31 Oct 2014

A dry sump system is on hold because there is a port in the engine block that has to be drilled, threaded, and plugged. Depending where it is, the concern is introducing aluminum chips into the oil galley. Balance that with: what’s peace of mind worth? Dry sumps are run on any car that sees high G loads, which Midlana certainly will on sticky tires, so this needs more digging.

Spent a few hours testing boost-by-gear; the good news is that it works pretty well. The bad news is that the boost control valve everyone uses isn’t that great (or it’s not being controlled well); it’s an industrial vacuum/pressure control valve that isn’t intended to be used proportionally. The issue is that the exact opening depends upon a lot of things, engine temperature and weather can really mess with an open-loop setup, resulting in boost that varies by as much as 20% – that’s a lot.

Lastly, I found out why the air/fuel ratio (AFR) was so stable – the O2 sensor’s bottomed at the low end of its range! It turns out that the range of the Honda (Denso) AFR sensor is from 11.5 to 20:1, great for a street car, not great for a turbo car because they’re tuned to run right at 11.5:1 at full throttle – basically pegged at the low end. The somewhat good news is that I have an Innovate handheld unit that uses a Bosch AFR sensor that works down to 10.5:1 (and no, I can’t just swap that sensor for the Denso – it requires custom circuitry in the ECU). Just for knowledge sake it might be interesting to know what the mixture really is, but what would I do about it once I know? The AFR was originally set to wherever the tuner felt was best. With water/meth, it’s richer, but so what, because what do I want the AFR to be if the water/meth quits working? The answer is I want it to be the AFR that my tuner originally set it for, which means that I shouldn’t mess with it. A plus for this argument is that the car runs great right now – rich or otherwise – so I’m not real motivated to lean it out any.

As I learn more about turbo engines I’m becoming less impressed with the Hondata KPro ECU. It makes the best of the hardware that it has, the existing Honda OEM interface circuit upon which it’s based, but there’s only so much Hondata can do with it. Imprecise boost control, an inability to do flex-fuel, and traction control being an expensive add-on, I’ve started looking into better standalone ECUs. I’ve got one in mind – we’ll see how it goes.

27 Oct 2014

Forgot to mention that I got a sheet rock screw in Midlana’s rear tire yesterday. Plugging it was easy enough but the concern now is, will it be okay at 150+ mph? The shame is that it only has maybe 3-4000 miles on it. Hard not to wish bad things on lazy/dim-witted construction workers who throw open boxes of sheet rock screws into the back of their stake-bed trucks, with them rolling around until they drop onto the street… grrr…

In other news, I was getting gas at the local station and heard an obnoxiously loud car tearing by. Expecting to see a lowered Honda, it was surprising to instead see an Arial Atom. I’ve seen the car twice now so he lives around here somewhere… it’s only a matter of time. By being so annoyingly loud, he’s already lost in my book, because it tips his hand, that he has neither a turbo nor supercharger… excellent.

26 Oct 2014

Good news, mostly:

Filled up the water/meth tank and spent the day testing and tweaking the system. The water/meth flow gauge worked well, with user-defined thresholds for too-much and too-little flow from zero to max. Once that was set up and working, numerous runs were made while slowly increasing boost. The good news is that it’s currently at 19 lbs, with traction in third gear now getting a bit iffy.

Now the puzzle: Using a mixture of 50/50 water/methanol, the water handles most of the cooling while the meth serves as both coolant and high octane fuel (supposedly it makes 91 octane act like 110 octane). Because the methanol is consumed, the total fuel mixture becomes richer since both gas and meth are being burned, which typically requires leaning it out a bit. So it was surprising to find that the Air Fuel Ratio (AFR) was the same whether I enabled the water/meth or not…

– I know that the mixture is getting consumed, the AEM flow gauge and logger show 1000 cc/minute being delivered to the two 500 cc nozzles.

– I know that the water/meth mixture is 50/50 by volume (ignoring that it’s not 50/50 chemically, but this doesn’t matter much).

– The level in the water/meth tank level dropped, so the mixture is definitely being consumed.

– Thinking outside the box, I suppose that the water could have separated from the methanol, settling to the bottom of the tank and being consumed first, but I really really doubt that happens since methanol loves water. So I don’t get it. With the days getting short that’s where things stand now. I’ve got a couple posts on car forums asking what could be going on, so that might be interesting.

In other news, during testing I took the same road where I drove my brother’s car last week. In Midlana it was a completely different road, with none of the kidney-jarring bumps. I keep telling my brother to fix the rear axle travel so that quites bottoming out and he says it’s in the works.

As a last note, I took Midlana onto the freeway, tearing up the onramp just because I could. Cresting the top, off on the right was a motorcycle cop having a talk with someone who’d just spun his car off into the weeds. Unfortunately right when I crested the hill the cop happen to look my way. I think several factors played into me not getting a ticket today: he was off his bike, already busy with someone else, and there was a lot of traffic noise so I doubt he heard me directly. But, he obviously saw me moving rapidly along and started to make a gesture. It was as if he was going to flag me down but half way through it decided that I had just barely squeaked under the threshold by this much. I waved, acknowledging us seeing each other and that I understood I was cutting it really close. And yes, I did watch my mirror for a while…

20 Oct 2014

Mid-afternoon I headed out the door to visit mom and in front of the door was the turbo, one of the very few times we’ve received a Sunday delivery. Meh, it’s been several weeks so another day won’t matter; I went to visit mom then installed it after I got back. Since the wastegate springs were changed again (to even lower boost), the first order of business will be calibrating the boost solenoid duty cycle versus boost pressure. After that it’s time to calibrate the water/meth system, when the real fun begins 🙂

19 Oct 2014

The turbo is still on the way so I made valuable Wife Points doing chores.

My brother stopped by in his LS3-powered Stalker and let me drive it – I’m not sure where to begin. The two cars are different in just about every way besides weight and horsepower, though how even that power’s delivered is different. The Stalker has tons of torque everywhere while things get going in Midlana above 3000 rpm. The different chassis layouts and the suspension makes it tough to compare, but if I had to come up with one analogy it’s that Midlana’s like a Ferrari and the Stalker’s like a race version of a 1963 427 Corvette (I got a ride in one time). Driving the two over the same road is an experience in opposites; Midlana soaks up the bumps while the Stalker’s rear axle threatens you with back surgery. One difference is how different his modified transmission is than mine. I’ve tried several times to find someone who’s got experience with my transmission to see if it’s acting normal or not – still haven’t found anyone. Shifting in my brother’s car is just a matter of lifting off the gas and shifting “with authority” – it goes right in with a muffled “bang.” With mine, it goes in with a much more harsh “Bang.” I don’t know, maybe mine’s fine and I’m just being overly sensitive, but it certainly is different! What’s disappointing is that my brother doesn’t fit in Midlana (in either seat!) as I’d have liked to hear his impressions, but oh well.

In other news, it was pointed out that just because there were 18-wheelers at Laguna Seca didn’t automatically mean that the drivers were millionaires. There are “arrive and drive” services where they’ll bring, prep, and service a car for you to race and all you have to do is show up. That’s pretty sweet, but a season of that’s got to be pretty expensive. Or maybe I just need to take up gardening… either way, trackdays are enough for me.

14 Oct 2014

Just got back from the SCCA Runoffs at Laguna Seca. It was the first runoffs that we’ve attended because they’re nearly always on the east coast or midwest. Personal impressions were, mmm, mixed:

1. Like autocross and trackdays, other than direct participants and their crews, there were few spectators. Judging from the large number of vendors and the lack of lines, I doubt any made much money. We wondered what’s wrong with the SCCA and Laguna Seca; why didn’t they offer a really low price for locals, like $20, instead of the nearly $100 (Disneyland does this all the time with lower pricing for locals). It would do a world of good to get people in to experience what it’s all about instead of casting it as an elite sport that attracts mostly, well, rich people, which leads into #2.

2. We were shocked how many huge car haulers there were, enormous 18-wheelers that held several cars plus complete onboard garages. Oh, there were some amateurs, out in the dirt lot with either a small motor home or just a truck and trailer – our people. I guess we were left with a somewhat bitter taste which only reinforced the feeling that we made the right decision years ago not to get into real racing. I mean, how much of a chance does a privateer have against a business-backed tax write-off where just the transporter costs $500,000. It’s sadly taken much of the “amateur” out of amateur racing, which leads to #3.

3. The Spec Miata race was okay, though neither of us gets very excited about a race where the only difference between cars is color. Sadly, all the excitement came after the race when the top 9 or so finishers were protested. Post-race engine teardowns found that nearly all of them had the same illegally-modified cylinder head. It turned out that everyone got their heads from the same machine shop (ironically, the owner of the shop was in the race as well) and probably had no idea they were illegal. It came down to the machine shop interpreting a rule one way and the inspectors interpreting it differently. Then there’s the issue of how in most races, if you’re found making illegal modifications, you’re truly disqualified – out, finished, through, off the list. However, for some reason all but one of the rule-breakers were moved to the bottom of the standings instead of being disqualified. All it did for me was underscore the feeling that not getting into this sport was a good idea. From all the strong remarks on the Miata forums, one has to wonder if the high blood pressure and high cost is worth the “fun.”

4. Other than all that, there were some really fun races, especially H Production race which included “normal” cars of all sorts of makes and models, though even there it’s hard to root for any particular make because many have ballast added due to the rules. That’s fine, but it skews the results in drawing any sort of conclusion about whether the Honda CRX that won is really any “better” than the Toyota Yaris that finished second hot on his heels.

5. SRF – Spec Racer Ford – was very interesting because without their shells they bare a striking similarity to Midlana – if it was a single-seater. I didn’t know anything about these cars when designing Midlana, though it wouldn’t have matter much. Of course, it does make one wonder about how a body shell similar to an SRF would improve top speed on Midlana, but that goes back to the question that’s already been bounced around: how fast do I really want to go? With the increased boost I’ll be at 150-160 mph at Fontana. My brother, with his now-400+ horsepower car is wondering the same about his car… At some point, mortality starts intruding into the picture!

6. Because the runoffs probably won’t be back to Laguna anytime soon, and because we had never done so before, we sprung for a suite “to see how the other half lives.” Wow, was that a new experience; people paid to be attentive, air conditioning, good food and drink, an unimpeded view of the last corner and front straight, indoor and outdoor shaded seating. I couldn’t help but have some fun with that, asking if I had to be careful to not spill wine on the commoners below, or “hey, if I drop a piece of bread down there, will the peasants fight over it?” Notice the last picture; in our suite we saw race results but in the simi-peasant suite next door, they were forced to watch what appeared to be daytime TV…

Here’s a driver who pulled off after he broke an axle or diff the last turn, safely pulling outside the fence where his wife could come talk to him. I can only imagine the conversation, something like, “And this is going to cost us how much?!”

On the way home we passed this place. You know the almonds you buy in the store? Literally billions are shelled each year and here are some (the facility is enormous, with this shot showing only about one third of the operation. This facility was on the aptly-name Brown Material Road. Not sure what they do with the shells… mulch? Compress it into “fire wood?”

In other news, the turbo shop reported that the turbo is good, so the oil must be due to excessive crankcase pressure – so be it. Two -12 fittings will be added to the cylinder head and run to a breather can that’ll separate the oil mist from the gases, then the gases vented out under the car. The turbo probably won’t be back in time for this weekend but the cylinder head breather and catch can will be worked on.

There’s a “car handling, skidpad, drifting” class as Willow Springs on 1 November. The timing isn’t quite right but this type of event is exactly what I’ve been waiting for, finally allowing figuring out the handling limits of the car. There’s nothing like getting a car into a slide to truly learn its personality.

5 Oct 2014

The water/meth installation is complete and has been checked out as much as possible short of road testing. The flow meter is calibrated and works well – a few people having written that it’s saved then several times. The thing about water/meth is that it makes 91 octane fuel act like 110 octane race gas, where boost and timing can be cranked up to make crazy amounts of power – until the water/meth flow stops. Even with the flow monitor – which instantly has the ECU back off on boost – I just can’t bring myself to run things too close to the edge; boost will be increased but timing will be left alone. As a side note, during calibration of the flow meter, I was surprised how quickly it ran through a gallon of distilled water; I’m glad I made the tank large, 2.8 gallons.

With the turbo at the retailer for testing, other odds and ends were completed, one being to add a latch to the glove box. I always wondered how cops would react, after asking me for registration, to me getting out of the car, opening the front hatch, and opening a bag of “stuff” to retrieve it. Not wanting to get Tazed or shot, a functioning glove box is a much better place for registration papers. The other completed task was swapping in 30% stiffer suspension springs. Still left to do in that department is heating up and bending the suspension arms to free up room for stronger steering tie rod ends. However, the current Santa Ana winds and temperature make being in the garage no fun at all, in spite of the “but it’s a dry heat.” That may be, but welding or using a gas torch push it into “being miserable” territory, and this is supposed to be fun, so it eventually chased me out of the garage.

After sending off the turbocharger, it was pointed out that there’s a pretty good chance that there’s nothing wrong with it, that the real problem may be that the engine block/cylinder head isn’t being ventilated sufficiently. At higher boost, there’s more blowby gases and if it can’t get out fast enough it can raise crankcase pressure. What can happen is that pressure flows back up the turbo oil drain line to the turbocharger and applies pressure to the backside of the oil seal, pushing oil past the bearing and into the intake tract – instant blue smoke and oil residue in the intake tract. Or, it might just be a defective turbocharger, I’ll have to wait and see. What’s promising is that the vendor tests the unit the right way, pressurizing the oil circuit and monitoring for pressure drop. The only concern I have is the potential conflict of interest, where if they say it’s fine it cost them nothing, but if they say it’s defective it’ll cost them quite a bit – I’ll be very impressed if they say that it’s the latter.

In other news, my brother sold his plane, a combination of lack of time and the expense taking the fun out of it. When he flew it to the new owner it averaged over 28 mpg at 200+ mph, which is phenomenal for an airplane. I asked how he felt about selling it (knowing that he’d probably never have another) and he just shrugged, sort of a “it was fun but with the LS-powered car nearly done, that’s enough for me.” He was happy that he was able to sell it for nearly exactly what he had in it – can’t complain about that.

The GoPro 4 came out today. Comparing specs I don’t see a good reason to go with the Black model which sports 4K resolution. Hardly anyone has 4K TVs yet and nearly all videos get uploaded to YouTube where they’re compressed down to 1080P anyway. I don’t think the shift to 4K will happen for several more years and between now and then GoPro will have better stuff, so I’m not falling for it. However, I will probably get the White model which is $100 less and has a rear video monitor that the top of the line unit doesn’t. The only downside is that it doesn’t offer 120-Hz frame rate at 1080P, useful for slow motion videos, but does have 720P at 120 Hz, good enough for YouTube. So with cooler weather on the way and the addition of a better camera, you’ll have something to look forward to instead of just endless blathering 🙂