In which I take an XP Miata hillclimbing to answer the question: Is Miata always the answer?

Updates: The supercharger controller is getting a physical relay in place of a solid state one that failed. It's also getting a different TPS calibration so it starts generating boost at lower throttle positions. I'm also likely to add an Arduino or similar that will integrate CAN-bus data from the Megasquirt into the TPS signal so I can do basic electronic boost control on the supercharger.

I should have the controller back next week. The first thing I'm doing is getting video of it working, the second thing will be getting a datalogged pull. Fingers crossed that this failure mode doesn't recur.

A large, mysterious package showed up in my driveway today!

I'm impressed at how dressed the JDM motors are, this one even includes the fuse box, and I think the MAF is somewhere inside that black plastic wrap. Fingers crossed. I have nothing but good things to say about used JDM engines, I couldn't find a used low mileage BP in any wrecking yards, no matter how far afield I looked. This one looks to be in nice shape, but I don't have much to go on other than external corrosion at this point. $2k for a 99 motor and six speed might seem steep (it doesn't seem steep to me but I also do spend time on miata.net, lol) but things like ignition coils and cam angle sensors are surprisingly valuable and will probably defray that cost a bit. Which reminds me, I should put my old AFM and airbox on Ebay.

I have some parts to order before this can go in the car. I feel like it's a good opportunity to upgrade to the supermiata twin disc clutch, it's only about $600 more than a FM level 2 and a good quality flywheel cost, and while it might not offer crazy lap time gains per dollar, I think it's something that will make the car better to drive, in a completely subjective sense. Planning on using the Blackbird drop engine mounts. Otherwise, there's not much else to do other than clean it up, put new seals on it and put it in the car.

---

Had a bit of a panic reading the 2019 Solo rules as I do every year. I see they finally added language banning ice cooled intakes/intercoolers in prepared, I can't believe it took this long for someone to try and exploit that loophole, heh. Then I noticed that there was a paragraph that restricts boosted cars to a single turbo or supercharger of any size or make, which worried me briefly.

But, X Prepared gets it's own section where the aerodynamic allowances are given, and there's a very important paragraph, which forms the basis of this entire build:

"Drivetrain and related systems (e.g., induction, ignition, fuel, electrical, cooling, oiling) and components (e.g., mounts, clutch, flywheel)
are unrestricted except as noted.
c. The engine orientation (transverse stays transverse and longitudinal
stays longitudinal) and the engine bay location must not be changed
(front-engine stays front-engine, mid-engine stays mid-engine, and
rear-engine stays rear-engine)."

Unrestricted. The best word in the English language. There are no limitations on what I can do to make boost. I fully expect to have to pull out this part of the rules as the season goes on...

Today was super cold, and it rained during my session, and the course was all about low speed grip, but whatever - the car didn't have the misfire issue I was seeing earlier under boost. It's turned all the way down, so this is about the baseline for boost, I don't think I can go much lower, really. It ran well for the first two runs and then things started to get super hot, and I think I ran into the thermal limiter? Time to get much more serious about heat management. 

It's progress, even if it identified several weak points in the system. I guess it makes sense, I'm stuffing so much extra energy into this engine that it generates huge amounts of heat in a very short period of time.

Didn't put on slicks, didn't care. Nobody else ran in my class, so I felt like I'd save myself the bother. Sliding around is fun, anyway, and I don't do it enough.

Interesting noises. Slightly similar to an Eaton, yet different enough to know it's something unique.

Also, was that a time slip?

Yes, that was a Post-It note with my time and penalties. The inside of my hardtop is covered in them, hahaha :)

It sounds and feels like a slot car when it's running on the course. When the engine is off and the supercharger is armed, stepping on the gas results in a sound like some practical joker stuck the world's largest hair dryer under the hood (I mean, because kind of that's exactly what happened?). If I can get it to work reliably, though, it will be quick when conditions are better.

How to do you feel this would work with supercharger only? It seems like it could be boost on demand, ie I want 8psi at 1500 rpms for example. 

I think it would work really well at low RPM. At the top end it won't flow enough for serious power... But enough to make a difference.

The smaller displacement the engine, the bigger the difference it will make.

Yes, boost by rpm should be possible, but you will need a big battery pack and a way to manipulate the TPS signal. 

I’m glad I decided to catch up on this thread, since I haven’t looked at it in several months.  I really like the idea of the electric supercharger, and I’m glad to see someone playing around with one.

re:heat soak
I wonder if adding some fins to the casing would be helpful, or machining a new case that has more fin “ribs” in it?  Or, you could get an eBay supercharger to cool your literal electric supercharger?  Final thought, is that at some point you/they might have to seal that motor and run it in oil with a small cooler.  Although, having it over the exhaust manifold probably isn’t helping things much.

It's a concept that has a lot of potential, but there's still a lot of development left to realize that potential. I'm keenly aware that I've just made my car much, much more complicated. As far as keeping it cool, for now I'm going to do as much as I can with ducting and heat shielding. I can make things a lot better than they are now. All the things you suggest are possibilities, but whatever I can do with passive solutions, I'd like to do first before adding yet more complexity to the car.

Speaking of making things better (and the exhaust manifold, and it's proximity to things):

Oops! It only took two runs with the supercharger running, and this bracket that had been perfectly fine for a month of driving and a turbo-only autocross event decided to unweld itself in pretty spectacular fashion. In hindsight it was only a matter of time, it's the wrong material to live in this place on the car. I'm not even close to the temperatures I'm going to see on the hill, either. Luckily the supercharger is located well enough by the coupler for me to be able to finish the event and drive home.

So, options. I could relocate the supercharger forward and mount it to the unibody, it's easy enough, but then there's a coupler going from the turbo that's on the engine to a supercharger that isn't. Even with 'solid' motor mounts, there will still be some movement. I liked this mounting solution because everything hung off the block. I felt like it deserved another go.

Moving to mild steel for that piece and altering it so it has more clearance around the manifold seemed like it might be sufficient to keep things from melting. The other argument for not reengineering everything was that I had an event on Sunday down in the Columbia river gorge, and if I wanted to drive at all I either had to pull everything off, switch back to my old intake, or fix the supercharger locator bracket on Saturday with enough time to drive 4 hours down to the hotel, hopefully mostly during daylight. My headlights still leave something to be desired.

I grabbed some angle stock and started cutting. My $100 Harbor Freight stick welder doesn't particularly like to strike an arc, or hold an arc, or do anything really. But, there's enough penetration there to make me happy, even if the welds make me sad with their ugliness. I'm glad I didn't have to learn to weld on a welder like this, it's not really much fun to use.

A few minutes with a flap disc and a saw, and it's much less awful.

Add a few holes...

And it's ready to test fit.

Looks promising! I altered the mounting points a bit and it supports the supercharger better than the old bracket did even before it changed from solid to liquid. There's way more room around the exhaust manifold. Radiant heat drops with the inverse square of distance, and I more than doubled the distance from the manifold.

I hit it with some fancy 2000 degree paint to protect it, and cured it as best I could in the limited time I had available.

Looks ok for something I globbed together on a two by four in my driveway. No time to admire my handiwork, I had to put everything back together and drive 250 miles.

All back together! The flex that was there before is gone, the supercharger doesn't move around at all now. It's not particularly heavy, but it's nice to know it's not dangling off the turbo by a coupler and is fully supported by the bracket. Sorry about the ugly 'heat shield' under the valve cover vent filter, it was just some scrap aluminum I had handy and bent into shape. I'll make something nicer this week. Notice that the nuts and lock washers moved to the other side of the bracket, one of the lock washers did melt, so that's a reasonable precaution. Now there's only a bolt head on the manifold side.

Everything was back together by mid-afternoon, so we loaded up the slicks and helmets and hit the road. Would it hold up?

The drive down was unusually pretty, but there wasn't really much extra time to stop and take selfies with the sunset. However, if I'm driving past it during the daylight or close to it, I always stop at this one scenic viewpoint on 97 right past Wenatchee, because it only takes a moment or two and if I don't have a moment to look at this view then my life has gone completely wrong and I really don't deserve to look at anything.

It was too dark to get a good picture of the scenery, but luckily I brought my own.

Adorable. The Cascade mountain range is puny in comparison to the mighty GTC300.

Everything seemed to be holding up fine, and the car managed to turn in almost 30 mpg as the air temperatures dropped into the 40s through the mountains.

Got into the Dalles, didn't actually even open the hood of the car, scavenged some sandwiches from the gas station and went to bed. Woke up earlier than any living thing should have to on a weekend (why is autocross so early?!?), drove across the river to the event site, tried unsuccessfully to combine eating breakfast with a wheel change, unloaded the car, and pulled up to tech as the drivers meeting was starting. Ugh, have to find a tech person and bribe them. Except we were supposed to self-tech at this event, which I would know if I spent more time on Facebook. So, I scrambled to check my own vehicle. Luckily it gets looked over by multiple people almost every weekend, so I checked the things that could have changed and made sure the lugs were torqued, and tried to find out what run group I was in. Apparently I was running first, and since it was tied to a work assignment, there was no easy way to finesse, beg, or barter my way into the second run group. I'd spent all the time I had working on the car and hadn't walked the course once, but had arrived in time to hear a stern lecture about the course walk being mandatory because they didn't want people getting lost on course and wasting everyone's time. Uh oh. I'm usually only happy when I have walked the course three or four times, and I'd never actually started an event without at least a cursory course walk.

I had to grid up one way or another.

There were five or six cars in front of me. I knew I could watch at least the first couple of cars run the course before I have to run to my car and belt in, I mean, fumble frantically with the harness while the grid enforcer looks at me with a disappointed face. I tried to memorize the basic layout of the course. Start into a fast slalom section, left into a crossover that feeds you all the way across the course, high speed sweeper right into another crossover, execute an arc at the turnaround using the full width of the runway, back through the crossover, sweeper right again, back through the FIRST crossover, another slalom section before the finish, one of those really annoying box things (yeah my autocross jargon is strong), and then on to the timing beam. At least that's what I think I see them doing.

It doesn't matter, it was time to run. Wisely, I had added a bunch of value to all the cells of the boost control duty table in the powerband, overnight. I tell myself I can just go slow and look around for the course. That's possible, right? Is it possible?

I don't have video of my first run, because I left the camera off. I expected things to go poorly and wanted to avoid any evidence of my autocross etiquette failure.

I was wrong! Things did not go poorly. The course was just really well designed, with two lower speed sections and a high speed section, and a minimum number of cones. Simple, but effective. I was only really flustered by the evil box o' cones thing at the end. I get there at speed and it looks like just... a box of cones. There's no apparent way in or out, it doesn't seem like the car will fit through any of the gaps. Whatever! I just drive at it and shoot for the largest gap I can see. Miraculously, the car finds a way through and the only thing I have left is trying to bring the car to a halt from full speed in the stop box on cold tires. That turns out to be the hardest part. I manage not to lock up, and I get a time slip with 45 seconds on it, and maybe a cone? I don't care about any of that, I didn't get lost, and the car is running perfectly.

Over the next 17 runs I raised the redline from 6500 to 7000 rpm (good for over a second) and figured out that the high speed corners could be taken mostly flat, which is good for about another second. I also turned up the boost a little.

In the afternoon we were running consistent times of almost exactly 38 seconds. Bouncing off the rev limiter was not helping, but I didn't want to raise it any further. That poor little motor needs to get home to the city after exceeding design specifications over and over and over. Top time of the day can go to a car that will go home on a trailer. That said, the Elises could easily have driven there and I couldn't quite catch them on Sunday.

Sorry, just raw footage for now.

The car is faster than ever. Needs an alignment, I know at least one cam moved at Maryhill, primarily because my steering wasn't straight after the last run there. Maybe I should make that a priority. It would be easier to drive, there's actually toe in right now and steering effort is... high.

Whatever, car is working, made the 500 mile round trip without missing a beat. Oh, and the little piece of metal that ate up my Saturday? I don't know why I even bothered checking on it.

Doesn't look any different than when I put it on the car. Ok. I think I can move on to other things, like making a heat shield for it that looks... less completely terrible. And sorting out the controller. And, then I can start on the rest of the car, because pretty much nothing has been done.

Wow. I can't believe how clean the inside of that valve cover is. I wonder how many miles this engine even has on it.

Give me that valve cover... I want to try something.

Ok, sure :)

I'll give it to you when I get back...

So, this happened.

I signed up for an autocross event on Saturday with Central PA region SCCA. There's just the minor matter of a 2500+ mile transit, but otherwise seems like a great chance to see the folks and run a different venue! I took the slicks off the car on Sunday after running with NWR, and packed the car full of tools and set out for Pennsylvania.

I didn't really think it through, which is lucky as I don't think I would have tried it. Oh well. Here we are. I'm in Madison for the night, should be in Cleveland tomorrow and off to a random hotel in central PA. Come say hi!

Of course there are lots of pretty photos, thanks for asking!

It's been really exhausting, but there's almost always something pretty to look at.

So I guess my 200 mile round trip to Brooksville wasn't so far. 

I enjoyed the drive, but that airport isn't hosting events anymore.

Still, you're welcome to come join us here in central Florida any time!

Now THAT would be a road trip.

Hmmmmmmm. This is intriguing. I have been thinking, if I build a teardrop trailer for it, I can carry a full set of slicks AND rain tires and also get the bits of downtime I need at the side of the road. Also have tools and such.

You're officially a bad influence.

dr_strangeland said:

 

You're officially a bad influence.

Ooh! It's like getting a promotion! Although I prefer to use the term enabler.

What venue in central PA? Its gonna rain here on the east side, maybe I'll take a ride

Sorry, I have been driving and not checking the forum. It's at the CPI Emergency Training Center in Pleasant Gap. (Which was hard to find, to be honest, there was some panicked driving around on country roads for me.)

Edit: Clearly I need to do some work on the whole social media thing. The workflow to post pictures here is too complicated, and the connectivity I have and the time that I have available don't really lend themselves to composing long-form posts on a forum. I'm trying the whole Instagram thing, but then I can't provide a narrative. Ugh.

My biggest problem was that I was trying to coordinate my dad coming out to autocross, and also get there, both of which actually happened, so that was worth all the effort. I did totally fail on updating this thread.

That said. Let's see, where were we?

Oh yeah. We'd found some friends.

And then I fell asleep in front of my laptop. I have been driving soo much.

Autocross was brilliant, the course was fantastic even though I ended up coning out my last and fastest run.

https://scca-cpr.com/site/wp-content/uploads/2019/05/2019-cpr-ev02_raw.htm

I'll post up video later. I managed to convince me dad to come out and watch me run, which took some coordination but was well worth it. He's never seen the car.

Yesterday was amazing and exhausting. I decided I was going to try and make it up to Medicine Bow, Wyoming in time to see Union Pacific 4014 running on track. I got up at 630 and hightailed it up from Cheyenne, and then waited... and waited. Two hours after it was supposed to be there, the Big Boy steamed into town.

Wow. Just... wow. Worth the wait, I would say. Plus 844 is really beautiful in it's own right, but overshadowed by 4014. It's not hard to see why. I can barely fit it into the frame. It's utterly immense and pretty in much the same way a mountain is pretty. How can anything be this enormous?

Go see it.

In reply to dr_strangeland :

Based on my OneLap experience (which is also why I didn’t chime in at the time), you probably want to be two-up for a run like that.  Ymmv.

I had some success with an iPad, Bluetooth keyboard, and Snapseed for doing updates “on the fly”... would have been better if I’d gotten the pad’s GSM connection working.  Something to th8nk about if you’re going to attempt again.

Nice job with the pics, though!

re:trailer

Leroy Engineering trailers are becoming a bit popular.  Might be “open” and modular enough to setup for tires/gear and sleeping with some forethought/fab.

Thanks! And Snapseed is a good idea...

The hillclimb season started with a bang. This was on my first run of the 2019 season:

Media dump forthcoming. I need to get this thread caught up! I've been so busy just getting the car ready for the season.

I finally finished the racecar roadtrip album! Lots of new pictures in here.

https://imgur.com/a/2X8JNv4

Enjoy! I'm going to work on catching this thread up over the holidays. Merry Xmas :)

We're back!

The car has a completely new drivetrain: 

• 1999 engine from a JDM vehicle
• six speed from the same car
• OS Giken diff with a 3.636 ring and pinion

Serious other improvements have been made, I finally upgraded the front brakes to the 949 boxmount BBK with a 1" Wilwood master cylinder. Front sway is now a Small Fortune Racing tubular bar with modified 949 endlinks. I've also been pulling more weight out of the car and making a serious effort to fix the cooling issues with better ducting. 

This season might be fairly low key, planning on running all the Maryhill events (two with NHA, one with SOVREN) and Virginia City. Maybe Bible Creek, I'm not sure.