'94 S52 6-Speed Track/Race Car

[dannyzabolotny]

What a happy accident, lol. Glad I could be of help! The headrests were definitely the worst part of the BRZ seat, they just look too modern in an E34.

[moroza]

Psst... some E34 front shock kits come with a 12/14mm sleeve to adapt between V1 and V2 mounts.

[circuit.heart]

Psst... some E34 front shock kits come with a 12/14mm sleeve to adapt between V1 and V2 mounts.

Too short and far too expensive. Cheapest thing I found was a $16 carbon fiber tube! Pics next time as I haven't cut and glued it to the E36 'rests yet.

Engine is finally together! Needed a friend's assistance to weld aluminum. Achilles pan baffle in:

080 by Brian Ma, on Flickr


Felt good to take a picture of the closed-up engine at the correct angle. I'll do all the hoses and harness once the motor's in.

081 by Brian Ma, on Flickr


To finish up the closing, I test-fitted the ATI damper and realized that it's nowhere near as daunting as what the E46 boys wrote (heat up hub in hot water, use special tool to press-fit hub onto crank nose). Nope - it slips on to the point that the crank key engages, and from there, the OEM jesus-bolt + 5/8" ID washer + 3/4" washer was sufficient to slowly park the ATI hub down onto the timing chain sprocket. As per instructions, anti-seize inside the ATI hub and assy lube outside the ATI hub is helpful to avoid galling aluminum or tearing rubber.

082 by Brian Ma, on Flickr


Loctite the 3/8" 12-point bolts provided for the accessory and A/C pulley, swap out Home Depot washers for BMW jesus-bolt washer, good to go.

083 by Brian Ma, on Flickr


Annnnnnnnnd just in time, my trans crossmember's been welded up! Friend in Europe is working on a few copies that we can sell, for use with any M5X/S5X ZF GS6 trans swaps.

084 by Brian Ma, on Flickr

[5mall5nail5]

Trans support looks good but I'd consider running a rib from the end of the curved portion on to the flat part that bolts to the body - everything looks good but I could see torque twisting/bending the flat portion there.

[circuit.heart]

Trans support looks good but I'd consider running a rib from the end of the curved portion on to the flat part that bolts to the body - everything looks good but I could see torque twisting/bending the flat portion there.

Appreciate the concern but I'm confident it'll work - if we don't make enough reaction torque to hurt rubber trans mounts, 1/8" steel isn't going to care. This design is based off the Achilles and RallyRoad E36 pieces that use even less metal but are already demonstrated to survive, the extra gusseting on mine was per recommendation from a friend that we could try to stiffen the tunnel while we're down there.

crossmember.jpg

In other moving parts of the project, finally found a manual brake (booster delete) conversion that I like. Coming from a racing background, the Chasebays/Sikky style booster delete just isn't a good idea... one fluid circuit braking all four wheels, what if a line gets clipped on track?

single-MC.png

Instead, I'm so excited to try this out - ordered yesterday from Massive Brakes. 6:1 or 7:1 adjustable pedal ratio, runs twin Tilton cylinders and a balance bar to adjust bias. Not even expensive at $320! Technically the kit is for E30, but we know the booster pattern fits E34 (thanks Chasebays), and the main linkage of the Massive piece is modular so I can do whatever's needed to mate it up to our OEM booster clevis.

twin-MC.jpg

Only need to make only two hardlines (inverted flare 3/16" for Tilton -> standard BMW bubble flare) and source two junction/distribution tees to replace my dead ABS pump, but this can be done after the engine's in the car and turned over.

[5mall5nail5]

Appreciate the concern but I'm confident it'll work - if we don't make enough reaction torque to hurt rubber trans mounts, 1/8" steel isn't going to care. This design is based off the Achilles and RallyRoad E36 pieces that use even less metal but are already demonstrated to survive, the extra gusseting on mine was per recommendation from a friend that we could try to stiffen the tunnel while we're down there.

No worries just a suggestion - I've broken the factory cross member w/ UUC trans mounts already, so I just want to have as solid a piece as possible - the bending moment on that flat area is my only concern is all.

Do yourself a favor and remove the ABS pump BEFORE the engine. It's a PITA. Would be much nicer to have the whole area open - I regret not doing that.

[dannyzabolotny]

Side note, I love all the R&D that Brian's been doing as far as track car stuff... makes me excited to build a full-on track E34 at some point. Like imagine how good an E34 would be if you fully gutted it, made a custom wiring harness + switch panel, installed massive sticky tires with flares, lexan side and rear windows, etc. I'm willing to bet it would be as good as an E36 track car if not better, due to the slightly longer wheelbase and far sturdier chassis construction.

[CaneDVM]

Dedicated E34 track car you say?
_A095902.jpg

Side note, I love all the R&D that Brian's been doing as far as track car stuff... makes me excited to build a full-on track E34 at some point. Like imagine how good an E34 would be if you fully gutted it, made a custom wiring harness + switch panel, installed massive sticky tires with flares, lexan side and rear windows, etc. I'm willing to bet it would be as good as an E36 track car if not better, due to the slightly longer wheelbase and far sturdier chassis construction.

[dannyzabolotny]

Dedicated E34 track car you say?
_A095902.jpg

I was actually thinking of your car when I wrote that, it’s awesome. I’d do a poor people version with like an M52/S50 because S38 maintenance would bankrupt me, purely on parts cost.

[circuit.heart]

Dedicated E34 track car you say?

What Danny didn't tell you is that we've found the super headass solution to power such an E34:


085 by Brian Ma, on Flickr

F@#! an S38

I have a 3D model of a Rotrex C38 that we'll print out and see if it can fit in the space allotted. I gotta say it looks VERY promising at first glance, it's like BMW left a hole there just for me to shove something nasty into. (Thanks Danny for looking at a rando car under the lift lol)

086 by Brian Ma, on Flickr


Please don't take this as intent to build, I'm only trying to have the car dialed in NA. I just love sleeper mods if it wasn't already obvious, and this is one of the ones that make me giggle.

@Jon, duly noted. I lifted the hood today for the first time in months to have a look at my ABS pump, I can get the pump out easier with the engine out but I definitely don't want to bend lines for the Tiltons till the engine is in. Conundrum.

[CaneDVM]

I was actually thinking of your car when I wrote that, it’s awesome. I’d do a poor people version with like an M52/S50 because S38 maintenance would bankrupt me, purely on parts cost.

Thanks man! And a totally fair assessment. The CO sampling tube on the #3 header primary popped off (bizarre) on the last track outing, and the resultant massive exhaust leak made a noise that when muffled through my helmet gave butt-puckering insta-panic that it threw a rod or something. The financial ruin of an S38 failure is always in back of mind lol. But the header failure prompted dropping the engine which has extended into all sorts of cool additions and Angry Ass development, so there's a silver lining. Will start a thread for that car, and not derail Brian here further.

What Danny didn't tell you is that we've found the super headass solution to power such an E34:

Attachment 689136

F@#! an S38

I have a 3D model of a Rotrex C38 that we'll print out and see if it can fit in the space allotted. I gotta say it looks VERY promising at first glance, it's like BMW left a hole there just for me to shove something nasty into. (Thanks Danny for looking at a rando car under the lift lol)

Attachment 689137

Please don't take this as intent to build, I'm only trying to have the car dialed in NA. I just love sleeper mods if it wasn't already obvious, and this is one of the ones that make me giggle.

That would be amazing (love centrifugal blowers) and I am indeed taking it as intent to build.

Brian

[circuit.heart]

Slow progress update:

Got the alternator on, had to chop the cooling duct off to tuck underneath the -10AN output of the modified S54 oil filter housing. A/C bracket sourced and installed, all tensioners installed, Turner underdrive water pump pulley installed, we are ready to slap the flywheel and clutch on and drop it all in.

087 by Brian Ma, on Flickr


The much more exciting part is that the brake parts have arrived! Going to do this first before the engine goes in just in case hardline-bending tools take up more space than I anticipate. Spent just under $700 on a pile of: 2x Tilton 3/4" master cylinders, an extra remote reservoir (for the OEM clutch master), Tilton balance bar, -3AN to 10mm bubble flare adapters, and of course the Massive Brakes system.

088 by Brian Ma, on Flickr


Assembly is pretty intricate, almost more R/C car than normal car. I'm gonna dump a few pics here just in case anyone else wants to run this setup with me. Step 1 is to bolt the pushrod to the bellcrank, then Step 1b, cut off the end of the screw (protruding past the nut) so that it doesn't catch on the housing.

089 by Brian Ma, on Flickr


Attach bellcrank to housing, it's not the easiest nut to torque down. Make sure you don't wipe off the already-provided copper grease (I think that's what it is) that comes on the shoulder bolt, this stuff makes the bellcrank operation super smooth.


090 by Brian Ma, on Flickr

Getting the balance bar into the bellcrank was slightly challenging. The hole wasn't perfectly round (from welding, I bet) but you also didn't want to hammer on the bar itself or the ball, so I lined it up as best I could and started tapping my way around with an Allen key.

091 by Brian Ma, on Flickr

[circuit.heart]

Kit instructions say to cut the Tilton MCs' pushrods to 80mm (from flange), so, we do exactly that.


092 by Brian Ma, on Flickr

Thread them into the clevises on the balance bar before locking down the positions of said clevises.

093 by Brian Ma, on Flickr


I followed Tilton's instructions on setting the relative lengths of the two pushrods. For me, the driver's side (right MC in pic) is going to be for the front brakes, so the pushrod was left longer. The front brakes displace more fluid, so when I stomp the pedal, this MC is going to displace further, and the balance bar will flatten/even out.

094 by Brian Ma, on Flickr


With the -3AN to 10mm bubble fittings (not shown) we actually don't need to make brake lines at all, correcting myself from earlier. Can really just bend the original hardlines till they mate up to the Tilton MC's and call it a day. Simple, light, cheap, works!

Now I just gotta fix this thing. I had a pilot bearing adapter machined years ago for the GS6-53BZ gearbox, thought I wasn't going to use it, lent it out, and somehow it has returned with larger dimensions than it left. Gotta turn the big end back down to 31.98mm OD / 8.98mm height before it'll be able to replace the bearing in the JB Racing alu flywheel. Hopefully that don't take too long.

095 by Brian Ma, on Flickr

[5mall5nail5]

I am interested to see how the manual brakes feel/work.

My E34 is "perfect" I just don't like having all the crap under the hood - and obviously worry about the check valve failing and a million horse pressures going into my booster.

[circuit.heart]

So I gave it an earnest shot to install... and ran into the first hitch.

The three brake hardlines in my car came out easy (left/right/"hind"), plugs for the ABS unit were surprisingly clean and slipped off no hassle, two nuts for the MC came off fine, and I was able to lift the MC + ABS pump combo out of the car while spilling only a reasonable amount of Castrol SRF. Four nuts for the booster took me a few minutes to undo, I separated the pushrod from the clevis (on the brake pedal), and even this came out surprisingly easy.

Then this lol.

096 by Brian Ma, on Flickr
097 by Brian Ma, on Flickr



So it looks like the E30 pushrod is not only significantly shorter, it's also M8x1.25 threaded, vs the M10x1.5 thread of my factory 525i pushrod. It took me a little browsing on McMaster, but I ordered two parts that should help take up the slack without needing to do anything drastic.

https://www.mcmaster.com/95316A900/
95316a900l.gif

https://www.mcmaster.com/90009A222/
90009a222l.gif


The combo of these two parts extends the Massive Brakes E30 pushrod by ~35mm, which, as far as I can tell, is close to achieving the ~118mm length needed and leaves plenty of safe thread engagement for the turnbuckle. Once it arrives I'll be itching to put the system back into the car and start hooking up the lines.


On the other side of things, I've got my custom trans crossmember back from powdercoat! Came out straight enough, once the engine is in (which has to wait for the brakes ^) then next step will be replacing my jank stock crossmember with this beauty and mocking up the SpecE46 Y-pipe.


098 by Brian Ma, on Flickr

Edited part number above after finding out some new info.

[a777fan]

So I gave it an earnest shot to install... and ran into the first hitch.

The three brake hardlines in my car came out easy (left/right/"hind"), plugs for the ABS unit were surprisingly clean and slipped off no hassle, two nuts for the MC came off fine, and I was able to lift the MC + ABS pump combo out of the car while spilling only a reasonable amount of Castrol SRF. Four nuts for the booster took me a few minutes to undo, I separated the pushrod from the clevis (on the brake pedal), and even this came out surprisingly easy.

Then this lol.

Attachment 690385
Attachment 690386

So it looks like the E30 pushrod is not only significantly shorter, it's also M8x1.25 threaded, vs the M10x1.5 thread of my factory 525i pushrod. It took me a little browsing on McMaster, but I ordered two parts that should help take up the slack without needing to do anything drastic.

https://www.mcmaster.com/95316A900/
95316a900l.gif

https://www.mcmaster.com/90268A457/
Attachment 690388

The combo of these two parts extends the Massive Brakes E30 pushrod by ~40mm, which, as far as I can tell, is perfect to achieve the ~118mm length needed and leaves plenty of safe thread engagement for the turnbuckle. Once it arrives (today!) I'll be itching to put the system back into the car and start hooking up the lines.


On the other side of things, I've got my custom trans crossmember back from powdercoat! Came out straight enough, once the engine is in (which has to wait for the brakes ^) then next step will be replacing my jank stock crossmember with this beauty and mocking up the SpecE46 Y-pipe.

Attachment 690389

nice engineering! Hope it all works out as the diagrams indicate when they arrive. That trans bracket also came out looking great.

[moroza]

Brainpower and the McMaster catalog will go a long way towards keeping an E34 running long after BMW has forgotten all about it and the only new parts available are "Anodized chrome JDM turbonator fits 525-series with V6 US stock buy now!" on Fleabay.

[circuit.heart]

Success!

I was told it's acceptable to bend hardlines around a socket (to approximate a mandrel) so I did exactly that. It's ugly, but it's done. Wish the brass brick could have been horizontal, but I'm at the mercy of whoever cut the threads in the Earl's piece.


099 by Brian Ma, on Flickr


Nice and small. Just need to pop the clutch feed onto a reservoir, mount it somewhere, and repeat with the two Tilton MC's. Working inside next, the adapters for the pushrod are arriving tomorrow and I will get the brake pedal working!

100 by Brian Ma, on Flickr

[5mall5nail5]

Is the brass piece just NPT female? Just tap it slightly deeper to get it where you'd like.

[circuit.heart]

Is the brass piece just NPT female? Just tap it slightly deeper to get it where you'd like.

I wish, it's 10mm inverted flare so there's not much mucking possible outside of sending it to machine shop (would defeat the low-cost point of all this).

Got the pedal clevis sorted out today. I found I was dead wrong about using the 48mm coupling nut lol, it's much too long and the Tiltons were nearly halfway down their travel no matter how short I turned the turnbuckle. So I ordered a 24mm version instead and it's great! It's also $0.66, practically free. Stuck a washer in between the male-male and the coupling nut to lengthen the available thread the turnbuckle can "use".

102 by Brian Ma, on Flickr


You don't have to remove the clevis or clevis pin at all to install! I had it out because of my 48mm mistake previously. What did make life easy was to remove the clip (at right), so the clevis pin can pop out 2mm and swivel away from the brake light switch. This lets the pedal swing out towards your face, which I utilized to install the turnbuckle.

101 by Brian Ma, on Flickr


Since both ends (pushrod and pedal clevis) can't spin anymore with this setup, linking it together means using the turnbuckle like a winch to draw the pedal back in. You can do it the "normal" way as well, taking out the clevis, assembling the pushrod to the clevis, and then hooking the clevis back into the brake pedal, either way works. I just couldn't remove my brake pedal switch so removing the clevis pin was too much hassle.

Anyways, it's done now, zero play in the brake pedal and good balanced actuation of the Tilton MC's. Ran out of daylight, sorry for dim pic.

103 by Brian Ma, on Flickr


Will sort out the three fluid reservoirs this weekend and get the sucker bled!

[a777fan]

[circuit.heart]

F---ing got it.

I spent all morning looking for a "wall" to mount three reservoirs to, and the short answer is that this doesn't exist. There's too much crap along the firewall of a stock 525i to free up space. So I first realized that the brass brick could be used to remote-mount the clutch MC reservoir, then tried to figure out how to put reservoirs directly on each Tilton MC.

Answer lies with the bracket above the MC's that holds the + power pole and diagnostic ports.

104 by Brian Ma, on Flickr


Remove this part, flatten a tab, and drill a new hole in it 1" below the original, and we can raise the whole bracket by an inch.

105 by Brian Ma, on Flickr


Shouldn't get in the way of the hood closing, but now there is just enough room to fit both Tilton MC reservoirs.

106 by Brian Ma, on Flickr


Like so -

107 by Brian Ma, on Flickr


If you squint, you can see in the above pic that I put a bracket on the brass brick. I put a stud vertically into bracket and now we can fit the clutch MC reservoir.


108 by Brian Ma, on Flickr

I'm not 100% confident that this won't interfere with the intake manifold or elbow until we've actually got the engine in, but in general the Massive setup takes up less space than the stock booster discus + MC + lines, so it should work. According to Lee @ Massive, you can actually invert the bellcrank to lower the Tilton MC's significantly (avoids modifying brackets like me), but I didn't like that it would make pedal response less linear, and the clutch MC reservoir actually can't sit any lower than how I have it anyways (it'll be lower than the intake of the clutch MC, you risk air bubbles in the line). So I quite like how this turned out.

The crappy hardline layout means I need to order a power bleeder to bleed now, but that's relatively small peanuts. We now have proper manual brakes for the E34.

[a777fan]

We now have proper manual brakes for the E34.

Sorry if I missed it; plus I’m a total newb with regards to track setup stuff. What do you gain with a manual brake setup over a boosted one?

[circuit.heart]

For the most part, you lose clamp force, but gain consistency. Boosted brakes don't "let off" as quickly or consistently depending on how much engine vacuum you have in the manifold. Since I left-foot-brake at WOT, I also run into issues where I don't have any vacuum in the booster sometimes, so it gets really annoying and potentially dangerous if I flub it up in a >100mph sweeper.

This particular manual brake setup introduces a balance bar between the two MC's, so that's a nice bonus as well. I can tweak brake bias at the track as needed. It's currently set at 50/50, relying on my caliper piston sizes (60/40) and rotor sizes (348/300) to do the biasing, but having the option to mess with it at will is great.

[5mall5nail5]

Do you still have ABS? I think you removed it, right? I've deactivated the ABS on my car as it was doing very odd things under certain conditions - one thing I will say is that on a lightened E34 w/ big brakes, stick tires, and no ABS... you can find yourself in trouble easy with overly sensitive braking. If my car gets light over a crest with a turn and I am riding the brakes at all it can get squirrelly without the ABS. In a case like mine, a manual brake setup would probably be nicer for predictability, but, from a street car perspective I don't want to give up the convenience... I just try not to drive too silly for the road.