POS13 - A Nostalgic RallyCross Project

Skipping out of this weekend's double header RallyX.  As work is getting busier, I figured my car-time was better spent in the garage this time around.

Step 1:  Polish your helmet... not a euphemism, it was filthy and a good indication of how much dirt is in the car during runs:

Next I pulled the rear suspension.  Apparently, the dust boots I jammed in there just kept the dust in, we'll have to see how long the shocks last.  I may post a learn me dust mitigation for suspension, because this doesn't work.

The lathe is down at my work's MakerSpace, so I looked to see if I could fit the longer 10" 225lb springs with the shorter spring perches.  It's a bit close to the bottom for comfort, but I think it'll work if I keep an eye on it.

Then I went back to the front suspension, I needed to mock up the front shocks, and start to get some notional travel measurements to plug into the spreadsheet to figure out spring rate and length that'll work with my car.   The first thing was to figure out how to mount just the free shock onto the hub.  I did the S-Chassis thing, and grabbed a handful of zipties... then spent the next few moments respecting the job a McPherson strut has to do!  even with the hub tied to the strut, it still wanted to rotate in caster quite a bit.

I rigged up the same system as I did with the back , put a long bolt in the brake disc, rig up a ruler next to it, and run the shock through it's travel. 

So we're looking at around 7.5" of travel, which is a tad more than the off the shelf options.  I threw a tape on there to figure out what length of spring I can jam in there at droop.  I also checked the rest of the suspension at that full deflection, and it's almost prefect.  There's no binding, and lower control arm is just about parallel, meaning I've got camber gain through the whole sweep, and no weird bumpsteer characteristics. 

I want to make sure to keep some distance for the shock ears, and that offset was looking like 25mm or so it's looking like after the math something in the range of a 250lb in 12 or 14" length might be ideal. 

One last check while I've got it all mocked up:  I wanted to make sure the camber wasn't stupid at ride height, here's it at 1/3rd compression and full compression:

 So 1* static, and 4* at full compression sounds about perfect!

The last piece of the puzzle is how to make the ears.  The new strut tubes measure out at a diameter 52mm.  The drifty coilovers measure down at 47mm, but these S14 KYB's are really close.

They're only welded on the bottom , so it should be easy to grind that weld off, slide the ears off the tube.   Then put a small relief cut on the back, and fit them over the new strut tube, hit everything with hammers and a lot, apply terrible welding, and I might have myself a real front suspension!

Did you leave the bumpstop in there when you measured?  If you bought the "long" inserts they should give you 8.5" of travel, I just measured one to double check.

I'd skip the dust boots entirely and just try to keep those shocks clean- at least then you can see whether there's junk packed in there.

In reply to ¯\_(ツ)_/¯ :

Yes, that's with the bump stop installed.  Things started getting sketchy on my measuring setup when I started compressing the bump stop, and the hub kept trying to flop over in caster, so it was tricky to get that last bit of compression.  I put a little zip tie marker on the shock to be a tell tale if it kicked the jack out, and it seems like there's an inch left of travel.

From the spreadsheet that got me 270lb/in at 7.5" of travel And 250lb/in at 8.5"  and from what I leaned on the rear is those are a tad high.  So last night I ordered a 250lb/in 12" length spring and a 225lb/in 14" length spring from the UK.

They seem to have the market cornered on 2.25" stuff, but most of them don't list the travel or binding point of the spring, so we'll have to see if I can get full travel out of those.

I'm not certain on the 12" spring, but can say that on my car the Gartrac 14" long 2.25"ID spring has no binding issues whatsoever, even with a bit of preload on it.

Very little progress on the car over the past month. 

I got tied in a life and death battle against rust on the LandOozer.  There was a rather massive powersteering leak, that I sort of located at the powersteering gearbox.  The least car-fund killing source of fixing it was a $50 rebuild kit from RockAuto, so I proceeded to pull the box.

It looked like an artifact brought back from the Titanic:

I surprisingly got 80% of it taken apart, but the potential source of the leak was the input shaft, which was held on by a spanner 'bolt' secured by a lock nut.  During the three day weekend of July 4th, I put gallons of PB Blaster, alternated with fire, hammers and, cursing into it.  With the only result as finally breaking the lock ring loose.

So I gave up on it.  After so much heat, I'd fused something internal, and the threads were so corroded, I couldn't even tell where the male threads met the female ones...

I discovered the downside of JonathanWardisms: steering boxes are almost non-existent, and the used ones are upwards of $400.  I stumbled across one locally that was for sale, and a good 'deal'  Now it's the best part of the whole truck!

After battling that for a while: Anyone want to buy a collection of rust and oil leaks in the shape of an old Toyota Landcruiser?

Made some small progress on the 240: 

19 year old me is super stoked about buying this!

39 year old me is much more impressed with buying this tiny grommet that keeps the hood prop from falling and whacking me in the head!

This new hot air intake might restore some missing torque, but mostly the idea is that the far side has less stuff in it, so I can build a box around it, and a larger air filter element.  When I came back for Panthera the last time, the air filter was so clogged with dust that the car was down on power by the time I got home.  It took two cleanings to get the AEM airflow to actually breathe again, and worse than that, there's dirt getting past the filter:

So I need to look at a pre-filter and trying to create an airbox (or maybe just fish out the OEM stuff), because I'm sure my rings aren't too happy with moondust.

The other part I need to fix are these intercooler holes cut with a can opener.  As an added bonus, I can finally relocate the coolant overflow to it's right place, and I'm using this as an excuse to un-relocate the battery from the hatch to back up here.  Work has brainwashed me into the benefits of Li-Ion, so I bought a 5lb replacement to just stick in this location.  Just need to weld some real metal back in to mount it to.

I am impressed that your coolant recovery tank doesn’t look like this!!

In reply to madmrak351 :

GKtech makes a new one!

https://us.gktech.com/s13-240sx-replacement-overflow-coolant-tank
 

Worth every penny, back in the day I used to harvest every one that'd hold water out of Pick N Pulls, and they'd still fail eventually.

In reply to rallyxPOS13 :

Thanks for that info. I will order one  that’s a great product.

Suspension success today!

I've been hesitant to tackle the front suspension, as I knew it'd make the car immobile for a few days, and didn't want to jack the wife's garage spot.   She's on a business trip, so perfect opportunity!   I pulled the old shocks to harvest the ears for use on the new coilovers.  The ears were attached to a circumferential clip that went all the way around the shock body, and it was only a couple mm shy of the diameter of the new tubes. They were simply welded along the seam on the bottom of the shock, easy enough to grind off, right?

I figured the dremel cutoff wheel is the perfect tool for this!  I was wrong.

The disc was just wide enough that it'd blow out the radius when I got close to the depth of the weld, that also put just enough bending load on the disc that it'd break.  I'd grabbed a couple 12 packs, and had motored through both of them, and I was still nowhere near the bottom of the weld.  Then it got medieval, and the hammer and chisel came out, thinking I could break what was left of the weld...  Still no good progress, so I cut the end off of the bottom of the shock suspecting there were spot welds somewhere I had missed.  You can seat the heat affected zone of the weld here:

You can see the bottom edge is below the reach of the cuts.  So I went back to lowes, charged an unreasonable amount of money for more cutoff wheels, and then came in through the bottom the cut just 'above' the welds from the inside of the tube.   Then I was able to drive the the ears downward off the tube

Then all that was left was to remove the small strip at the weld itself...  which was still super stubborn.  I burned through a couple grinding discs, and obliterated a pack of sanding drums.  It seems that every piece made by dremel has a thermal 'fuse' function, and when working on steel, its set to ablate the bit at ~20% of the way through whatever you're trying to cut.  I REALLY need to get an air compressor set back up!

So again, big hammers and chisels came out, I relieved the strut with a longitudinal cut, and just wailed on the edge of that cut with the chisel and hammer:

Then I cleaned up the area so it'd slide without gouging. 

And just before the dogs started eating the furniture, I was able to test fit the ears onto the tube:

So in the end, 100% not worth trying to salvage those ears.  I should have just measured and made new ears.  It would have been significantly cheaper, and way less effort.   But I'm a stubborn bastard, so I'll try the other side tomorrow, and then weld them up later in the week.  To save on dremel consumables, I'll just start with sawzalling off the end of the strut, then go in and cut off the weld from the inside. 

I wonder if a plasma cutter would have made things easier. 

In reply to irish44j (Forum Supporter) :

It's funny, my wife and I have a long running marital joke that whenever a big holiday is coming up for either of us, the answer for "Do you want anything for ____?" is "Plasma Cutter"   I currently don't have an air compressor, so it wouldn't work anyway.  It's been a while since I've used one, but I think it'd be hard to control whether it'd blow out the weld or the side of the tube.

I thought about what the right tool would be on my 3rd trip to Lowes...   The air tools I used to have: the 4" cutoff wheel wouldn't fit any better cutting the weld from the top, and it's too big to fit inside.  So I think I'd sawzall or chop saw the tube off, and use a die grinder on the inside to get the weld flush with the inside of the tube.   

Now, if I was smart I'd take it into work's makerspace and chuck it in the lathe and try to cut it from the inside.   However, I'm not sure the tool post would clear the spinning ears.  I need to use the thing more to get comfortable with it.  It was just recently fixed from a gearbox leak, so I'll start with machining the perch on the rears.

I worked too late today to make progress on the other side, but I did a quick fitup of the ears to the strut to make sure nothing was too far off from my initial measurements. 

Initially, I was worried, the added diameter slightly pinched the ears together, and it wasn't fitting over the hub, even with a bit of persuasion. 

So I was able to fit them up to the hub first, and then work the strut in from the top:

I realized that I'd not accounted for the offset from the strut when I did my preliminary camber measurements, so I fitted up the camber gauge to the hub face to do a quick check.

At full droop it's +5, at assumed ride height it's +1 degree, and on the bumpstops it's -1.   The good news is there's camber gain through the whole sweep, the bad news is that static camber isn't great.  I may look at extending the lower control arm to compensate, but we'll see how it actually sits.

The 14" spring fits with no preload at full droop, so that's good!

I set the ears as far up as I think I can get away with, about 0.5" from the spring perch for the 14"m spring with no preload at full droop.  I'm assuming I can just zap these to the threaded portion of the housing with no consequences?  The bottom clears the balljoint through the full motion.

I plan on welding the top and bottom all the way around, then up this seam, and a few tacks on the surface inside the ears.

You'll want to wire wheel all the coating off where you're going to weld but I don't see a problem with welding to the threaded portion.

Can you get your camber adjustment at the knuckle?  I don't know what the clearance looks like there for an eccentric or a slot but as long as you can get it into the negatives at ride height it should be ok.

In reply to ¯\_(ツ)_/¯ :

The OEM had an eccentric up top, but I'm worried that it'd slip in a bumpy RallyX environment.  Besides it was long gone when I got the car because the top hat was adjustable.

The good thing about owning a car subject to drift tax is that there are tons of options to set up more camber/angle to support drifting. 

Cheaper than eccentric bolts are just some weld-in extensions for the lower control arm: https://villainsdrift.bigcartel.com/product/lca-extensions

There's a myriad of option that extend the tie rid to match the longer LCA.

Speaking of welding, went to stick together my struts today.....  and I'm  out of gas   No places are open on the weekend, so to be continued next week!  Same Matt time, same Matt channel.

Oh! And if it's not obvious to folks reading this thread, I'm way over my head with this suspension.  Thanks to ¯\_(ツ)_/¯  Irish44j and others who have blazed this path before, I feel confident enough to tackle creating rally suspension from scratch....

However today I had a thought of stupidity that landed in a question to these others:  Do I need to grease the inside of the inverted strut?   It wasn't sliding freely the last time I did a travel check, and a bronze bushing doesn't seem like the only thing that should be adding lubricity! 
 

If so, is there something special I should get for that application, or will normal synthetic axle grease suffice?

In reply to rallyxPOS13 :

In theory DU bushings don't want grease, in theory it actually wears them faster- in practice, I have done both red Mobil grease and dry and it seems like I manage to kill the struts some other way before I wear things out.  They shouldn't be binding just from sitting though, that's a bit disconcerting- check that you didn't turn the wiper seal inside out, that can add some resistance. 

So with a replacement tank of welding gas, I was able to burn some metal together.  My father is a Metallurgist, and I understand the process...   but, it still feels like a superpower to take two pieces of metal, and just melt them together!

Before I got to that, something needed to be done about these balljoints.  I believe the brits call this knackered 

While I was changing those, a package came.... but ain't nobody got time for that!

So weldin!  I practiced a bit on the old shocks to get the settings right.  When I got it to work right, it was at the edge of my abilities as a welder, if I was able to 'push' it in there, it got great penetration, and looked like it should, if I slowed my hand or got too far away, it's put a bead on the outside.

Here's the end result!

A quick bit of grinding to knock down the sharp edges, and a lick of tractor paint to match the rears, and here we are with the housings!

I literally laughed out loud when I got these put together.  The 14" springs make this look so wrong:

Thanks all for the tips on assembly!

The (just) fit on the car:

A quick test drive around the block proved a few things:

• Night and Day over bumps, the front of the car has come back alive and can soak up anything the tarmac and potholes can throw at it.
• I completely forgot that the top nuts were 'grind to match, and there was around 10mm of 'gap' causing the front to clunk everywhere
• No front swaybar is a crazy-weird feeling.  I'll give it shot, but I'm not certain it's better yet.
• My sciencebrain was so preoccupied with whether or not it could get all the travel, it didn't stop to think if it should....  My car now has a very distinct Carolina Squat.

To take up the gap in the top nut, I went ahead and got some more overnight parts from.... Wales:

These washers allow a bit of angular tolerance on either end of the spherical bearing, and keep things from binding through the range of travel.

I also fitted the 12" springs I purchased to try and lowered the front very slightly.

There's a rallycross coming up this weekend, a rain delay from last weekend, I may sign up and give it a try in the dirt!

Nice!  The Carolina Squat problem, and wherever full bump ends up, is why the other end of this solution sometimes involves raised strut towers- what you've got should work OK though as long as the bump and droop from ride height can be made reasonable, might just need 12" springs and helpers instead to achieve that.

Good progress!! Looking forward to hearing how it works for you at the upcoming event.

So remember how we, all respectable car enthusiasts bemoan those trucks with Carolina Squat:  "they can't see"  "the headlights are aimed at the sky" "dangerous on the road"

.....ummm yeah, all true:

I somehow forgot the start of my trip is at 0dark:30, and completely didn't adjust the singular headlight (the other's actuating rod literally fell off in the road somewhere).    So instead of pointed horizontally down the road, it was like 15deg up, and a good karmic kick in the nuts, it was super foggy on the drive out on my rural twisty roads.   Dawn couldn't come fast enough, and I was glad there was no oncoming traffic!

I got to the site and unpacked, here's how bad the stance looks in daylight:

It seems like I skip enough events that I always run the same configuration out at Panthera, but today it'd be a great comparison to the last event I was out there with my fancy new front shocks, I'd also disconnected the front swaybar to get more front end compliance.

The only other update to the car is the intake, and I sealed the giant hole between the tire and airfilter to keep it from getting clogged with speed-tape.

After my first run:  GREAT SUCCESS!!!!   It was literally a transformation compared to the last time.  I was able to place the front of the car wherever I wanted to, the car rotated on turn in, and I didn't have any severe bumps that jostled me and broke my concentration.

I'd trade the headlight pointed directly at my face for this!

There's a long sweeping decreasing radius RH corner in the middle of the course, it's got some bumps throughout the corner, and a cliff o' death off to the left, previously I was never able to drive it well, with the car porpoising around.  This time I nailed the turn a few times with a glorious slide on the power going in, and a nice pirouette under brakes as I came to the tight apex.

The only downside, is that there were a couple tricky chicanes, and I was struggling to drive them well.  One was super tight, like the Miata-guy-designs-the-autocross-chicago-box tight, but the other one was very fluffy with moondust, and I struggled to put the car right, and either hit the outside cone, or slowed to a 1st gear crawl.  I may re-connect the sway bar next time to see if it feels better for those transitions.

The spring rates felt good, and I put a zip-tie tell tale on the shock to see if I was using the full travel.  On the parade lap, it was ~3.5" from the top, so just getting at the bumpstop, and after the runs, ~1" from the top, which was at full bumpstop squish.

There were some clunking noises by the end of my first run, and I found the nuts on the top of the struts had worked loose with steering, so I tightened those up again, and during the afternoon runs, had to tighten them a couple times again.  I'll need to think about that a bit more.

Speaking of suspension noises, there was a creaking/groaning coming from the rear, even on the drive in.  It was so bad I jacked up the car, and checked out the diff...   apparently it's the spring grinding on the sleeve.  Not the end of the world, they're only $20, but the greater issue is that it means there's some bending or unconcentricity going on back there I need to investigate:

The intake seems a success, I think I can do better job of putting a box around the element, and sealing that, but it made it through the runs and home when it was super dusty.

Overall it was a good event, I got to work a corner with BlueJ, and it was a good way chat the time away working the course.  There were a couple neat cars there, gridded next to me was an AE86 rallycar (with BlueJ's car in the background)

After noticing a few details like the Volvo axles, etc, I realized this was Adam Crane's "Patches" a previously green car that I remember reading about on the old RallyAnarchy forum.

There was also a 323 GTX out there!  Great to see one of those that hadn't succumbed to rust:

On another note, my times were only 7-10% off of the leaders, and I wound up not DFL for the first time at a DC event!

I celebrated another hot, dusty day with a nice cold Sheetz-shake on the way home:

Matt, it was great getting to hang out more on Sunday. I'm glad you've joined our class of Missfit Rwd'ers! 

I'm glad it handles better, even if it does sit funny!  Allow me to cast my vote now for "lift the rear to match"

I would check that those strut top nuts are fully seating- mine rarely come loose so there is probably something that either needs a spacer, or has too much spacer, somewhere in your top mount assembly there.

That chicane was tough for everybody. When Adam said there was a tight chicane everybody looked at me because I usually love chicanes but I certainly did not love this one lol.

In reply to bluej (Forum Supporter) :

Yeah, it was great to hang out!   Now I just need to get out there more often and drive better!

In reply to ¯\_(ツ)_/¯ :

I'll have to pull stuff apart and inspect to see what's going on.

I'm kinda torn on lift the back vs drop the front. 

I've been going back to RallyAnarchy and reading Martin's old 240SX suspension adventures with JVL, and he had raised the rear shock towers similar to yours, and had some crazy setup on 40mm bilsteins with a 14" long 175lb spring and a short 6" 300lb spring to give a pseudo bumpstop, or progressive rate or something.  Interestingly enough, he wasn't able to raise the front shock towers as much.  I don't think we've got the hood clearance in an S13.

The good thing about buying into a driftcar is that there's basically a choose your own adventure book on suspension geometry, and I'm tempted to throw something like GKtech's front spindles at the car, it'll drop the fronts a couple inches and keep the same travel.  It also has added benefits like better steering angle and faster steering rate.  Just need to confirm it wouldn't restrict me from using smaller wheels.

https://us.gktech.com/240sx-front-drop-knuckles