Twin Seq. Dry sumping for beginners :D

[Turbo-Brown]

I did lots and lots of shinying today! Love making things shiny!

The guy in our composites department reckons he should be able to make a start this week once he's got the tools!

[rix313]

Wowsers

[Turbo-Brown]

First trumpet was started today!

Spent some time recently having Covid and also getting round to a job I've put off for over two years: fitting an adjustable tool post to the lathe. Tedious but useful !

[Turbo-Brown]

Took a total punt on the front suspension leg from an E90 this week

The difficulty with converting to 5 stud appears to be that you either have to source super rare and expensive parts from an E30 M3, source nearly rare and still quite expensive parts from an E36 M3 that MUST be post 1996 or you're into sleeves to adapt the E30 spindles to accept E36 hubs.

Various people say the E36 route doesn't give great suspension geometry too.

I have looked at the sleeve route and even have a few sets made from about 10 years ago, but you end up with the hub hanging off the end of the spindle and it all looks a bit flimsy.

The difficulty in converting from one hub to another is that the spindles appear to be friction welded to the steering knuckle and are a funny diameter that doesn't match any off the shelf bearings, so you can't change the spindle and keep the knuckle, and there's little point making your own hub as you'd have to sleeve the bearings anyway.

Enter the E90!

The upright is aluminium and clamps the strut.

It's almost unthinkable that the geometry is a match for the E30, and the ball joints don't have a taper....and it's supposed to have two lower arms which react lateral and longitudinal forces respectively....but the struts are cheap!

Assuming the geometry isn't right, they have one great benefit: the spindle and hub now bolt onto the knuckle.

This means I can survey the E30 front struts, pivot points etc and make a new knuckle that gives perfect E30 geometry but accepts E90 hubs and struts.

Hooray!

[martauto]

Nice one mate, it takes an engineer to think "outside" and come up with a solution with what is to hand.
If this pans out (sorry , when!! ) would there be any chance you could document this as it would be a huge benefit for alot of guy`s ??
That tool post is the dogs mate !!

Cheers Mart.

[Turbo-Brown]

I'll post up the measurements I take for sure!

Tricky bit is measuring everything up since the geometry is all angles and axes!

Can't wait to start measuring and CADding!

[Turbo-Brown]

It comes as no surprise that the E90 and E30 bits are wildly different!

Having clamped something flattish across the hub faces , you can see the difference in offsets to all the mounting points.

On the plus side, the E90 setup weights substantially less than the E30! Makes sense, the E30 is a shock in a tube with a steel knuckle whereas the E90 does without the extra tube and has an aluminium upright.

Will start measuring tomorrow!

[rix313]

I love people that try this stuff! Very inspiring. While I don't have a picture to hand, it reminds me of something the Mercedes GT3 car has on the rear. The AMG GT race car uses the older SLS rear upright. What they did on the new 'GT' car, is alter all the lower wishbone mounts and geometry. They machine the base of the upright and it has a bolt on adaptor to accept the new wishbone mounting location. If that makes sense? I wonder if there's enough meat on the E90 hub to do something with a similar idea?

[Turbo-Brown]

That's a good shout that!

If I could bolt on using the four bolts that hold the hub to the upright it would save making a whole new upright!

Of course those bolts are M12x1.5 (instead of M12x1.75) and grade 12.9.

Zinc plated 12.9 bolts are fine when you're BMW, but for the rest of us, they can be dangerous!

If the manufacturers don't follow the right process, I've seen the heads fly off like bullets, caused by a phenomenon called hydrogen embrittlement.

[rix313]

If I could bolt on using the four bolts that hold the hub to the upright it would save making a whole new upright!

This what was going through my mind when I was looking at it. Some support bolts at the bottom too

[Turbo-Brown]

Guess the next sticking point would be whether the top mount is in the right place to give correct geometry.

[flybynite]

I think the problem is the same as the E36, in that the E30 strut is offset from the centreline of the hub whereas everything after (including the E90 by the looks of the photo) the strut lines up with the centre of the hub.

It is adding castor to the strut to centre the wheel in the arch that does a lot of the damage to the handling.

I think this needs its own thread?

[rix313]

Depends if you can use castor adjustable top mounts? You can use the eccentric lower bushes for a start. Depending what suspension you end up running, you can get castor adjustable top mounts. Might help get it back into spec. If you did make an adaptor for the base though, you can again factor all this in.

[flybynite]

Depends if you can use castor adjustable top mounts? You can use the eccentric lower bushes for a start. Depending what suspension you end up running, you can get castor adjustable top mounts. Might help get it back into spec. If you did make an adaptor for the base though, you can again factor all this in.

With the E36 M3 way you have to use everything, eccentric lower bushes and some top mount adjustment. If you use the top mount to straighten the strut you lose the centering of the wheel and run into clearance problems.

The problem is the line between the strut top and the hub centreline. The E30 got round it by offsetting the mount on the bottom.

Because the base of the strut is tied to the hub centreline on later hubs there has to be a compromise somewhere else.

The best solution I have seen is the BMP engine bed for the S50. It uses the twin pickup sump for the S50 to move the steering rack but for some reason they went to all the bother then set it to E36/46 spec which has the wrong Ackerman angle for the shorter E30 wheelbase.

[Turbo-Brown]

Created a new thread here:

viewtopic.php?f=2&t=281425&p=2978641#p2978641

Looks promising at first glance !

[martauto]

Created a new thread here:

viewtopic.php?f=2&t=281425&p=2978641#p2978641

Looks promising at first glance !

I have made this a sticky as this will work out just fine !!

Mart.

[Turbo-Brown]

These look siiiiick!

My friend has been busy doing carbon fibre things by the looks of it!

[rix313]

They are awesome dude

[Turbo-Brown]

Decided to take a break from machining suspension parts and experiment with the turbo actuators.

Have decided on pneumatics with digital control.

Like all good experiments, this one begins with a jury rigged pump running off the lathe, a solenoid valve, a couple of Arduinos, a position sensor and a "happy birthday, you're 4" balloon

Aim of the game is for the Arduinos to control the inflation of the balloon, which is like controlling boost.

[Turbo-Brown]

Few code tweaks and the control system seems to work pretty well for a first stab, have also modified the main wastegate to fail safe.

My control system relies on having positive pressure.

Plan is for that pressure to come from a pump and the turbos when on boost.

So in the case of the wastegate, a spring holds it wide open until the control system wants some boost and shuts the gate. If there's a system failure, killing the system defaults to negligible boost.

[Turbo-Brown]

Air filter enclosure almost complete.
Last layer of carbon on the lid and it's done.
Uses an E90 M3 air filter.

[Turbo-Brown]

[Speedtouch]

Very neat, and probably quite heat-resistant too.

[Turbo-Brown]

Hopefully it'll take the heat! Eek!

Having finished the filter housing, moved on to the Air Diverter Valve (ADV) assembly.
Have fabricated this, made it from glass fibre and carbon over the years, but don't think I ever fitted these attempts to the car.... space is TIGHT!

Got everything fitted to the car this time and have bought some aluminium elbows.

The design is now fabricated from elbows and an E36 328i throttle plus some machined adapters.

Bit more welding and need to fit the pneumatic cylinder to the throttle then this assembly is done!

[Turbo-Brown]

[Turbo-Brown]

Made an adapter for the air inlet to the little turbo and welded it on today, starting to look finished this bit of the puzzle!

Needs lots of tidying inside though!

[Turbo-Brown]

Modified the pneumatic cylinder which actuates the air valve this weekend, and made up the bracketry for it.

All getting a bit squashed over this side of the engine bay, not too many components to make now.

The air valve handles part of the transition from small to large turbo and is either fully open or fully closed.

When the control system sees the required boost and that the small turbo wastegate is wide open, the air valve should open.

Tricky part is knowing when to close it again!

[Turbo-Brown]

Woo, wastegate for the little turbo pretty much complete!

[Turbo-Brown]

Pleased with this, shut is full boost on small turbo, open is full boost in large turbo

In between regulates small turbo boost.

[Turbo-Brown]

Hooray! I made actual parts that fit other parts for the dry sump today!

This is the third design of dry sump pump drive.

One design was to stand the pump on end and drive it off the old pump mechanism.

One was to drive it by chain off the jack shaft.

Was considered my life and design choices when it struck me I might be able to squeeze the chain drive down the back of the front oil seal housing....and here we are!

[Turbo-Brown]

Make a sump, cut it up. And all day long, you'll have bits of sump everywhere.

Need to make a mini sump for the pump and fabricate the suction plumbing.

Also need a way to connect the suction and pressure feeds to the dry sump tank.

[Turbo-Brown]

Been slowly fabricating the feed pipes to the pump. The brass fittings are strainers.

The pressure feed is built into one of the brackets I machined a while ago.

Next up is to rebuild the sump around the pump.