AW11 MR2 Rallycross build

In reply to wheelsmithy (Joe-with-an-L) (Forum Supporter) :

In reply to Professor_Brap (Forum Supporter) :

I'm glad you all are enjoying the journey.  I wish I knew better where it was leading.  I am also surprised that the skid plate works as well as it does, but I'm not about to complain about it.  

I've realized that I sorta left things hanging with the last post, offering up no pictures of a bumper (straight or not) on a truck, and no pictures (as seems to be the habit) of finished home improvement projects completely unrelated to motorsports.  The flower bed was generally a success, I mean, it's got flowers in it and the wife likes it.  It distracted her enough that when I mentioned I was going to purchase more springs for the MR2, she didn't complain.  The final bed is about 11'x3' (not counting the border), and has about 8-12" of pretty useable soil in it.  Cutting the beams involved using power tools very early in the morning, which I'm sure the neighbors enjoyed.  But, those are the neighbors with the dirt bikes, so I don't feel too guilty.  

As for  the truck, bumper attached again, and it is indeed straight again (well, for the first time for me).  It's also a lot more solid and bumper like now, like if I were to bump into something with this it might move it out of the way a little before crumping.  The cuts in the lower portion of the plastic cover are still there, annoying me.  Not sure what I'll do about those, probably suffer their existence for now.  

I have a collection of truck bits that need installing, wire for the brake controller, paint for the frame, and a new parking brake cable (so, yeah nothing exciting).  But, I also have the MR2 in the garage, and a stack of new brake parts for it.  I suspect that I'll procrastinate the dirty painting the frame job until after I finish mucking with the fun car, that sounds like me anyway.  

man, I did not enjoy painting (and patching) the Sequoia's frame......good luck and definitely wear clothes you don't care about AND a full-face mask if you can. Nothing sucks more than some black frame paint drip on your cheek ;)

Another weekend, another bit of rather boring scheduled maintenance.  As I mentioned earlier, there's something up with my drivers front brake caliper, it's locking up way sooner than it should.  I'm also still having trouble getting the brake bias as far rear as I want it to be.  The plan is to fix all that this weekend.

The GRM way to fix the front caliper is probably to rebuild it, after all, it's pretty hard to destroy a giant chunk of cast steel.  And that was my plan too, but reman calipers were cheap enough to change my mind.  Since I'm doing the drivers front, I also got a passenger caliper assuming that one is thinking about acting up any moment now.  As it turns out, this was probably a good plan because whoever changed the brake pads on this car last was an a dolt, and this time that wasn't me.  

In this photo of the caliper I pulled off the car, if you look closely you might notice that the pad spring thingies are missing.   You'd be able to see them at the top of the caliper if they were installed.  Also missing were the pad wear things, but no big loss there.  If you look a little less hard, you might notice that this caliper is still fully assembled, I haven't removed the caliper from the frame.  There's a good reason for that, the caliper guide pins (both of them) are stuck but good.  Probably the same dolt that didn't install the springs also didn't bother putting any grease on those bolts, and they happily rusted into the rest of the caliper body.  Both front calipers were like this.  Luckily I got reman calipers with brackets.  I mean, I can probably get those off, but since I don't need to I'm not gonna bother.

The next minor issue I ran into was with the reman calipers; the bolts for the caliper guide pins were a little too long.  In the photo above, in the circled bit, you can see the threads sticking out of the bracket, perilously close to the rotor.  I fixed this by adding a few washers to the bolt.  acutally, the calipers actually came with some lock washers which didn't have another use and were the correct size.  Those still weren't quite long enough, so I raided my box full of washers for a one more each.  My other big annoyance with the reman calipers also relates to the guide pins, one of the bolts has a 12 mm head (like the stock one), and the other bolt has a 13 mm head (grrr).  Toyota doesn't use 13mm heads anywhere, meaning sometime in the distant enough future that I forget about this, I'm going to look at that bolt and guess it's either a 12 or 14, and possibly round it off.  

That brings us to pads.  In the front (which is what we're looking at here), I got I got only the best Raybestos brand crap I could find.  The idea here is that I don't really want a lot of bite in the front since I'm trying to shift more brake bias rearward.  The pads came with all new clips for the calipers, but of course those clips didn't actually fit.  Sure sign of amazing quality right there.  Because I'm changing pad compounds, and because why not, I also got new rotors.  

All in all, the fronts went on pretty quick.  The rears though, they weren't so agreeable.  To begin with, there's a lot less space back around the rear caliper because there's an axle and a hand brake cable crowding things up.  That meant that it wasn't possible to get any of the power tools on any of the bolts to break them loose.  I also had quite the time getting the bolts back on the caliper bracket after I took it off (to replace the rotor).  But, the real fun started when I tried to install the new pads.  

Between the new pads being not worn and thicker, and the rotor being not worn and thicker, there was just no way to get the damn caliper over the pads.  To do it, I needed to push the piston back around 1-2 mm, but when I tried to do that in the normal way (which is probably not the Toyota approved method), the piston was bottomed out.  I even tried opening the bleed valve to release some pressure on the brakes and push it in a bit more, but that didn't work.  It was about this time I said berk it, and went inside for a bit. 

Eventually I bothered to check the Toyota service manual, and they say you have to rotate the piston clockwise to push it in, because of course you do.  I'm actually not sure if that's a normal thing, only that it wasn't required the last car I changed the brake pads on.  After rotating the piston, everything went together pretty quickly. 

Above you can see the new pads installed.  Those are EBC yellows, which will probably dust up a storm and will likely destroy the rotors.  Importantly though, they're super grippy and don't require much heat in them to work.  I don't really care about the brake dust, the wheels get a nice thick protective covering of dirt on them in short order.  Anyway, it's not like they were expensive.  

So with that last bit of knowledge gained, I went off to start on the last wheel of my brake job.  Of course, that's the oportune time for this to happen

It should come as no surprise that that is the bolt for the caliper guide pin, because remember that dolt who didn't grease the fronts...  Apparently he also didn't grease the rears.  It sheared off pretty deep inside the guide pin, which means that there's not an easy way to grab hold of it.  Also, since it's still rust-welded to the bracket, there's no way to take apart the caliper, and I'm not sure I can remove the guide pin either.  In short, it's good and buggered.  

Since I don't really want to be thinking about the buggered up brakes, I found some other projects that needed doing.  First on the list was a long overdue shop upgrade.  The garage in insulated, but doesn't have anything in the way of heating or cooling.  Just an attic overhead eating into my ceiling space, and generally making the place unbearibly hot in the summer.  So I finally broke down and went to the big box store and picked up this

It's woefully undersized for the garage.  That said, something is better than nothing, and it lives right next to the work bench, making the most important section of garage pretty reasonable.  Initial tests seem to point towards it working better than I expected actually, I'm pretty excited to have the garage temperatures in the high 70's rather than the 90's.  I also don't have a lot in the way of outlets in the garage, so I routed the power through the attic as well.  It uses the same outlet as the lathe. 

Speaking of the lathe, I also started a small lathe project to make sure I was good an distracted from working on the brakes.  I need to make a set of couplers to couple the tender and full springs together.  The plan is for the tender to go on the bottom of the struts in the front, which means that the coupler will be sharing space with the threaded coil over collars.  Given the tolerances that I have to work with, this pretty much guarantees that the coupler will rub on the threaded sleeve.  If I make them out of aluminum (I already did that), this is going to destroy the threads pretty quickly since they're also aluminum.  Instead I'm making them out of UHMW.  This is a form of polyethylene which has a very low coefficient of friction, so it should be good for sliding over threads.  The UHMW doesn't absorb water (good), and is reasonably grease/crap resistant (also good), but I might end up with some compression issues.  I guess we'll find out.  

Oh, and also it doesn't machine nearly as nice as acetal (Delrin).  It'll produce long chips like acetal, but the surface layer will ride up over the cutting tool.  Kinda like you're skinning an animal (a cylindrical white animal).  The skin makes getting the chips out of the way particularly difficult.  Ideally I would have made this part in PTFE and avoided all of these issues; if you price out a 3.5" cylinder of PTFE you'll see why I didn't.

That there is me hogging out the general shape for two couplers.  Both steps of the OD there are final size, and I was roughing out the ID.  I only have drills up to 1" in size (seriously, a 1" drill is a monster).  To get a bit more before switching over to a boring bar, I chucked up a hole saw in the lathe, and surprisingly it worked.  The chips it made were essentially dust, but there's a 2" ID hole in there now.  There's a bit more work to do on this before they're ready, but I should have the new springs on before the weekend.  

On the brakes front, I decided to just throw some cash at the problem and ordered a pair of reman rear calipers.  I figure that having two full sets of calipers for the car isn't such a bad thing, so I'll keep the cores and get the rebuilt when I'm bored and have some time on my hands (probably never).  The reman rears came in today, so I went out to see if I couldn't get the problem brake dealt with.  As I was getting all the clippy bits assembled on the new caliper though, a problem jumped out at me

Notice how the rubber boot on the left caliper guide pin is floppy and loose?  Yeah, that's because I'm pretty sure it's not the right boot, or maybe not the right caliper.  The metal ring is supposed to fit into a recess on the caliper, and this one, well it's just too darn big.  So, I guess I'm returning this one.  

In other news, there's an event up in Harrisburg this weekend.  Up until just now, I was pretty confident that I'd have all the car work done in plenty of time to attend.  I'm somewhat less confident now.

Back to the lathe project, the couplers are going to turn themselves after all.  To finish these up, I really needed a longer reach boring tool than I had, which was just some crudely ground 1/4" tool blank.  So, I finally got around to ordering a set of el-cheepo ones to finish off the project.  Turns out boring it a lot easier with the proper tool, in case anyone thought otherwise.  

Net result was that I got the first one finished, and stacked things up to see how they'd go together. 

The new stack is on the far left.  That's an 8" 200 lb/in spring, with a 150 lb/in tender spring stacked on top.  The old tender spring is on the far right, you can see that it's much longer.  Length-wise, I think I could actually use the red tender springs with the 8" primary spring, there's enough adjustment on the coilover for that.  The problem is that those springs come from logical units land, and I live in freedum units land.  I'm pretty sure the red ones are 60mm ID, which is not quite the same as 2.5" ID like the rest of the set up is meant to work with.  It's different enough that they don't fit over the lower or upper spring perches quite, and clearance over the threaded collar is also tight (but they fit).  

I was going to trim the ID a bit with a drum sander, actually I already did one.  Then looking at it, I gazed on the exposed steel and thought about how well that does in this part of the country.  Shortly after I bought a pair from a slightly more reputable company.  

The new tenders are actually short enough that I can probably maybe get away with using the 10" springs with them.  You can see those for comparison in the photo above.  My actual plan, at least to start, is to leave the coil over perches exactly where they are now and shove the 8"+tender stack on them.  That'll mean a pretty significant amount of preload, which should be good for bumpy stuff.  Then I went off to make another coupler.  That didn't go so great, here's attempt #2 of making a second coupler.

What happened here is that I cut just a hair too deep when trying to make the second ledge.  The good news is that the plastic flexed out of the way for me, so I didn't cut all the way through.  But, it's also pretty obvious that the strength was compromised a bit; that ledge isn't supposed to fold over like that.  This morning I made attempt #3, and actually got it right this time, so I got to assembling the struts

One strut with tender spring, and the other without, and proof of the existence of a second coupler out front.  To get these on, I also a while back picked up a somewhat fancier spring compressor.  The one I had compressed springs ok, but the hooks to go over the coils were too large for me to use them on the coil overs.  The new ones have a different style of hook, and work quite well.  

So, do I have the spring perches in the right place?  I'm not sure, probably not, and I'll find out soon.  I have a 150lb spring in series with a 200 lb spring, with the springs in series their combined rate is 86 lb/in.  The tender spring has 1.75" of travel, with the tender spring at maximum compression the primary spring will also be compressed 1.3".  So, the total travel of the series spring is around 3 inches, with a total force of about about 263 lbs.  Based on the approximate weight of the car, there's another 200 lb or so per corner in the front (I should measure this someday), meaning there will be an additional 1" of compression of the 200 lb/in primary spring.  So, 4" of compression total, and I have around 1-1.5" of preload (I didn't measure it, maybe I should have), meaning the strut is going to compress 2.5-3".  That should put static ride height kinda close to the middle of the strut (shock has 165mm of travel).

I have generally put tender spring on top, but not really sure it matters as long as your coupler piece has clearance over the threaded body and won't contact it.

I was originally planning on putting them on top as well, if I were using 0-rate helper springs that's what I'd do.  Those compact down a lot smaller, and so won't overlap the threaded strut body at full compression.  These are longer (when fully compressed), so they will which means the coupler needs to be able to slide over the threaded body.  I actually made a set of these in aluminum for this purpose, but once I started looking at the tolerances it became clear that any amount of mis-alignment of the spring would mean the coupler would crash into the threaded body at full compression.  

I switched to slippery plastic couplers which are always over the threads for this reason.  The tolerances are very tight, so whatever the coupler is made of is guaranteed to rub on the threads.  So, what every it's made of better be low friction, and a lot softer than aluminum, but somehow still robust enough to not fall to pieces.  I'm not actually sure my solution to this is going to work, hopefully it does.

Nesegleh (and Chris) had a similar problem with the Rally Volvo, and came up with a different solution involving extended the spring perches, and the helper springs still on the bottom but not needing a coupler.  

Spring compressors?  For coilovers?  Why? Half the point is that you can just spin the perch down when you need to change springs- I understand the concern about losing your adjustments, but taking a measurement fixes that easily.

Interested to hear how the dual rate setup treats you, seems like it might do some weird stuff when the smaller spring bottoms out.

In reply to lxnm :

Even if a small A/C unit can't entirely cool a garage, it can at least pull some of the humidity out.  That used to help a little in my ex's garage.  What helped the most in her garage was replacing the west-facing wooden garage doors with insulated doors. With an afternoon sun beating on them, the wood doors would basically turn into giant radiators of heat.  Replacing them with bonded insulated doors made a huge difference. We also noticed improvements when we insulated the walls. Again, the west walls that get the brunt of the afternoon sun made the most difference. 

In reply to ¯\_(ツ)_/¯ :

The spring compressor are being used because I'm running rather a lot of pre-load, both front and back.  To get the ride height reasonable in the rear with the 125 lb/in springs there's about 1" of preload, and getting that by just turning the perch is possible but not easy.  If the perch design were different (aka normal) I'd be able to put a wrench on it and it wouldn't be that big of a deal.  The story is the same in the front, except that it's easier to turn the perch (the series spring rate is softer than the rear). 

If my calculations are correct (a big if), the weight of the car should bottom out the smaller spring, meaning the strut should act like it's just got a single rate during normal driving situations.  "Normal" probably doesn't apply to dirt though, and it won't take that big of a bump to unload the front enough to start extending that small spring.  Then funny stuff might happen when it bottoms out again, which could be interesting.  

I put the wheels on to see how the ride height is, since the fronts are just vaguely guesstimated based on some very questionable eyeballing.  Surprisingly, they look ok.  Here's the front

And here's the back (I can't get both ends in a photo while the car is in the garage)

I did some quick measurements just to check: fronts are 642 mm (left) and 634 mm (right), and the rears are 627 mm (left) and 621 mm (right).  So drivers side is a little higher when there's no driver in the car, and the front is still a little bit higher than the rear.  Of course, I didn't take a measurement before I changed things, so those numbers are pretty meaningless.  

On the springs conversation, I figured I should check and see if they were acting like I thought they would (even if they act like I planned, it doesn't mean that I planned them out very well).  Anyway, I took some photos, first at static right height

The tender spring is indeed completely compressed, as expected.  Now that I'm looking at the photo, there also doesn't seem to be all that much room before you hit the bump stops.  You can also see the stupid design of the spring seats which makes it hard to get a wrench on them while the coil overs are on the car.  And then another photo at full droop.  

That ruler is sitting on the edge of the spring seat, and is mostly parallel to the springs.  Up on the shock shaft, there's also a zip tie that marks the static compression point.  We can use these photos to do a better job of the crude estimations I made above, even though I'm not sure how much value they offer...

The tender spring uncompressed is 2.64", at full droop with preload it is 1.75" long, so it's compressed 0.89".  That means that the 200 lb spring must be compressed 0.67", which adds up to 1.56" of preload, a little higher than my estimate.  The static compression of the strut is 2.37", bringing the total spring compression under static load 3.93" (surprisingly close to my initial estimate).  In terms of droop travel, for the first 0.87" of droop the tender spring will stay completely bottomed out, and after that it will start to expand.  

Is any of that good and reasonable?  I have no idea, if anyone here knows please chime in.  My current plan is to take it to an event and find out.

Back to brakes, since they need to be done today if I want to take the car to Harrisburg tomorrow to test out my poorly thought out front suspension choices.  I pulled off the drivers rear caliper, and then spent a bunch of time swearing at it trying to get it to come apart.  The brake pads were wedged in there pretty good and didn't want to let the caliper come loose from the bracket.  The obvious thing to do would be to swing the caliper out of the way, like the manufacturer intended, but there was that broken bolk messing up that plan.  Eventually I got it, some less eligant bludging instruments may have been involved

Next up was getting that damn bolt out, which involved a  healthy second serving of colorful langage.  I tried a bunch of things that didn't work, including welding a nut to the remains of the bolt and impacting it off.  What finally actually worked was heating the bracket with a torch and twisting it out with a pair of vice grips.  I probably should have started with that...

That was the hard part, eveything else went pretty smoothly.  I cleaned up the threads with a tap, cleaned up all the taps with a wire brust because they were pretty grody, added greese in the right places, and it was all back together

The new bolt is just one from McMaster Carr, it's stainless which hopefully will aid in it's removal next time.  While not required, I also got some replacement bolts to hold the bracket onto the hub, I suspect that I'll actually need those when I do the passenger side rear next.  

After that I slapped it on the car, bled the breaks, and took the car for a test drive.  About half way through that, the brake warning light came on telling me that I was an idiot and forgot to top up the brake fluid after I finished bleeding thing.  But, the brakes seem to work, which is good.  Fronts still seem to lock up first even with the proportioning valve set to full rear, but both fronts are locking up at the same time which is an improvement.  The suspension also felt good, but I won't really know how that is until I get it on some bumpy stuff.  Hopefully tomorrow.  

On Friday it rained a nice slow drizzle, the kind of rain that usually covers a broad area.  A healthy amount of water fall in the DC area, Baltimore, and Philadelphia, but almost none of it in Harrisburg.  In other words, conditions looked good, if a little hot, for a rallycross.  Brakes felt fine on the drive out to Harrisburg, but I gave them another check while I swapped the tires over looking for fluid leaks.  Everything was dry.  All that was left to do was drive the car.  

The Harrisburg farm lot is much smaller than either Summit Point or Panthera, and it's bumpy. That means lower speeds, but the bumps should be good for testing out the front spring tender situation at least.  The events also tend to be a little more casual than the DC events, and a little less competitive.  I actually like these events, just show up and enjoy yourself.  

It turns out that not only did Harrisburg not get rain on Friday, they hadn't had rain for quite some time, making for quite the dust bowl.

Apparently it hadn't rained since they regraded the lot, making for a very loose surface.  There was very little grip, and a lot of moon-dust.  If you got off the established line even a little bit, you lost traction immediately.  That seemed to happen a lot.  

My morning runs were awful.  Starting run two, I started experimenting with downshifts into first, something I haven't really done on the new transmission.  Attempt #1 was particularly abysmal, with a bunch of grinding gears, and eventually me giving up and putting it back in second.  For attempt #2 the down shift went smoother, but on the upshift I assumed that my left foot was on the clutch; it was quite squarely on the brake.  At the end of the morning, my fastest run was my first, even after the cone penalty.  That left me in 4th place of 6 cars in modified rear.  

The dust got worse in the afternoon; all the morning runs had done a pretty good job of digging up the loose top surface of dirt and the wind had died down a little.  Cars were having serious issues driving into their own dirt cloud, especially near the finish.  The time between cars increased as well, which resulted in fewer runs.  By the time the second run group happened, things had actually improved a little bit.  But, this was still the scene at the start line.  

My times in the afternoon improved quite a lot.  I was able to do most of the afternoon course in 1st gear, which meant a lot of wheel spin (I was probably worse than average at kicking up dust for the corner worker to breath, sorry).  I think the car may be starting to make more sense to me, my times were generally more consistent and I was cleaner.  My final run was within about 1.5 seconds of Shawn's times in the turbo Miata (which is very good for me), but apparently I found a cone somewhere.
 At the end of the day, I had moved up to 2nd place in class, distantly behind Shawn even though he had an off course during the morning runs.  

For his last run, I convinced Shawn to take the MR2 instead of the Miata.  He actually go two runs, since there were timing issues on the first go round.  I wanted to get his take on the current state of the suspension in the car, and make sure there wasn't something I was missing.  His take was that with the engine in the back, the car doesn't handle like a Miata (no surprise there), in particular he reported a healthy amount of lowspeed on throttle understeer.  This isn't something I've particularly noticed, maybe I've just gotten used to it; Shawn thought it was just how a mid-engined car was going to behave.  He also said I've tuned things to have more understeer than he prefers in general, so that he had to aim more towards the inside of the corner than normal.  If he had done the same with the Miata, he would have hit cones.  On the upside, the rear never felt like it was going to come around on him.  Overall, he put down a time in the MR2 less than 0.1 slower than his fast time in the Miata.

I basically agree with Shawn on all of this.  The car did feel more understeery at Harrisburg than it did at Summit Point.  I think this was because of the looser surface, and lower speeds.  But, I've also gone out of my way to tune in a bit more understeer in the car so that I can throw it around more without it coming around on me, and that seems to be working.  I didn't say anything about the tender springs up front because, well, there's nothing to say.  Had I not known they were there, I wouldn't have noticed them.  No strange behavior at all, even on this fairly bumpy course.  The obvious thing to do now is to just drive it this way for another few events, and see if I continue to like it.  

Well, Shawn does own an MR2 as well lol.....but we all know that give him any small car and he'll crush it. He's driven mine on a few occasions and I don't think he particularly enjoyed all the extra weight, haha....

That venue's size and course layout possibilities are definitely conducive to small, light cars though. Last time I was there I took a run in Shawn's Miata (keep in mind, I had never driven ANY miata before that moment, ever) and I put down a time equal to my fastest time in my own car, even while driving poorly and hitting my head on the hardtop several times on bumps and almost spinning out. Honestly, the only way to compete against Miatas it seems is at places at Panthera with big hills where power comes into play :)

Any other DC MR people up there?

The smaller courses there would definitely benefit from setting up the car to be a little more enthusiastic to turn, whereas the longer faster stuff probably does better with the more stable setup I have now.  

No other DC people there in MR, Keith + codriver is a BMW boat and a Nissan stage car filled out the class.  Spiro and Danger Pea and Tyler's jeep were there though. 

I haven't done a whole lot of work on the car for a while, but then there's not really a whole lot to do right now.  Just drive it, and get faster.  There's an event coming up this weekend though, and a little bit of standard maintenance I should get around to before then (check the oil, knock out the filter, install the passenger seat since I'll have a codriver, boring stuff). Tyler did get a really awesome shot of me at the Harrisburg event though

That's not to say I didn't get anything car related done this weekend, I stumbled on a pretty awesome piece of garage furniture in Virginia and went to pick it up.  Like all the best garage furniture, it's not light.  In this particular case, I estimate the thing weighs about 400 lbs, and  I suspected that getting it into the truck was going to be an adventure.  I wasn't wrong.  

They guy I was buying it from had it on a trailer (very reasonable, I should get one of those), and it was basically impossible to lift the thing into the truck.  All of this was aided by a healthy dose of rain, which of course started right around the time I got there to pick the thing up and stopped right around the time I left.  After hemming and hawing over how to get the thing into the truck, the seller went to the neighbors house and got a fork lift

Once it was in the truck, it wasn't that difficult to get it covered and strapped in place.  Ratchet straps are pretty awesome for this.  By the time I got the load all strapped in place, the sun had come out and it was turning into a reasonably nice day.  Of course, I was going to have to drive back through the rain to get this thing home

Prudently, the seller never asked how I was planning on getting the thing out of the truck when I got home.  I don't happen to have a giant fork lift, so alternative methods would have to be used.  So, what is this thing?  It's a cabinet of drawers, 70 long narrow drawers to put parts (and probably junk) in.  The previous owner had clearly used it as the largest junk drawer ever, and it came with all the junk still in the drawers.  So, the first step to getting this this out of the truck was to remove all 70 drawers (well, all 68, 2 are missing).  

From there, the alternative methods got somewhat precarious.  With the drawers out, the cabinet was light enough that I could barely lift one end of it, probably about 300 lbs total.  I went and got my wife to supervise, so that in case I dropped a 300 lb cabinet on myself, someone would be there to I'm not sure what.  It seemed like a good idea.  Then I slid the cabinet out and onto the motorcycle jack (that thing certainly is handy), with a little bit of stabilization from the transmission jack.

You can see the drawers I took out in the background on the bench.  You can also see that there was nothing but gravity holding the cabinet onto it's wooden base.  I removed the transmission jack and was left with a massive heavy weight delicately balanced on top of a scissor jack waiting for the slightest reason to fall on someone.  The scissor jack doesn't lower enough to drop the cabinet back onto the base, and even if it did that would leave the scissor jack forever trapped inside the cabinet.  To get this off, I made creative use of the car lift

To no one's surprise, the cabinet was a lot more stable on the 4 arms of the car lift than the small platform of the scissor jack.  If I had a full height lift (and ceilings high enough to allow for it), I could have just used the lift to pull the thing out of the truck and skipped all this stuff with the motorcycle jack.  Anyway, that was all the exciting parts.  From here, I just pulled out the scissor jack and lowered the lift.  The lift arms are low enough that the clear the wheeled base of the cabinet.  All that's left is to sort through all the junk that came with the cabinet, and put the drawers back in.  That's in progress now.  

Oh, I also have to find a place in the garage to put this thing, it's kinda big.  

This weekend I was out at Summit Point again for another Rallyx, this time with my nephew as co-driver as he has recently moved to the area.  Nephew has never done any performance driving before, and actually isn't so hot on a standard either.  Friday evening was a manual transmission crash course, given that he did pretty well.  

Since the last event in Harrisburg, I've done essentially nothing to the car.  The most exciting car modifications were topping off the oil, knocking some of the dust out of the air filter, and putting back in the passenger seat.  Very exciting stuff.  The MR2 fits 4 wheels/tires or a passenger seat, but not both.  So, my wife and nephew followed behind in a Subaru filled with the tires and whatnot, reminding me yet again that I really would like a trailer.  

Saturday was Barn course which is long, with long straights and usually lots of grip.  I struggled with it all day.  By the end of the day on Saturday, I was just starting to put down some runs that sorta kinda felt ok.  They still weren't as fast as what the quick guys were putting down, but they no longer felt frustratingly slow either.  In the end I came in 10th of 17.  Others have mentioned here before that the MR class here is very competitive, the spread in times for the top 8 cars at the end of the day way 15 seconds, and as you go up it gets even tighter.  From 8th to me is a gap of about 30 seconds, that's the gap I'm trying to close, and Saturday felt like the gap was widening not closing.  

Sunday was short course, the tightest corners on short course are not as tight as they are on barn course, but there are fewer long straights, and it's much bumpier.  I generally like short course better than barn, maybe related I was driving better as well, coming in 9th of 16.  Similar to Saturday, the top 8 drivers were within about 13 seconds of each other at the end of the day.  Unlike Sunday, I was only 4 seconds behind the car in 8th, and I was still finding time at the end of our runs.

The other MR2 was there, this time with a new skid plate attached to the bottom of the car.  The plate itself seemed plenty study for rallyx, 3/16" aluminum, but the mounting points left something to be desired.  I have the skid plate attached to the front and rear engine mounts, and the attachment points for the stock engine cover which are (kinda flimsy) tabs off of the front mount for the rear trailing arms.  He used nutserts and these large aluminum standoffs.  It seemed like it would be plenty strong in compression, but maybe not shear.  This worry seemed to play out in practice, as he pulled out the nutserts attaching the front of the plate, and then collected the finish trigger on one of his runs.  

The Saturday runs were cut short first due to dust causing delays, and the above skid plate causing more delays.  Then they were cut short even more due to a call from the track about nearby lightning.  I know a little more about lightning than the average person, and was a little surprised that my phone hadn't alerted me to anything.  Checking the maps, there was a large electrically active storm to the north pretty far away and moving east.  To the south there was a very small thunderstorm which is probably what the track saw.  By the time we got the call the cell had already died but we still needed to wait 30 minutes before we could resume runs.  There was nothing coming our way, so had we waited I think there was a very good chance that we could have finished the last run in the dry.  Unfortunately we were also right up against the time limit for when we needed to conclude for the day.  So we ended 2 runs short.

Setup-wise, the car is nice and stable at high speeds, and holds sweepers like a champ.  But, I had a lot of trouble in the tighter sections of the course, which frequently came right after one of the long straights.  The car just will not under any circumstances turn if you even glance at the brake pedal.  It's not new that you can't brake and turn at the same time, this is normal stuff.  But right now, trail braking or modifying your line with the brake pedal just doesn't seem to be much of an option.  I want to get the car to initiate a little bit of rotation under trail braking, and right now it's just plowing straight ahead.  

My reading on this is that the brake bias is still too far forward, even after changing pad compounds.  I can try and replace the brake proportioning value with just a straight junction and see if that helps.  If that doesn't work, the next step is to put the proportioning valve on the front brakes.  I think the car balance right now is a little too far towards under steer as well, so I should either soften the front or stiffen the rear.  Here's the front of the car under suspension load (heavily cropped, somewhat potato quality).  

That looks roughly similar to the photo of the BMW above (in as much as you can compare them).  In contrast, here's a photo of the rear under load in a sweeper

It's a little hard to tell from these which end should be altered.  The rear hits the bump stops more often than the front, but still only rarely (over large bumps).  The front essentially never bottoms out.  Probably I should only change one end at a time, so arbitrarily I'll start by stiffening the rear a little bit and see how that feels.  Next event is in September, in Harrisburg.  That'll give me a bit of a shakedown before heading out to Panthera in October.  

Some more photos by Alan Olson from the event

And one of my codriver

I haven't been working much on the car for the last few weeks.  I've had a set of springs for the rear sitting on the table since basically the last event, but just hadn't gotten around to putting them in.  Finally got around to it this weekend, the will bump the rear from 125 lb/in springs to 150 lb/in springs.  Not really a big boost, but then I'm not looking for a big change.  Here's what the rears look like after 5 days of rallycross

It looks like there's some rubbing happening on the threaded coilover collar, some of the threads have been ground flat.  I had similar issues going on back in my Miata days, but always thought it was due to the spring coming unseated at full droop.  That can't be the case here though.  I'm not planning on moving the spring seat way up there, so it's not really causing any harm, it just annoys me.  

During the test drive, the new springs felt fine, not that much different than before which is about what I expected.  But, on the way home a new rattle started up in the car.  I figured this was the intake tube rattling on the firewall since it's not siliconed shut.  That's right behind the drivers head, so small rattles there are pretty obvious.  Back in the garage, the rattle continued with vigor while idling, so that I could confirm that it was not the intake tube, or any seat belts, or any loose items in the car, and you couldn't hear it in the engine compartment.  The rattle seemed to be coming from under the arm rest, so I took that out and it seemed to be coming from even farther down, under the central tunnel.  You could actually feel the metal vibrating from the rattle. 

This is generally bad news.  Under that center tunnel is the gas tank, and the rattle seems to be coming from around about where I think the fuel pump is.  There isn't any access to the fuel pump without removing the tank, and removing the tank is apparently not a fun procedure.  

On a more positive front, an exciting care package of custom MR2 stickers arrived from MrFurzzy's wife which are just the coolest things.  They actually arrived some time ago, but I hadn't gotten around to posting about it.  Anyway, one of these is now installed on the hood, to replace my missing hood emblem.

my coilover collars did the same thing, ground down the thread. One option is to get some barrel-profile springs that are the correct diameter at the bottom and top but slightly wider in the middle. That's what I have right now on my car and no more contact. Usually sold at circle-track places.

In reply to irish44j (Forum Supporter) :

Huh, I didn't know that these existed.  Certainly seem like they would do the trick.  Now to convince the wife that I need another full set of springs...

lxnm said:

In reply to irish44j (Forum Supporter) :

Huh, I didn't know that these existed.  Certainly seem like they would do the trick.  Now to convince the wife that I need another full set of springs...

The ones i have are Swift brand, so that is another option

Well, I found the rattle at it wasn't nearly as big a deal as I feared.  The offender was this bolt here

That's the bolt that holds the center front of the rear skid plate, and the rear of the mid-plate to the front engine mount on the car, it's threaded into a captured nut that came on that mount from the factory, and it's come loose.  The mid-plate there is the meat in a skid-plate chassis sandwich, and when that bolt is loose it can rattle something fierce.  Probably making the bolt looser.

The slightly less good news is that the bolt came loose because the threads on the captured nut are toast, the bolt just spins and spins even though the bolt threads look fine.  That's as good a segue as any to show off the now in location parts cabinet which, among other things, houses my nuts.  It nestles in right next to the lathe, which seems like a good spot for it, and the drawers are long enough to house my scrap round stock as well. 

Anyway, new nut in place, no more rattle.  Didn't have to take out the gas tank.  I had planned on this problem taking me all weekend to fix...

This weekend there was a rally cross at the small field in Harrisburg.  These are usually pretty low key events, with a much smaller modified rear class, and generally a less competitive attitude.  This weekend was no different.  It did provide me with a good opportunity to test out the new rear springs, and hopefully will help keep me from getting too rusty before the next DC event in late October.  

Also it rained.  Well, it didn't exactly rain, but it didn't not rain either.  It was more of a light misting of water coming down for the duration of the AM runs, and generally got everything good and wet.  But, under a thin layer of wet dirt was a deep, soft layer of dust.  It made of an interesting surface for sure.  The wet also made the dirt stick to the car extra good, none of us stayed clean for long.  Here we are just after the first run. 

The class was 5 drivers in 4 cars, with all but one being regulars in the DC region, making for unusually diverse competition at one of these events.  ¯\_(ツ)_/¯ was there in the orange BRZ, and Buckler/Royer co-driving Buckler's E30.  The odd man out was in a stage rally 200 sx who seemed to be doing a bit of a shake down of the car.  

The competition was surprisingly close.  Bucklers first run was suspiciously fast, like 10 seconds faster than the next fastest run in the class all morning kinda suspicious.  It seems there was an accounting error in his favor, but he mostly squandered it by hitting 3 cones.  My morning runs were inconsistent.  The first run was ok, about 2 seconds off my own good run pace which is a pretty typical first run for me.  That was followed by a string of runs that just felt terrible.  I kept sliding off line, and into the wet where there was no traction.  And then sometimes the car would dig in to a rut, and find a nice patch of grippy dirt.  That also tended to send me off line and into cones.  

Things finally started coming together for me for my last two runs, when I started getting the times I thought I should be able to do and they started cleaning up.  My last run was actually within tenths of the fastest run of the morning in MR (excluding Bucklers suspicious first run), and it was clean.  I'm not usually this close in times to ¯\_(ツ)_/¯ or Buckler, so that's a good thing.  At the end of the morning runs, Buckler was in first place (with his suspicious first run), I was in 3rd, and the car had a healthy coating of dusty mud

The 'rain' stopped immediately after our morning runs, and the track quickly dried out.  Afternoon runs had a lot more traction than they did in the morning.  My runs were a repeat of the morning runs.  My first run felt good, but was dirty.  I don't know where I found 3 cones, but apparently I did.  That was followed by a couple of slow runs where the car just wouldn't do what I wanted it to do.  Then I figured it out, and put down a good time.  My fastest run of the afternoon was actually the fastest run of the of MR, and it was clean.  But, with my sloppy first run and floundering middle runs, I was still in 3rd place for the afternoon runs, and 3rd place overall.  

Overall it was a good event.  The car seems to be handling well with the new, slightly stiffer rear springs.  My troubles with consistency were entirely due to my own driving, the car was doing great.  I didn't notice any heavy understeer, but that could change on the bigger, faster DC region tracks.  In a month or so, I'll find out.