E30 Track car build

[Mark E30 328i]

Just thought I'd put up a few pics of the track car that I'm building. Originally I was going to build the car using a 1UZFE lexus engine, but I have decided that it would be far too ocomplicated, involving and expensive. So I have opted to build it using an M52 B28 out of an 728i. Sorry the next few posts are going to be coppied and pasted from another site just to get this one up to date.

Mark

Couple of pics...



Very tidy shell with very little rust, patch on the rear valence and on the N/S sill where the the front wing has collected a load of crap.
Going to be a slow project due to financial constraints, but should be good when it's finished :

Nice thing about the 1UZ on that set up, it should be getting on for high 300'sbhp and simmilar torque. And the engine itself is lighter than the M20. Should make a potent track car.
The main things that I'm going to have to deal with are obviously sorting out the rust issues, converting to 325/touring running gear and then deciding how to get the power from the flywheel to the diff. I'm currently thinking about using a 325 box that I have picked up and making an adaptor plate and having a custom flywheel made.
The wish list includes:
325/touring running gear
Medium cased LSD
Reinforced diff hanger
Fully polybushed
Having thoughts about convirting the front lower arms to allow some castor adjustment
Welded in cage
Turreted rear end
Coil-overs all round
And of course the lexarse engine.
Not going to be a particularly fast moving project but should be interesting.
I have just spent the first day, striping off bonnet, wings and have started going to work on the rear subframe.
Have to say that the BM is one of the more stress free cars to work on, everything just seems to be so well thought out and engineered

Little update.
As you've probably seen I've aquired a donor car (lol). Which will probably go back on the road for a small profit which should help fund a few bits and peices like an actual donor, suspension and a cage.
I have also aquired a full set of powerflex bushes, unfortunately including concentric front arm bushes, so it's looking like adjustable ones are going to be sooner rather than later.
I have spent a little time looking at the rust and ascertaining how far it goes (scraping back with a screwdriver. Next job on that front will be to buy some wire wheels to go on an axle grinder and go to work cleaning and cutting back.
The other job has been removing the rear subframe set-up, which has been problematic, having to drill out hex bolts that have rusted and rounded and the rear bushes siezing to their locating stubs. Simply rectified by spending a day away from the job, coming back to it and realising I had been leavering the wrong bit lol!
Last but not least, I've burnt the troublesome bushes out of the subframe today which felt quite enjoyable!




Quick update, just purchased a 325 medium cased LSD and also one of the more expensive parts of the build... A lovely weld-in cage from custom cages. Bought a new one second hand lol. Full weld-in job with additional door diaganols and triangulation to strut tops, which is nice.

Quick pic of the offending item.
Not really done a great deal on the car as i'm getting married very soon so have no time until early july.

Few pics of what i've been up to..



Couple of bits of rust, either cut or ground out, need to buy a wire brush attachment for the angle grinder to finish off.

Small update. No progress made really, however been spending a fair bit of time designing (stealing ideas) for the suspension and also running a fair amount of maths on the engine side of the budget.

I have been in the process of looking at the DTM/ Group A rear suspension set-up and feel that it isn't too much hastle to a) replicate the design and b) manufacture. So the rear suspension geometry is going to have hopefully the same level and ease of adjustment as the DTM cars. The rear sub-frame and trailing arms are going to get reinforced, be fully rose jointed and have adjustment to camber, toe and roll centre. I have decided to change the rubber subframe bushes to nylon ones which I will have turned up. Not too sure about the aluminium ones reacting with the bodywork of the car.

The diff will also be welded to the boot floor (Indirectly lol) and cage will be triangulated to it. The cage I have is the custom cages one with one or two extra bits and peices added on, triangulation to strut tops etc. the other bracing that I'd like to add are down to the subframe mounts and poss a couple of other diaganols too.

With the front suspension the DTM system should be fairly easy to replicate, however I do need to consult someone in the know on the geometry of the lower arms in relation to the subframe, lowering the roll centre etc. I'd like to keep it as simmilar as possible and encorporate aspects such as the additional bolt connections on the rearward mounts.

I'm also entertaining the idea of their adjustable ARB's but there is a lot more RnD involved in this due to the way tapered spring steel is used and the weight of the car will have an effect on this. But it's an engineering excercise to play with at a later date.

And the final developmet for now is that I have an engine for the car. I have decided for what I am after i.e 400-450bhp and a little less torque using the 1UZFE is going to be way too expensive. I am now using an M52 B28. I have just bought a 728i with a replaced engine due to nickasil, so is perfect for what I have in store.

So the plan with the engine for now is to install it on the standard management or Megasquirt or vems and have a shade under 200bhp for me to get used to RWD again and at a later date turbo it. I will also do the necessary when the engine's out like installing the .140 MLS gasket and the ARP headstuds and then turboing will be more of a bolt on process.

From the turboing point of view is to use a TD05 20G or a TD06 20G which should do the job nicely. Unless I can save the extra money required for a Holset and external waist gate.

Heres a link to the pics I've been studying http://www.s14.net/jakesdtmtours/suspension.html

Another small update. No pics as of yet. After a fair bit of planning I've decide that the 1st thing to focus my attentions on the adjustable rear subframe. 1st item of which is in the pic below.

After spending a lot of time looking at the pic trying to figure out how it works (different nuts etc. locking against each other), I have finally decided that the centre 'nut' in the assembly is actually a turnbuckle, but not in the conventional sence. The turnbuckle when taken out of the assembly will look more like a bolt (i'm thinking about using an M20/22), however with a hole bored through the centre and a reverse thread tapped into it. The half nut to the left is a check nut to lock off the rod end and the flanged nut on the right is to lock off the turnbuckle and also to clamp on the camber adjustment barrel (far right). Mocking up something simmilar should provide this item.

Next thing to look at is the camber adjustment barrel. I have decided to simplify what they have done here. What I intend to do is use some tube (i've 48mm od to hand with a wall thickness of 4mm), weld a plate to the top and have 2 circlip grooves turned into the bottom, a lower disk will be located between the two. Inside this barrel will be a solid round bar with tapped holes in the top, bottom and side. The top and bottom to recieve threaded rod, which will allow adjustment of camber and the side one to recieve the toe adjustment assembly. Fairly straight forward when not typed!
This will then be welded to the rear arm in place of the mounting bush assembly. The trailing arms themselves will be braced something simmilar to the early DTM cars with a triangulating bar between the arms and bracing between the main body, hub and lower suspension pick up, simmilar to the pic below.

Not really bought much for this yet bar some L/H threadded M16 rodends and half nuts and some other bits and peices un-related, full set of bearings and bottom ball joints etc.

[Mark E30 328i]

Another little update. Been spending more money
Just won on ebay... Some Gaz adjustable inserts, going down the budget coil-over route with the rally design type coil-over conversion jobbies.

A turbo manifold from the states for the princely sum of £46 plus £10 postage

I know they're LH drive only however the plan is to use it upside down to get around that problem. Other issues involving cracking should hopefully sorted out by some decent bracing of the turbo (less strain on the manifold) and these ones also crack due to the the manifold flange being one peice, so will be chopped up to allow for a little differential movement.
Also bought some G60 discs which will require the bore enlarging to suit the BMW hubs. I've also found a drawing of the bracket required to allow the calipers to fit the E30 uprights and it's so simple to make, it's child's play lol.

[Mark E30 328i]

Just recieved the exhaust manifold, TBH it's quality is pretty good considering it only cost me £50 or so. The mating flange to the head is not perfectly flat, however i'll cut the flange into individual sections per primary and this should mean when torqued up they'll pull flat. It's only a question of .25-.5mm. The welds seem to be tidy and look to have made good penitration, however will need a lot of gringing with a dremil to smooth the way.
Also bought an ebay again lol FMIC for just over £60. The quality is supprising again. The only thing that really lets it down is the fact that the plate/bar design is a lot more open than a more expensive item, thus less cooling capacity. Stupidly bought it without taking any measurements and luckily fits perfectly between the front bumper mounting points
Only other little update, is that the rod end adjusters are now finished thanks to my mate Jon . Simply just an M24x45mm bolt with a L/H thread tapped through the centre. I'll try and get a pic when I've sorted a camera.
So next job is to make up the camber adjustment barrels. Going to be something a little different to the DTM but same basic principal.

[Mark E30 328i]

Little update Managed to get hold of my new front ARB (dirt cheap lol). Came from prodrive originally, off of one of their GT2 DB9's. Really happy with this as they are like hens teeth and the blades themselves are a couple of hundred each, if you can find them. Theyre going to be a little stiff but hey ho it's not the end of the world.
I'm also hoping to replicate something along the lines of the DTM version with cockpit adjustableness. Ultimate toy eh!


The likelyhood in finding another set is pretty slim, so I'm just going to use a traditional rear one to start with then get an Eibach rear when funds allow. Could anyone tell me what the largest rear ARB is and where to find one

[osborni]

Schroeder makes sway bar parts that might interest you. Replaceable torque tubes to fine tune roll resistance. Rear bars can be found on ebay for $25 or so. Not sure what shipping to the UK would be.

http://www.schroedersteering.com/SwayBarPage.html

HRP also has adjustable sway bar parts. (listed under "chassis components")

http://www.hrpworld.com/index.cfm?tp...ction=category

[Mark E30 328i]

Couple of quick pics of the in-situ adjusters

[Mark E30 328i]

Had a couple of days in the workshop, borrowing my uncles as it's pretty much got everything in it bar a mill, which would be really usefull!
First thing I made up these brackets which are to fit the RX7 calipers to the E30 uprights. Very simple, found the pattern off of the net. They need a couple of coats of paint to tart them up a little, but pretty much ready

Next thing I looked at were the adjustment barrels. Fairly simple in construction. Basically to a short length of 50mm box section and welded a plate on one end. The plate having a 1/2" hole in the centre for the threadded bar. Then I took a shorter section of 50mm Dia dowel bar and grinded 4 flats on each so that it could be located into the box section. At each end of the dowel bar I tapped M12 threadded holes then made up a bottom cap to enclose it all. This was made from 2 plates spot welded together one smaller than the other to locate it in the bottom of the box section.
That's pretty much it, I need to source a M24 tap and corresponding drill bit so tha I can fit the adjusters that are in a pic above.

[robjohnson]

Nice work. I have a similar project and VERY similar cage to your drawing. Let me know if you want some pics.

[1travel1]

Very hard to working time for this part .
If you want, please contact me .

[Mark E30 328i]

Nice work. I have a similar project and VERY similar cage to your drawing. Let me know if you want some pics.

Yes please more than welcome

Very hard to working time for this part .
If you want, please contact me .

Don't understand mate?

[Mark E30 328i]

Another little update. Been spending most of my time sorting out the house, but all other available time's been sent on stripping down the donor 325. Glad to say that, I've now finally finished stripping the donor and can start work on modding.
So spent a couple of hours removing the spring seats and fixing brackets and grinding back flush to fit a set of rally design coilover conversion tubes which I've purchased today.

So these will be welded on when they arrive and the new Gaz inserts err, inserted. Then I should be able to figure out what length springs I can order.
After that I'll look in to turning the bore of the brake disc centres out to clear the E30 hubs, then I can fit the new hubs/bearings, discs, mounting brackets and calipers. That'll be pretty much the front legs sorted.

[Mark E30 328i]

Little update again. No pics as the camera batteries were flat! Not much to see really. Spent a couple of hours yesterday stripping down the spring seats and welds off of the original damper bodies and welded the new coil over tubes on. Also modified the retaining collars as the flange on the top of the had rusted off, so they were cleaned up on the lathe and some m24 nuts were welded back on. Should make future removal easier. Going to tidy up and repaint with a little Hammerite smooth then get some pics up.

Next job on the struts is to remove the hubs and replace with new ones, the bolt on the caliper brackets, discs and RX7 calipers. Get some pics up soon.

Any know the size of the retaining nut for the hub/bearing assembly?

[Mark E30 328i]

Another update, been mostly spending time transfering parts over from my donor car. The track car came absoloutly bare.
Most importantly, I've now finished modifying the rear beam to accept the adjustable trailing arms. Basically I've pretty much replicated the DTM rear beam that allows control over the roll centre, this was done using some 2" dia tube running through the beam to retain the strength of the beam and to allow access to the head of the M16 retaining bolt. Then on top of that some 50x50 box section with plates welded to the top and bottom to hold the retaining bolt in location.


Effectively the assembly on the left hand side is what I have just fabricated.

Heres a pic of the inesrts that will run through the modified beam. Made up from some 50x50 boxsection with the front cut out of it two 3mm plates with M16 holes drilled through the centre and then a short section of 50mm dia tube to pass through the beam

Here's the rear beam with the outer subframe bracket removed and having been cleaned up. A lot of care and attention was taken to measure the spacing of the trailing arms and the previous location of them too. The above sleeves/barrels were then welded back into the stock place. Further adjustment can be made from there.

Here's the finnished beam. Just need to press out the bushes and turn up some nylon items to replace them.

Please excuse my untidy welding, great penetration but the tidyness is getting better lol

[jmitro]

nice work

[Fidhle007]

Subscribing for adjustable subframe reference.

[Fidhle007]

Two quick questions now that I finally read through: why not use aluminum subframe mounts instead of nylon and what is your plan for the inner trailing arm pivot?

[Mark E30 328i]

Two quick questions now that I finally read through: why not use aluminum subframe mounts instead of nylon and what is your plan for the inner trailing arm pivot?

Sorry for the late reply. IIRC the aly reacts with the body shell unless insulated. The inner piviot is just a OE rubber bushing. There's enough give in standard rubber ones. Got one side finished and it works really well.

I'll get some pics sorted once the rear subframe's finished

[Mark E30 328i]

Time for an update
Finished fabricating the rear subframe and trailing arm set-up, which seems to work a treat. Just need to turn up the subframe bushes out of some delrin which is going to happen soon.


Needs a little lick of paint just to tidy it up. I've built up the new LSD with the shafts and prop off of the 325i that I had broken earlier on. Need to turn up the subframe bushes and rebuild the rear braking system, then I can put the rear end set-up on the car.
I've now taken the M52 out of the 7 series and have also started looking at mounting the turbo. I have trial fitted the ebay manifold inverted and should just clear enough after making up an up pipe to convert the T3 flange to TD05. In the pics below you can see the flange clearence and roughly where I'd like the turbo to be mounted.


I have also started to fit the M20 flywheel. Struggling as its fouling on the engine. Have I got to grind a little off of the sump casting?
Lastly I have also started on the fabrication stage of the adjustable front lower arms and am modifying at the moment the front subframe to accept a clevis set-up. Not too much to see at the moment appart for a chopped up subframe.

[yyi]

very interesting fab work. subscribed.

[Mark E30 328i]

Did a little more pottering in the workshop last night. Made up some delrin engine mounts

And started to modify the front subframe to raise the roll centre and change over to a clevis set up to take a rose joint.
Chopped out the existing set up

Cut out to form a platform level with the chassis rails

And then welded in plate to re-inforce and for something to weld the clevis to


Thats all for now. Going to do a little more tomorrow night
Had a little more time in the workshop, and I have finished off the front subframe. This time doing the more fiddly bits of fabricating and welding the lower arm mounting points. Lots of measurements checking for allignment etc. all of which were off of the square edges of the subframe which are parralell with the chassis rails.
Firstly made up the clevis/mounting point, this was using some 50x50 box section, drilling holes through the diaganol centres and then cutting off the front face for access on the car.

This was then welded to the cut out sections after allignment and finally bracing was added to the back of the clevis, however not pictured here.

The last thing done was to knock up some rose joint spacers, not all the same length in the pic below as I'm yet to work out how short they need to be.


Also, just gotten back the bits and peices that I haven't been able to turn up, the delrin for the rear subframe bushes, G60 brake disks and the housings for the bottom ball joints
So hopefully I will be able to fit the rear subframe, get the front legs near complete and fabricate the lower arms.
Quick question, on the front lower arms i'm going to fabricate a turn buckle to adjust castor. This turnbuckle isn't going back to the stock location (where the lollypop bushes are mounted) due to ease of component fabrication. Now the question is, should I have the turnbuckle behind the lower arm (like a compression strut) or in front (my logic is that steel is more durable under tension rather than compression). Or will this mess up the geometry elsewhere?
Thanks

[Mark E30 328i]

Had a spare hour earlier on today, so have fitted the flywheel, clutch, box and starter off of the 325 12v.
Flywheel fitted and torqued up.

Friction plate centred. The lovely people of spec had sent a centring tool with their kit which was really useful.

Pressure plate fitted and torqued. BMW having lovely locating lugs on their flywheel made life easier.

Finally gearbox and starter motor. Problem I had with using the 325 M20 box is that the 4 smalle bolts don't line up with their corresponding holes if they had them at all. I guess this is fine as the 4 larger ones do the majority of the work?

[Mark E30 328i]

Doing well for project time at the mo! Did a little in the workshop last night, which was making up the rear subframe bushes out of delrin. TBH It's really good stuff to machine and even a complete tule like me can get a half decent finish. I was hoping to press the bushes in as they are, but the delrin really isn't as compressive as i'd first thought, so i'll have to get my man to run the mill down both sides to create a rebate for the little pressed lugs in the bush housing, or file them down lol.


Also started to look at fabricating the new lower arms, which involved pairing off some tube section in the lathe, and organising some solid bar for tapping to M16 for the rose joint. No pics of this though.

[Mark E30 328i]

Just spent most of a steady day at work, working and painting up the sub frames and trailing arms. My welding looks way better with a lick of paint. Also just spent half an hour in the work shop and have just done one of the most awkward bloody jobs on the car... Bolting the rear subframe and diff up. It's amaising how weak you are when your led on your back on the floor. Good news is that the delrin bushes are great and fit wonderfully. The bad, is that the roll centre adjustment part of the sub frame clashes with the floor of the car. No big deal, I'll just cut some access windows in the rear bench Also fitted up the front sub frame just to see what it looked like. No dramas there!
Pressed in delrin bushes

Built up sub frame and diff

Bolted in after half an hour of banging my head on sharp objects

Here you can see the subframe fouling on the chassis, the bush hasn't pulled all the way home

Just to the right of the hole is where I'll have to make an access window

And a quick pic of the front subframe mounted up

[SA E30]

I personally would have attached the front clevis to the angled part of the subframe much like the DTM cars, and like we did.





Really enjoying the fabrication work! Keep it up!

[Mark E30 328i]

Cheers mate. I'm enjoying doing it. I couldn't find any pics of the DTM cars from a decent angle. I knew that they lowered the roll centre, so made an educated guess from the pics I had seen. Where did you get your bottom ball joints from?