Hey guys, been lurking for a while, i'm sure that i'll have a lot of stupid questions, please forgive me as im new to haveing to tune with a laptop, im used to carbs, wrenches, and screwdrives, lol. I've been reading a lot, and using a little: Tunercat (only set gearing change and shift points right now), Datamaster, FreeScan, and Logworks.

anyways, first stupid question the i've been looking for the LT4 knock module for my 1994 camaro, the one one i saw on summit was for the corvette, im sure this is the right one, just want to verify that.

moving right along, the car (in signature) seems to run pretty good, i am running the LM2 wideband and it seems to be running on adverage about 12.6 with a bit of fluctuation, i think that this is right about where i want it since i will be running nitrous.

Throttle response seems a little slow and i know it can pull a little harder. I just did one datamaster log while driving across town with a short WOT near the start of the run. It seems to be knocking like crazy while accelarating, i know i have to check all the plug wires and exhaust. No wires are touching the headers and all the header bolts seem to be tight. Im not sure how to interpret the knock count on this car though. The run started with a Knock Count of 6759 jumped up to 7020 when i went WOT and by the time i let off WOT it was at 10588 and at times had pulled 10deg of timing by the end of my 15 minute drive to the store the knock count was at 11564. It seems like it is knocking like crazy, some of it may be real, some may not, i dont know. I know the least ammount of knock is the best but how do i figure out what is acceptable when working with numbers in the 5000-10000 range, what is the normal starting point? Also besides the LT4 module, and making sure everything is tight, how do i go about fixing knock.


Also how should i be adjusting my timing. I know on my old 72 i just go out with a light and try to add in 1-2 degrees at a time and watch my slips on the track (or the seat of the pants method on the street) to see where my best performance is, and if it starts getting hard to start, performance drops, or pinging at all i back the timing off. But how do i go about this when im dealing with these huge tables in tuner cat, and what should i be looking for?

Sorry if these are basic tuning questions, i have read through quite a few threads on various sites, if there is something that i missed or would be helpful to read can you please point be in the right directions (link would be great) I'm new to all this style of tuning but definatly learn fast. I want to get the N/A tune dialed in, im running the HSW interface with the N2O that atuomatically pulls the timing and adds the fuel when the N2O is being used so for now i need to figure out how to get the N/A tune/timing dialed in.

I also have a data master file and my tunercat .bin file if someone could look at them and give me some advice, im still trying to figure out how to interpret them all.

Thanks

Doug

 

okay so after taking a closer look at the datamaster log i have seen a few patterns emerge, there appears to be only a few instances of knock recorded, which i have clipped and pasted below, other that what is here most of the rest of the Knock Retard is less than 1.5 degrees and appears to be fairly random, i think it is best to start with the KR that comes from recorded knock and produces the biggest retard. Looking at the data below and if i understand all this tuning stuff so far it looks like i should go into the spark advance tables in tuner cat and drop the values at 90 and 95 MAP and 4000rpm by 1-2 degrees and record another run and see if i still get a knock and repeat this again at 60 and 65 map and 3200rpm. Is this the correct way to go about it.

Record # TimeStamp Knock Count Spark Retard Spark Advance RPM MAP TPS % Speed
mS Counts Degrees Degrees RPM KPa Percent MPH
927 203814 6759 0 40 3525 70.5 46.3 21
928 204035 7020 3.9 34 3975 92.3 94.1 23 4 KR at 92 map acel thru 3900 rpm 34 spark advance
929 204254 7020 2.7 34 3475 94.5 100 36
930 204469 7020 2.7 33 3150 96 100 31
931 204687 7020 1.8 34 3050 97.1 100 30
932 204907 7020 1.2 34 3050 96.3 100 32
933 205126 7020 1.2 35 3250 96.7 100 33
934 205345 7020 0.8 35 3375 96.7 100 35
935 205562 7020 0.6 36 3525 96 100 37
936 205781 7020 0.4 36 3625 94.9 100 39
937 205997 7020 0.4 37 3825 94.5 100 40
938 206220 7020 0.3 37 3925 94.9 100 42
939 206436 7020 0.3 37 4050 94.1 100 44
940 206656 7262 5.1 32 4225 95.2 100 46 5.1 KR at 95 map accel thru 4200 rpm 32 spark advance
941 206871 7882 10 27 4350 95.2 100 47
942 207090 8632 10.2 28 4450 95.2 100 49
943 207307 8632 10.5 27 4600 95.2 100 51 10.5 KR at 95 map accel thru 4400 rpm 27 spark advance
944 207537 8632 8.1 30 4750 94.9 100 52
945 207745 8632 6.5 31 4875 93.7 100 54
946 207965 8632 5.2 33 4975 93 100 55
947 208182 8632 4.2 34 5050 92.6 100 57
948 208404 8632 3.4 34 5200 96.3 100 58
949 208621 8632 2.8 36 5275 92.3 100 60
950 208837 8632 2.3 36 5475 92.3 100 61
951 209054 8632 1.6 37 5575 91.9 100 62
952 209274 8632 1.4 37 5650 95.2 100 64
953 209493 8632 1.2 38 5725 94.1 100 65
954 209714 8632 0.9 38 5875 92.6 100 66
955 209930 8632 0.9 38 5900 94.5 100 67
956 210146 8632 0.8 38 6050 94.9 100 68
957 210366 8632 0.7 38 5950 93.7 100 69
958 210588 8632 0.7 37 4600 95.2 100 72
959 210802 8632 0.7 37 4125 93.7 100 72
960 211025 8632 0.7 37 4150 96 100 73
961 211240 8852 4.1 33 4225 94.9 100 74 4.1 KR at 95 map steady 4200 rpm 33 spark advance
962 211457 9333 10 28 4275 93 100 75 10 KR at 93 map steady 4200 rpms 21 spark advance
963 211676 10588 10 27 4275 96 100 76
964 211896 10841 10 31 4325 74.9 48.2 77
965 212113 10841 0 44 4100 28.1 18.4 77
966 212333 10841 0 13 3050 16.6 0 77




Record # TimeStamp Knock Count Spark Retard Spark Advance RPM MAP TPS % Speed
mS Counts Degrees Degrees RPM KPa Percent MPH
1334 292703 10841 0.5 41 3125 60.5 37.3 34
1335 292924 10841 0.4 41 3200 60.2 37.3 35
1336 293143 10841 0.4 42 3250 59.1 37.3 36
1337 293360 10841 0.4 42 3300 57.6 37.3 37
1338 293578 11100 5.6 36 2975 61.3 37.3 39 5.6 KR at 62 map decel thru 3000 rpm 36 spark advance
1339 293795 11100 4.3 34 2375 72 37.3 38
1340 294016 11100 4.3 33 2400 72 37.3 39
1341 294233 11100 3.1 35 2450 72.3 37.3 40
1342 294454 11100 3.1 36 2450 69.4 34.5 40
1343 294670 11100 1.9 39 2450 61.6 31 41
1344 294890 11100 1.3 40 2450 59.1 29.8 42
1345 295104 11100 1.4 38 2175 59.4 29.8 42
1346 295326 11100 1.5 36 2000 64.2 29.8 42
1347 295542 11100 1.4 37 2025 63.9 29 43
1348 295761 11100 1.4 39 2000 63.9 29 43
1349 295980 11100 1.2 40 2025 62.8 27.8 44
1350 296200 11100 1.1 41 1975 60.2 26.7 44
1351 296417 11100 0.6 43 1950 55 23.5 44
1352 296636 11100 0.6 43 1900 53.5 23.5 44
1353 296853 11100 0.4 43 1900 52.8 22.7 45


Record # TimeStamp Knock Count Spark Retard Spark Advance RPM MAP TPS % Speed
mS Counts Degrees Degrees RPM KPa Percent MPH
2319 507827 11100 0.6 41 3425 62 40.4 38
2320 508049 11100 0.6 41 3500 62 40.8 39
2321 508265 11319 3.5 36 3300 64.2 40.8 40 4.2 KR 64 map 3300 rpm 32 spark advance
2322 508482 11319 4.2 32 2500 76.4 40.8 41
2323 508702 11319 3.2 34 2525 77.5 40.8 41
2324 508922 11319 2.6 35 2550 75.3 40.4 42
2325 509138 11319 2.4 35 2550 74.9 38.4 43
2326 509361 11319 1.7 38 2575 67.2 34.1 43
2327 509575 11319 1.5 39 2575 65.3 32.9 44
2328 509797 11319 1.2 40 2575 63.1 32.9 44
2329 510013 11319 1.8 35 2150 69.4 32.9 45
2330 510231 11319 1.8 35 2100 70.5 32.9 46



Record # TimeStamp Knock Count Spark Retard Spark Advance RPM MAP TPS % Speed
mS Counts Degrees Degrees RPM KPa Percent MPH
2695 589950 11319 1.3 37 3475 77.9 50.6 38
2696 590169 11564 6.1 33 3550 76 51.4 39 6.1 KR at 76 map 3550 rpm 33 spark advance
2697 590385 11564 4.7 34 3650 75.3 51.4 40
2698 590605 11564 3.8 35 3775 74.2 51.4 42
2699 590822 11564 3.2 38 3925 73.5 51.4 43
2700 591041 11564 2.6 39 4000 72.3 51.4 44
2701 591258 11564 2.6 39 4125 70.1 51.4 45
2702 591480 11564 2.2 40 4150 72 51.4 46
2703 591695 11564 2.4 35 3275 80.8 51.4 49
2704 591915 11564 2.2 34 2950 84.2 51.4 49
2705 592133 11564 1.9 35 2925 76.8 43.1 50
2706 592353 11564 1 40 2925 60.9 32.2 50
2707 592567 11564 0.6 41 2875 55 30.2 51

 

Here are a few suggestions for someone who fought KR for years:

Do a search because I cant remember all of them.

Common cause: headers banging against the firewall. Roller rockers installed.

Put in very high octane gas that guarantees knock will go away...like 100 octane or something and rerecord. Don't use those little bottles from the local auto parts store. Get tank of 100 octane.

Don't modify your computer and the tables until you know for sure what is going on.

You have a cam in the thing so you have touched the top end. List what you did there.

 

The LT4 knock module shows up as being for the Corvette because the 1996 Corvette LT4 was the only engine that used it. It will work in 94-97 F-Body PCM's.

When is your wide-band sensor indicating 12.6:1? That's too rich for closed loop, and slightly on the rich side for WOT (PE mode). But the actual A/F ratio you need will vary based on the engine specifics, so its only a rough guideline. 12.6:1 would not be rich enough for a healthy shot of nitrous. May be marginal for the 50-shot. Again, do not rely on the A/F gauge. Check your plugs after a nitrous pull, looking for signs of detonation. You tune your nitrous "externally", using the fuel and nitrous jets. Optimize your NA tune first. Then adjust A/F ratio and ignition timing externally.

The "knock count" is (surprisingly) not a measure of knock being detected by the knock sensor. It appears to be driven by the PCM looking at the engine's operating conditions, and incrementing the knock count when it sees the engine operating under conditions that MAY produce detonation. And the PCM does not necessarily pull timing (knock retard) based on increasing knock count. Once it does detect significant knock signals from the knock sensor, it will start to pull timing based on incrementing knock count.

Note also the the "knock count" is merely a storage register, that starts at "0", and increments upward every time it encounters engine operating conditions that MAY produce knock. It isn't unusual for the knock count to increase on cold start. The knock count keeps incrementing up intil the register reaches its maximum capacity (64,000??) and then resets to "0" and starts incrementing upward again. So a knock count of say 35,862 means absolutely nothing. Look primarily at knock retard.

Appears you have basically a stock engine, with the "mild cam". Shouldn't have knock problems with that setup. Knock is caused by low octane fuel, excessive compression ratio, high coolant temperatures, high intake air temperatures and lean A/F ratio. "False" knock can be caused by mechanical noises that fool the knock sensor (a small piezo microphone) into sending a signal to the PCM. A loose motor mount (since the knock sensor is mounted right next to the passenger side motor mount) will cause false knock retard. Anything rattling against the engine or exhaust system can cause false knock. A noisy valve train. Your cutout may produce enough noise to cause problems. Have you compared the knock retard for runs with the cutout open and closed? Is there any difference in the results? 10deg of knock retard is definitely going to make your engine feel sluggish.

When you say it is "knocking like crazy", are you actually hearing knock? If so, you have a major problem, because if the PCM is pulling 10deg of timing and you still have audible knock, you have a major problem. You should never actually hear knock. The knock sensor should pick it up BEFORE you can hear it, and retard the timing quickly to eliminate it.

Before you adjust the timing tables, find out why you are getting knock retard. If you had a high compression, high HP setup with major mods, you would jump on the timing tables, but with a "stockish" setup, solve the knock retard first. After that, play with the WOT (high MAP) portions of the timing table to maximize the performance, while watching for knock retard with the scanner. Let the knock sensor listen for knock. Its much more sensitive than the way you tuned your older engine.

Posting the data the way you do makes it almost impossible do review. You upload your scan file to an FTP site, and post the link. If you are using DataMaster, the files are in .uni format, and only people with DataMaster can review them. If you post them as both .uni and .csv (an export option in DM), more people can take a look at them.

 

okay guys thanks for the input

as far as the cam specs, i wish i knew that was put in before i got the car, everything else on the motor appears to be stock besides the ingition system (full MSD)

i have not heard the knock so that is good, i just say the numbers jumping from 5200 to 11,000 and thought that seemed really high but again im not totally sure, and when i replayed the file in data master the retard block was flashing a lot, when i looked at the .csv file it seems that most of the retard was very small .2-1.0 and was not commanded by a knock count.

i'll try different fuel and see what happens then

any suggestions on a site that i can post up the .csv files for someone to review them?

thanks for your help guys