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stupid_fast

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stupid_fast last won the day on July 19 2018

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  1. Other than a bit of a mishap installing the rear main seal, Gollum's new loaner motor ready to go. I dropped it off earlier today. Came out of a 240z in running condition that my buddies doing a v8 swap on. Had a pair of SU's and a points dizzy on it! To my surprise it was a P90/F54. Put front & rear seals and replaced the valve stem seals, installed an A cam and a newer OSK timing sprocket from my engine while I was at it. Looks like a clean original turbo motor, but there is evidence the timing chain has been changed at some point. Should be a good runner for Gollum to get some seat time while he collects parts for his swap.
  2. I'm usually driving to the track in my blue Geo Metro. I'll keep an eye out for your car as well! Won't be out at Sonoma for a while unfortunately.
  3. Leon, My first time in lemons was at the last Sonoma event in the rain, the E36 was fantastic to drive! Its a monster in the wet. I'm in the unicorns aint U's car #201. It'll be a couple months before I'm ready to go to the track with the z, after moving and all. Also waiting on funds for a new wheel & tire setup. I'll definitely let you know, it should be either sonoma or thunderhill. Probably will be with SpeedSF to start out as I've already gone to several of their events before. I'd be interested in some other track events as well, as long as they aren't super novice oriented. Open passing and plenty of run time makes me happy.
  4. Thanks Rossman, drifting is fun but the scene here is annoying me. There are a few Z's drifting out here as well, but they're not great cars for it. Here's a bit more details on the gearbox I blew up. The annoying part of all this is that I replaced the T5 since it was known to strip out gears! The S13 box was rebuilt before I installed it in 2016. It received fresh bearings, synchros and clearances checked to FSM spec. I also blocked off the oil passages in the sandwich plate (jb weld held fine for this) , and relocated the rear bearing oil scraper to 5th instead of on 1st to reduce oil transfer to the back of the box. Note, there were also two main shafts available. The top one has a larger diameter, and longer splines on the output shaft. I threw away the larger one, the output splines were twisted so I decided it was unsafe to use. Another topic from mid 2017, The turbo CV ends I had were worn out and making very loud horrible noises. They never completely failed, but the noise was unbearable for driving the car any significant distance. As the axles were over $700 each from Nissan, and rare to find used I needed to find a better solution. These were toast! My other pair were just as loud, even though they still had plenty of grease in them. So what's the solution? Most nissan CV axles used the same spline through the 80s and 90s. The 300zx CV joints aren't an option anymore, as they're either expensive from nissan or not available in the aftermarket. I looked at the Infiniti M30 based on a single comment I found here on hybridz. It has an R200 long nose with the same differential spline, and suspension similar in design to the z31. Its also a newer model, and it only came with an NA VG30e and automatic transmissions. Junk yard axles are likely to be in good condition. The stub axles are required to run M30 outer CV joints. They're similar to Z31, use bigger bearings and significantly larger spline. M30 on left, S130 on right. The M30 stubs kick out the track an extra 5mm, and the brake caliper requires a spacer to function properly. The next issue to deal with is the axle lengths, the M30, Z31, and pretty much all newer nissan axles are too long. The two shorter axles are S130, the longer ones are M30. The S130 turbo axle shafts are pretty much identical including the spline. The only difference is that the tripod bearings are pressed onto the s130 axles, vs c-clip fit for the M30. Another benefit, the CV boots are now readily available for $15 aftermarket or $40 from Nissan. The end caps are a pain to get off and on the first time, slap them against the tripod bearing a few times they'll pop off. They're press fit need to be clamped and sealed when replaced. I used sleeve retainer 640. haven't had an issue yet. The M30 factory axle bolts come with some sort of thread locker, so I always put more on when I replace them. $75 replacements are much better than paying over $1500 for a custom axle solution. S13 inner tripod CV joints are functionally identical to M30 outer CV joints. New aftermarket S13 inners are available for $40/each from febest. I've found that usually the outer CV joint wears out before the inner. Since I stripped out my gearbox before having an issue with one of these axles, I'd say they're strong enough for most use cases. The M30 long nose 3.91 also fits with minimal modification, just need to swap over the input flange & grind a bit off the casing.
  5. Leon, Thanks! Its nice to know someone finds my ramblings entertaining. I'll do my best to keep this updated as things progress with the car. Although I have all the parts, I'm taking my time rebuilding the gearbox for now as there's several tech discussions I need to go back and read. On another topic, i just ran another lemons race in my friends E36 on the Thunderhill 5 mile. I really want to get my z on that track and make it set some respectable lap times.
  6. The steering rack issue ended up just being a small installation oversight due to the way I put the center seal in, I had pushed it over the gear and it cut the seal. I assembled the rack from the other side of the main shaft and was able to get everything to seal up no problem. After a proper alignment on a nice dug-in rack and a new set of tires, I was ready to head to my next event at jackson county sports park in Medford Oregon. Dropped the cars off at the track, and went back to town to spend the night. We arrived at the track in the morning, attended the drivers meeting and I ended up being the first one on track, drove for a few laps and started getting comfortable and BAM! Stripped out 3rd gear on the initiation into the first corner. This is was a late KA / SR larger gearset. (there are two gearsets for the KA with the same ratios) I pulled the gearbox at the track, cleaned up the bits and resealed it and dropped it back in to drive home. A waste of a track day, but at least I got home without a tow. Luckily I have a spare gear set on the shelf, so all will be fixed soon. The blown gearbox being pulled apart. Here's my spare big gearset vs another early KA box I got. The big gearset is about 2mm bigger on each gear. The state of my new garage is bad as well, so lots of things need to be addressed before this thing will be back out.
  7. The all caps post is really annoying to read. Please structure your future posts better. There are no schematics available online for proprietary ECUs. The transistors are hitachi. From left to right D970, D970, B791, B566A You can figure out the resistor values by reading the color bands. The white resistor thing is marked 'ARW 0.5 ohmK JRM NK' The big one is marked 'RS3B 0.1 3 RIKEN Z' Your ECU may or may not work if the burned components are replaced, but its worth a try if you have the ability to do it.
  8. I was referring to Gollum's megasquirt logs. I've just updated the rom data translation spreadsheet with my more recent findings. https://github.com/eccs-reengineering/280ZX-Turbo-ECCS/blob/master/Rom Data Translation/S130T_ROM_Address_Translation.xlsx You're welcome to look, and if you have any questions about a specific table I can test the results of changing it. I've modified and tested almost every bit of used data while the engine is running to find out what it does. I've verified which maps are in fact used, and which are not by checking which tables are referenced and loaded by the assembly code. The next step is to verify if in fact the AFM is hitting its limit. If so, the real solution would be finding a way for the ECU to measure flow past the AFMs max flow capability. Edit, found what appears to be the injector constant (Generally referred to as the K constant in the Nissan world) it is a DWORD at 1F44 on the stock rom. Adjusting this dword changes fueling characteristics across the whole range.
  9. I made a mistake by saying 'air flow would be consistent'. I'm trying to figure out the explanation as to why there's a severe drop in AFR after a certain RPM, but the fueling would remain constant with a flat AFR target above that value.
  10. Ah every time I think I understand something I learn some new information. I've uploaded a video example of how the AFR targets react over the RPM range. This may illustrate what I've been trying to explain on the lean out above 4000rpm. Also the video is slightly offset from the innovate & address tracing, but it gives you a general picture of what the afrs are at a given target. 2019-03-15 13-20-35_Trim.mp4
  11. Good stuff, based on the megasquirt logs I've found the VE on this motor is somewhat flat from 4000 to 6000 so makes sense that airflow would be consistent. A minor detail to include for sake of information sharing; The S130 AFM uses an inverted signal, approximately 4.78v is the maximum with the flapper closed, and fully open is 84.2mv. I've verified these settings as correct within OEM specs across about 5 AFMs, including one that was factory sealed and the PCB traces in very good shape. There's a +8V reference from the ECCS unit, its also grounded directly to the ECCS unit not the chassis. I just need to find a passenger, I live far from most of my friends. I like the idea of logging for future modifications though. I'll check out the 944 data from tunerpro. If its a 3" bosch AFM, its quite possible it could be an identical unit mechanically, however I don't think any other cars in the era used the JECS inverted output resistor board. Although that detail is more prevalent to comparing code, and not so much the tuning side of things.
  12. @bradyzq I see, if the TP drop is normal then I may be maxing out the AFM's flow capability. L28ET torque curve on a stock turbo is from 3000 to 4000 rpm with the peak somewhere around 3600rpm, so it backs up what you're saying. My Multimeter doesn't have any logging unfortunately, its kind of difficult to check a voltage meter while driving. A logging oscilloscope also works, but I don't have one that interfaces with a computer. The best approach I thought of would be to log not only the AFM 0-5v output, but also RPM. That would give the most useful data. At least I can correct the top end fueling using the data, and don't have to get a rising rate FPR. Re:quattro, I think I understand now, the fueling tables make a lot more sense if continuous injection is factored in. So the ECU fuel control is more for closed loop correction and enrichment in boost using the map sensor. I was wondering why it was missing any kind of VE table.
  13. Useful info, thanks. I agree I don't think the ECU is actually dealing with a KPA scale. For tuning purposes, it helps put the tables into perspective and compare to other timing maps and megasquirt logs. I got a little overexcited that the TP scale was matching up to kpa almost perfectly. Good info on the BMW stuff, I'll look into it. Maybe someone figured those out and that knowledge will help decipher the code here. The main reason I referenced the Audi ECM is because it uses the same hitachi chipset, not because its a similar EFI system. I believe those are a primitive speed density system from what I could tell ... I think you're referencing a different mechanical injection system which were somewhat common in the 80s. I believe some Volvos also used the system you're describing. The AFM as I can tell hasn't maxed out, as my fueling with flat targets from 4400 to 6000 are pretty consistent and don't lean out much in that range. In that range the afr change is maybe 0.4 from 4400 to 6000, not what I'd expect if the AFM was at its maximum but I've been proven wrong before. I need to get something like the Moates SuperLogger or an Arduino with custom code to communicate with Tunerpro so that I can get some proper logs of what the AFM input is actually doing. My current logging system is primitive at best, using the Innovate AFR output and tracing rom address hits. When I get my car on a dyno we should have a better idea of how much flow I'm actually pulling through it. The fact the calculated TP drops steadily after 4000rpm seems to indicate the ECU is off somehow, but everything in my setup is pretty much as good as you can get it and there's just not enough of these systems around to compare my results. I haven't spent enough time cruising above 4000rpm to check if the AFR targets are accurate at lower load. Z31 ECCS employed a VQ table for the MAF, I believe they may have implemented that due to the fueling error on the s130. There's some lingering unused data on one of my 1982 ECM's that seems to imply they were trying to implement a similar feature. I no longer use spring tension for tuning. I set the spring tension so the AFR targets are dead on from 10kpa to 120kpa, up to 4000rpm. I briefly documented this on the last post on page 1. This method works for best closed loop operation and overall driveability in cruise ranges. Correcting the top end & boost areas by adjusting the AFR target table I get repeatable results, I can slap a factory sealed AFM on and will get the same AFRs. The later E36's and some other cars also have WOT maps, its pretty common to have multiple fueling maps. As you say, it won't work for turbo unless its some kind of an enrichment table based off of manifold pressure ... Now that would be interesting.
  14. After chatting with Gollum about tuning and pouring over his megasquirt logs and comparing our timing charts, I got familiar with KPA. I noticed something very interesting, the TP scale in the ECCS acts a lot like a KPA scale. With some logging I compared it to the vacuum gauge, with an in/hg to KPA conversion table handy it looks that my hunch is confirmed. The TP scale does convert to KPA! So, here's some factory tables with the converted KPA scale for reference. Please note, above 3600rpm and above around 120kpa the AFM is very inaccurate. The KPA scale is accurate in same ranges that the AFR targets are accurate. Also note in later ECCS models this is a 'theoretical pulse width' scale, and not KPA. But its interesting that it does follow KPA in stock configuration.
  15. An update, which will be expanded upon with more technical posts later on when I'm able to dig into it. With a rebuilt rack after the failure at my last Thunderhill west event 9/23/2018 I rebuilt my power steering with all new seals. The pump was also rebuilt including a very expensive OE reservoir cap to fix all my leaks. On returning to Thunderhill west a couple weeks ago on 3/17 I show up to the track, turn my car around in the pits to unload my track gear and there's a puddle of ATF on the ground. The rack blew out before I even got it on track! The driver side boot was full of ATF, same side that failed last time. Unfortunately with the smog test due and some other personal things getting in the way I have no time to fix until later next month, I'll be recording here and hopefully finding a mistake in the rack rebuild that caused the seals to blow out again. I still ran on track, just removed the PS belt & drained the rack. In car footage will be on youtube once I get around to splicing all the good bits together. Anyway, its been a long time since I washed my car and I finally did it today. Also haven't taken many pictures of the car in its current state. Goes to show what a bit of cleaning can do even to a beat up car!
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