinox electric steering mod?  Much lighter than the hydraulic systems and frees up space where the steering pump and hoses were, there are a number of threads on it here and on Classiczcar.

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On 9/19/2019 at 6:03 PM, grannyknot said:

I'm taking notes,  those clearances are looking good, I wonder why @m3240z felt he had to shave D/S oil pan to get enough room, you seem to have lots?

Have you considered the Saturn/Equinox electric steering mod?  Much lighter than the hydraulic systems and frees up space where the steering pump and hoses were, there are a number of threads on it here and on Classiczcar.

I'll have to look into that. I didn't know about that until just now apparently :)


In other news. I went to mock up all of the rear suspension parts so that I could start to evaluate the driveline angles b/w trans and differential and ran into all sorts of issues. I also want to note, that my car has been wrecked or had any rear end repairs done that could cause misalignments and because all of my parts are from T3, I'm trying to sort through things with them, but I'm open to input from the forums too.


3 main issues despite the fact that it does look quite good 😛




My first issue is that the T3 mustache bar and front differential cross member seem to not be compatible with each other. The back of the differential sits what I think is too low. Either that or the front differential crossmember and isolator push the front of the differential too high. High enough that it starts to put a good amount of twist or torque into the billet aluminum mustache bar. My differential is a 1983 280zx r200 with the proper cover, so it should be a completely standard swap from the R180 that came in the car. Is my assumption wrong that this mustache bar should not be under significant twist when completely unloaded?


It's hard to tell put you can kind of see the slope of the differential in this pic. This picture includes the front isolator.





This Picture is the same set up, but with the front isolator removed. You can see the diff sits much more level. At least by my eye...





The second issue I'm having is that the "power braces" I bought are too long. The holes are slotted but even in their shortest position, I cannot get the bolts to line up with the drop mounts.




The third issue is that even if I was comfortable torquing the mustache bar by just tightening down the front cross member, the hole in the front cross member does not line up with the isolator when the isolator is secured to the differential.  You can see in the picture that the middle through hole and the isolator threaded hole are shadowing each other.




I'm also using an RT mount on the top side, so I played around with the idea using the isolator that came with the front cross member to suspend the differential from the top. This did not work at all for the moment, as the mounting holes on the differential fell well forward of where they would need to be. In this pic, I got one bolt through (the one close to the front of the car) but this causes the other hole to rotate away from where it would need to be.




I feel like I'm battling a combination of tightening sequence of all of the bolts / slight part incompatibilities / old cars never having things exactly in the original fresh out of the factory locations.


I'm open to any suggestions of things to try.






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The shim idea would move the diff backwards, but unfortunately since the power braces attach to the front cross member and the drop mounts, their position is independent of the mustache bar.


I also need to check where the axle outputs are positioned with all of this. I don't want to slide the whole thing back and then mess up the half shaft angles.

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Do you still have the stock parts? If you can install them and take some measurements of where the Diff normally is and compare that to where it is with the TTT stuff.  As I understand it the TTT parts are suppose to replicate the stock positions so if you mount all the stock hardware you should be able to replace any one of those parts with the TTT part and still have everything fit.  Maybe try that one piece at a time to see if you can isolate the problem.

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Here comes an update... I think I figured it out and finally have the whole rear differential where I want it now. So here goes my attempt at an explanation...


I had all of the stock parts so I reinstalled all of that and decided to take some measurement of the output shaft locations. The numbers are a bit arbitrary here but are for reference only.

I measured a fore/aft location of about 10.25" and an up/down location of about 7.75". Keep those in mind.


IMG_20190928_170932.thumb.jpg.a9af2e5d31db1fb7c7773b40cf19d7de.jpg   IMG_20190928_170918.thumb.jpg.dda3b280848d09e011d1c4d7b50ab59a.jpg     


Then I put all of the new parts back in as you expect and as designed by T3 with the spacer between the mustache bar and the diff. I redid the same measurements and came out with:

fore/aft location of about 9.125" and an up/down location of about 7.75".

You'll notice that the fore/aft measurements are different by 1.125", where the new parts sat further forward in car than the old parts.


IMG_20190928_162602.thumb.jpg.70e3a80c08e624fb4495eccf1ec62c0f.jpg  IMG_20190928_162717.thumb.jpg.10f406c7aa042ba3d82e924acc9216fe.jpg


Now, that being said, the T3 front differential mount and cross member with the parts in this configuration were very close to lining up although were out by approx 0.25". I could probably have made this work.




However my desired set up is to use the 3-1108 GM transmission mount to hang the diff from the Technoversions R/T mount I'm also using, in concert with the the snubber on the bottom. But the issue with this was the the differential was sitting much too far forward to have the R/T mount line up with the forward set of holes on the diff. (no picture of this... sorry)


So, I decided to try one more thing... (and maybe you see where I'm going with this...) I removed the spacer b/w the mustache bar and the differential. It is exactly 1.125".  I reinstalled everything less spacer and what do you know... the R/T mount and the front set of holes on the differential line up. So I got the 3-1108 poly mount installed and the differential hanging that way.  I took the front differential cross member and snugged that up. All is good, except now I'll be using a snubber on the bottom to "sandwich" the nose of the diff. I also redid my measurements one more time in this configuration and the numbers came out much closer to those with the original equipment.


IMG_20190928_191429.thumb.jpg.c45baba9aedf45536d548c1d2640704c.jpg  IMG_20190928_191406.thumb.jpg.679857746fd0f9e0dc80fcb9c3ba5f3a.jpg  IMG_20190928_191538.thumb.jpg.557fe9fba81f8e94183ec7fdf107919d.jpg


so in summary my current set up is:

R200 from an '83 280ZX

T3 Mustache bar (with 1.125" spacer removed)

TechnoVersions R/T mount and 3-1108 GM transmission mount to hang differential

                                -  This also put the nose of the differential a bit lower to reduce the pinion angle which I was having issues with before

T3 differential front crossmember with snubber (needs cut down to fit properly per normal process)


I'll get some more pictures up soon that show the overall setup better, but I am waiting for a new set of T3 power braces to come in. My original issue with those was that they were too long, and T3 is being great and sending me a new set of them to try out.


With the differential in its place... Now I can move on the the transmission and figure out where that needs to be in order for the driveline to be angled properly. I got my laser and mag base in today, so that should be happening this week.

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So tonight I focused on just gathering some information on the relationship b/w the differential and the transmission.

I got a 20ga boresight laser and a mag base from amazon and used that to see where each was pointed. The differential was pointed almost exactly where it needs to be, and the transmission was a little off, but it still needs actually mounted, right now it's just sitting on the stock trans cross member. I also probably need to work on something to better hold the laser on the transmission. The current solution of just holding it there isn't very consistent.


IMG_20190930_193004.thumb.jpg.a90e84933a8e2513f57bec45bce66b35.jpg IMG_20190930_192908.thumb.jpg.41cd843a2e1caa4abb752fb1f73fd769.jpg IMG_20190930_193224.thumb.jpg.28cf4ce574d12a955d5ded20671c4b9e.jpg


IMG_20190930_195153.thumb.jpg.3515a8966c74111f4c064d482e9d516d.jpg  IMG_20190930_195145.thumb.jpg.3ca9788169a8dc7c012a95a5c8a38b07.jpg


I also got a digital angle finder and took the angles of each flange. The difference in the angles right now is about 2deg and I'd like to get it closer to 1deg given that I am planning on using a single piece driveshaft with a BMW guibo on one end and a CV joint on the other.


IMG_20190930_201916.thumb.jpg.53d766dac958788ffb9a4f0d55d6e13c.jpg  IMG_20190930_202005.thumb.jpg.fba7ae166b4460254246a03386885ebd.jpg  IMG_20190930_202111.thumb.jpg.052c77b6c6ac0e1ecf4ea6b44ea0f13b.jpg

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  • 2 weeks later...

After a taking a break for a while, I've been working on getting the transmission mount sorted out. I took some measurements, drew up some CAD and fired up the 3D printer. I got it fitted in and it really looks like it's going to work out quite nicely. The laser pointer is near dead on, but I still need to put the angle finder on it one more time to verify that all of the misalignment is < 1deg. The plan is to send out the drawings before the end of the week to be laser cut. Hopefully I can get it welded up by mid next week.


IMG_20191015_180416.thumb.jpg.a3fc67e2dd2c5d13de3919672400d141.jpg  IMG_20191015_182423.thumb.jpg.f73937fd7e4757a13b6ce1eb14f0046d.jpg


IMG_20191015_183513.thumb.jpg.b227c7f055f50a1c74a50df8c116f28f.jpg  IMG_20191015_183530.thumb.jpg.17d2499a0e620d3d126414dd81748df8.jpg



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  • 1 month later...

I hadn't realized it's been so long since my last post...

a couple things have happened... I got the rear end completely sorted out and mounted just how I wanted it with the RT suspending the diff from the top and the snubber sandwiching it from the bottom. 


IMG_20191019_191651.jpg.7170b9a24616ac14382ef4a7a093dfd3.jpg  IMG_20191019_191811.jpg.84b29c8827d766544e7ab731b299a330.jpg


I (just for fun) mocked up the driveshaft and am working on an adapter to go from the BMW CV joint to the R200 input flange. Anyone interested in machining this guy for me?


IMG_20191018_163345.jpg.2492f9f8df90c551e9fd886e5dab5a89.jpg  IMG_20191210_201939.jpg.2d481a85c7edfb757fdacb1db7c50a0c.jpg






I got the transmission cross member welded up and in position






I started to work on refurbishing the HVAC unit. Right now, I'm still up in the air if I want to install AC or not... but i'll at least have the equipment behind the dash if I want to.This basically involved taking EVERYTHING apart, cleaning, greasing, repainting and replacing every piece of foam. I also retro fit the Kia Sportage blower fan.


IMG_20191103_161928.jpg.0dc62ff5e582a36fa0b9cf7ae1dd4edb.jpg  IMG_20191103_110455.jpg.78d9437298463a29fc0d372a0baa67b2.jpg


I got some of my accessory gauges mounted in the new dashboard too. I'm going to continue working on the dash over the winter when i'm not out in the garage as much. Next up will be the two main gauges... I just need to get a hold of some of the Skillard adapters for Speedhut gauges.




I also took delivery of some more T3 goodies... this time the front control arms along with BC coilovers. i'll be cutting my strut housings soon and then it's time to look for a professional welder to bring it home... since you really only get one good go at welding these up... I'll hand it over to a professional.


IMG_20191206_144550_01.jpg.5273dec86b157d6b289a681306513356.jpg  IMG_20191206_150201_01.jpg.3834054756bf035d9404124a3d5e6159.jpg


Lastly, I settled on my wheel and tire package and ordered those. 15x8 0 offset Atara racing wheels with 225/50/15 R888r tires - these should fit under the body with no flares. Picture below is the same setup (minus the different style wheel)








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  • 2 weeks later...
  • 1 month later...

Been a while since I posted anything,  but here's few small updates.

I refurbished the turn signal stalk, and cleaned up the combo switches and put together the NRG quick release hub with my wheel. I still need to find a horn button that I like to finish it off.


IMG_20200202_113935_01.jpg.06775b3c7d79f591607af2fa05b3d39a.jpg  IMG_20200202_113926_01.jpg.f27a9de629b0639d5fb60dae1c8dde8d.jpg 


I also cut down the strut housing in prep for the coilover installation and had everything sand blasted.  Currently those are out being welded. I figured I'd leave to the hands of a professional. I still need to paint them, but the weather here in Michigan has been prohibitive to spray painting.


IMG_20200122_191212.jpg.9ad3e0e36306e380c595754e4cae3e14.jpg  IMG_20200117_170705.jpg.8a66e93bbe1cce9aed7a40ef687f2d12.jpg


I also started working on getting the large gauges installed using the Skillard adapters.




Lastly, i received all of my wheels and just did a quick mockup of the Arizona Z car front brakes and ... they fit! so good new there.


IMG_20191226_141218_01.jpg.e157e3335d0caae19afc8ee13c0bf42d.jpg     00100dPORTRAIT_00100_BURST20200106192047251_COVER.jpg.f4932909e472bfb1e46f1c5545952ca4.jpg


Next things up are: 

- getting all of the new wheel bearing assemblies painted and pressed together

- finishing restoring the dashboard and getting everything I can installed into the new Vintages Dash.


Once spring hits, it's going to be full speed ahead with working on the Body Shell. It needs modifications made for a new steering rack, fuel cell, pedal box, Recaro seat etc...






Edited by carbuilder723
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