Log results - lots of knock! Eeeek!

[andymoraitis]

I just thing that when things get haywire as a result of either the MAS or the ECU, all of the readings get wierd. I'm pretty I read that the O2 sensor was fresh so I think we can rule that out. Something electrical is happening and it's skewing a ton of readings at once. For an O2 to get that funky in closed loop, the ECU is seeing something weird and crapping itself.

Now there's a mental image or you!

Neal: Once you're back on stable ground, we'll talk about the chip and I promise not to blow in your ear. I only did it to Nathan since he said he liked it.

[Gromit]

Originally Posted by andymoraitis

I just thing that when things get haywire as a result of either the MAS or the ECU, all of the readings get wierd. I'm pretty I read that the O2 sensor was fresh so I think we can rule that out. Something electrical is happening and it's skewing a ton of readings at once. For an O2 to get that funky in closed loop, the ECU is seeing something weird and crapping itself.

Now there's a mental image or you!

Neal: Once you're back on stable ground, we'll talk about the chip and I promise not to blow in your ear. I only did it to Nathan since he said he liked it.

I would concur with this. The wacky readings occur consistently within their own wackiness at exactly the same place every time. Failing parts typically provide erratic readings that are non-repeatable. At least, that's been my experience.

As for the ECU "crapping itself" when all this occurs, I'm telling 'ya, I cracked the case open & there was no stink! J/K...

OK, now we're back to that blowing in the ear thing. Andy, if you really feel a need to demonstrate your skills, I'll put my wife on the line at the appropriate time. We actually work on the car together & she's fully apprised of the whole situation. She's also got a degree in engineering so you'd better be prepared to blow differential equations in her ear.

Steve - thanks for the info on the 3G/EVO MAS. I'll look into that & compare to the GM MAS option.

One thing which has just occurred to me - the car is a 92 with a non-EPROM ECU. I've read stuff alluding to the need for a daughterboard to override the existing micro-chip controller & allow for the socket. Is that the ticket, or would I have to somehow procure an EPROM ECU to use the custom chip?

[steve]

Originally Posted by Gromit

One thing which has just occurred to me - the car is a 92 with a non-EPROM ECU. I've read stuff alluding to the need for a daughterboard to override the existing micro-chip controller & allow for the socket. Is that the ticket, or would I have to somehow procure an EPROM ECU to use the custom chip?

Sure you can use the daughterboard, they are only $700.
You will need a EPROM ECU or be prepared to tune with the SAFC.

Steve

[Gromit]

Originally Posted by steve

Sure you can use the daughterboard, they are only $700.
You will need a EPROM ECU or be prepared to tune with the SAFC.

Steve

Well, that makes things a little more problematical. Let's say that ultimately I plan to get an EPROM ECU, have it socketed & custom chipped, upgrade the MAS to a 3G, & get bigger injectors. I'm wondering about these 2 routes:

1. I can just get an EPROM ECU from somewhere & throw it in the car & see if that changes anything, i.e., verify that the ECU was or wasn't the cause of the problem. Then get it socketed, get the chip, etc.

2. If I were to leave the ECU alone right now & assume it's not the problem, with my current set-up just throwing in a 3G MAS is gonna cause problems. I read thru some old threads & it sounds like the 3G MAS is what I want to go with - can be had relatively inexpensive, direct fit on the intake, not too hard to wire in, etc. But I think the airflow was something like 67% more than stock 1G - my 550's ain't gonna to be able to compensate for that. So I'd need bigger injectors - which is fine since the custom chip down the road would allow for much bigger injectors, anyway - but right now my SAFC's only good for maybe 650's? Big enough to handle that increased flow? Is it possible that the 3G MAS + big injectors sort of balance each other out & leave the SAFC within a capable tuning range? I guess what I'm trying to get at is whether or not I can just do the MAS upgrade 1st & see if that was the problem. I don't want to get slightly larger injectors which are limited by the SAFC, but then need to get even larger ones down the road, yet again.

Oh, I guess there's that 3rd option still floating around out there where I just go ahead & sue that K-Fed assclown. That seems more & more appealing everyday...

[power=dsm]

i'm almost positive you can run a 3g mas and 550s tuned by a safc.

i don't see why you just don't throw in a 2g mas, they're very inexpensive and buy an intake for it, (check out ebay) 2g mas and your 550's balance each other out!

[DSM90AWD]

Originally Posted by power=dsm

i'm almost positive you can run a 3g mas and 550s tuned by a safc.

i don't see why you just don't throw in a 2g mas, they're very inexpensive and buy an intake for it, (check out ebay) 2g mas and your 550's balance each other out!

According to Jeff O (whom has cardinal knowledge of the various MAS flow rates) the 2G MAS flows 33% more air volume at the same Hz as the 1G MAS and the 3G 67% more (readings at 1000Hz).

With 550s flowing 22% more than 450s, you'd still have to correct via AFC/Eprom ~11% for a 2G MAS and ~44% for the 3G MAS. 44% is a ton of adjustment for an AFC and would have a strong impact to the timing tables as well. If going with the 3G, I'd suggest running a larger injector so less correction (and timing impact) would be needed.

Obviously an EPROM would be the best option

[Gromit]

Originally Posted by DSM90AWD

According to Jeff O (whom has cardinal knowledge of the various MAS flow rates) the 2G MAS flows 33% more air volume at the same Hz as the 1G MAS and the 3G 67% more (readings at 1000Hz).

With 550s flowing 22% more than 450s, you'd still have to correct via AFC/Eprom ~11% for a 2G MAS and ~44% for the 3G MAS. 44% is a ton of adjustment for an AFC and would have a strong impact to the timing tables as well. If going with the 3G, I'd suggest running a larger injector so less correction (and timing impact) would be needed.

Obviously an EPROM would be the best option

Right, that's what I was getting at - 550's ain't gonna cut it with the 3G MAS. But normally, it's advisable to stick to 650's or smaller with a SAFC since you'd have to take out too much fuel for larger injectors - same problem of too big an adjustment for the SAFC & causing the ECU to freak out about the timing. But would running the 3G MAS allow you to use injectors larger than 650's with a SAFC & not have major tuning problems? In other words, I'd have a lot more air with the 3G MAS but I'd also have a lot more fuel with, say, 720's & the adjustment on the SAFC wouldn't have to be so big in either direction. Ultimately I'll probably get the EPROM ECU & the chip, so I'd rather go with the biggest injectors I'd likely want.

[kraka]

Or run a 2g mas and call it a day...Keep it simple...

An Eprom chip can compensate for the injectors and the larger mas...

[DJ23GSX]

Not sure if this problem is fixed yet but those logs look very similiar to mine when i was overrunning my 1g maf at 19psi with a small 16g and 560's. I had similiar mods and all i did was put in a 2g maf and all was good. How hacked is your 1g maf??

[Gromit]

Originally Posted by DJ23GSX

Not sure if this problem is fixed yet but those logs look very similiar to mine when i was overrunning my 1g maf at 19psi with a small 16g and 560's. I had similiar mods and all i did was put in a 2g maf and all was good. How hacked is your 1g maf??

No, the problem hasn't been fixed yet. Do you have your logs that show the MAF overrun? I'd be interested to see how they compare. I can't decide which is the culprit - the MAF, the injectors, or the ECU so I haven't decided which route to take to address the problem. I've been searching through a lot of old threads but I think I have more questions now than answers. I think the injectors are too small regardless for what I want to do - they reach over 90% IDC by 4200 rpm. Oh, & my 1G MAF is completely stock - not hacked at all.

[PRESSURIZED]

Hey man, just go to www.xceedspeed.com and do a search for "DSMdave" on that site. Get in contact with him. He has a warehouse in DETROIT (my home town) and has everything you need bro and more, cheap.

The 1g MAF is crap and is easily overrun......

[DJ23GSX]

I don't have any logs from my overrun issues anymore. Try a 2g maf and even if it doesn't solve the problem its still money well spent over the 1g maf.

I am kinda having the same issues your having now with my car. My IDC's are climbing to 110% around 6k and i am getting knock like crazy. Only wierd this is my car ran perfect with 0 knock all summer at 20psi with my IDC's topping out at 93% but sometime in the last week or so somethings gone wacky. I haven''t changed anything in the car (except oil) since it was running great. I cranked up the base fp quite a bit and i was able to lean out the safc about 8% which brought my IDC under 100% but now its back over 100% even with the base fp at 45psi.

[Gromit]

Originally Posted by DJ23GSX

I don't have any logs from my overrun issues anymore. Try a 2g maf and even if it doesn't solve the problem its still money well spent over the 1g maf.

I am kinda having the same issues your having now with my car. My IDC's are climbing to 110% around 6k and i am getting knock like crazy. Only wierd this is my car ran perfect with 0 knock all summer at 20psi with my IDC's topping out at 93% but sometime in the last week or so somethings gone wacky. I haven''t changed anything in the car (except oil) since it was running great. I cranked up the base fp quite a bit and i was able to lean out the safc about 8% which brought my IDC under 100% but now its back over 100% even with the base fp at 45psi.

Oh well...I looked at your profile & your mods are quite similar to mine. Frustrating when something seems to go wacky out of the blue like that. I don't know the history of your knock problems, but have you ruled out a failing knock sensor as the problem? How's the ECU look? What happens at that 6k point when you get high IDC's & all the knock? I have a pronounced stuttering for a short period when the ECU yanks the timing. I'm looking into MAF overrun, fuel delivery, & inadequate injectors as the source of my problems, but haven't gotten a solid grasp on all of it yet. I haven't gone with the 2G MAF as the quick fix because I have a hard intake pipe & don't want to get a new 1 of those to accommodate the oval piping. I'll probably just go with the 3G MAF which flows more anyway & is a direct fit.

[DJ23GSX]

Originally Posted by Gromit

Oh well...I looked at your profile & your mods are quite similar to mine. Frustrating when something seems to go wacky out of the blue like that. I don't know the history of your knock problems, but have you ruled out a failing knock sensor as the problem? How's the ECU look? What happens at that 6k point when you get high IDC's & all the knock? I have a pronounced stuttering for a short period when the ECU yanks the timing. I'm looking into MAF overrun, fuel delivery, & inadequate injectors as the source of my problems, but haven't gotten a solid grasp on all of it yet. I haven't gone with the 2G MAF as the quick fix because I have a hard intake pipe & don't want to get a new 1 of those to accommodate the oval piping. I'll probably just go with the 3G MAF which flows more anyway & is a direct fit.

My car just stops pulling hard cause so much timing is being pulled at 6k. My knock sensor, fuel filter, plugs and o2 sensor were all changed in the spring. I have phantom knock at low rpms but it goes away once the car is warm. I've tried loosening the knock sensor, tightening it and even washers between it and the block with no luck. I am thinking maybe lifters even though my motor has all brand new internals with less than 6k miles on them and I can't hear them at idle either. The knock issue i am having now is affected by changing safc setting so i know its not phantom knock i have. I also know that i loose all fuel pressure as soon as i shut the car off. This was present from the begining and the 0 knock tunes. I was able to narrow down the leak after the regulator. If i pinch off the return hose and shut down the car it holds the pressure fine but i haven't check this since the new knock issues. So far the lowest i have seen my knock is 11. Mind you a few weeks ago i was at 0 knock all the way to redline.

The studdering and the change in airflow is exactly what i had with the maf overrun. If you haven't already take out the lower honeycomb and back the screw all the way out on the maf and see if this problem still exist. My 1g maf i ported that whole bottom section and was able to run 18psi without overrun.

[Gromit]

Finally got some info here to dredge up this thread & update it. Seems I am on the right track now so I wanted to post the results in case anyone with similar issues searches & finds this thread.

Looks like all you Wiseguys, er, I mean Wisemen, were pointing me in the right direction. My conclusion was I was probably overrunning the stock 1G MAF (here's a good read on what seems exactly like what I experienced - http://www.vfaq.com/TMO/Tuning-Tips.htm - go down to the section on Airflow Hz), definitely maxxing out my 550's, & getting too much timing with the already-aggressive 1G maps. Over the last couple months I got larger injectors (FIC 650's), a 3G MAF, & a Stage III custom chip/EPROM ECU package from Jeff at DSMChips. I retained my SAFC for fine-tuning ability, setting all the Ne points to 0% correction for the moment. Everything is now installed & I had a chance to make a couple short runs over the holiday weekend. My chip compensates for the injectors & the 3G MAF, caps the timing at 18* advance on the high map, & sets the WOT AFR to 11.5:1 since I've got access to 94 octane. It also has the 2X Karmen feature so my airflow value as displayed is 50% of actual, allowing me to log greater than 1606 Hz.

For the 1st run I lowered the boost to roughly 12 PSI (note that both logs I post here are only 2nd gear pulls - didn't think I needed to be running 95+ mph over the holiday weekend ). Here's that data:

TIME O2-R BARO MAFS RPM KNOCK INJP IDC AIRT
11/23/2006 13:58:41 35° 0.78V 13.89psi 125.8Hz 3063 0 5.89ms 19 87.8°F
11/23/2006 13:58:41 26° 0.84V 13.89psi 213.9Hz 3219 0 7.68ms 26 87.8°F
11/23/2006 13:58:42 22° 0.88V 13.89psi 245.3Hz 3313 0 8.70ms 30 87.8°F
11/23/2006 13:58:42 18° 0.88V 13.89psi 301.9Hz 3469 0 10.24ms 37 87.8°F
11/23/2006 13:58:42 15° 0.88V 13.82psi 364.8Hz 3656 0 12.03ms 47 87.8°F
11/23/2006 13:58:42 14° 0.86V 13.82psi 440.3Hz 3906 0 12.29ms 51 87.8°F
11/23/2006 13:58:42 15° 0.86V 13.82psi 434.0Hz 4125 0 11.78ms 51 88.7°F
11/23/2006 13:58:43 16° 0.84V 13.82psi 452.9Hz 4344 0 11.78ms 54 88.7°F
11/23/2006 13:58:43 17° 0.84V 13.75psi 484.3Hz 4594 0 12.29ms 60 88.7°F
11/23/2006 13:58:43 17° 0.84V 13.75psi 522.1Hz 4844 0 12.03ms 62 88.7°F
11/23/2006 13:58:43 18° 0.84V 13.75psi 540.9Hz 5063 0 12.03ms 65 88.7°F
11/23/2006 13:58:44 18° 0.84V 13.67psi 566.1Hz 5250 0 12.03ms 67 88.7°F
11/23/2006 13:58:44 19° 0.84V 13.67psi 591.3Hz 5531 0 12.03ms 71 87.8°F
11/23/2006 13:58:44 19° 0.84V 13.67psi 610.1Hz 5688 0 12.03ms 73 87.8°F
11/23/2006 13:58:44 18° 0.84V 13.67psi 622.7Hz 5906 0 12.03ms 75 86.9°F
11/23/2006 13:58:44 20° 0.84V 13.67psi 629.0Hz 6031 0 11.78ms 75 86.9°F
11/23/2006 13:58:44 20° 0.84V 13.67psi 635.3Hz 6188 0 11.78ms 77 86.0°F
11/23/2006 13:58:45 21° 0.84V 13.60psi 647.9Hz 6344 0 11.52ms 78 85.2°F
11/23/2006 13:58:45 21° 0.84V 13.67psi 654.2Hz 6531 7 11.26ms 78 84.4°F
11/23/2006 13:58:45 19° 0.84V 13.60psi 660.5Hz 6688 6 11.26ms 80 84.4°F
11/23/2006 13:58:45 20° 0.84V 13.60psi 666.7Hz 6844 6 11.01ms 80 83.6°F
11/23/2006 13:58:45 20° 0.84V 13.60psi 673.0Hz 6969 6 11.01ms 81 83.6°F
11/23/2006 13:58:46 20° 0.84V 13.60psi 666.7Hz 7250 6 10.50ms 81 83.6°F
11/23/2006 13:58:46 22° 0.84V 13.60psi 654.2Hz 7281 5 10.24ms 79 83.6°F
11/23/2006 13:58:46 23° 0.84V 13.60psi 654.2Hz 7469 4 9.98ms 79 84.4°F
11/23/2006 13:58:46 25° 0.84V 13.60psi 660.5Hz 7563 4 9.47ms 76 84.4°F
11/23/2006 13:58:46 31° 0.86V 13.96psi 69.2Hz 7281 0 1.28ms 9 85.2°F
11/23/2006 13:58:46 45° 0.70V 13.96psi 25.2Hz 7594 0 1.28ms 10 85.2°F
11/23/2006 13:58:47 45° 0.68V 13.96psi 31.5Hz 7531 0 1.28ms 10 85.2°F
11/23/2006 13:58:47 45° 0.78V 13.96psi 31.5Hz 7313 0 1.54ms 12 86.0°F

I recorded BARO & AIRT to see that my new MAF appeared to be working correctly. Got a little bit of knock up top, but way better than previously. Also, no more bad stuttering. I added 2-3% fuel with the SAFC, raised the boost & did another pull. The next log was done at 17 PSI:

TIME O2-R BARO MAFS RPM KNOCK INJP IDC AIRT
11/23/2006 14:06:58 30° 0.92V 13.96psi 151.0Hz 2469 0 6.40ms 16 98.6°F
11/23/2006 14:06:59 19° 0.84V 13.96psi 151.0Hz 2500 0 6.66ms 17 97.7°F
11/23/2006 14:06:59 19° 0.86V 13.96psi 169.8Hz 2594 0 6.91ms 19 96.8°F
11/23/2006 14:06:59 18° 0.86V 13.96psi 188.7Hz 2656 0 7.42ms 21 95.9°F
11/23/2006 14:06:59 17° 0.88V 13.96psi 201.3Hz 2750 0 7.94ms 23 95.0°F
11/23/2006 14:07:00 16° 0.88V 13.96psi 226.4Hz 2875 0 9.22ms 28 94.1°F
11/23/2006 14:07:00 15° 0.88V 13.96psi 264.2Hz 3063 0 9.98ms 32 92.3°F
11/23/2006 14:07:00 15° 0.88V 13.89psi 301.9Hz 3219 0 11.01ms 37 91.4°F
11/23/2006 14:07:00 15° 0.88V 13.89psi 358.5Hz 3375 0 12.03ms 43 89.6°F
11/23/2006 14:07:00 14° 0.88V 13.89psi 390.0Hz 3594 0 12.54ms 48 88.7°F
11/23/2006 14:07:01 14° 0.86V 13.89psi 427.7Hz 3844 0 13.06ms 53 87.8°F
11/23/2006 14:07:01 13° 0.86V 13.82psi 471.8Hz 4094 0 13.57ms 59 86.0°F
11/23/2006 14:07:01 13° 0.86V 13.82psi 515.8Hz 4375 0 13.57ms 63 85.2°F
11/23/2006 14:07:01 14° 0.86V 13.82psi 540.9Hz 4594 0 13.57ms 66 84.4°F
11/23/2006 14:07:02 15° 0.86V 13.75psi 566.1Hz 4844 0 13.31ms 68 83.6°F
11/23/2006 14:07:02 15° 0.86V 13.75psi 603.8Hz 5094 0 13.31ms 72 82.9°F
11/23/2006 14:07:02 16° 0.86V 13.75psi 629.0Hz 5281 0 13.57ms 76 82.1°F
11/23/2006 14:07:02 17° 0.86V 13.75psi 641.6Hz 5469 0 13.31ms 77 81.3°F
11/23/2006 14:07:02 17° 0.86V 13.67psi 660.5Hz 5719 0 13.06ms 79 81.3°F
11/23/2006 14:07:02 18° 0.86V 13.67psi 673.0Hz 5844 0 13.06ms 81 80.5°F
11/23/2006 14:07:03 19° 0.86V 13.67psi 679.3Hz 5969 0 13.06ms 83 80.5°F
11/23/2006 14:07:03 19° 0.86V 13.67psi 710.8Hz 6188 0 13.06ms 86 79.7°F
11/23/2006 14:07:03 20° 0.86V 13.67psi 717.1Hz 6406 0 12.80ms 87 79.7°F
11/23/2006 14:07:03 21° 0.86V 13.67psi 723.4Hz 6563 0 12.54ms 87 78.9°F
11/23/2006 14:07:03 21° 0.86V 13.67psi 735.9Hz 6719 1 12.54ms 90 78.9°F
11/23/2006 14:07:04 21° 0.86V 13.60psi 754.8Hz 6844 0 12.29ms 89 78.1°F
11/23/2006 14:07:04 21° 0.86V 13.60psi 748.5Hz 7031 0 11.78ms 88 78.1°F
11/23/2006 14:07:04 21° 0.86V 13.60psi 767.4Hz 7250 0 11.78ms 91 78.1°F
11/23/2006 14:07:04 22° 0.86V 13.82psi 364.8Hz 7094 0 2.05ms 15 78.9°F
11/23/2006 14:07:04 45° 0.88V 13.96psi 62.9Hz 7219 0 1.79ms 13 80.5°F
11/23/2006 14:07:05 45° 0.82V 14.03psi 37.7Hz 7125 0 1.28ms 9 81.3°F

Looks even better. At this point I plan to spend some time making some small adjustments - I'm going to go ahead & rewire my 255 lph fuel pump just to make sure there's no issues with that. I also have a set of revised lifters waiting to go in. Then I'll see about running some seafoam through the system. I don't plan to do too much tuning over the winter since temps are pretty cold right now & I'd just have to re-tune in the summer. It runs fine at 17 PSI so I'll probably leave it there for now. Next Spring I'm looking to get a wideband O2 & possibly meth injection so I can raise the boost to somewhere around 22 PSI.

I have only 1 issue right now that is a bit perplexing. With this chip my FTRL at idle is pegged rich - 81.2%. This is only at idle - as soon as I give it some throttle it stabilizes near 100% (i.e., if I drive around in 1st gear at roughly 1500 rpms it's good, but goes right back to 81.2% if I come to a stop). FTRM & FTRH are both good, although not fully settled yet as I haven't done a lot of higher throttle cruising since installing the chip. And I cannot correct the FTRL with the SAFC - adjusting to the full -50% does not change it at idle. The chip guy suggested just lowering the base fuel pressure as the injectors were likely flowing more than they were rated for. Any thoughts on this?

Thanks for all the previous input!

[andymoraitis]

That looks much better Neal and I'm glad the new tune is working for you. I would try Jeff's recommendation about lowering base pressure a bit to see if the fuel trims come back in line, but other than that. I think you're on the road to much happier days.

That custom setup is pretty nifty isn't it?

I just wanted to clue you in as to why you're not seeing the timing cap take effect. As an example, the high load timing maps in a chip are made to activate above 2.1 g/rev and you're likely not there yet with only 17 psi of boost. If you turned the boost up to say 20-21 you'd get onto that high map and you should see your timing peak at 18. It will likely knock less as well.

Edit: I just noticed these are 2nd gear pulls. Try them in 3rd as airflow should be considerably higher.

[Gromit]

Originally Posted by andymoraitis

That looks much better Neal and I'm glad the new tune is working for you. I would try Jeff's recommendation about lowering base pressure a bit to see if the fuel trims come back in line, but other than that. I think you're on the road to much happier days.

That custom setup is pretty nifty isn't it?

I just wanted to clue you in as to why you're not seeing the timing cap take effect. As an example, the high load timing maps in a chip are made to activate above 2.1 g/rev and you're likely not there yet with only 17 psi of boost. If you turned the boost up to say 20-21 you'd get onto that high map and you should see your timing peak at 18. It will likely knock less as well.

Edit: I just noticed these are 2nd gear pulls. Try them in 3rd as airflow should be considerably higher.

Hey Andy,

Yeah, this custom set-up is the shiznit. I will lower the base fuel pressure a bit & see what happens with the FTRL. My concern there was that everything else was in line & lowering the base would effect everything across the board. But I'll try it & see what the result is. My other thought was whether or not Jeff could adjust the flow rate/deadtime for just the idle setting. If lowering the base fuel pressure doesn't help I'll talk to him further about it.

In any case, I agree that this is definitely the right direction & by Spring I should be right where I want to be. Thanks for the info on the timing cap - I did read some stuff about that in another thread & on Jeff's board, so I wasn't concerned there. I went with the 2nd gear pulls right now because I usually do 3rd gear pulls very early in the AM on the weekends - there's a nice on-ramp that works well for this - but it's too freakin' cold at oh-dark-thirty these days.

At least I know what direction I'm moving in & can now tweak things a bit to get my desired results.