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HybridZ

rt260, BMW M Powered


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A little history.... http://forums.hybridz.org/showthread.php?t=118747

 

 

Last summer, I installed a set of coilovers/HTS dampers from Beta Motorsports, and a fresh 3.36 NISMO Comp. LSD center section, along with a rear disc brake conversion (280zx). A stock L28E and 5 speed was dropped in as well.

 

 

Last week, BRAAP offered me a scorching deal on a BMW S52 drivetrain... http://forums.hybridz.org/showthread.php?t=150131

 

 

 

BRAAP_S52.jpg

 

 

Why?... I've built/driven/campaigned a number of V8Z's. They're loads of fun. Fast, affordable, and effortless to maintain. However, the silkiness and refinement of the Z was lost in every case. I love the smoothness and aural qualities of the L6, but the L6 is so technologically challenged that it requires an incredible amount of money, time, and talent to build generous, street-able power. Some modern alternatives include the JZ and RB. Each has merit. So does the S52 :wink:

 

Stock trim is 240HP, with a fat torque curve. 250-260HP is 'easy'. 300HP is not unreasonable with some effort. A street-friendly 9-10lbs/HP is looking feasible... N/A. And boosted results have been very respectable.

 

 

M_Power.jpg

Edited by RTz
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  • 2 weeks later...
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BRAAP and I weighed the S52 package this afternoon. On the same digital scale, a stock L24, fully dressed & dry, weighed in at 389.4 lbs. The S52, with equivalent components and oil, water, motor mount brackets, weighed in at 406.6. These two motors are within a handful of lbs of each other. A very welcome surprise.

 

The ZF trans weighed in at 83 lbs (wet), also very close to the L-series weight.

 

BRAAP will be posting the pictures in this thread, post 2 and 13... http://forums.hybridz.org/showthread.php?t=125246

 

The car will be weighed before and after to finalize the numbers.

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An interesting discovery... we noticed, after removing the intake manifold, the backsides of all the valves are spotless. Absolutely no build up. Not representative of a 190K motor. I also noticed a non BMW tag on the block, "LKQ Corporation"... an automotive recycler. Maybe it runs like a low mileage motor because it is? :mrgreen:

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  • 2 months later...
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Turns out the '96 and later EFI is a nuisance. BMW incorporated a security system (EWS II), with a matching ECU (Siemens), and key w/embedded resistor & antenna. As I understand it, the matching ECU is a non-issue, but the rest of the system must remain functional. I'm not super excited about the extra complexity and cost of retrofitting the EWS system in the 260.

 

An alternate choice is to use an earlier harness and ECU. BMW did use an an earlier EWS system (EWS I), but Conforti makes an EWS delete chip that fits the older Bosch ECU, for $300. Much cleaner and not a bad price... until you start sourcing a harness, ECU, and schematic. Now we're sneaking up on the price of a midrange aftermarket ECU. There goes the budget :wink:

Edited by RTz
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  • 2 weeks later...
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With the drivetrain sitting in the '77, it was clear the tranny needed to sit as high as possible. For giggles, I stuffed a stock Datsun mount under the trans, and found it to be a near perfect fit. Only needing to trim some of the flange off the front side, re-weld the flange at the cut, drill two holes for the fasteners, and a little massaging of the surrounding bolt hole area with a press (to provide enough flat area for the bottom washers to rest against). Took longer to clean and paint than to modify...

 

 

 

TransMount2.jpg

 

 

 

TransMount1.jpg

 

 

 

TransMount4.jpg

 

 

 

 

This location puts the tranny about as high as practical, with the height of the output shaft about 1/8" lower than stock, and the motor longitudinally within an 1/8" of of the pictures above. If the rest of the swap was this easy, I'd have it done in a couple of weeks :icon45:

Edited by RTz
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De-greased the slimy bugger...

 

 

Degrease1.jpg

 

 

Degrease2.jpg

 

 

 

BRAAP donated the only structurally straight parts car on the property, a '75 (thanks!). Dropped in the S52 and gearbox, and bolted up the trans mount. Fits well, mostly...

 

 

 

TestFit.jpg

 

 

TestFit2.jpg

 

 

 

Heater lines look workable...

 

 

FirewallClearance.jpg

 

 

Oil pan is going to clear...

 

 

OilPan.jpg

 

 

 

With the front of the motor sitting on the steering rack, I rigged up an adjustable mag-base and laser pointer. Spun the output shaft by hand and adjusted the base until the circle became small enough to be useful...

 

 

 

RackInterference.jpg

 

 

Laser.jpg

 

 

 

Prognoses?... The laser intersects the pinion flange about 1 5/8" too low, and the digital level says the diff and engine are within one-tenth of a degree of each other. Not only does the front of the motor need to come down, so does the nose of the diff.

Edited by RTz
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  • 4 months later...
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.

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Motor mounts are fab'd from 10ga (.135" thick) mild steel. Still need some finishing touches and paint...

 

 

MM1.jpg

 

 

MM5.jpg

 

MM2.jpg

 

 

MM3.jpg

 

 

MM4.jpg

 

 

 

A few notes...

 

Currently using stock BMW 325 isolators. These are not known to hold up to abusive driving, so a set of aftermarket isolators will be fitted.

 

To get drive line angles sorted, I lowered the nose of the diff. (with an RT mount, of course :wink:) and the crossmember is shimmed down 1/2". In this position, the oil pan is flush with the bottom of the crossmember.

 

Clearance between the pan and the rack is 1/2" at the lowest point (diver's side). If the racks radial-locating-dongle-bracket (or whatever the heck it's called) is slid to the passenger side, the full 1/2" clearance can be kept.

 

The transmission mount was modified from the previous post. I was aware that the trans. mount was offset to the pass. side, and I was thinking that it aligned with the diff. I'm only half correct... it's offset about 1/2 the distance... 7/16" at the mount, wherarese the diff. is offset 15/16". I'll post the modified pictures next time I remove it.

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One of the aspects of this swap I'm looking forward to is no blasted U-joints in the driveshaft. Using the BMW shaft means a Guibo up front and a CV joint in the rear. So, an adapter was built to mate the BMW CV to the Datsun pinion flange...

 

 

DiffFlangeA.jpg

 

 

 

DiffFlangeB.jpg

 

 

 

DiffFlangeC.jpg

 

 

 

DiffFlangeD.jpg

 

 

 

DiffFlangeE.jpg

 

 

 

DiffFlangeF.jpg

 

 

 

DiffFlangeDone.jpg

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You happy with driveline angles we discussed ie straight line from gbox output to diff flange?

 

 

Yes, I am now. The combination of the RT diff mount, 1/2" crossmember spacers, and offsetting the trans mount 7/16", puts the driveshaft nearly dead straight, and the bottom of the oil pan flush with the bottom of the crossmember.

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Probably my most eagerly awaited built... you can't get this one done fast enough for me Ron, been dreaming about this one since Hybridz started!

 

 

So, I can count on you stopping in for a visit once it's drivable? :mrgreen:

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