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Location:
Lost in the K hole
Registered:
May 2002
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 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 14:13
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my engine got pulled off the dyno today at 4000rpm due to it pinging (not badly, but pinging none the less). it was happily making a wad of power up to 3500rpm, when the power suddenly leveled off significantly, and she started pinging... then she hit 4000rpm exactly, she came back to life, made more wads of power (and i think stopped pingning)... but then the dyno run ended as the driver was too nervous to continue.
im quite familar with this 'hit' of power at 4k rpm, but have never experienced any pinging in the 3.5-4k hole preceeding it. the engine has had pinging issues in the past when running hot, or with hot intake temps, or if trying to drive at WOT @ 20kmh in 4th gear... im trying my best to sort this issue out generally, but there seems to be something specifc going on around 3.5-4k.
i initially put this 3.5-4k issue down to the stock ecu not being tuned to the new engine characteristics, and simply experiencing a switch from closed loop to open loop at 4k rpm, and the power coming with the extra fuel open loop provides.
but todays run done at WOT should all be in open loop, and the afr's are reflective of this...
despite odd occurences in the power output and pinging, the afr curve is smooth, and calmly goes from 14.4 at 2000rpm, to about 12.3 at 4000rpm when the run was stopped. nothing odd occuring in between.
problems ive considered:
TPS is not calibrated to the size of the new throttle body setup (compared to stock) and i have noticed with my AFR gauge that it seems to stay in closed loop too long when driving normally (ie not WOT)...
eg, new throttle body can be only slightly open, but the engine is under quite a bit of load, but she stays around 14.5:1 ... until 4000rpm where it shifts into open loop, mixtures suddenly go rich, and power kicks in considerably. ive noticed it can get quite lean just before this 4k rpm transition, and ive tried not to 'gun it' too hard on the pedal in this area for fear of pinging.
however - today, the run was all done at WOT, and she STILL had this weird drop in output at 3.5-4k rpm .... plus she started pinging. HOWEVER, the afrs are clearly NOT closed loop during the run, and were steadily going from 14.4 (at 2000rpm) to about 12.3:1 (by 4000rpm). Nothing terribly interesting occurs to the afr plot when she was supposedly pinging (afr of about 12.8:1 at this point), and then BAM... 4k rpm kicks in, power goes right back up... nothing reflected in the afr plot...
im stumped
maybe cam timing
maybe some ecu open loop tansition
maybe the whole thing is up the fuck and needs a new ECU 
i just dont have the cash for anything serious managemnt wise, and im trying to dodge it all together to make it work adequetley.
im considering water/methanol injection (i have all the stuff here to hook it up, just need to make an RPM trigger to make it work)... but this has its downside as i understand things should be leaned out to optimise the benefit.
ive also played with the flap spring in the AFM (as she was originally running REALLY rich in open loop mode - almost 10:1). i leaned it out a bit, then reset the ecu to let it 'learn' closed loop settings with the new spring preload. this hasnt changed closed loop mixtures at all, and has leaned out the top end nicely as seen on the afr curve today (12.5:1 or so - though i didnt get to see what it continued to do as the power increased). however, it made zero difference to whats going on in the 3.5-4k rpm black hole 
i installed a new radiator and thermo fans to keep engine temps down (she does ping a lot more if i let it get up in the temp range... so i try and keep it on the cooler side of normal operating temps).
im not sure if this cooler temp changes the fuelling via some kind of correction factor (richer mixture), or whether it is the cooler cyl temps in themselves which are to blame for losing the pinging.
i did notice today that she was NOT running hot at all on the rollers.
bugger it... i dunno. i know it needs a proper ecu, but plain and simple - it isnt going to happen $$
... just this damn 3-4k rpm thing... what is going on!
ayway, if youve got any ideas! please fire away.
in the meantim, im resetting the cam timing back to stock, bringing ign timing back to about 18deg total adv, and ill start again from there...
ps - many many gtech runs have been done, and she consistantly gets 14.9 @ 98.5mph on the 1/4 (1400kg car inc driver). also happily does 0-60mph in about 6.3secs. i calculate rwhp to be around 185 using these results.
mods:
10.8:1 c/r
- head decked
- block decked
- piston tops decked
piston tops shaped, chamfered and polished
comb chambers shaped and polished
valves ground and swirl polished
ported in and ex ports
port matched manifold
custome plenum and upper manifold
twin 57mm throttle butterflies with custom 3" mandrel intake pipe - (single 60mm stock)
stock cams (254 dur - shitty skinny cams!)
-in adv about 7-8 crank degrees
-ex retarded about 2-4 crank degrees
-(have full timing data if you want it)
rods ground, polished and peened
arp b/e fasteners
everything balanced
headers 6-2-1, 1.5" primaries, 2" secondaries, 2.5" common + cat + muffler
about 25deg total ign advance
metal head gasket
also:
intake pipe origin and filter is located outside the engine bay (behine front apron) and all intake piping within the bay is wrapped in fibreglass heat wrap, then covered in aluminium heat tape.
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Location:
Brisbane
Registered:
February 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 14:25
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sounds lo tech, but can you put a timing light on it then run it thru the pinging zone to watch for any unwarranted advance?
needs an engien load but it might help you point finger at either: spark, fuel or air.
btw: does the engine have knock sensors? and they're hooked up? does it make any difference if they're unhooked?
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 14:37
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-hmmm, ill see what the knock sensor tells me. it is hooked up at the moment, but ill see what the ecu does without it... or atleast connected, but not screwed into the block
-ill also try disconnecting the ACIS as mentioned in the other thread - or rather, try locking it open in the position that it flicks to at 4000rpm
-i think itll be hard to watch the timing without being on a dyno. if it comes to it, yeah, very good idea, but ill try a few low cost things first, see what happens.
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Location:
1st street on the right
Registered:
November 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 20:46
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Certainly sounds more timing related to me. Does anyone have an aftermarket ECU that you could plug in for a day to try to better establish WTF is wrong. Does the 7m run a knock sensor? I'm guessing you have a list of codes (http://www.tigersport.freeserve.co.uk/diag-supra.h tm) 52 or 53 are for knock sensor.
Disributor internals? Bob weight spring stretched/broken? base plate loose?
Or course you could always tell people that the lag to 4k is the integrated turbo spooling up. 
Another side note I found a site for a guy in the states who fitted a 7mge to a 4runner and replaced the timing Chain before fitting.
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Location:
sydney
Registered:
March 2003
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 23:19
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Have you changed the spark plug heat range, ie gone a heat range or 2 cooler?
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Location:
Brisbane
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Sun, 18 January 2004 23:29
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So you weren't watching the ignition timing while it was on the dyno? If your fuel mixtures are spot on, it's pretty obviously something to do with ignition. That's the next thing I'd be checking out!
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 01:19
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| Norbie wrote on Mon, 19 January 2004 10:29 |
So you weren't watching the ignition timing while it was on the dyno? If your fuel mixtures are spot on, it's pretty obviously something to do with ignition. That's the next thing I'd be checking out!
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no, i wasnt... looking and listening to too many other things 
i have a funny feeling that the timing got retarded to hell with the pinging (and to some degree accounts for drop in power).
but the story doesnt hang together - why does it all snap back into line at 4k ?
GT - yes, replaced plugs with one range colder again (now two colder than stock). gap is opened up to 1.1mm and spark size is nice and meaty.
sideshow - i think youre missing the point. its not that id dont want to spend the money, its more like i dont have the money. youd probably notice that most of the mods ive done are very labour intensive, and not in themselves expensive. i did everything myself at home over about 12 months, and hardly spent a cent. individual engine components such as cams and ecu etc are things i'd have no choice but to just shell out $ to go any buy (or have ground etc). so unfortunately these items never got done.
ive been a student for, shit, 8years now... us folk arent falling over with the weight of the cash in out pockets
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Location:
Brisbane
Registered:
February 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 01:25
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ed: i've got a built& tested megasquirt that you could loan? do you want try another fuel ECU?
if you're brave you could disable the aux air circuit and run spark & fuel from it? tho finding a suitable trigger to fire this might be problematic as you need a locked dizzi with a suitable trigger/sensor- the computer works out the appropriate delay before send trigger to the coil
sensors required for fuel are:
TPS
MAP (built in, all you need is piping)
Coolant (GM)
Air temp (GM)
coil trigger
O2 (narrow band)
Stewart (oldcorollas) might know of a Syd based unit - there was some guy on the oz forum for megasquirt selling a unit.
this may not get around the timing issue - but there's a version of the box (same hardware but drives a coil only) that does spark (and is called, not surprisingly, megaspark)
i know you drop back to a 8x8 map - but there's a guy running a turbo MR2 on this, a 5ME supra, 2 cruisers, a 2T-G RA40 (in Canberra), two 4AGTE MR2s, ... so a there's a few toy-drivers who like 'em.
anyway, PM me offlist if interested.
[Updated on: Mon, 19 January 2004 01:26]
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 05:03
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It sounds like a lot of timing for something that isn't running right, maybe you should back it off until you work out the problem.
The pickup in the power curve couldn't be the ASIC(?) kicking in could it?
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Location:
sydney
Registered:
March 2003
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 08:43
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i would venture a guess that your mecha advance is just fully in at around 3500-4000rpm. so it basically ramps up quick from idle, then flattens out at that point....
so between 3500 adn 4000 your advance is too high..
you could
a) fit stronger springs
b) lighten the dizzy weights (work out how much by weighing the 'pivoted' weight, calculating centripetal force at the 'all in' rpm, (this is the spring force too), then reducing pivoted weight so you can achrive the same force at higher rpm)
c) reduce mximum advance by bending the stops
d) reduce static timing.
this is of course assuming you have mech advance 
Cya, Stewart
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Location:
melb
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 12:22
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what makes/made you think that your compression ratio is not too high? modern engines do run high comps but they are also run by modern efi systems - your efi system is far from modern.
cant you retard the timing? or add an octane booster?
I think you need to find some way to map out your timing curve and see what its doing. how this is done cheaply and with no equipment I do not know.
I would return everything I could to as per factory spec.
ie exhaust, intake, cam timing, then slowly add everything until the problem appears.
maybe im stating the obvious.
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 13:07
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Chris, 10.7:1 just isn't that high. The combustion chamber has nice squish zones and they have all been deburred. With good tuning, this motor should be able to cope with up to and possibly over 11:1. This will be a timing related issue - sure the compression ratio is too high for the std ECU timing but it is unlikely to be detonating because of excessively high compression. With a more appropriate advance curve, this motor should run just fine.
Unfortunately, Ed can't have his cake AND eat it too. He can't run 37-38 degrees total advance AND and have nearly 11:1 comp. He will just have to dial back the timing, short of getting some sort of standalone ECU (or having a mechanical dizzy made to suit with the advance characteristics sorted as per Stewart's suggestions). Water injection may be helpful.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Mon, 19 January 2004 13:21
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Ed, i'm also assuming you are runnign good 98 octane??
i pretty much only run Mobil 8000 now, optimax feels sluggish...ish..
ii have about 10.2:1, and run huge amounts of advance... i think this is partly because i'm runnign fairly rich (about 11.5 or 12:1 at 4000rpm, and 12.5-13:1 at 8000rpm), which soprt of quenches the mixture a bit.. i also have about a 1/3rd of the combustion zone as squish.
anyhoo, i have around 20 base advance atm, with another 10-15 with vac advance (only way to get it to idle nicely  ) total mech advance is around 15 degrees or more.
i have run over 25 deg base advance with no pinging, and even up to about 30 deg base... no pinging, but way down on power...
i plan to halve the pivot weight of advance weights, which should raise my 'all in advance' rpm from about 4000 to 5or6000rpm... not as steep a slope, but thats ok
Cya, Stewart
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:17
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| gianttomato wrote on Tue, 20 January 2004 00:07 |
Unfortunately, Ed can't have his cake AND eat it too. He can't run 37-38 degrees total advance AND and have nearly 11:1 comp. He will just have to dial back the timing
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been here, done this 
for starters, 37-38deg? its set at about 15 on top of a static 10, so lets say 25. what the ecu does with this from here, i dont know.
thing is however, ive dialled back the timing considerably, and the engine turns into a rolling turd-mobile. idle quality, and power off idle goes to utter shit, and in that 3.5-4k hole, the engine bogs down amazingly. it really really doesnt like the timing kicked back like that at all. and thats not me being greedy, thats me listening to the engine, and feeling its response. theres more timing in it if i wanted to wind it right up, but ive simply set it to where the engine sounds/feels happiest. trust me when i say its totally crap and unwell with low advance (i guess youd have to drive it)...
as for the ign advance being responsible for the pinging: not necessarily... TWO causes of pinging - pre ignition (ignited explosion:: hot spot, hot plug, ign adv too far) and detonation (spontaneously detonated explosion:: combustion chamber pressure, comb charge temp, engine load). i think i have the latter... and im presently thinking its related to the cam timing.
i know, dave, that it must sound like ive just wound up the ign tmiming, and now its pinging. trust me when i say i wish it were that simple, as id be happy as shit to fix it so simply. however, whats going on is really damn confusing, and far more complicated than that. the very nature of this flat spot is what is producing the conditions casing the detonation. i wish you could drive it, and youd be sitting, saying "what the fuck just happened there" ?? the engine really hits a wall. the engine sound totally changes, power dops right off. she feels really 'thin' (if that makes sense: she feels weak and fragile, shallow. as opposed to feeling totally grunty, phat, and full of life everywhere else in the rpm range). and its ONLY at this point that the pinging occurs. NOWHERE else in the rpm range, under damn heavy loads at WOT is there even a suggestion of knock. instead she is totaly on song, and hauling ass...
"its really odd"
franky:: its definitely NOT the ACIS. i disconnected this last night, and it made abs ZERO difference to whats going on. sure, the induction note doesnt have the funky change it used to, but the flat spot is still dogs balls obvious.
stewart:: i too have apprx 30% squish, with highly polished chambers, pent roof etc etc. running 98 mobil 8000 aswell. timing as stated above (not that crazy)
[Updated on: Tue, 20 January 2004 04:46]
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:27
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dave, re: your water injection statement... this reflects your misunderstanding of whats going on.
water injection would be great for preventing detonation associated with increasing load and rpm etc, without having to swamp the comb chamber with fuel in order to cool it. im NOT getting that kind of detonation. from 4-7k rpm, the engine HAULS without a hint of complaint whatsoever. as i said, its only this 500rpm band where the engine falls off the trolley.
water injecting this 500rpm band would do nothing but prevent detonation in an otherwise still dysfunctional rpm band. the power would still be shit, the engine would still sound really odd, and regardless, come 4000rpm, everything would still be back to normal.
i would rather figure out wtf is going on with the engine at 3.5k, solve it, and the performance and prevention of detonation will follow in step.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:38
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this is really weird Ed.....
hmm, if the mixtures are spot on/rich, and you wind back total timing 10 deg, will the hole/pinging still happen??
if so, i'd have to agree that it could be pre-ignition rather than pinging..
around 3500-4000 is where you would expect peak torque to occur??
if so, you might just have too high a volumetric efficiency for the compression you have...so too much mixture is getting in, and then the rise in temp during compression is too much...
if you back off timing and it still happens then....
try using small throttle, and see what happens. keep using larger throttle openings until the problem occurs. if it starts at say 70% or whatever of full throttle, then you might just be getting too much air in there
water injection is one way to fix it (if timing doesn't work) but the more common way to do it is to cover the problem with fuel and ignore it  heh heh...
hmm, tried setting plug gaps smaller? say 0.9 or 1.0? i have had issues with to high a plug gap, even tho i get massive sparks from the HEI (like 30mm). i found that at cetain rpm (which changed with the timing) the spark was just being blown out....
anyhoo, a few things to try..
back off timing see if it has any effect,
back off throttle opening to the point where it stops happening
decrease plug gaps and see if it makes a difference
also maybe try AFM to make it richer across the board to see if you can drwon out the prob with fuel at the rpm range?
oh, and you're plugs are now 7's??
good luck
Cya, Stewart
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Location:
Brisbane
Registered:
February 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:50
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ed: what about the TPS? - if it's at a spot where the butterfly(s) open a bit, but the TPS doesn't register a change on opening, the ECU isn't going to know that there's a bit more air flying past.
e.g. Throttle position changes from 60% to 64% but the TPS is still at %60 it's going to give you less fuel than what you need to safely combust fuel
i know this flys in the face of the AFR readings ...
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:56
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| oldcorollas wrote on Tue, 20 January 2004 15:38 |
you might just have too high a volumetric efficiency for the compression you have...so too much mixture is getting in, and then the rise in temp during compression is too much...
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this is where my mind is heading also. VE goes up (damn i did a good job porting it didnt i!!), starts pinging (inaudibly) timing gets retarded big time by ecu, power falls away... cam timing effectiveness moves on with increasing rpm, VE decreases, knock drops off, ecu advances timing again, power surges back up.
this is why i want to play with the cam timing again (havent had time to do it lately).
re: richening mixture out - this makes the top end horridly rich. the mixtures presently are great for everything except this band (so it would seem). perhaps h20 injecting this band would be beneficial...
lets play with cam timing first and see what happens...
cheers
ed
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 04:59
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| thechuckster wrote on Tue, 20 January 2004 15:50 |
ed: what about the TPS? - if it's at a spot where the butterfly(s) open a bit, but the TPS doesn't register a change on opening, the ECU isn't going to know that there's a bit more air flying past.
e.g. Throttle position changes from 60% to 64% but the TPS is still at %60 it's going to give you less fuel than what you need to safely combust fuel
i know this flys in the face of the AFR readings ...
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this is quite similar to how the TPS is currently running on the now massive T/b. the siignal to the ecu is not calibrated for the now 100% bigger butterfly size. the relevance of this lack of calibration, though, is questionable when done at WOT...
i agree though, that the TPS signal is 'one' issue in many that needs fixing for improved drivability, but it is not resonsible for this present issue.
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Location:
Home
Registered:
December 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 05:34
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Have you actually reduced your valve overlap with those mods?
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Location:
Adelaide
Registered:
June 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 06:13
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Hi mate-at a guess I'd say its a timing issue. Whilst I wouldn't think the compression isn't too high, possibly when combined with the standard ignition curve it may a little too much (ie if you could mod the curve it may go away as others have mentioned). From memory the 7m has an electronic dizzy and the spark is advanced/retarded by the ECU?(meaning you cannot effectively change the ignition curve)
One thing that may explain the pinging stopping at 4000 is that the engine may be moving away from peak torque (the point where timing becomes most critical and likely to detonate) and passes through the upper threshold point for detonation. There will also be a lower threshold when the pinging commences as the torque ramps up. Is your motor likely to be making peak torque in the 3500 to 4000 zone you mention? IF any of this sounds plausible to you, I have two suggestions.
1. Get a jerry can of Avgas, drain the tank and put it in and then go for a drive and see if it narrows the band where pinging is occurring or eliminates it. (find a good steep hill and load it right up from low revs-the reason it will ping on the rollers is that ususally a car is dynoed at higher loads than are generated on the road)
2. Retard your timing by loosening and twisting the dizzy whilst checking with a timing gun (this will simply retard the timing by the same amount across the whole revrange) and see if this helps. The engine will most likely feel more sluggish in the areas where there was no pinging but pick up where there was pinging before. The more you retard the base timing the narrower the band of pinging should become.
Failing this I'd suggest dynoing the car and checking the timing under load.
Ultimately I think you may need to either run diffent fuel, a cheap water injection setup or change the ECU to a programmable one. The water injection will be the cheapest and easiest to hook up.
Hope this helps
Sean
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 09:21
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| amichie wrote on Tue, 20 January 2004 16:34 |
Have you actually reduced your valve overlap with those mods?
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no, infact ive increased it to a whopping 32deg...
though if you measure that at 50thou, its almost nothing - but still WAY better than stock overlap (ie ZERO).
sean, that all makes sense, and parallels what i have been considering myself. ill have a play and get back to you all with further details.
cheers
ed
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:33
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ok, heres the long awaited dyno curve of whats going on!!
notice the silky smooth afr plot (which is right where i want it). also notice the big fuck-off power failure at 3500rpm, which then snaps back into life at 4000rpm :wtf: ...right after 4000rpm, the run was stopped by the operators as they werent happy with what had occured in the 3500-4000rpm band.
i admit, looking at the afr plot, that it looks like the dyno operator DID take his foot off the pedal, and plant it again, which may over emphasise things (but i cannot be sure). be believe me (and other witnesses) when i say, though, that the drop in power, and the consequent kick in the ass at 4k is very, very real.
and just for the hell of it, compare and contrast with glens 2jzge  ... yes his has a similar power abberation, but obviously not anywhere near the magnitude as mine (plus it wasnt pinging!). please not thatthe differences in AFR plot are due to scale differences between the two printouts. i scaled the images for RWKW comparison, not afr. edit: note that the 7m's run only actually begins at 70kmh where the pedal is depressed (see afr accel spike)... as opposed to the 2jz which come onto the graph already at WOT
7MGE in Blue, 2JZGE in Red
[Updated on: Tue, 20 January 2004 12:53]
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:43
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oh man (Glen) 
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Location:
Melbourne
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:48
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geee once thos bugz are squashed i think you maybe sticking it up some 2jz owners, look at the way it comes on mmmm torque!
Allan
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Location:
Melbourne
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:49
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P.S have you cleaned and matched those injectors yet???
Allan
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:50
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'stock' 2jzge thank you very much Allan!
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:51
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| Allan wrote on Tue, 20 January 2004 23:48 |
geee once thos bugz are squashed i think you maybe sticking it up some 2jz owners, look at the way it comes on mmmm torque!
Allan
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mmmm, 7m's are shit
edit: note that the 7m's run only actually begins at 70kmh where the pedal is depressed (see afr accel spike)... as opposed to the 2jz which come onto the graph already at WOT
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 12:56
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| Allan wrote on Tue, 20 January 2004 23:49 |
P.S have you cleaned and matched those injectors yet???
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no...
and glen, it might be stock, but remeber, you had atleast a 20hp head start
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 13:25
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That still leaves all the stuff you've done to be done 
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Location:
Lost in the K hole
Registered:
May 2002
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Location:
Brisbane Qld
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 22:41
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Ed,
I remember somewhere that the knock sensor is cut out of the calculations mid way through the rev range. That could be the reason for it flicking back to normal timing at 4000.
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Location:
Adelaide
Registered:
June 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Tue, 20 January 2004 22:51
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Hey ed, does the dyno shop have the file saved? If so can you get the printout showing tractive effort as well?
Sean
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Wed, 21 January 2004 06:53
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no, not saved
you interested in having a look to see if peak torque was around there? it wouldnt suprise me if it is.
i tried a new knock sensor today in a new location (over cyl 3 instead of 2)
made zero difference
i was going to just have it dangling off the loom, but realised it needed to be earthed in order to work (engine gors FULL rich otherwise - makes your eyes water ) i have to hook something up.
water injection is in progress (as it cant hurt, and i have all the bits)
tomorrow is cam timing day - assuming i dont get called out in the middle of tonight!
cheers
ed
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Thu, 22 January 2004 03:52
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ok...
re the flat spot:
it ISNT the cam timing
it ISNT the base ign timing
it ISNT the knock sensor
i mucked around with everything this morning. set everything back to stock. zero difference. sure the character of the engine changed generally, but the big mofo flat spot remained as-is. no amount of changes to base ign timing made sfa difference. changes in cam timing ditto.
i dont usually have any audible evidence of pinging as it is, so it was impossible to tell if id done anything by dropping back the base timing in that regard...
...so i just set the timing back to a point where it wouldnt ping audibly trying to go up a hill @ 30kmh in 4th gear, which turned out to be 16-17deg BTDC.
exactly what this means, in not entirely sure. when you brigde the diag terminals to set the timing, how much advance is the engine ecu givin? 10 deg? does that maen ive just dialled in a further 7deg on top of that?
i honestly cant tell the difference b/w having the terminals bridged, or open, they both looks the same under the timing light. interestingly enough, either bridged or unbridged, give the throttle a quick squeeze, and the timing swings around to almost 40-45deg BTDC!! yikes!
anyway, nothing i did removed the flat spot whatsoever. atleast i can be confident now that the ign timing is ok. i think ill install some water injection over the next few weeks and see what that does. if anything itll let me wind the advance up more amd lean out the mixtures a little more, and i can be sure she aint pinging then!
cheers
ed
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Fri, 23 January 2004 02:01
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possible solution....
ive just been reading about a berko altezza 3s with vvti thats had a bit of work done to it. apparently they guy is having issues with the ECU retarding timing when the vvti kicks in (and changes the VE and torque profile of the engine) - attempting to supress knock.
sounds similar to what could be happeneing with mine. cams come on around 3k rpm, VE and torque go up, thing starts to ping inaudibly, ecu retards timing, power falls away dramtically. perhaps on the dyno, the load was high enough that the ecu couldnt retard timing any further, and the knock became audible (along with the big drop in power)
me think water injection could be a big winner in this situation
cheers
ed
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Location:
Brisbane
Registered:
February 2003
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Fri, 23 January 2004 05:31
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| ed_ma61 wrote on Fri, 23 January 2004 12:01 |
possible solution....
<big snip>
me think water injection could be a big winner in this situation
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you should try water+methanol (50:50) - there's an initial stumble when my water inject kicks on on boost - but with the mix, it's a pleasant surge ...
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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7mge tuning, pinging, AFR's and other crap... LONG
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Fri, 23 January 2004 05:38
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ive been reading that the stumble is related to the % h2o vs water... for reducing temps, increasing ign (and supressing knock) ive been reading figures as low as 3-5% fuel/h2o ratio. any idea what youre running? perhaps drop a smaller jet in?
im planning a 2 stage jet system at the moment. 3% fuel/water comes on at 3k rpm, followed by a second jet yielding a total of 6% fuel/water at 5k rpm
any thoughts?
cheers
ed
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