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02-05-2019, 12:36 AM | #199 | |
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I'm not convinced that we actually need the expansion tank return pipe so long as the upper hose is solid. It appears to be internally plumbed so that it acts as a proper expansion tank via the top hose, so I'm going to cap off the bottom outlet which is dimensionally identical to the outlet at the back of the external water pipe on the head. With the uprated radiator and significant additional oil cooling capacity I think I'd rather have the water velocity through the radiator than the scavenging effect from the overflow tank. |
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02-11-2019, 01:58 AM | #200 |
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Quick no-photo update: spent most of today analyzing the snippet of schematic that AEM sent me for their VANOS drivers and hundreds of potential alternative motor / solenoid drivers (the TLE5205 they use is only available as surface-mount and I don't want to have boards spun yet). Turns out that bridging the outputs of the cheap and cheerful L298 dual H-bridge driver provides nearly identical performance to the TLE5205, and the L298 is still available in through-hole packages.
Sometime this week I will prototype the IAC and VANOS solenoid drivers with parts I have on hand (woo! That never happens!) and hopefully the parts I need to finish the water and power steering cooling systems will arrive. Prototypes of the drivers should be good enough to deal with cam break-in, getting the car to idle, and the dyno tune / engine break-in. |
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02-11-2019, 11:01 PM | #201 |
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Here’s the day I’m having: I read the I/O table on the L298 wrong so my prototype only gives me half the outputs I need - I don’t have the inverted signal I need to drive the “close” solenoids. It’s halfway there but I need to add a transistor or something to invert the second input rather than just grounding it
Out of time tonight, will have another crack at it tomorrow. This looks like it’s going to work though! |
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02-12-2019, 03:13 PM | #202 |
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This is... far from my finest work. However! As a prototype, it's peachy. Here's a circuit diagram, omitting some of the L298's pins (Vs, Vss, GND, etc.): What this does: The 2.6k resistor acts as a pull-up to +5V. Since the Infinity gives me a low-side switched (i.e. either ground or high-impedance) PWM signal to drive the solenoids, this will be ~4V when the Infinity's output is "high" and 0V when it is "low". This signal goes directly to In 2 / In 4. The 1k resistor also acts as a pull-up to +5V, but it is grounded via the transistor's emitter. When the input signal is pulled high through the 2.6k resistor, the voltage present at the transistor's base allows current to flow from the collector to the emitter, effectively grounding out the 1k resistor and keeping the signal at In 1 / In 3 at around 0V. When the input signal is low, there is no voltage present at the transistor's base, so the 1k resistor is no longer grounded out and it pulls In 1 / In 3 up to around 4.5V. This means that In 1 / In 3 always have exactly the opposite input that In 2 / In 4 have, so the single PWM input gives me a pair of high-current PWM outputs, one the exact inverse of the other. Baddabing, baddaboom, I can drive the IAC and VANOS solenoids. Now to build two more and actually test this shit in the car. |
02-12-2019, 05:45 PM | #203 | |
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02-15-2019, 01:21 AM | #204 |
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WDS indicates that the VANOS coilpack has flyback bypass diodes in it, so this is a much simpler solution than using an H-bridge. I need to prototype this but I think it's pretty close if not something that'll work. |
02-16-2019, 12:17 PM | #205 |
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One general thing to always consider with a push-pull or bridge is to make sure there isn't a quiescent state where it sits with one side locked up.
Like with the ignition on and the engine not running. Not sure how this works with the stock DME, but you need to have PWM any time Vcc is applied. I heard the coils are good for about 30 seconds continuous. What I heard, anyways.
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02-16-2019, 12:41 PM | #206 | |
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02-19-2019, 02:52 AM | #207 |
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Lol!! i think my brain just exploded!
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02-20-2019, 08:26 AM | #208 |
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Your project brings new definition to the phrase "built, not bought"!
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2017 M2 - Camber Hubs, MPE, and some other goodies 2006 Z4M - Epic Tune / Eventuri CAI / Euro Headers / Stromung / FA 500 / AS SSK / Arc 8s 2004 Z4 3.0i - Gone, but not forgotten! |
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02-24-2019, 11:34 PM | #209 |
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Took a bit of a detour back to fabrication this weekend rather than continuing with the electronic bits.
First, closed up the power steering system so it's ready to fill: Second, made a little bracket for the oil cooler thermostat: Third, started adding the second locating brackets for the rad[s] support: I have the bracket and tube cut for the other side but didn't weld it up today. These will tie in to the bottom of the oil cooler support and should provide a decent frame for mounting the front splitter. |
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02-25-2019, 11:59 PM | #210 |
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Welded up the tube and bracket for the other side:
Not pictured: made a retainer clip for the block-off cover on the overflow tank's lower outlet. |
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03-03-2019, 08:57 PM | #211 |
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Made the other two h-bridge drivers I need (one each for inlet / exhaust VANOS, one for the IAC):
Tied in (just ~tacked for the moment) the radiator mounts to the lower subframe: The bars running under / beside the radiator is where the lower rad mounting tabs will be mounted. I feel pretty good about the quality of welds I'm getting lately - starting to really get the hang of TIG, I think. Good enough for these jobs, at any rate. I also realized that the IAC has a +12V input and one input for each of open / close solenoids, vs. the VANOS unit that switches +12V on the solenoid sides and have fixed GND supply. Need to check the WDS to see if the IAC solenoids have bypass diodes; if not, I can just run them backwards but I'll need to install the diodes on the driver. If so, I should also just be able to use the switched grounds on the h-bridge controller for them. e: WDS confirms that IAC solenoids do not have bypass diodes and that they're expecting low-side switching from the ECU. Bizarre. Last edited by mattfwalters; 03-03-2019 at 09:13 PM.. |
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03-10-2019, 03:48 PM | #212 |
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Some good results this weekend (thanks, once more, to my buddy Chris who came down to help again) - the car tries to idle on IAC now! Built a little flange to mount the three h-bridge drivers on and wired up some connector pigtails (+12V / Ground; 3 input signals, out + inv out for IAC, out + inv out for intake / exhaust VANOS controllers):
Wired up the IAC solenoid last night (for high-side switching, like the VANOS solenoids, unlike how they are driven by the stock DME), threw the battery on the charger, and when we went out this morning it fired up right away and tried to idle. We also put on the section 1 pipes so the rear wideband O2 sensor reads properly and it's now very obvious that the mixture is insanely rich on both banks. Couldn't get it to re-start until I realized the intake air temp sensor wasn't plugged in (ECU thought air temp was 0 degrees C); after correcting that it fired up again and sounded rich but better. It blew a bunch of ultra-rich smoke out of the garage. First time running with water in it, no leaks; now I have a short checklist before cam break-in and buttoning things up enough to get the car on the dyno: * ATF fluid in the power steering system so I don't blow up the PS pump * Figure out how to fix the input scaling on the rear wideband sensor to correct for what I assume is a pull-up resistor * Fix the base map so it isn't trying to run the car at 10:1 or richer at 1,400RPM * Put a connector on the VANOS solenoid leads, plug them into the h-bridge driver board, and verify that they're working properly It's been a good weekend so far, despite the time change. |
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03-16-2019, 06:54 PM | #213 |
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I figured out the Mystery of the Wideband O2 Sensor Scaling.
I set the Infinity up to look at the wrong input. It was reading one of the drive-by-wire pedal position inputs, so every time I stabbed the pedal the ECU thought the front bank was going super rich but when I was out of the throttle it thought the front bank was super lean. So! That pretty much explains things going pig-rich after start. Input scaling no longer required, it just reads properly now that I've specified the correct input. Imagine that. Added ATF to the power steering system and manually moved the rack back-and-forth a few times. I'm sure it needs actual bleeding but oddly enough have never bled a power steering system before, so need to figure that out. Advice about this process / BMW PS racks appreciated! Also, target of opportunity: cut, bent, drilled, and spot-welded in a bracket for the lower-left radiator support. Now I just need to set up VANOS, which I may actually do after cam break-in because the car is trying to run pretty nicely right now and there shouldn't be any problem with having the cams in idle / start position at 2,200 RPM, right? |
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03-16-2019, 09:02 PM | #214 | |
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03-17-2019, 01:29 AM | #215 |
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03-17-2019, 07:52 PM | #216 |
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I'm realizing that the VE tables the Infinity ships with are (1) for turbo applications; and (2) "safe" almost to the point of absurdity. I've taken 25% or more out of the VE across the board and for the first time today while revving the car saw 13:1 AFR. Soooo... yeah. Getting there.
Also realized that I had misconfigured the tach output so I did the cam break-in at ~3k RPM instead of ~2k2 RPM (was 2-pulse / rev and tach was expecting 3-pulse / rev so reading 1/3rd low). Whoops. It seems happy enough though. I added a switch for the IAC / VANOS controller so I can turn it off until right before starting the car, haven't wired up the VANOS control yet but I did put the pins on the wires so I think I'm going to do that on the dyno at this point. Car's ready for a dyno break-in and I need somebody with more experience tuning the Infinity + S54 to avoid doing something dumb. I will be calling my tuner tomorrow. Tonight I'm probably going to hang the rest of the exhaust in prep for dyno tune; I wanted to do the new fuel system first but at this point I'm dying to find out if this engine is as mean as it sounds. If I run out of fuel on the dyno, so be it. I may even bleed the clutch and brakes and throw the wheels on. I will not back it out of the garage and rip around the block. I will not back it out of the garage and rip around the block. I will not back it out of the garage and rip around the block. I will not... |
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03-19-2019, 09:31 AM | #217 | |
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What's a little rip around the block gonna hurt? Great work Matt!
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03-23-2019, 10:05 PM | #219 |
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Thanks, both!
So today I installed the whole SuperSprint system. I really, really, really like how it sounds now - still lots of rumble, but a bunch of angry rasp and growl too: This seems to have sorted out some of the engine's VE challenges while revving, hence the lean pops at the end of the video. Here are a few traces from the datalog of that run: Note the 18:1 flatlines after the last two throttle stabs Here's some SuperSprint porn: It's a good day, but man do I ever need to get this thing on the dyno. My tuner is currently on vacation so I'm thinking I'll probably just drop the oil and pull out the new front supports and get them all welded up properly tomorrow. That'll mean for sure that he gets back tonight and calls me tomorrow with the last open slot until June. |
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03-27-2019, 09:04 AM | #220 |
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SO great!
You've gone where few could or would go....such a build; is the Bronze Beast a track-only assault vehicle....or will I have the pleasure of enjoying seeing you on Seattle streets??
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