CU Zcar Posted December 18, 2003 Share Posted December 18, 2003 Figured I'd chime in with my dyno runs for comparison. I can't see bastaad525's sheets but from the descriptions, my car is doing a similar dive into rich a/f's. Posted below are my hp, then a/f, plots from the dyno. BTW I did this as part of my Z club's dyno day, we each got 2 runs on a DynoJet for $35. Real cheap place but there's some bad to go with it, my friend brought his new MS Protege and ran over a brake drum doing a load of damage to the valences/sideskirts, and he learned upon talking to the proprietors about it that they have no insurance (!) I'm glad we had no mishaps with cars up on the dyno itself! I dunno if I'll go back there, they didn't have a good fan in front of the car either, got really hot... anyway: Analyze away if you like I'm thinking the torque dip from 3-4k is either the over-rich condition hitting its worst, or some issue with my fuel injection (using most of the 83 auto ZX ECCS) which I still need to further sort out. Or maybe there's a little bit of boost spike occurring that I didn't notice. The car is stock except the threaded WGA that came with the turbo, it tends to boost to about 8psi. There was also a little pinging evident towards the end. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted December 18, 2003 Share Posted December 18, 2003 Looks like you don't have enough timing or some sort of ignition thing (like incorrect heat range or too much gap.) That's why the line is real jugged I think. Mine looked like that at low stock timing, I turn the timing 2-3 deg and the line smoothed out and also gained 30-40 ft/lb in the mid range and 20 RHP if I remember correctly. Don't attemp to advance timing without a good hearing Quote Link to comment Share on other sites More sharing options...
yo2001 Posted December 18, 2003 Share Posted December 18, 2003 I got one with Z31 ECU and timing corrected. Fuel pressure at 40 psi and boost on 12psi. Quote Link to comment Share on other sites More sharing options...
Jersey Posted December 18, 2003 Share Posted December 18, 2003 Hey Yo... first off, nice sheet, and to you also CU. Yo - why doesn't your HP and tourque curve crossover @ 5250? It looks more like 4600? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted December 18, 2003 Share Posted December 18, 2003 great to see all of these dyno runs so we have an idea what to shoot for Quote Link to comment Share on other sites More sharing options...
mobythevan Posted December 18, 2003 Share Posted December 18, 2003 Yo's graph is weird because the HP and TQ scales are different. Quote Link to comment Share on other sites More sharing options...
Jersey Posted December 18, 2003 Share Posted December 18, 2003 ahhh.... now i see it moby, thanks. Strange it's done that way, no? Now i'm going to have to take his sheet and edit it Quote Link to comment Share on other sites More sharing options...
yo2001 Posted December 18, 2003 Share Posted December 18, 2003 Yes, My dyno guy likes to rescale the sheet. Also having a boost spike doesn't help the graph either. I also like to add that WB O2 on the dyno is usually about .5 richer than what really is on the street. (so 13:1 is like about 13.5:1 on the street) So always tune it fatter on the dyno I was told. Quote Link to comment Share on other sites More sharing options...
Jersey Posted December 18, 2003 Share Posted December 18, 2003 Thanks. I really need to do a dyno one day and seeing others results helps. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted December 18, 2003 Share Posted December 18, 2003 Those results are excellent. It's very interesting to me to see the differences in the Z31 and the S130 ECUs; makes me glad I did the conversion - the Z31 has much better control over the mixture it seems. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 18, 2003 Share Posted December 18, 2003 Speaking of plug gap, what are you guys getting away with for spark plug gap? I had a few issues that seemed to be cleared up by lowering the gap, now I am hearing that 0.020"-0.028" is probably the range to be in for a boosted engine. Can anyone confirm? Quote Link to comment Share on other sites More sharing options...
yo2001 Posted December 18, 2003 Share Posted December 18, 2003 I did gap my plugs down to .033" I think. Iran the same plugs recommended for 4G63 I think. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted December 19, 2003 Share Posted December 19, 2003 Well, I had some long winded reply to the gap question but, I lost it all so I'll just say I run the stock .044 until the car missfires under load and then regap to .032. That was when I was runing the 82 computer now I can run the stock gap until the plugs are changed out when I feel it's time. About a year is all I ever go without changing them out no matter what. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 19, 2003 Share Posted December 19, 2003 Those results are excellent. It's very interesting to me to see the differences in the Z31 and the S130 ECUs; makes me glad I did the conversion - the Z31 has much better control over the mixture it seems. I agree... Z31 ecu conversion looking better and better Still think I'll go with something else eventually like HKS piggy back computer... it's cheap and can adjust the AFM signal to compensate for that richness in the middle, and I wont have to go to the extent of changing things out I would with the Z31... plus it will probably cost less (HKS is like $200). CU-Zcar - yeah your graph is nearly idendtical to mine... so that's three I've seen so far with stock '81-83 ECU's that all had that flat rich spot in the middle. I'm also curious, what fuel pump and injectors are you running and are you running a stock FPR or adjustable and if so what pressure? You A/F ratio stays on the rich side much longer than mine does, leaning out at just above 5000rpm, whereas mine starts leaning out closer to 4000rpm. I wonder if this is due to you running a better pump or whatever or is just a result of you running less boost than me (10psi vs 8psi). I love how your AFR levels off at like 11.x:1 all the way up to 6.5k rpm... by 5000rpm mine is already much leaner at almost 13:1. Strange also that you were getting any ping... at boost levels so close to stock and running on the rich side all the way to redline I find that really odd. It certainly doesnt' LOOK like you're getting any ping, which usually shows up on a dyno graph as a really jumpy line when it starts occuring. Strangest thing of all is I can actually VIEW your graphs with no problems!!! I can't even view my own! My plug gap was set to .045 when I was at the dyno... I've been going back and forth with it trying to get rid of my misfire at idle (which didn't work) and gapped them down as low as .035" but the car didn't seem as torquey with them that low. I dont get any apparent miss under load though just at idle or when decelerating. I've actually been meaning to post a question asking about the optimal gap for a turbo motor. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted December 20, 2003 Share Posted December 20, 2003 I'm running NGK plugs one heat range colder than stock, gapped about 0.035". Haven't felt any missing like I would occasionally feel at the stock gap. I do have a factory ignition system though - be nice to upgrade and keep a big gap. Quote Link to comment Share on other sites More sharing options...
fl327 Posted December 20, 2003 Share Posted December 20, 2003 car feels like it runs better with stock ngk set at .035 tried .40 and 12 psi, maybe with msd try it again. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 20, 2003 Share Posted December 20, 2003 car feels like it runs better with stock ngk set at .035tried .40 and 12 psi' date=' maybe with msd try it again.[/quote'] I really NEED to replace the MSD 6A that I fried... man I know they aren't really good for any more power but it DEFINATELY made a difference in how clean and smooth the car ran, and you can definately run a bigger gap with it.... I actually tried a little comparison, just wanted to see how bright the spark was on the MSD and off... worlds of difference between stock and the MSD. I'll try gapping my plugs back down a little and see what happens. Quote Link to comment Share on other sites More sharing options...
Jersey Posted December 20, 2003 Share Posted December 20, 2003 I'm running the 6's with MSD 6A @ .042 boosting around 16psi and she pulls smooth all the way up the R's. I should get video of my boost gauge. Random thought, sorry (1:30am) Quote Link to comment Share on other sites More sharing options...
CU Zcar Posted December 20, 2003 Author Share Posted December 20, 2003 bastaad525- I'm running a stock ZXT pump, FPR and injectors, and at that it's a mismatched set - four are the ones that came with the engine and two from a friend who bought them for his N/A car but doesn't need them yet (they replaced two of the orig. set that were leaking from the injector body!). I'm actually about to replace all of them with a set of 24lb/hr Ford SHO injectors so I can return my friend's injectors, 24lb works out to about the same as 260cc. I hope So yea it's all stock, along with the DP and I have a 2.5" exhaust and glasspack as well. No other muffler though. I'd guess your leaning out would be just due to the extra boost, or maybe your pump has seen better days. You sure your fuel filter is clean? That or the fuel damper would be the only things I could think of causing a restriction, unless your car just decides to run the injectors less for some reason or has a kink somewhere. As for the ping, maybe I'm just hearing things (?) I'm always scared when I hear something like it. But a friend of mine offered the suggestion that he's seen cars ping from being way-over-rich like mine. He's got more experience than I, so I can't say I disagree with him that it could or couldn't happen. I'll get the right plugs in my car and fix my timing and hopefully my fuel sometime and I'll have to see what happens Lastly, my images are visible cause I'm hosting them off-site, I have some web space that my school gives me. Even when I'm logged in I sometimes have trouble seeing people's Gallery images so I just by-passed the whole thing and linked to my images. Some ISP's give all their users a little space on the web, you should check with yours and see if you have some and where to upload to if the Gallery continues to give you trouble. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 21, 2003 Share Posted December 21, 2003 Betting you were right about the fuel pump seeing better days, well a combination of that and yeah the increased boost must be making a big difference in the mixture as well. Fuel filter is less than 2 mos old... dont know about the restrictor thing. Quote Link to comment Share on other sites More sharing options...
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