Is Trimalyzer not intended for cars with MAF?
Thanks
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Is Trimalyzer not intended for cars with MAF?
Thanks
it has a poorly tested maf analyzer, but for an LT1 i think eehack's built in analyzer would be a better choice for maf tuning
I'm trying to use MAF mode on my 0411, as of now the hard part is datalogging. I can datalog ok, just nothing as good as obd1 with the history tables in tuner pro. Very tough to figure them out without the tables. MAF mode did work on my $OD MAF truck.
why not try to run trimalyzer on your logs
This might be obvious, but how does the analyzer correlate to the changes I can make in the MAF calibration?
Attachment 15792Attachment 15793
It's actually kind of complicated at the moment. So first, take a stock MAF curve and look at it in the graph view in TunerPro. When you're done changing things, you'll want your curve to look something like that.
Second, the "AFGS" value in Trimalyzer/EEHack refer to the number in the second column in TunerPro's MAF table. So if Trimalyzer says "add -19% to 16-20," then go to all the values in the MAF table that have a value of between 16 and 20, and use the multiply function in TunerPro to multiply them by 0.81.
Once you're done with all the values, open up the graph view again, and try to smooth the curve as best you can.
I look forward to the day MAF tuning will be a little more automated, but for now, that's the method.
Looks like I'm finally making a positive change! You would laugh if you knew how long I've been struggling with this. I still have a long way to go. That was 61 minute test drive. I didn't floor it because I didn't want to go in open loop.
Thank you
why?Quote:
I didn't floor it because I didn't want to go in open loop.
this isn't some tunerpro history table with no filtering
eehack is smart enough by default to not use your open loop data for tuning closed loop trims.
it rejects other types of data too (like in cells with not enough data to average in and stabilize, and data from before the engine has warmed up enough)
you can 'floor it' all you want and it shouldn't affect anything
by the way you're definitely on the right path but what's up with those knock events!?
I'm wondering that myself. That's why I posted the pic. I am decreasing my advance 2* in those areas and see how it takes it.
i really doubt that's spark knock just by the pattern. if it is i'd drop more than 2 degrees just due to the insane quantity of knock. maybe start with 5.
I just got back with a 2* change before I saw your message. What does the pattern suggest? My headers are close to knock sensors. I had to a put a 5 qt. pan back on and remove my winged pan. I nailed it a couple times on this 32 minute drive.
usually real knock runs along the map axis, like your WOT knock where you 'nailed it', that looks like real knock (in red)
the many tiny knock events around 2k rpm could be a rollerized valvetrain or some other harmless mechanical noise that really peaks out near that 2k rpm point screwing with your knock sensor
Thanks for the reply. I have CTS-V lifters, Scorpion non-aligning aluminum rockers with guideplates. Are these inherently noisy?
could be but who knows
every engine is different
I installed a set of tall aluminum valve covers to see if there was any difference. There was not. My small alternator was not charging, so I was in a hurry and stayed in third most of the time. I still need to address the 95 kpa knock.
the lt4 had lighter valves too
try the original knock module to see if its better
I couldn't find the knock module. So if anyone has one for 1995 Corvette they can sell me or loan me, I'm all for that. Nonetheless, I had a couple knock sensors I ordered a week or two ago and installed them. That seemed to change some. I am also thinking of changing the knock sensor connectors, since the replacement wires are so much thicker and not 25 years old. I went for a 28 minute drive, mostly in third.
Thanks again
wait
you have dual knock sensors
and a y body
and an lt4 knock module
will that even work? i thought that module was for single sensor
that knock is still crazy. its definitely not real.
I'm not sure what you are getting at. My car was built with dual knock sensors.
All LT1/LT4 Corvettes had dual knock sensors. On the 92-95 they were wired in series and went to a single input on the PCM. On the 96 they were each given a separate input to the PCM.
The knock modules for all the C4 Corvettes were incredibly similar and used nearly identical circuitry (according to one of the engineers), which I can also confirm by looking at one of my spares and then looking at photos of the knock modules from, for example, the MEMCAL-equipped cars. However, when pressed about pinouts, said engineer was not quite as forthcoming with information. So unfortunately as of yet I still do not have accurate information as to exactly what each of the 8 pins actually do.
A95Y, you can try the band-aid fix of adding teflon tape to the threads of the knock sensors to "desensitize" them, but unfortunately without the ability to fine-tune the frequencies the knock module is filtering out, you may be out of luck for getting accurate knock feedback on your OEM setup.
Member 69427 on the CorvetteForum knows about electronic timing control. He designed some of the systems. He seems very generous with information.
That’s exactly who I was talking about. I provided photos and data and asked for a pinout of the older knock module since he admitted to having documentation of it, and afterwards he went silent. It seems he’s willing to discuss the theory behind its operation but is mum about certain specific details.
I would love to be proven wrong, though!
I've run numerous guideplate setups with two different non-aligning roller rockers (one chromoly steel and one stainless bodied) and had all sort of false knock issues ('95 Y-body LT-1).
After switching to the Scorpion shaft mount setup referenced in my signature, and Morel solid roller lifters (only needed due to very high spring load) I can finally drive an hour or two with zero knock events. Had I gone the shaft mount rocker setup from the start I would have had $500 more to spend on other fun stuff. You live and you learn.
FWIW - just speaking from experience. Not everyone has false knock problems with roller rockers. My suspicion is it's more prevalent with aluminum head engines and first-gen ODBII ecu programming (and dual knock sensors).
That's interesting. I've looked at shaft rockers in the past and was dumbfounded by the cost. Why the .200 offset? What kind of valve covers do you have?
To test this on my car, I have some roller tipped stamped steel rockers in a box somewhere from days gone by. Can I leave my guide plates in for a test? I am thinking not.
Thanks. Here's a crappy video showing some of the necessary mods. [link] (81mb)
I was also initially dumbfounded by the cost, until I owned two sets of very expensive stud mount roller rockers, two sets of custom length pushrods, three sets of adjustable guideplates, and all the time I wasted trying to make it all work. Hindsight is what it is.
Stock valve covers but some of the supports had to be trimmed to clear the shaft mount bases. Slightly modified 3/8" thick perimeter bolt standoff spacers were glued to the heads with rtv to give necessary clearance. Longer center studs were custom fabricated by a guy with a tig welder and lathe who needed an excuse to (use them / get away from his wife). Getting the stud height correct (the seals want about 0.040" crush) was the toughest part. The 0.200" offset corrects the difference between lifter bore centerlines and valvestem centerlines so there's no lateral deflection. Added bonus here is there was some seat of pants increase to be felt with the shaft mount setup due to eliminating all valvetrain deflection.
If I had it to do over again I would have spent more time milling the 3/8" standoffs so the valvecovers would have fit better.
I doubt your roller tipped stamped rockers are self-aligning, and even if so the guideplates themselves are a possible source of noise. Without the 0.200" offset there is no way to get stud mounted rockers to align with the valve stems without having the pushrods non-parallel, which causes sideways deflection. The rocker arm tip is pushing down on the valvestem, while the spring load causes the rocker arm to want to sweep away from the cylinder bore center, loading the pushrod against the guideplate.
Thanks for making that video. It's very informative and you have done a really nice job there.
When I first read the post, I read it as you getting .040 crush on the valve stem seal. I'm thinking, how in the hell am I ever going to figure that out. lol
I have a set of tall valve covers I can use while I'm trying to figure out doing it the way you did or maybe an alternative method.
Do you have to shim the mounting surface to get the proper rocker arm sweep on the valve stem? Is the preload and final adjustment done with the adjuster?
Do you just bolt them down and set your lash?
Thanks
Edit: was your knock similar to what shows in my graph?
These look promising.Attachment 15885https://www.jesel.com/premium-stud-rockers
Yeah, no. The valve cover mounting studs I made had a 1/4x20 base thread so I left the nuts that lock against the head bosses loose. Adjusting the heights on these so the valve cover seals were "good" was quite a chore. At least a quart of Mobil 1 0W-40 was sacrificed in finding the right amount of seal compression. If I could've found a source for 304L stainless bar stock of the right diameter I would have just turned them to a pre-determined height and been done. But I'm not quite equipped with the tooling to do that efficiently. It's quite a redneck operation I run here, and I'm not ashamed to say so.
I couldn't find anything pre-fabricated that I was comfortable paying (ridiculous amounts of money) for, so I did this, and I love the "sleeper" look. Bear in mind I already had a set of coil brackets for my coil-near-plug setup fabricated that wouldn't fit a F / B body (stamped steel) valve cover design, and didn't want to toss them in the scrap bin.
Yes, and sort of. If you go to something like this you'll want to buy an adjustable length pushrod and get accustomed to spending hours hunched over your front tires (or just do what I did and yank the engine for the fifth time in 2 years). See my next comment about final adjustment / lash.
My lifters are solid, so after finding a shim height that gives a good sweep pattern and have the bases torqued down I set my lash "the old fashioned way" with a feeler gauge. But with hydraulic lifters you can probably set them once and be done. The manufacturer says you should only go to 3/4 of a turn from bottomed out for lash adjustment, so in my case I was contemplating 7.250" pushrods to give me roughly 0.040" preload with the Melling LS[x] hydraulic lifters. Once you get your preload set you can just treat them like LS lifters and run each cylinder pair down until the shaft seats on the pedestal, and you're done forever.
Bear in mind that the 7.250" pushrod length is dependent on your valve stem length, head gasket thickness, and how much your head decks have been milled. You don't (or I've apologetically overlooked if you have) specify any modifications, but Lloyd likes to put +0.100" stem valves in when he works on a pair of heads.
Not entirely. The knock pattern that you're seeing running along the RPM axis - left to right - is probably all or at least mostly false knock.
On the other hand, the knock pattern you're seeing running along the MAP axis - top to bottom - is probably not. You should look at your timing tables and see if something seems to match up.
Neat info on the Jesel LS type lifters "for legacy applications". I'm sure they're priced $$$$$$$ accordingly. On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
You have no idea. I have a piece of rope, a divining rod and a hammer.
I bought some cheap aluminum valve covers. They were around $100 a few years ago. I had to modify them a little with some brute force. I also had a smaller alternator made by a local shop to lose some weight for drag racing. I like the sleeper look as well. I wouldn't want to keep those valve covers on forever, when i make the change. It's good to know I have something ready to go.Quote:
I couldn't find anything pre-fabricated that I was comfortable paying (ridiculous amounts of money) for, so I did this, and I love the "sleeper" look.
I have 2 sets of heads. Currently, GM LT4 castings built and ported by Lingenfelter. Nothing on the receipt indicates any alteration in valve stem length. My other set are the stock heads, again built and ported by Lingenfelter. Both sets have the same components, the flow numbers are about the same. I should have stayed with the OE heads and saved a couple grand. My block has been decked.[/QUOTE]Quote:
Bear in mind that the 7.250" pushrod length is dependent on your valve stem length, head gasket thickness, and how much your head decks have been milled. You don't (or I've apologetically overlooked if you have) specify any modifications, but Lloyd likes to put +0.100" stem valves in when he works on a pair of heads.
Yea, they look like the optimum setup to me. I just got an email back from Jesel and.......wait for it..................$1550. I thought they'd be cheaper for some reason. I almost pulled the trigger on the Scorpions today. I'm still sleeping on it.Quote:
Neat info on the Jesel LS type lifters "for legacy applications". I'm sure they're priced $$$$$$$ accordingly. On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
Boy, the guy at Jesel did not like it when I asked him if Scorpion made their shaft rockers and I asked him for help on pricing. He said they make their own parts in the USA. He said you can’t compare Scorpion to Jesel, they are two completely different companies and he was already giving me a discount on the premium studs. He didn't think he could help me and good luck. The old saying "It doesn't hurt to ask" did not apply in this case. Oh well.Quote:
On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
These performance parts companies are pretty much all like this. The lifters I bought are branded Lunati, but they look identical to Morel branded lifters that normally sell for slightly less (when Jegs isn't offering a $100 discount). I'm relatively sure all the LSX lifters on the market are made by Melling and possibly one other company.
Before you go dumping a bunch of money I feel compelled to ask if you've looked for all other possible causes of false knock. Such as:
* exhaust hitting the body
* a cracked piece of exhaust equipment (cracked welds on my exhaust tips set the sensors off like nobody's business)
* single mass flywheel + rough clutch engagement
* loose motor mounts
* <I'm sure I'm forgetting 15 other things>
I am going to have to put some SA rockers on and remove the guide plates and re evaluate. I have an A4. I will check for the obvious.
Tried getting lucky with the exhaust. Spfautsch had mentioned this as well.
Attachment 15916
There are some short pipes still attached that go down the start of the tunnel. I woke the whole county.