Guest vegas datsun Posted November 27, 2006 Share Posted November 27, 2006 Holy ♥♥♥♥! Nice car Tim Quote Link to comment Share on other sites More sharing options...
v8dats Posted November 27, 2006 Share Posted November 27, 2006 wow great numbers! love that l28! Quote Link to comment Share on other sites More sharing options...
Garrett76Zt Posted November 27, 2006 Share Posted November 27, 2006 Congrats Tim! Now get that thing to the track so I know what I'm up against, hehehe. Again, Awesome numbers man! Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 28, 2006 Share Posted November 28, 2006 oh yeh.. Tim.. is this pump gas? race gas? methanol or water injection? nitrous? Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 28, 2006 Author Share Posted November 28, 2006 oh yeh.. Tim.. is this pump gas? race gas? methanol or water injection? nitrous? Sunoco 94 octane pump gas. No water or meth injection, no nitrous. The amient temps were a bit low - ~50degF. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted November 28, 2006 Administrators Share Posted November 28, 2006 You know how these BMW guys can get! Sure do Nice job Tim! Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 28, 2006 Share Posted November 28, 2006 Awesome job, Tim! Overall, are you happy with that Tec system? I've always wanted one of those, but it was always out of my price range (and possibly my installation skill level...) In an attempt to help solve your tuning problems, allow me to ask: would less backpressure really make for higher manifold temps? I would expect the reverse, but that's just my gut feeling. Is it plausible that your new probe location closer to the turbo would be reading higher numbers than it was? I read in your first post there was some confusion about the BHJ damper marking time correctly, then you saying that you were surprised at how much timing you were able to run. Are you sure you've got it right after all? I'm just trying to be helpful, not mr nitpicky guy, sometimes it helps me to hear stuff from somebody else when I'm stuck... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted November 28, 2006 Share Posted November 28, 2006 wowzers there batman!!! That motor is INCREDIBLE!!!!!! Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted November 28, 2006 Share Posted November 28, 2006 I'm with veritech, reduced back pressure should mean reduced EGT (PV = nRT), and more timing should be increased EGT (the charge has longer to burn so tends to do so more thoroughly?). Re boost creep, remember that most commonly occurs when the wastegate cannot vent from the amount of gas coming out of the engine, down to the amount of gas needed to maintain the compressor PR. If you increase PR, you need to vent less gas, and I think the problem will go away. Best of luck with it all, Dave Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 28, 2006 Author Share Posted November 28, 2006 Awesome job, Tim! Overall, are you happy with that Tec system? I've always wanted one of those, but it was always out of my price range (and possibly my installation skill level...) In an attempt to help solve your tuning problems, allow me to ask: would less backpressure really make for higher manifold temps? I would expect the reverse, but that's just my gut feeling. Is it plausible that your new probe location closer to the turbo would be reading higher numbers than it was? I read in your first post there was some confusion about the BHJ damper marking time correctly, then you saying that you were surprised at how much timing you were able to run. Are you sure you've got it right after all? I'm just trying to be helpful, not mr nitpicky guy, sometimes it helps me to hear stuff from somebody else when I'm stuck... Thanks for the input. The backpressure thing seems odd to me too, but it's the most obvious thing that has radically changed from my old setup. Well, that and the new EGT probe and probe location (well, not radically different, but different nonetheless). The main reason that I was suspecting the lower backpressure was that I suspect that I'm now past the "crossover" point, such that my exhaust manifold pressure is now lower than the intake manifold pressure. This could make things act significantly different from before - for instance there should no longer be any problems with exhaust gas reversion, and depending on how low the exhaust manifold pressure is, I could actually have 'blowthrough' instead, as is sometimes the problem with supercharged engines. I have not yet had an opportunity to measure the exhaust manifold pressure, but hopefully I'll be able to get to it soon. It's also certainly plausible that the new probe could be reading differently than the old one, although I would expect that this would mean that I always had the higher EGTs, and the old gauge just didn't register them properly (i.e., I suspect that the old gauge would have read too low, rather than the new gauge being too high). I've verifed that the timing is now correct, first by verifying true TDC and that the pointer is exactly at "0" degrees on the damper, and then by locking the timing down to a single value and verifying with a timing light. The thing that was most surprising to me was that the new, correct timing should be 4.5 degrees advanced from the old timing already (i.e. 0 degrees indicated on the old setup was really -4.5 degrees), and I still ended up with higher advance numbers than the old map by a fair margin. So far I'm pretty happy with the TEC3, aside from some small issues, like the latest firmware rev changes the idle controller algorithm to be backwards for a previously working GM IAC. They don't admit that this is the case, but it appears that it is - rewiring the IAC is the only way to get it to work for most. It is really nice to be able to run in full sequential mode, rather than the phased sequential mode that was the best available from the TEC2 - you can get acceptable idle performance from a much larger injector this way - I never would have dreamed of using 150lb/hr injectors with the TEC2. For the most part, the TEC3 sets up very similarly to the TEC2, so there wasn't much learning curve required there. Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 28, 2006 Share Posted November 28, 2006 I was thinking it was either that your old probe wasn't getting a good reading, or it was possibly hotter in the new location, right by the restriction to exhaust flow than it would be upstream a little bit...What is the usual solution to the blowthrough problem you are describing? Changing the cam to one with less overlap? Are you stuck just reducing the boost pressure at that point? Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 28, 2006 Author Share Posted November 28, 2006 I'm with veritech, reduced back pressure should mean reduced EGT (PV = nRT), and more timing should be increased EGT (the charge has longer to burn so tends to do so more thoroughly?). Re boost creep, remember that most commonly occurs when the wastegate cannot vent from the amount of gas coming out of the engine, down to the amount of gas needed to maintain the compressor PR. If you increase PR, you need to vent less gas, and I think the problem will go away. Best of luck with it all, Dave Thanks Dave - I was hoping you would chime in. In my experience more advance means lower EGTs and less advance means higher EGTs, so I'm not sure what you mean there (longer burn should translate to more energy transferred to work, thus lower temps when the valve opens). The boost creep thing is pretty strange - it seems to be keeping the same characteristic regardless of PR - it had pretty much that same ramp rate with the boost controller turned off as is does now at 20psi. Just with different pressure offsets. I think you can kind of see this in the last HP plot, where the thin line reference is a previous run at lower boost. Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 28, 2006 Author Share Posted November 28, 2006 IWhat is the usual solution to the blowthrough problem you are describing? Changing the cam to one with less overlap? Are you stuck just reducing the boost pressure at that point? I'm not sure - I've never had that problem before... I don't know that blowthrough will necessarily result in higher EGTs, but it seems logical that it might - maybe from fuel/air mix continuing to burn in the manifold (?). I was kind of hoping maybe somebody has had some experience with this - we must have some V8 supercharger guys here, right? Hell, there are even a couple of superchaged L6s here, and I even know who he is... Quote Link to comment Share on other sites More sharing options...
speeder Posted November 28, 2006 Share Posted November 28, 2006 Tim, We never put an EGT guage on kjones' supe'd car - I was always curious as to what numbers would be seen. Ken's cam is pretty big, with way more overlap than a turbo cam...and max boost seen so far is 14 psi. Also, he's making nowhere near the power you are, so I'm not sure what conclusions could be drawn. I'm currently battling high EGTs on the turbo car also, even having swapped guage types like you did. At 22 psi boost, 1650-1700F is measured at the center of the turbine inlet on my 1/2" spacer, probably about 4 inches from the nearest exhaust valve on my BAE log manifold. This is with temporarily cranking in as much advance as I dare to try (25-26 at max boost with double and triple checking base timing), and even with with lowering AFRs down to the 10.5 range. Scary, but things are holding together...Of course, this is with a smaller turbo - mine's only a T67 with .63 A/R turbine. Not much help here, I'm afraid. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted November 28, 2006 Share Posted November 28, 2006 Tim, Good point re longer burn meaning more work, meaning lower EGT. I've never played with an EGT gauge, but that makes sense to me. It also makes sense that blowthrough would result in higher EGT due to burning in the exhaust manifold. A simple way to decrease blowthrough is to reduce the turbine housing A/R. This creates more of a restriction to flow, and will increase exhaust manifold pressure. Plus you get the added bonus of better response. Maybe a 1.01 housing just to test? Dave PS. I am sick, so I apologize if that doesn't make sense. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 28, 2006 Share Posted November 28, 2006 Looks good Tim, I would go to the 11.5 AFR, and make sure you have someone outside the car on the dyno to listen for detonation---we just spent a few hours at Dynamic tweaking on JeffP's setup and he couldn't hear the detonation that both the dyno operator and I could hear while standing beside the car on opposite sides. Matter of fact, the ONLY detonation Jeff heard was on the last run of the day at 20psi. It came on at 6300 and I gave a fast "CUT POWER" signal because it was on HARD, but Jeff "just started to hear a few pings" inside the car! So have a second set of ears listening. Jeff was a bit underwhelmed at his passes, he was making about 525 at 16psi of boost at 6800 rpms, and that moved up to around 565 at 20psi, but with detonation stopping the run before 6300rpm, which was 600 rpm below it's peak point, the graph was still climbing at that point when the run was shut. We noticed on his that anything in the 10's was down on power, and that power was rising between 11.0 and 12.0, depending on where the curve was, some places made more power near 11.4, others made more power around 12.4 so its not a single number for all points on the graph. One thing we did notice was his in-car WBO2 was reading 10:1 when the dyno five gas was showing 9.5:1 and lower, so the span on the older DIY kit may not give the best, truest resolution below a 10:1 AFR. Some places were 10:1, others were 9:1, 9.5:1, etc... seems power will drop precipitously below 10:1 AFR, no matter what (think that is obvious). There was some flutter in the BOV at 20psi, and it had been a long day so he called it a day at that point to cogitate on the curves and the datalogs taken on the last few runs. Have to make a few more tweaks, check some more things, and go back for another (hopefully final) session to dial it all in through the whole range. What is it, after thanksgiving everybody has time to make it to the dyno? LOL Quote Link to comment Share on other sites More sharing options...
jgkurz Posted November 28, 2006 Share Posted November 28, 2006 Tim, All I can say it Wow. That kind of power level on pump gas is quite an accomplishment. I aspire to achieve a fraction of your results.... My understanding is that boost creep is caused by the wastegate not being able to divert enough exhaust gas away from the turbine. Typically this is caused by a wastegate that is too small. I'm sure everyone knows this. Your 60MM WG and the way you have it plumbed to your header make this an even stranger problem. Your setup should easily support your goals without boost bleed or creep. My guess is that the GT42 is moving so much more volume through the engine that the boost controller gain and/or duty cycle needs to be adjusted to compensate for the flow change. BTW, I found this website very informative on wastegates. http://tinyurl.com/yg5kdh I have no idea why the EGT's are so hi. I know speeder has struggled with this also so maybe it's related to cam timing or the split pattern profiles we all run in turbo L28's. I know this is a stretch but there has to be something else causing the hi EGT's other than AFR's. We should not have to go below 11.5 to get normal temps. Lastly, I'm not sure why you need larger than 72lb/hr injectors. At 50psi and 77lb/hr you should be able to support 673 crank HP at 80% duty cycle and .55BSFC. This is according the the RC Injector site. If you go to the 150lb/hr won't you start having idle control problems? Maybe you plan on making way more power than your charts indicate? If you really want to get tricky you could use the staged injection capability of the Tec3 and add a second set of injectors. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted November 28, 2006 Share Posted November 28, 2006 John, Tim needs larger than 72/77 ld/hr injectors because his turbo is capable of ~850hp. Dave Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 28, 2006 Author Share Posted November 28, 2006 John, Tim needs larger than 72/77 ld/hr injectors because his turbo is capable of ~850hp. Dave Short answer on the injectors (I'm at work) - ~630 hp number given earlier would translate to around 740hp at the crank. So that agrees pretty well with the limit for six 77 lb/hr injectors. The 150lb/hr injectors are definitely more than I need - hopefully the fact that I can run full sequential will mitigate the idle issues. I'm also hoping to run them at a bit lower base pressure. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted November 28, 2006 Share Posted November 28, 2006 hopefully the fact that I can run full sequential will mitigate the idle issues. I'm also hoping to run them at a bit lower base pressure. Gotcha. For some reason I assumed the 630HP was crank HP. I've thought of running full sequential with my Tec3 and one option I have found was a cam timing sensor that Ron Tyler (on this forum) made for a friends car. He basically fabricated a distributer like device in place of the factory distributer for the cam timing them used individual coils mounted on a bracket right next to the spark plugs. If I remember correctly the SP wires were about 2" long. Now I got to get back to work myself.... Quote Link to comment Share on other sites More sharing options...
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