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  1. That's interesting that you mention that. I have the same unit triggered by an MS2 and have some weird power delivery issues, where the torque drops off rapidly, then come right back, producing a really oddball (and sorta disappointing? It makes 258whp but should be able to do more) power curve. Did you have the opportunity to dyno yours with the problematic MSD StreetFire? I'm curious what it looked like on your setup. Posted mine below for reference Some other members here have speculated that it is caused by noise coming in through the optical pickup on my L28ET distributor, but I originally was thinking it might be a problem with the MSD StreetFire unit. Now you've got me wondering... I've got an MSD 6AL box to try as well as a different trigger wheel for my distributor so I can basically eliminate either or both from my setup. Will definitely post back in this thread once I have more information.
  2. I don’t think there’s a known “safe advance map” for our engines, but what I said about timing slightly increasing after peak torque is a really common pattern. If you take your car to a dyno and have someone tune the timing, that’s how your spark map will end up. Guaranteed. In the meantime ensuring that your base timing is set right and then reviewing a lot of other tunes and staying conservative is probably alright. But you shouldn’t lose several degrees of timing as you run up through the RPMs. Also yeah it sounds like you’ve got a problem with your alternator or some kind of wiring issue. I mentioned that you may want to try to relay the megasquirt directly off the battery rather than scabbed into some other part of the electrical system (not that you’ve done that I obviously don’t know what’s going on with your wiring), that may help if you want to try something that should only cost a few dollars rather than needing to do a whole alternator swap. FWIW I’m running a 90A Gm 1 wire and based on datalogs I fluctuate a whopping .1v over the course of a very long drive, essentially keeping a rock solid 14v constant. That should be your goal and would probably be a decent place to start solving problems with your install. Definitely post results as you try things out and they get better. I messed with my L28ET megasquirt setup for quite a while before I finally started becoming happy and relatively satisfied with it. Good luck!
  3. Hi, I took a look at your log and tune and have a few suggestions - Your TPS doesn't appear to be calibrated right. It looks like you are going WOT and only achieving about 85% TPS - Your spark plugs are the wrong heat range. They are too hot, 6 is an N/A heat range. You should be running a 7 heat range plug like a BKR7E or BPR7E. 0.028 gap should be fine - Based on logs you make boost really late for such a small turbo. Is this just you only jumping on the throttle later in the powerband or is this where you have to be to make pressure? Do you have boost leaks? You should make or buy a boost leak tester and test. For comparison I am running a older, less efficient, larger frame turbo, and making positive pressure at 2k and start making decent power around 3k. - I'm not sure how accurate your wideband is but things look a bit fat under boost generally. I'm seeing high to mid 10 AFR's on some of your pulls, low 11s on others. Try to target mid to high 11s under boost if you can - Your spark map looks too conservative to me. In fact, all of your timing seems to diminish as RPMs go up. This is actually the opposite of what you want: Once you are past peak power, you should look to slightly increase timing to to carry power higher in RPM range. FWIW my tune on my L28ET (that I messed with on a dyno and whatnot but admit is far from perfect) is at 24 degrees advance at 180KPA, yours is between 22 all the way down to 18 depending on RPM. Again, FWIW, messing with my timing, under power, I was able to gain 5-10HP per degree of timing added - if something like that is true on your engine, you could imagine yourself dropping 20-40HP as you remove timing at the top of your powerband. Maybe this is some of the flattening out at 4500 that you're feeling? I'm not recommending that you just jump everything up to like 22 degrees at that load or whatever, but you should definitely review some other people's tunes and whatnot and consider tinkering with this a bit - I don't recommend running a tiny gap. I thought I was having ignition issues on the dyno, de-gapped a new set of BKR7E plugs to 0.020, and then fouled them out after only a couple of pulls, losing power after every pull. I don't think a single coil setup can reliably run this small of a gap. I slapped another set in at 0.028, got all of the power back, and then did several more pulls without issue. - Definitely fix the alternator issue or look into something shorted out and drawing too much power. I really recommend swapping to a 1 wire GM alternator. They are way cheaper than Datsun alternators, super reliable, and you can get them at almost any parts store. The swap took my less than an hour after my ZXT alternator failed. Highly recommend. No reason for you battV to be moving the way it is and I'm sure it's making megasquirt pretty angry. Test out your voltage in a few spots on your wiring harness. It might be that you just need to put the megasquirt on a relay more directly tied to the battery if you’re getting 14v elsewhere. According to the megamanual, your megasquirt should be powered off of a relay powered directly from batt positive itself and not from any other source. - Try a higher averaging lag setting on your RPM input, it might help it smooth out RPM input a bit. It's really shaky in your current setup. I've been messing with this on my tune too - Move your MAP signal, it looks a bit dirty. You may want to try moving it somewhere on the manifold where a single cylinder's pulses can't affect it so much hope you find this helpful wrenching on a megasquirt system can be both frustrating and reeally rewarding once the stars align and it finally works properly! edit: also wanted to note that you should separate your BOV and MBC lines. Generally people put their BOV on a dedicated vacuum line from the intake manifold, and then run the MBC/wastegate off of the charge piping or off the compressor itself if it has a nipple another note I just thought of: how are your grounds? In my experience, megasquirt gets angry with poor grounding. All of megasquirt’s grounds should be run back to the intake manifold and grounded together, separate from all of the car’s other grounds.
  4. It's hard to guess what kind of power an engine might make because there are a lot of variables in play, but you should be able to get a relatively close estimation by using your phone with a "dyno" app like pocketdyno, dynolicious, probably some others, if you can put in accurate weights, c/d, frontal area, gearing, tire size, etc. I'd recommend several pulls and average them together. Otherwise a couple of dyno pulls are usually only in the $50-100. That said if you are taking guesses before you start to get actual numbers, my shooting from the hip guess is 155whp, having looked at other L series dynos in the past...
  5. Was it running fine before upgrading the injector size? If so, after installing the new injectors, did you update the injector size in your general options in tunerstudio? You will likely need to do a bit of tweaking on the VE table as well in my experience
  6. I use a Schneider cam in my 240Z and I heard that they suffer from soft core issues. Because of this, I had my cam nitrided before installing it, and I also use high zinc motor oils, mainly rotella-T. I've got about 5k on my build and currently no signs of cam wear
  7. FWIW I have run 550CC RC engineering injectors on a stock ZXT rail without issue, controlling them with a MegaSquirt II unit. Definitely echo what cgsheen is saying about needing an aftermarket ECU. With stock ECU, you need to stay very close to stock-specced injectors and fuel pressure or you are going to have a difficult time
  8. Thanks for the help! I took your advice and dropped a recent log file and MSQ in to MLV, which I also attached to this post, and was able to generate the following scatter: I have MPH calculated for 3rd gear only and no actual VSS input which is why I only get a single line here. Otherwise this is looking to me to have a large scatter, like in the graph you posted. I am guessing this should look more like a solid line? So this would point to slop? I am guessing this is somewhat mechanically tied to the rotation of the distributor, so maybe switching to the diyautotune trigger wheel won't help a whole lot and I should be looking at other triggering approaches. I guess it's also worth noting that my RPM's jump around in a similar way to the other pic that you posted as well: edit: also, I did a fair amount of reading this evening and I wanted to note that I think you may be backwards on the lag settings: 100 is no smoothing, 0 is lots of smoothing. The MSQ I posted has a lag setting of 80. I looked around at some other L28ET MSQ files and I'm going to try out 50, which should add a fair amount of smoothing, and will see if that makes a noticeable difference with my setup. I'll also take another datalog and see if the RPMs are smoothed at all 2019-08-04_09.29.41.msq 2019-08-04_09.18.13.msl
  9. Thanks for the critique Tony! I really appreciate the detailed response and the suggestions Currently, the hoses to the turbo are 15mm hoses so I will look in to blocking off the internal bypass on the block. Are there any symptoms that I should expect to be seeing at the moment since I have the internal bypass open still, or is this merely a precaution? I'd not heard previously that re-circulating the rear coolant port into the lower part of the thermostat housing could help with rear cylinder heating issues. I was actually already looking in to having the costly head cooling mods done as I am noticing that cylinders 5 and 6 are definitely slightly leaner looking when I pull the plugs, which I suspect is due to hotter combustion chamber temps. I am going to try re-recirculating the rear coolant port to the lower part of the thermostat housing before removing the head and going through additional headache having it drilled out, etc, and see if this helps.
  10. Thanks for the info! I didn't know that the dizzy's pickup could be robbing much power if any. I am using a bone stock 280ZXT dizzy with Magnecor wires and MSD StreetFire ignition. I am definitely struggling still with power dips, as was seen on my dyno graph. Originally we thought that the tune was just a bit rich in those spots but that does not appear to be the case any more although I am getting the same dips in power on a re-dyno (no new graph to share, sorry, didn't make much more power although power is up a bit from smoothing out the AFRs and leaning things out a tiny bit). I was beginning to suspect that the MSD StreetFire was not able to produce a strong enough spark, but I'm glad to hear an opinion that the dizzy's lack of resolution itself may be at fault. Are there any simple tests I can do to rule out lack of resolution as an issue? I get that you're saying I should do a crank-mounted trigger, but as a stopgap, I've ordered the DIYAutotune 280ZX/300ZX optical trigger disc and will be installing it in the next week or two and re-timing the car to see if that helps with the power dips. DIYAutotune claims these are good for full sequential fuel and spark so this should be a worthwhile upgrade in terms of resolution. Additionally, I have a friend willing to let me borrow an MSD 6A box to replace my StreetFire unit to see if a stronger spark will help, but I think I am going to hold off on trying that until I see what the better optical trigger does for me. edit: Just want to note that looking at the datalogs with a few other people, I've been unable to determine any reasons why there are dips in power - the only things that ever show up on graphs are the dips in hp/tq themselves- AFRs are holding steady, spark advance steady, boost/MAP signal steady, MAT steady, etc so it really does seem like something mechanical or spark-related at this point.
  11. Yeah certainly the downpipe was too small and using the off the shelf MSA unit was a mistake. Definitely building a new 3.5" one is on the list and I am fairly certain it will yield a large power increase. According to logging on this dyno run, timing ranged from 18-20 degrees of timing under boost (it has a bit more advance higher up in the RPM's.) Bigger downpipe could definitely allow for a bit more here as adding another degree produced no more power at this boost level. I think I was likely also being held back to some extent by high MAT temps, which were reaching mid 130F ranges with approx 90F ambient. AFRs were mostly holding steady at low 11's but were in to the mid 10's where the dips in power occurred. Also want to say that the car is really a blast to drive. Very usable power here, accelerates nicely and pulls hard in every gear. I'm not disappointed by "only" making 258whp but will definitely be back at the dyno looking for more. Mostly I am really happy to have the car working properly and producing good reliable power at this point
  12. I've been lurking this thread for a few years and I finally have a dyno sheet to share! 1- car: 1973 240Z 2- State of the engine: L28ET, P90A head converted to solid lifter, 8:1 +1mm JE forged pistons, Schneider/MSA Stage III turbo cam 3- 258WHP @ 5760RPM, 16PSI 4- 262WFTLBS @ 4940RPM, 16PSI 5- short list of relevant mods if applicable: LoneWolf intake manifold, 240SX throttle body, .63/.63a/r 60 trim T3/TO4E w/ stage III turbine wheel, MS2 3.57 running MSNSE, RC Engineering 550CC injectors, Bosch 044 fuel pump, Aeromotive FPR, MSD StreetFire Ignition, Factory '83 280ZXT dizzy, crappy 2.25" downpipe to 3" exhaust, crappy same-sided intercooler getting doused in watermeth 6- anything else you feel might HELP OR HINDER your hp figures: The downpipe is way too small - pretty sure this robbing 30-40hp, needs a much larger intercooler, needs a heavier wastegate spring for more boost. Potentially could use a cooling mod on the head to run more timing. I will do some of these things over the winter and re-dyno next spring. edit: revisiting some of the data logs from these pulls, the dips in power at 4k and 5k are due to the tune going a bit rich in those spots. Those were also noticeable while driving. Obviously haven't been able to re-dyno yet and won't for a while, but I've fixed these on the butt dyno already.
  13. That actually might explain why my coolant temp tends to climb slowly following load, then relatively quickly drop back to thermostat temp after returning to cruise. Definitely interested in more opinions here if anyone has any
  14. Well I guess I should have scribbled that out, really a lot of that is from the original drawing in the cooling diagrams thread. I don't know the actual direction of flow there so that is likely wrong in the drawing (or right meaning my hose routing is nonsense?)
  15. Also, looking at the cooling systems diagram thread a bit longer, I do see that turning off the heater on an earlier Z would essentially block coolant flow from the back of the head so now I am thinking this is likely a fine setup to run on the dyno Thursday. Just trying to cross my t's and dot my i's.
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