AW11 MR2 Rallycross build

Somewhat boring update, today I changed the oil.  This is a pretty boring thing, but I did a little inspection work while I was under there. 

First the skid plate, this had to come off to get the the oil drain.  There were a few big bumps where the back of the car bottomed out, so I was interested to see if there were any significant signs of damage.  Amazingly, it's holding up ok

All the paint has been scratched off the back end (towards the back of the car) of the plate, and there's some new dents in it, but otherwise it's actually holding up ok.  There is a new pretty deep gouge going all the way from front to back near the center lines of the car (the 2 center bolt holes).  That may have been the rough knock I felt on track.  Pretty amazed this thing has held together as long as it has.

Next up, the air filter.  I haven't changed the filter all season, and that's pretty amazing to me.  Before I switched to the Donaldson pulling from the cabin, I'd need to change/clean the air filter every day of racing, sometimes more often than that.  And there have been some dusty events.  So, it's probably time to take a look at how that's holding up.  Here's the outside and inside of the filter, the inside still looks pretty white

I could probably get away with knocking the dirt off this filter and putting it back in the car, but I replaced it with a new one anyway.  I also cracked open the air intake plenum to see if there was any dirt getting past there.  Somewhat hard to photograph this without removing the plenum all the way, and I didn't want to do that.  The foreground here are the velocity stacks on the ITBs, the stock units are curved.  The background is the inside wall of the plenum, and there's a lite dusting of dust in there.

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I suspect that the dust is getting in around the seal of the plenum, rather than through the filter.  The plenum is this stamped metal thing, which hinges at the bottom and bolts along the top and sides.  I don't really trust its seal.  The filter on the other hand is spotless on the inside.  

What this means is that when I finally get around to rebuilding the other engine, I'll probably replace the plenum with a billet unit.  Super expensive, but I'd really like the fresh engine to last a while.  

This weekend was a DC Rallycross event at Panthera training grounds, in 'not close to much' West Virginia.  Panthera has long stretches of closed dirt track with tight turns, some long straights, and lots of elevation.  It's a lot of fun to run there.  The two major issues with the site are how far away it is from basically everything (limiting the number of people who show up), and the runs which form on the hill from rain run off.  It seems like some work on the rut situation has been done recently though, and the road condition was really good pretty much everywhere on site this weekend.  Awesome!

I drove up with my co-driver/wife on Friday, this was a two car operation.  Still don't have a trailer to tow with, so that meant driving the MR2 out there.  But, with a passenger seat installed, there's not enough storage room for a set of tires.  Also, co-driver understandably doesn't much like long drives in the MR2.  So, most of the equipment and parts went with the co-driver in a second vehicle outfitted with amenities like AC, heat, and a radio.  

The trip out there actually wasn't uneventful.  It started out the day prior, when I discovered that the battery in the cargo vehicle was dead and needed replacement.  This was followed up Friday evening on the way to the site when I found out that both headlights on the cargo vehicle were also out, and needed to be replaced.  Apparently I didn't do a very good job of checking that everything was in order on the sag vehicle...  Then on the way there, we had a near encounter with a dead deer on the road.  I swerved and ran over it's leg, the sag vehicle just lumbered over the carcass like it wasn't there...  In the end, we arrived in Moorefield in one piece.  

Saturday morning the fog settled into Moorefield valley, then froze leaving a nice layer of ice on the car.  This posed no issues for the cargo vehicle with it's fancy pants defroster, but the situation for the MR2 was a bit more troublesome.  I had a scrapper to get the ice off, and a rag to keep the inside of the windshield sorta clear.  But, as soon as I started moving it still fogged up something fierce, and no amount of cloth wiping would solve it.  Turned out the fog on the outside was also condensing on the windshield, awesome.  Getting out of town was a little interesting, but luckily the fog cleared up near the highway.

Saturdays course was short and tight, going up hill through a sequence of tight switchback sorta things.  The tight course favored the lighter, less powerful cars, and I had one of those.  Also the road surface was excellent, or as excellent as the clay in these parts gets.  My first run was overly cautious, and about 2 seconds behind a competitive pace.  And then I picked it up and put down shockingly competitive times, for me anyway.  Unfortunately I also hit cones, and in this class you have to be clean to be competitive.  

End of the day on Saturday left me in 6th place out of 13, about 15 seconds behind the lead car.  6 of those seconds were extremely avoidable cone penalties.  This is still the best I've ever finished in this region, and not because of lack of entries either.  I actually beat a few people who are usually significantly quicker than me, so it was a good first day.

Sunday didn't go as well for me, more on that in a bit

Sunday's course was significantly longer and quicker, utilizing a good portion of all the road we had to work with.  A quick run on Sunday was around 2 minutes, and people were reporting hitting the rev limiter in 2nd gear.  Pretty cool to be able to do a course like this at a rallycross!

That said, I usually struggle on courses like this.  I'd like to blame it on the car somehow, but it's really just a lack of guts and driver skill.  On Saturday I was around 0.5 seconds on a 44 second run as compared to the fastest drivers of the Modified Rear class.  If we scale that up to a 2 minute run, I should expect to be around 1.5 seconds slower.  Even my fastest runs were 5 seconds off pace, and those were usually dirty.  I hit a lot of cones.

That's not to say I didn't have a good time, I did.  Would totally do it again, and given the choice between a short slow course I'm competitive in or a long fast course I'm not, I think I'd take the long and fast one.  My co-driver enjoyed herself too.

I did best one key competitor of mine on Sunday, the other MR2!  But, in classic fashion on this front, I only beat him because he broke his car, again.  The breakage was related to his skid-plate, again.  After the plate failed him last event, he went back to the drawing board and re-engineered it with a tubular frame providing reinforcement.  But apparently it was not stiff enough, or maybe damage had already been done, and he developed a crack in his oil pan.  Luckily the oil (mostly?) stayed in the car and he just needs to replace the pan, he just wasn't so reckless as to continue to run a car which was threatening to loose essential oils all over the course.  

In reply to lxnm :

I was right ahead of Mike's MR2 and narrowly missed the rock that ended up doing in his oil pan- it was a big one, I wouldn't have wanted to hit it either.

¯\_(ツ)_/¯ said:

In reply to lxnm :

I was right ahead of Mike's MR2 and narrowly missed the rock that ended up doing in his oil pan- it was a big one, I wouldn't have wanted to hit it either.

Nick was ahead of you and didn't mention it, so we can only assume the large rock was kicked up by the massive power of the M3.

Yeah, it sounds like Mike's re-engineered skid plate is much much stronger than before.  It didn't fall off or anything.  The plate is 3/8" aluminum which is pretty beefy, and the frame is 1" dom piping, which should also be reasonably stout.  Looking under the car, it doesn't look like it deformed much/at all after hitting the rock, so it's not clear how contact with the oil pan happened.  It's a better, stronger, and heavier solution that what I have for sure.  

This last weekend there was a rallycross up in Harrisburg, and I figured I'd go.  More seat time is good right?  This particular event was organized as a fund raiser for a Pennsylvania food bank, and was a little more casual than a normal rallycross (which are honestly already pretty casual).  I decided to go kinda last minute though, and didn't end up having quite enough time to get the passenger seat removed so I could take my rally tires up.  But, it's not like I'm trying to be competitive, snow tires should be fine for fun runs.  

We were encouraged to dress up the cars for Halloween as well.  I didn't have too much time to put into it, but tried to do a little something.  The MR2 has an tendency to suck dirt into the engine, to this new livery seemed appropriate

There are small horns (in the photo) and a tail coming out of the trunk to match the theme.  I painted the logo in there with tempra paint, so it'll come right off with some water.  It turns out that tempra paint doesn't stick to cars very well.  I mean, I shouldn't be surprised, it's designed to wash off which kinda requires it to not stick.  It just doesn't stick more than I thought it wouldn't stick.  Still, it came out ok, especially if you don't look too close at the lettering.  

The winning costume was done by Tyler Powers who dressed his jeep up like a toaster

The bread is made out of pet beds, and held onto the roof with magnets.  The most amazing thing is that it stayed on the roof through the entire event.  

In other news, on the way up there I noticed the handling of the car was a little off.  The last time it felt like this, it was because the rear ball joints were cooked.  I should probably check on them and make sure they're ok before the next DC event at Summit.  

I don't know that I mentioned it, but in the afternoon I swapped cars with Tyler.  Here's a photo of him driving the MR2, not the fastest line but certainly a fun line

Next weekend is the last rallycross for the DC region for the season, so this weekend is inspection weekend.  I'll do more serious maintenance after the season is over, for now I'm just looking for anything obvious that is wrong with the car.  In particular, I suspect that maybe there's an issue with the rear ball joints because the car kinda feels like it did when those were toasted last time.

But, the ball joints both look basically new; probably because they are.  Boots seem to be in good shape, no obvious play (but I'll check more carefully).  Skid plate looks like it's looked all season (battered but holding together), and there's no evidence of contact between the plate and the transmission or exhaust.  But, while crawling around under the car I did notice this

That is the front engine mount, and I'm pretty sure you're not supposed to be able to see over the top of it.  Looks like the bolts holding it in place have come loose, maybe I better fix that...

This weekend was the last rallycross of the season, the weather was seriously beautiful, and the folks at Summit had prepped the courses for us so that we had nice dirt without massive ruts to drive on.  Pretty hard to get better conditions than this.  

Day 1 was barn course, the grippy fast one.  I don't usually do awesome on this course, but I did particularly bad this time around.  I started off my first run by somehow managing to forget to don my helmet.  I caught myself at the first corner, but it still ended with me DNFing the run.  Not a great way to start the day, and run 2 didn't get much better.  Coming to the end of the long straight I hit the brakes and not enough happened.  I'm not actually really sure what happened, it seemed like I got on the brakes early enough, but clearly not actually.  I ended up going up onto the berm at the end, and around the outside cone nabbing an off course.  This nabbed me a coveted off course, and cemented by place in last in class for the day.

After 4 runs in one direction, we swapped direction and did 4 runs in the other.  Light being limited, this was all done with basically no break in between.  It wasn't enough.  The run group was plagued with delays and red flags including a car stuck on course with a dead battery.  As the sun got lower in the sky, visibility started getting bad

When you would turn into the sun, the glare off the dust on course could very easily blind you.  If you were lucky, and the person in front didn't kick up too much, you only went blind briefly.  On the other hand, if you happened to be behind ¯\_(ツ)_/¯, things could be a lot more difficult.  The event was reduced to 1 car on course at a time, which really made things slow to a crawl, and ended the day 1 run short for the run group.

Day 2, Sunday, was on the short tight course.  I like this course better, and on Sunday I had Tyler co-driving.  That was good, as it helped me push past my poor driving from the day before and enjoy myself.  We quickly ended up in a tight race at the bottom of the class to see who could get more penalties.  Tyler and I drive very differently, Tyler is quite happy to just throw the car into a corner and try to catch it.  I tend to take a tidier line.  But the car is set up to be throwable; Tyler was overall about 1 second a run faster, but he found a lot more cones.  Tyler also successfully de-beaded a tire, a first for this car

We were luckily able to borrow a spare from our competitors Matt and John (in the shark colored E30).  In the end, the large number of penalties left both Tyler and I very near to the bottom of the class.  But, I really enjoyed the day.  It'll be interesting to see if Tyler can clean up his runs, if he can his times are really quite competitive in class.  

Well, I haven’t gotten around to updating this post in a kinda ridiculously long time. I didn’t do much to the MR2 over the winter, approximately nothing in fact, so that’s part of it. But, there have already been a few events this year, and so I’ve been doing stuff lately.

The biggest change for this season is that I’ve picked up Tyler as a codriver, which is exciting I guess. Last season he was driving in Stock AWD in a Jeep Renegade (heh). That worked out pretty well until this winter, when he sorta a little bit destroyed the rear diff. Apparently Jeep wasn’t actually planning on people sliding the renegade around in the dirt all the time, go figure.

For sure our driving styles are quite different, with Tyler being far more aggressive than I. Sometimes his aggressive lines work out, and he gets blisteringly fast times.

Sometimes he overcooks it, and goes off course.

It’s always exciting to find out which it’s going to be. Tyler’s fast times are easily competitive with the top drivers in Mod Rear, but then he blows it by going off course, or taking out a wall of cones or something. Overall, he’s just a little quicker than me (I also hit cones after all). If/when he cleans up his lines, I think he’ll be fighting for one of the top spots. My times seem to be getting a little quicker too, which is good.

One of the other nice things about having a second driver is reducing the hurt on a new set of tires. It’s getting super hard to find rally tires in the country in 14” sizes. We had to get these shipped over from England.

We had exactly zero advice given to us about what the quick tires to get were, not because we didn’t ask around but because no one really seems to know. This isn’t autocross for sure. We went with these Yokohamas because they were available in the size we needed them, and were in stock so that they’d get here in time for the event. Seems like pretty sound logic.  Tyler also took it upon himself to refinish those wheels, they were in good shape but ugly.  While they look good and all, I think he spent way too much time on something that's just gonna get bashed up on course.

Not a lot going on with work on the actual car though, it seems to handle itself just fine. The other MR2 keeps telling me that a quicker rack would help, and it probably will, but I haven’t actually had too many problems with keeping up with the steering wheel since I replaced the stock rim. I’m not sure I can say the same for Tyler, his more aggressive driving usually has the wheel turning a lot more, a lot faster. But, with 2 drivers in the car now, it was time to finally get around to putting in a second seat.

I didn’t get one of the over engineered T3 seat mounts this time around. I wasn’t really all that happy with it, since it required a lot of modification for something that was supposed to just go in. Instead, I just bent up some 1/8” bar, and made a mount. I actually like this one better than the T3 mount, it has the seat a little lower than the drivers side, and it’s easier to get the seat in and out of the car.

For this last event (which was like a week ago now), we looked the car over and found nothing major wrong.  Just the gear shifter was catching sometimes when you'd try and shift from 2nd into 1st.  It wasn't that big a deal, but I investigated, and it looked like the in/out shift linkage was maybe just a little too far outboard (towards the driver seat).  So, I adjusted it a bit more inboard (towards the passenger seat), and that seemed to clear it up.  Queue foreboding music.

On my second run of the day, I tried a downshift into a tight S-curve, figuring I could use the power to get out of it.  The subsequent upshift was a little crunchy (I was hurried), but it went into gear fine, and my run went great till I crossed the finish line and put the car in neutral.  It was at that point that I discovered that I could only shift between 3rd and 4th, bugger.  After a fair amount of investigation, I found the cause was that the square bushing had falled off the shift linkage lever.  This is pretty hard to see from the top of the car, but now that it's back in the garage, I got a pretty good photo.  There's supposed to be a square thing on that round shaft, to move the selecter shaft in and out.

That bushing is maybe 1/2" square, and must have fallen out somewhere on the track.  It's gone, never to be found again, and the timer was ticking for our mechanical.  Luckily zipties came to our rescue!

The ziptie at the bottom of this image is the boring one.  It's holding on the dirty end of the intake, after the hose clamp that you can also see in the photo bound up on me.  The important ziptie is the one you can see through the hole in the (no longer used) battery tray.  That ziptie is holding the selecter shaft in the 1st/2nd position, instead of the normal 3/rd/4th position.  The transmission is still a 2 speed transmission, but it's the right 2 speeds now.  

This actually allowed us to finish all our runs, and held up through the whole day, something like 20 runs or so.  But, it didn't get me home.  Driving home in 2nd gear sounded like a E36 M3 idea.  But, Mike was kind enough to tow me back.  I drove his MR2 (on my street wheels), and he towed mine.  

So, the car is home and I'm working on a more permanent repair now.  Also, I need to go to Mike's house and get my street wheels.  

Well, transmission linkage is 'fixed'.  I made a replacement bushing out of some scrap delrin I had lying around, using the lathe to bore a proper sized hole and part off the stock, then a disc sander to take down the sides.  The end result looks like this

I didn't have the original bushing to take measurements of, but I'm pretty sure I remember it being square.  This one isn't square on purpose, to extend how far inboard/outboard the lever can go while still having good purchase on the selector shaft.  Here it is installed in place

This photo makes it more obvious why the lever being a little too far outboard is a problem, and why I made the new bushing more rectangular.  This tested out fine, I can get into all gears, and shifting is reasonably smooth and getting better as the bushing beds in a bit.  Hopefully the new rectangular bushing solves the issue, and it doesn't fall out again.  I also have the hole bored a little undersized, enough that I had to press the bushing on the shaft.  That'll likely loosen up over time (or it's already loosened up), but should hopefully maybe also help keep the thing in place.  

But, in case all that fails, I made 2 of them.

Thanks for posting all the details of your rallycross efforts with an MR2.  I'm about to pick one up from another board member and live rallycrossing my Impreza.  I'm now worried about air filtration and bottoming out in the MR2.